Добавил третью главу занимательного программирования

author: Eugen Wissner <belka@caraus.de> 2025-12-17 12:12:16 +0100
committer: Eugen Wissner <belka@caraus.de> 2025-12-17 12:13:15 +0100
commit: 6d7c43c85f8852ed3b3fa9cefc742bc87e941842 (patch)
tree: 20da65c403c17b962027469897500de626a958f4
parent: 2878f1e34c2c2e19d5b7f6fd368dbf9ec0c6277f (diff)
download: book-exercises-6d7c43c85f8852ed3b3fa9cefc742bc87e941842.tar.gz
34 files changed, 4191 insertions, 0 deletions
diff --git a/Занимательное программирование/3/1_move/geometry.pas b/Занимательное программирование/3/1_move/geometry.pas
new file mode 100644
index 0000000..cc00fd7
--- /dev/null
+++ b/Занимательное программирование/3/1_move/geometry.pas
@@ -0,0 +1,302 @@
+unit Geometry;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils;
+
+type
+  { Вершины }
+  Vertex = record
+    x, y, z: Real; { Координаты вершины }
+  end;
+  { Ребра }
+  Edge = record
+    src, dest: Integer; { Индексы соединяемых вершин }
+  end;
+
+  Object3D = record
+    vertices: array of Vertex; { вершины }
+    edges: array of Edge; { ребра }
+    xc, yc, zc: Real; { координаты центра объекта }
+  end;
+
+  Matrix = array[1..4, 1..4] of Real; { матрица 4x4 }
+  Column = array[1..4] of Real; { столбец }
+
+function LoadObject3D(filename: String): Object3D;
+function CopyObject3D(Shape: Object3D): Object3D;
+
+{ умножение матрицы на матрицу }
+function MMMult(lhs, rhs: Matrix): Matrix;
+{ умножение матрицы на столбец }
+function MCMult(lhs: Matrix; rhs: Column): Column;
+{ матрица поворота модели }
+function RotateMatrix(xa, ya, za: Real): Matrix;
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+procedure RotateShape(var Shape: Object3D; xa, ya, za: Real);
+procedure MoveShape(var Shape: Object3D; tx, ty, tz: Real);
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+
+implementation
+
+function LoadObject3D(filename: String): Object3D;
+var
+  F: TextFile; { исходный файл }
+  NV, NE: Integer; { количество вершин, количество ребер }
+  Shape: Object3D; { модель }
+  i: Integer; { счетчик цикла }
+begin
+  AssignFile(F, filename); { открываем  исходный файл }
+  FileMode := 0; { в режиме "только чтение" }
+  Reset(F);
+
+  ReadLn(F, NV); { считываем количество вершин }
+  SetLength(Shape.vertices, NV); { и корректируем размер массива }
+  for i := 0 to NV - 1 do { считываем каждую вершину }
+    ReadLn(F, Shape.vertices[i].x, Shape.vertices[i].y, Shape.vertices[i].z);
+
+  ReadLn(F, NE); { то же для ребер }
+  SetLength(Shape.edges, NE);
+  for i := 0 to NE - 1 do
+    ReadLn(F, Shape.edges[i].src, Shape.edges[i].dest);
+
+  CloseFile(F);
+  LoadObject3D := Shape;
+end;
+
+function CopyObject3D(Shape: Object3D): Object3D;
+begin
+  CopyObject3D.vertices := Copy(Shape.vertices, 0);
+  CopyObject3D.edges := Copy(Shape.edges, 0);
+
+  CopyObject3D.xc := Shape.xc;
+  CopyObject3D.yc := Shape.yc;
+  CopyObject3D.zc := Shape.zc
+end;
+
+function MMMult(lhs, rhs: Matrix): Matrix;
+var
+   i, j, k: Integer;
+   r: Matrix;
+   s: Real;
+begin
+  for i := 1 to 4 do
+    for j := 1 to 4 do
+    begin
+      s := 0;
+      for k := 1 to 4 do
+        s := s + lhs[i, k] * rhs[k, j];
+      r[i, j] := s;
+    end;
+  MMMult := r;
+end;
+
+function MCMult(lhs: Matrix; rhs: Column): Column;
+var
+  k, i: Integer;
+  s: Real;
+  r: Column;
+begin
+  for i := 1 to 4 do { аналогично MMMult }
+  begin
+    s := 0;
+
+    for k := 1 to 4 do
+      s := s + lhs[i, k] * rhs[k];
+    r[i] := s;
+  end;
+
+  MCMult := r;
+end;
+
+function RotateMatrix(xa, ya, za: Real): Matrix;
+var
+  xr, yr, zr: Matrix;
+begin
+  { матрица поворота вокруг оси Ox }
+  xr[1, 1] := 1;
+  xr[1, 2] := 0;
+  xr[1, 3] := 0;
+  xr[1, 4] := 0;
+
+  xr[2, 1] := 0;
+  xr[2, 2] := Cos(xa);
+  xr[2, 3] := -Sin(xa);
+  xr[2, 4] := 0;
+
+  xr[3, 1] := 0;
+  xr[3, 2] := Sin(xa);
+  xr[3, 3] := Cos(xa);
+  xr[3, 4] := 0;
+
+  xr[4, 1] := 0;
+  xr[4, 2] := 0;
+  xr[4, 3] := 0;
+  xr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oy }
+  yr[1, 1] := Cos(ya);
+  yr[1, 2] := 0;
+  yr[1, 3] := Sin(ya);
+  yr[1, 4] := 0;
+
+  yr[2, 1] := 0;
+  yr[2, 2] := 1;
+  yr[2, 3] := 0;
+  yr[2, 4] := 0;
+
+  yr[3, 1] := -Sin(ya);
+  yr[3, 2] := 0;
+  yr[3, 3] := Cos(ya);
+  yr[3, 4] := 0;
+
+  yr[4, 1] := 0;
+  yr[4, 2] := 0;
+  yr[4, 3] := 0;
+  yr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oz }
+  zr[1, 1] := Cos(za);
+  zr[1, 2] := -Sin(za);
+  zr[1, 3] := 0;
+  zr[1, 4] := 0;
+
+  zr[2, 1] := Sin(za);
+  zr[2, 2] := Cos(za);
+  zr[2, 3] := 0;
+  zr[2, 4] := 0;
+
+  zr[3, 1] := 0;
+  zr[3, 2] := 0;
+  zr[3, 3] := 1;
+  zr[3, 4] := 0;
+
+  zr[4, 1] := 0;
+  zr[4, 2] := 0;
+  zr[4, 3] := 0;
+  zr[4, 4] := 1;
+
+  RotateMatrix := MMMult(MMMult(xr, yr), zr)
+end;
+
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+begin
+  MoveMatrix[1, 1] := 1;
+  MoveMatrix[1, 2] := 0;
+  MoveMatrix[1, 3] := 0;
+  MoveMatrix[1, 4] := tx;
+
+  MoveMatrix[2, 1] := 0;
+  MoveMatrix[2, 2] := 1;
+  MoveMatrix[2, 3] := 0;
+  MoveMatrix[2, 4] := ty;
+
+  MoveMatrix[3, 1] := 0;
+  MoveMatrix[3, 2] := 0;
+  MoveMatrix[3, 3] := 1;
+  MoveMatrix[3, 4] := tz;
+
+  MoveMatrix[4, 1] := 0;
+  MoveMatrix[4, 2] := 0;
+  MoveMatrix[4, 3] := 0;
+  MoveMatrix[4, 4] := 1
+end;
+
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+begin
+  ResizeMatrix[1, 1] := sx;
+  ResizeMatrix[1, 2] := 0;
+  ResizeMatrix[1, 3] := 0;
+  ResizeMatrix[1, 4] := 0;
+
+  ResizeMatrix[2, 1] := 0;
+  ResizeMatrix[2, 2] := sy;
+  ResizeMatrix[2, 3] := 0;
+  ResizeMatrix[2, 4] := 0;
+
+  ResizeMatrix[3, 1] := 0;
+  ResizeMatrix[3, 2] := 0;
+  ResizeMatrix[3, 3] := sz;
+  ResizeMatrix[3, 4] := 0;
+
+  ResizeMatrix[4, 1] := 0;
+  ResizeMatrix[4, 2] := 0;
+  ResizeMatrix[4, 3] := 0;
+  ResizeMatrix[4, 4] := 1
+end;
+
+procedure RotateShape(var Shape: Object3D; xa, ya, za: Real);
+var
+  rm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  rm := RotateMatrix(xa, ya, za); { сгенерировать матрицу вращения }
+  c[4] := 1; { последний элемент столбца всегда равен единице }
+
+  for i := 0 to High(Shape.vertices) do { цикл по всем вершинам }
+  begin { High(a) возвращает верхний индекс массива a }
+    c[1] := Shape.vertices[i].x; { инициализация столбца }
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(rm, c); { вызов преобразования }
+
+    Shape.vertices[i].x := c[1]; { внесение изменений в модель }
+    Shape.vertices[i].y := c[2]; { в соответствии с полученным }
+    Shape.vertices[i].z := c[3] { результатом преобразования }
+  end
+end;
+
+procedure MoveShape(var Shape: Object3D; tx, ty, tz: Real);
+var
+  mm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  mm := MoveMatrix(tx, ty, tz);
+  c[4] := 1;
+
+  for i := 0 to High(Shape.vertices) do
+  begin
+    c[1] := Shape.vertices[i].x;
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(mm, c);
+
+    Shape.vertices[i].x := c[1];
+    Shape.vertices[i].y := c[2];
+    Shape.vertices[i].z := c[3]
+  end
+end;
+
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+var
+  mm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  mm := ResizeMatrix(sx, sy, sz);
+  c[4] := 1;
+
+  for i := 0 to High(Shape.vertices) do
+  begin
+    c[1] := Shape.vertices[i].x;
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(mm, c);
+
+    Shape.vertices[i].x := c[1];
+    Shape.vertices[i].y := c[2];
+    Shape.vertices[i].z := c[3]
+  end
+end;
+
+end.
+
diff --git a/Занимательное программирование/3/1_move/graphics_3d.lpi b/Занимательное программирование/3/1_move/graphics_3d.lpi
new file mode 100644
index 0000000..67fa0db
--- /dev/null
+++ b/Занимательное программирование/3/1_move/graphics_3d.lpi
@@ -0,0 +1,90 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectOptions>
+    <Version Value="12"/>
+    <PathDelim Value="\"/>
+    <General>
+      <SessionStorage Value="InProjectDir"/>
+      <Title Value="graphics_3d"/>
+      <Scaled Value="True"/>
+      <ResourceType Value="res"/>
+      <UseXPManifest Value="True"/>
+      <XPManifest>
+        <DpiAware Value="True"/>
+      </XPManifest>
+      <Icon Value="0"/>
+    </General>
+    <BuildModes>
+      <Item Name="Default" Default="True"/>
+    </BuildModes>
+    <PublishOptions>
+      <Version Value="2"/>
+      <UseFileFilters Value="True"/>
+    </PublishOptions>
+    <RunParams>
+      <FormatVersion Value="2"/>
+    </RunParams>
+    <RequiredPackages>
+      <Item>
+        <PackageName Value="LCL"/>
+      </Item>
+    </RequiredPackages>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+    </Units>
+  </ProjectOptions>
+  <CompilerOptions>
+    <Version Value="11"/>
+    <PathDelim Value="\"/>
+    <Target>
+      <Filename Value="graphics_3d"/>
+    </Target>
+    <SearchPaths>
+      <IncludeFiles Value="$(ProjOutDir)"/>
+      <UnitOutputDirectory Value="lib\$(TargetCPU)-$(TargetOS)"/>
+    </SearchPaths>
+    <Linking>
+      <Debugging>
+        <DebugInfoType Value="dsDwarf3"/>
+      </Debugging>
+      <Options>
+        <Win32>
+          <GraphicApplication Value="True"/>
+        </Win32>
+      </Options>
+    </Linking>
+  </CompilerOptions>
+  <Debugging>
+    <Exceptions>
+      <Item>
+        <Name Value="EAbort"/>
+      </Item>
+      <Item>
+        <Name Value="ECodetoolError"/>
+      </Item>
+      <Item>
+        <Name Value="EFOpenError"/>
+      </Item>
+    </Exceptions>
+  </Debugging>
+</CONFIG>
diff --git a/Занимательное программирование/3/1_move/graphics_3d.lpr b/Занимательное программирование/3/1_move/graphics_3d.lpr
new file mode 100644
index 0000000..619b96b
--- /dev/null
+++ b/Занимательное программирование/3/1_move/graphics_3d.lpr
@@ -0,0 +1,28 @@
+program graphics_3d;
+
+{$mode objfpc}{$H+}
+
+uses
+  {$IFDEF UNIX}
+  cthreads,
+  {$ENDIF}
+  {$IFDEF HASAMIGA}
+  athreads,
+  {$ENDIF}
+  Interfaces, // this includes the LCL widgetset
+  Forms, Octahedron, geometry
+  { you can add units after this };
+
+{$R *.res}
+
+begin
+  RequireDerivedFormResource:=True;
+  Application.Scaled:=True;
+  {$PUSH}{$WARN 5044 OFF}
+  Application.MainFormOnTaskbar:=True;
+  {$POP}
+  Application.Initialize;
+  Application.CreateForm(TForm1, Form1);
+  Application.Run;
+end.
+
diff --git a/Занимательное программирование/3/1_move/graphics_3d.lps b/Занимательное программирование/3/1_move/graphics_3d.lps
new file mode 100644
index 0000000..a00e45a
--- /dev/null
+++ b/Занимательное программирование/3/1_move/graphics_3d.lps
@@ -0,0 +1,179 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectSession>
+    <PathDelim Value="\"/>
+    <Version Value="12"/>
+    <BuildModes Active="Default"/>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="-1"/>
+        <TopLine Value="5"/>
+        <UsageCount Value="39"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+        <IsVisibleTab Value="True"/>
+        <TopLine Value="7"/>
+        <CursorPos X="23" Y="20"/>
+        <UsageCount Value="39"/>
+        <Bookmarks Count="1">
+          <Item0 X="19" Y="50" Left="1" Top="84" ID="3"/>
+        </Bookmarks>
+        <Loaded Value="True"/>
+        <LoadedDesigner Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+        <EditorIndex Value="2"/>
+        <TopLine Value="70"/>
+        <CursorPos X="31" Y="302"/>
+        <UsageCount Value="39"/>
+        <Loaded Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="1"/>
+        <CursorPos X="4" Y="20"/>
+        <UsageCount Value="39"/>
+        <Loaded Value="True"/>
+        <DefaultSyntaxHighlighter Value="Text"/>
+      </Unit>
+    </Units>
+    <JumpHistory HistoryIndex="29">
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="125" Column="15" TopLine="112"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="194" Column="64" TopLine="168"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="37" Column="43" TopLine="23"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="172" Column="43" TopLine="158"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="68" Column="39" TopLine="67"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="40" Column="37" TopLine="31"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="139" Column="11" TopLine="128"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="187" TopLine="175"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="172" Column="9" TopLine="164"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="211" Column="17" TopLine="199"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="171" Column="45" TopLine="160"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="257" Column="18" TopLine="247"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="134" Column="7" TopLine="126"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="137" Column="14" TopLine="126"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="146" Column="23" TopLine="130"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="70" Column="19" TopLine="60"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="93" Column="12" TopLine="77"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="137" Column="14" TopLine="121"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="27" Column="45" TopLine="11"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="266" TopLine="248"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="31" Column="11" TopLine="19"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="73" Column="23" TopLine="58"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="77" Column="27" TopLine="63"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="143" Column="37" TopLine="132"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="146" Column="37" TopLine="136"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="18" Column="23" TopLine="18"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="106" Column="23" TopLine="96"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="19" Column="23" TopLine="18"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="20" Column="23" TopLine="7"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="19" Column="23" TopLine="7"/>
+      </Position>
+    </JumpHistory>
+    <RunParams>
+      <FormatVersion Value="2"/>
+      <Modes ActiveMode=""/>
+    </RunParams>
+  </ProjectSession>
+</CONFIG>
diff --git a/Занимательное программирование/3/1_move/octahedron.lfm b/Занимательное программирование/3/1_move/octahedron.lfm
new file mode 100644
index 0000000..34b256e
--- /dev/null
+++ b/Занимательное программирование/3/1_move/octahedron.lfm
@@ -0,0 +1,75 @@
+object Form1: TForm1
+  Left = 352
+  Height = 673
+  Top = 32
+  Width = 600
+  Caption = 'Form1'
+  ClientHeight = 673
+  ClientWidth = 600
+  DesignTimePPI = 120
+  object BackScreen: TImage
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object Screen: TPaintBox
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object StartStopBtn: TButton
+    AnchorSideLeft.Control = Owner
+    AnchorSideLeft.Side = asrCenter
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = Owner
+    AnchorSideBottom.Side = asrBottom
+    Left = 472
+    Height = 48
+    Top = 615
+    Width = 118
+    Anchors = [akRight, akBottom]
+    BorderSpacing.Right = 10
+    BorderSpacing.Bottom = 10
+    Caption = 'Пуск'
+    TabOrder = 0
+    OnClick = StartStopBtnClick
+  end
+  object ResizeField: TFloatSpinEdit
+    AnchorSideLeft.Control = Owner
+    AnchorSideBottom.Control = Owner
+    AnchorSideBottom.Side = asrBottom
+    Left = 10
+    Height = 28
+    Top = 635
+    Width = 63
+    Anchors = [akLeft, akBottom]
+    BorderSpacing.Left = 10
+    BorderSpacing.Bottom = 10
+    TabOrder = 1
+    Value = 1
+  end
+  object Label1: TLabel
+    Left = 10
+    Height = 20
+    Top = 615
+    Width = 125
+    Caption = 'Изменить размер'
+  end
+end
diff --git a/Занимательное программирование/3/1_move/octahedron.pas b/Занимательное программирование/3/1_move/octahedron.pas
new file mode 100644
index 0000000..a5aae45
--- /dev/null
+++ b/Занимательное программирование/3/1_move/octahedron.pas
@@ -0,0 +1,162 @@
+unit Octahedron;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, ExtCtrls, StdCtrls,
+  Spin, Geometry;
+
+type
+
+  { TForm1 }
+
+  TForm1 = class(TForm)
+    BackScreen: TImage;
+    Label1: TLabel;
+    ResizeField: TFloatSpinEdit;
+    StartStopBtn: TButton;
+    Screen: TPaintBox;
+    procedure StartStopBtnClick(Sender: TObject);
+  private
+
+  public
+
+  end;
+
+var
+  Form1: TForm1;
+  IsRunning: Boolean = false;
+
+implementation
+
+{$R *.lfm}
+
+procedure ShowShape(Shape: Object3D); { нарисовать объект }
+var
+  i, Xs, Ys: Integer;
+  x, y, z: Real;
+const
+  N = 300; { "глубина" экрана }
+begin
+  for i := 0 to High(Shape.edges) do { цикл по всем ребрам }
+  begin { координаты первой точки ребра }
+    x := Shape.vertices[Shape.edges[i].src].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].src].y + Shape.yc;
+    z := Shape.vertices[Shape.edges[i].src].z + Shape.zc;
+    if Abs(z) < 0.01 then z := 0.01; { избегаем деления на нуль }
+                                     { вычисляем экранные координаты }
+    Xs := Round(Form1.Screen.Width div 2 + N * x / z);
+    Ys := Round(Form1.Screen.Height div 2 + N * y / z);
+
+    Form1.BackScreen.Canvas.MoveTo(Xs, Ys);
+                                       { координаты второй точки зрения }
+    x := Shape.vertices[Shape.edges[i].dest].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].dest].y + Shape.yc;
+    z := Shape.vertices[Shape.edges[i].dest].z + Shape.zc;
+    if Abs(z) < 0.01 then z := 0.01; { избегаем деления на нуль }
+                                     { и ее экранные координаты }
+    Xs := Round(Form1.Screen.Width div 2 + N * x / z);
+    Ys := Round(Form1.Screen.Height div 2 + N * y / z);
+
+    Form1.BackScreen.Canvas.LineTo(Xs, Ys); { рисуем ребро }
+  end;
+end;
+
+{ TForm1 }
+
+procedure TForm1.StartStopBtnClick(Sender: TObject); { главная процедура }
+var
+  oldtime: TDateTime;
+  Model, BackModel: Object3D; { трехмерный объект }
+  Vx, Vy, Vz: Real; { значения составляющих его скорости }
+  pause: Integer;
+const
+  MSecsPerFrame = 25; { скорость работы (кадров в секунду) }
+  xa = 0.01; { скорость вращения вокруг оси Ox }
+  ya = 0.05; { скорость вращения вокруг оси Oy }
+  za = 0.08; { скорость вращения вокруг оси Oz }
+begin
+  if IsRunning then
+  begin
+    IsRunning := false;
+    StartStopBtn.Caption := 'Пуск';
+    Exit;
+  end;
+  StartStopBtn.Caption := 'Стоп';
+  IsRunning := true;
+
+  Model := LoadObject3D('octahedron.txt'); { загрузить объект }
+  ResizeShape(Model, ResizeField.Value, ResizeField.Value, ResizeField.Value);
+
+  Model.xc := 0; { начальное положение }
+  Model.yc := 0; { объекта }
+  Model.zc := 200;
+  Vx := 10; { и составляющие }
+  Vy := 15; { скорости }
+  Vz := 20;
+
+  while IsRunning do
+  begin
+    oldtime := Now;
+
+    { отразить от стена (3D-аналог "молекулы в закрытом сосуде") }
+    if Model.xc > BackScreen.Width div 2 then
+    begin
+      Model.xc := BackScreen.Width div 2;
+      Vx := -Vx;
+    end;
+    if Model.xc < -BackScreen.Width div 2 then
+    begin
+      Model.xc := -BackScreen.Width div 2;
+      Vx := -Vx;
+    end;
+
+    if Model.yc > BackScreen.Height div 2 then
+    begin
+      Model.yc := BackScreen.Height div 2;
+      Vy := -Vy;
+    end;
+    if Model.yc < -BackScreen.Height div 2 then
+    begin
+      Model.yc := -BackScreen.Height div 2;
+      Vy := -Vy;
+    end;
+
+    if Model.zc > 1000 then
+    begin
+      Model.zc := 1000;
+      Vz := -Vz;
+    end;
+    if Model.zc < 200 then
+    begin
+      Model.zc := 200;
+      Vz := -Vz;
+    end;
+
+    RotateShape(Model, xa, ya, za); { поворот модели }
+    BackModel := CopyObject3D(Model);
+    MoveShape(Model, Vx, Vy, Vz); { переместить объект }
+
+    BackScreen.Canvas.FillRect(Rect(0, 0, Screen.Width, Screen.Height));
+    ShowShape(Model); { очистить экран и нарисовать объект }
+                      { отобразить объект на основном экране }
+    Screen.Canvas.CopyRect(Rect(0, 0, Screen.Width, Screen.Height),
+        BackScreen.Canvas, Rect(0, 0, Screen.Width, Screen.Height));
+
+    Model := CopyObject3D(BackModel);
+    Model.xc := Model.xc + Vx;
+    Model.yc := Model.yc + Vy;
+    Model.zc := Model.zc + Vz;
+
+    Application.ProcessMessages;
+    pause := Round(MSecsPerFrame - (Now - oldtime) * MSecsPerDay);
+    if pause > 0 then Sleep(pause); { задержка }
+
+    if Application.Terminated then Exit;
+  end;
+end;
+
+end.
+
diff --git a/Занимательное программирование/3/1_move/octahedron.txt b/Занимательное программирование/3/1_move/octahedron.txt
new file mode 100644
index 0000000..770d229
--- /dev/null
+++ b/Занимательное программирование/3/1_move/octahedron.txt
@@ -0,0 +1,20 @@
+6
+-100 -100 0
+-100 100 0
+100 100 0
+100 -100 0
+0 0 -141.42
+0 0 141.42
+12
+0 1
+1 2
+2 3
+3 0
+4 0
+4 1
+4 2
+4 3
+5 0
+5 1
+5 2
+5 3
diff --git a/Занимательное программирование/3/2_projection/geometry.pas b/Занимательное программирование/3/2_projection/geometry.pas
new file mode 100644
index 0000000..cc00fd7
--- /dev/null
+++ b/Занимательное программирование/3/2_projection/geometry.pas
@@ -0,0 +1,302 @@
+unit Geometry;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils;
+
+type
+  { Вершины }
+  Vertex = record
+    x, y, z: Real; { Координаты вершины }
+  end;
+  { Ребра }
+  Edge = record
+    src, dest: Integer; { Индексы соединяемых вершин }
+  end;
+
+  Object3D = record
+    vertices: array of Vertex; { вершины }
+    edges: array of Edge; { ребра }
+    xc, yc, zc: Real; { координаты центра объекта }
+  end;
+
+  Matrix = array[1..4, 1..4] of Real; { матрица 4x4 }
+  Column = array[1..4] of Real; { столбец }
+
+function LoadObject3D(filename: String): Object3D;
+function CopyObject3D(Shape: Object3D): Object3D;
+
+{ умножение матрицы на матрицу }
+function MMMult(lhs, rhs: Matrix): Matrix;
+{ умножение матрицы на столбец }
+function MCMult(lhs: Matrix; rhs: Column): Column;
+{ матрица поворота модели }
+function RotateMatrix(xa, ya, za: Real): Matrix;
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+procedure RotateShape(var Shape: Object3D; xa, ya, za: Real);
+procedure MoveShape(var Shape: Object3D; tx, ty, tz: Real);
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+
+implementation
+
+function LoadObject3D(filename: String): Object3D;
+var
+  F: TextFile; { исходный файл }
+  NV, NE: Integer; { количество вершин, количество ребер }
+  Shape: Object3D; { модель }
+  i: Integer; { счетчик цикла }
+begin
+  AssignFile(F, filename); { открываем  исходный файл }
+  FileMode := 0; { в режиме "только чтение" }
+  Reset(F);
+
+  ReadLn(F, NV); { считываем количество вершин }
+  SetLength(Shape.vertices, NV); { и корректируем размер массива }
+  for i := 0 to NV - 1 do { считываем каждую вершину }
+    ReadLn(F, Shape.vertices[i].x, Shape.vertices[i].y, Shape.vertices[i].z);
+
+  ReadLn(F, NE); { то же для ребер }
+  SetLength(Shape.edges, NE);
+  for i := 0 to NE - 1 do
+    ReadLn(F, Shape.edges[i].src, Shape.edges[i].dest);
+
+  CloseFile(F);
+  LoadObject3D := Shape;
+end;
+
+function CopyObject3D(Shape: Object3D): Object3D;
+begin
+  CopyObject3D.vertices := Copy(Shape.vertices, 0);
+  CopyObject3D.edges := Copy(Shape.edges, 0);
+
+  CopyObject3D.xc := Shape.xc;
+  CopyObject3D.yc := Shape.yc;
+  CopyObject3D.zc := Shape.zc
+end;
+
+function MMMult(lhs, rhs: Matrix): Matrix;
+var
+   i, j, k: Integer;
+   r: Matrix;
+   s: Real;
+begin
+  for i := 1 to 4 do
+    for j := 1 to 4 do
+    begin
+      s := 0;
+      for k := 1 to 4 do
+        s := s + lhs[i, k] * rhs[k, j];
+      r[i, j] := s;
+    end;
+  MMMult := r;
+end;
+
+function MCMult(lhs: Matrix; rhs: Column): Column;
+var
+  k, i: Integer;
+  s: Real;
+  r: Column;
+begin
+  for i := 1 to 4 do { аналогично MMMult }
+  begin
+    s := 0;
+
+    for k := 1 to 4 do
+      s := s + lhs[i, k] * rhs[k];
+    r[i] := s;
+  end;
+
+  MCMult := r;
+end;
+
+function RotateMatrix(xa, ya, za: Real): Matrix;
+var
+  xr, yr, zr: Matrix;
+begin
+  { матрица поворота вокруг оси Ox }
+  xr[1, 1] := 1;
+  xr[1, 2] := 0;
+  xr[1, 3] := 0;
+  xr[1, 4] := 0;
+
+  xr[2, 1] := 0;
+  xr[2, 2] := Cos(xa);
+  xr[2, 3] := -Sin(xa);
+  xr[2, 4] := 0;
+
+  xr[3, 1] := 0;
+  xr[3, 2] := Sin(xa);
+  xr[3, 3] := Cos(xa);
+  xr[3, 4] := 0;
+
+  xr[4, 1] := 0;
+  xr[4, 2] := 0;
+  xr[4, 3] := 0;
+  xr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oy }
+  yr[1, 1] := Cos(ya);
+  yr[1, 2] := 0;
+  yr[1, 3] := Sin(ya);
+  yr[1, 4] := 0;
+
+  yr[2, 1] := 0;
+  yr[2, 2] := 1;
+  yr[2, 3] := 0;
+  yr[2, 4] := 0;
+
+  yr[3, 1] := -Sin(ya);
+  yr[3, 2] := 0;
+  yr[3, 3] := Cos(ya);
+  yr[3, 4] := 0;
+
+  yr[4, 1] := 0;
+  yr[4, 2] := 0;
+  yr[4, 3] := 0;
+  yr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oz }
+  zr[1, 1] := Cos(za);
+  zr[1, 2] := -Sin(za);
+  zr[1, 3] := 0;
+  zr[1, 4] := 0;
+
+  zr[2, 1] := Sin(za);
+  zr[2, 2] := Cos(za);
+  zr[2, 3] := 0;
+  zr[2, 4] := 0;
+
+  zr[3, 1] := 0;
+  zr[3, 2] := 0;
+  zr[3, 3] := 1;
+  zr[3, 4] := 0;
+
+  zr[4, 1] := 0;
+  zr[4, 2] := 0;
+  zr[4, 3] := 0;
+  zr[4, 4] := 1;
+
+  RotateMatrix := MMMult(MMMult(xr, yr), zr)
+end;
+
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+begin
+  MoveMatrix[1, 1] := 1;
+  MoveMatrix[1, 2] := 0;
+  MoveMatrix[1, 3] := 0;
+  MoveMatrix[1, 4] := tx;
+
+  MoveMatrix[2, 1] := 0;
+  MoveMatrix[2, 2] := 1;
+  MoveMatrix[2, 3] := 0;
+  MoveMatrix[2, 4] := ty;
+
+  MoveMatrix[3, 1] := 0;
+  MoveMatrix[3, 2] := 0;
+  MoveMatrix[3, 3] := 1;
+  MoveMatrix[3, 4] := tz;
+
+  MoveMatrix[4, 1] := 0;
+  MoveMatrix[4, 2] := 0;
+  MoveMatrix[4, 3] := 0;
+  MoveMatrix[4, 4] := 1
+end;
+
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+begin
+  ResizeMatrix[1, 1] := sx;
+  ResizeMatrix[1, 2] := 0;
+  ResizeMatrix[1, 3] := 0;
+  ResizeMatrix[1, 4] := 0;
+
+  ResizeMatrix[2, 1] := 0;
+  ResizeMatrix[2, 2] := sy;
+  ResizeMatrix[2, 3] := 0;
+  ResizeMatrix[2, 4] := 0;
+
+  ResizeMatrix[3, 1] := 0;
+  ResizeMatrix[3, 2] := 0;
+  ResizeMatrix[3, 3] := sz;
+  ResizeMatrix[3, 4] := 0;
+
+  ResizeMatrix[4, 1] := 0;
+  ResizeMatrix[4, 2] := 0;
+  ResizeMatrix[4, 3] := 0;
+  ResizeMatrix[4, 4] := 1
+end;
+
+procedure RotateShape(var Shape: Object3D; xa, ya, za: Real);
+var
+  rm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  rm := RotateMatrix(xa, ya, za); { сгенерировать матрицу вращения }
+  c[4] := 1; { последний элемент столбца всегда равен единице }
+
+  for i := 0 to High(Shape.vertices) do { цикл по всем вершинам }
+  begin { High(a) возвращает верхний индекс массива a }
+    c[1] := Shape.vertices[i].x; { инициализация столбца }
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(rm, c); { вызов преобразования }
+
+    Shape.vertices[i].x := c[1]; { внесение изменений в модель }
+    Shape.vertices[i].y := c[2]; { в соответствии с полученным }
+    Shape.vertices[i].z := c[3] { результатом преобразования }
+  end
+end;
+
+procedure MoveShape(var Shape: Object3D; tx, ty, tz: Real);
+var
+  mm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  mm := MoveMatrix(tx, ty, tz);
+  c[4] := 1;
+
+  for i := 0 to High(Shape.vertices) do
+  begin
+    c[1] := Shape.vertices[i].x;
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(mm, c);
+
+    Shape.vertices[i].x := c[1];
+    Shape.vertices[i].y := c[2];
+    Shape.vertices[i].z := c[3]
+  end
+end;
+
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+var
+  mm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  mm := ResizeMatrix(sx, sy, sz);
+  c[4] := 1;
+
+  for i := 0 to High(Shape.vertices) do
+  begin
+    c[1] := Shape.vertices[i].x;
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(mm, c);
+
+    Shape.vertices[i].x := c[1];
+    Shape.vertices[i].y := c[2];
+    Shape.vertices[i].z := c[3]
+  end
+end;
+
+end.
+
diff --git a/Занимательное программирование/3/2_projection/graphics_3d.lpi b/Занимательное программирование/3/2_projection/graphics_3d.lpi
new file mode 100644
index 0000000..67fa0db
--- /dev/null
+++ b/Занимательное программирование/3/2_projection/graphics_3d.lpi
@@ -0,0 +1,90 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectOptions>
+    <Version Value="12"/>
+    <PathDelim Value="\"/>
+    <General>
+      <SessionStorage Value="InProjectDir"/>
+      <Title Value="graphics_3d"/>
+      <Scaled Value="True"/>
+      <ResourceType Value="res"/>
+      <UseXPManifest Value="True"/>
+      <XPManifest>
+        <DpiAware Value="True"/>
+      </XPManifest>
+      <Icon Value="0"/>
+    </General>
+    <BuildModes>
+      <Item Name="Default" Default="True"/>
+    </BuildModes>
+    <PublishOptions>
+      <Version Value="2"/>
+      <UseFileFilters Value="True"/>
+    </PublishOptions>
+    <RunParams>
+      <FormatVersion Value="2"/>
+    </RunParams>
+    <RequiredPackages>
+      <Item>
+        <PackageName Value="LCL"/>
+      </Item>
+    </RequiredPackages>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+    </Units>
+  </ProjectOptions>
+  <CompilerOptions>
+    <Version Value="11"/>
+    <PathDelim Value="\"/>
+    <Target>
+      <Filename Value="graphics_3d"/>
+    </Target>
+    <SearchPaths>
+      <IncludeFiles Value="$(ProjOutDir)"/>
+      <UnitOutputDirectory Value="lib\$(TargetCPU)-$(TargetOS)"/>
+    </SearchPaths>
+    <Linking>
+      <Debugging>
+        <DebugInfoType Value="dsDwarf3"/>
+      </Debugging>
+      <Options>
+        <Win32>
+          <GraphicApplication Value="True"/>
+        </Win32>
+      </Options>
+    </Linking>
+  </CompilerOptions>
+  <Debugging>
+    <Exceptions>
+      <Item>
+        <Name Value="EAbort"/>
+      </Item>
+      <Item>
+        <Name Value="ECodetoolError"/>
+      </Item>
+      <Item>
+        <Name Value="EFOpenError"/>
+      </Item>
+    </Exceptions>
+  </Debugging>
+</CONFIG>
diff --git a/Занимательное программирование/3/2_projection/graphics_3d.lpr b/Занимательное программирование/3/2_projection/graphics_3d.lpr
new file mode 100644
index 0000000..619b96b
--- /dev/null
+++ b/Занимательное программирование/3/2_projection/graphics_3d.lpr
@@ -0,0 +1,28 @@
+program graphics_3d;
+
+{$mode objfpc}{$H+}
+
+uses
+  {$IFDEF UNIX}
+  cthreads,
+  {$ENDIF}
+  {$IFDEF HASAMIGA}
+  athreads,
+  {$ENDIF}
+  Interfaces, // this includes the LCL widgetset
+  Forms, Octahedron, geometry
+  { you can add units after this };
+
+{$R *.res}
+
+begin
+  RequireDerivedFormResource:=True;
+  Application.Scaled:=True;
+  {$PUSH}{$WARN 5044 OFF}
+  Application.MainFormOnTaskbar:=True;
+  {$POP}
+  Application.Initialize;
+  Application.CreateForm(TForm1, Form1);
+  Application.Run;
+end.
+
diff --git a/Занимательное программирование/3/2_projection/graphics_3d.lps b/Занимательное программирование/3/2_projection/graphics_3d.lps
new file mode 100644
index 0000000..6b42edd
--- /dev/null
+++ b/Занимательное программирование/3/2_projection/graphics_3d.lps
@@ -0,0 +1,175 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectSession>
+    <PathDelim Value="\"/>
+    <Version Value="12"/>
+    <BuildModes Active="Default"/>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="-1"/>
+        <TopLine Value="5"/>
+        <UsageCount Value="40"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+        <IsVisibleTab Value="True"/>
+        <TopLine Value="39"/>
+        <CursorPos X="45" Y="55"/>
+        <UsageCount Value="40"/>
+        <Bookmarks Count="1">
+          <Item0 X="17" Y="46" Left="1" Top="78" ID="3"/>
+        </Bookmarks>
+        <Loaded Value="True"/>
+        <LoadedDesigner Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+        <EditorIndex Value="2"/>
+        <TopLine Value="235"/>
+        <CursorPos X="10" Y="150"/>
+        <UsageCount Value="40"/>
+        <Loaded Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="1"/>
+        <CursorPos X="4" Y="20"/>
+        <UsageCount Value="40"/>
+        <Loaded Value="True"/>
+        <DefaultSyntaxHighlighter Value="Text"/>
+      </Unit>
+    </Units>
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diff --git a/Занимательное программирование/3/2_projection/octahedron.lfm b/Занимательное программирование/3/2_projection/octahedron.lfm
new file mode 100644
index 0000000..34b256e
--- /dev/null
+++ b/Занимательное программирование/3/2_projection/octahedron.lfm
@@ -0,0 +1,75 @@
+object Form1: TForm1
+  Left = 352
+  Height = 673
+  Top = 32
+  Width = 600
+  Caption = 'Form1'
+  ClientHeight = 673
+  ClientWidth = 600
+  DesignTimePPI = 120
+  object BackScreen: TImage
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object Screen: TPaintBox
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object StartStopBtn: TButton
+    AnchorSideLeft.Control = Owner
+    AnchorSideLeft.Side = asrCenter
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = Owner
+    AnchorSideBottom.Side = asrBottom
+    Left = 472
+    Height = 48
+    Top = 615
+    Width = 118
+    Anchors = [akRight, akBottom]
+    BorderSpacing.Right = 10
+    BorderSpacing.Bottom = 10
+    Caption = 'Пуск'
+    TabOrder = 0
+    OnClick = StartStopBtnClick
+  end
+  object ResizeField: TFloatSpinEdit
+    AnchorSideLeft.Control = Owner
+    AnchorSideBottom.Control = Owner
+    AnchorSideBottom.Side = asrBottom
+    Left = 10
+    Height = 28
+    Top = 635
+    Width = 63
+    Anchors = [akLeft, akBottom]
+    BorderSpacing.Left = 10
+    BorderSpacing.Bottom = 10
+    TabOrder = 1
+    Value = 1
+  end
+  object Label1: TLabel
+    Left = 10
+    Height = 20
+    Top = 615
+    Width = 125
+    Caption = 'Изменить размер'
+  end
+end
diff --git a/Занимательное программирование/3/2_projection/octahedron.pas b/Занимательное программирование/3/2_projection/octahedron.pas
new file mode 100644
index 0000000..4059739
--- /dev/null
+++ b/Занимательное программирование/3/2_projection/octahedron.pas
@@ -0,0 +1,156 @@
+unit Octahedron;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, ExtCtrls, StdCtrls,
+  Spin, Geometry;
+
+type
+
+  { TForm1 }
+
+  TForm1 = class(TForm)
+    BackScreen: TImage;
+    Label1: TLabel;
+    ResizeField: TFloatSpinEdit;
+    StartStopBtn: TButton;
+    Screen: TPaintBox;
+    procedure StartStopBtnClick(Sender: TObject);
+  private
+
+  public
+
+  end;
+
+var
+  Form1: TForm1;
+  IsRunning: Boolean = false;
+
+implementation
+
+{$R *.lfm}
+
+procedure ShowShape(Shape: Object3D); { нарисовать объект }
+var
+  i, Xs, Ys: Integer;
+  x, y: Real;
+begin
+  for i := 0 to High(Shape.edges) do { цикл по всем ребрам }
+  begin { координаты первой точки ребра }
+    x := Shape.vertices[Shape.edges[i].src].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].src].y + Shape.yc;
+                                     { вычисляем экранные координаты }
+    Xs := Round(Form1.Screen.Width div 2 + x);
+    Ys := Round(Form1.Screen.Height div 2 + y);
+
+    Form1.BackScreen.Canvas.MoveTo(Xs, Ys);
+                                       { координаты второй точки зрения }
+    x := Shape.vertices[Shape.edges[i].dest].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].dest].y + Shape.yc;
+
+    Xs := Round(Form1.Screen.Width div 2 + x);
+    Ys := Round(Form1.Screen.Height div 2 + y);
+
+    Form1.BackScreen.Canvas.LineTo(Xs, Ys); { рисуем ребро }
+  end;
+end;
+
+{ TForm1 }
+
+procedure TForm1.StartStopBtnClick(Sender: TObject); { главная процедура }
+var
+  oldtime: TDateTime;
+  Model, BackModel: Object3D; { трехмерный объект }
+  Vx, Vy, Vz: Real; { значения составляющих его скорости }
+  pause: Integer;
+const
+  MSecsPerFrame = 25; { скорость работы (кадров в секунду) }
+  xa = 0.01; { скорость вращения вокруг оси Ox }
+  ya = 0.05; { скорость вращения вокруг оси Oy }
+  za = 0.08; { скорость вращения вокруг оси Oz }
+begin
+  if IsRunning then
+  begin
+    IsRunning := false;
+    StartStopBtn.Caption := 'Пуск';
+    Exit;
+  end;
+  StartStopBtn.Caption := 'Стоп';
+  IsRunning := true;
+
+  Model := LoadObject3D('octahedron.txt'); { загрузить объект }
+  ResizeShape(Model, ResizeField.Value, ResizeField.Value, ResizeField.Value);
+
+  Model.xc := 0; { начальное положение }
+  Model.yc := 0; { объекта }
+  Model.zc := 200;
+  Vx := 10; { и составляющие }
+  Vy := 15; { скорости }
+  Vz := 20;
+
+  while IsRunning do
+  begin
+    oldtime := Now;
+
+    { отразить от стена (3D-аналог "молекулы в закрытом сосуде") }
+    if Model.xc > BackScreen.Width div 2 then
+    begin
+      Model.xc := BackScreen.Width div 2;
+      Vx := -Vx;
+    end;
+    if Model.xc < -BackScreen.Width div 2 then
+    begin
+      Model.xc := -BackScreen.Width div 2;
+      Vx := -Vx;
+    end;
+
+    if Model.yc > BackScreen.Height div 2 then
+    begin
+      Model.yc := BackScreen.Height div 2;
+      Vy := -Vy;
+    end;
+    if Model.yc < -BackScreen.Height div 2 then
+    begin
+      Model.yc := -BackScreen.Height div 2;
+      Vy := -Vy;
+    end;
+
+    if Model.zc > 1000 then
+    begin
+      Model.zc := 1000;
+      Vz := -Vz;
+    end;
+    if Model.zc < 200 then
+    begin
+      Model.zc := 200;
+      Vz := -Vz;
+    end;
+
+    RotateShape(Model, xa, ya, za); { поворот модели }
+    BackModel := CopyObject3D(Model);
+    MoveShape(Model, Vx, Vy, Vz); { переместить объект }
+
+    BackScreen.Canvas.FillRect(Rect(0, 0, Screen.Width, Screen.Height));
+    ShowShape(Model); { очистить экран и нарисовать объект }
+                      { отобразить объект на основном экране }
+    Screen.Canvas.CopyRect(Rect(0, 0, Screen.Width, Screen.Height),
+        BackScreen.Canvas, Rect(0, 0, Screen.Width, Screen.Height));
+
+    Model := CopyObject3D(BackModel);
+    Model.xc := Model.xc + Vx;
+    Model.yc := Model.yc + Vy;
+    Model.zc := Model.zc + Vz;
+
+    Application.ProcessMessages;
+    pause := Round(MSecsPerFrame - (Now - oldtime) * MSecsPerDay);
+    if pause > 0 then Sleep(pause); { задержка }
+
+    if Application.Terminated then Exit;
+  end;
+end;
+
+end.
+
diff --git a/Занимательное программирование/3/2_projection/octahedron.txt b/Занимательное программирование/3/2_projection/octahedron.txt
new file mode 100644
index 0000000..770d229
--- /dev/null
+++ b/Занимательное программирование/3/2_projection/octahedron.txt
@@ -0,0 +1,20 @@
+6
+-100 -100 0
+-100 100 0
+100 100 0
+100 -100 0
+0 0 -141.42
+0 0 141.42
+12
+0 1
+1 2
+2 3
+3 0
+4 0
+4 1
+4 2
+4 3
+5 0
+5 1
+5 2
+5 3
diff --git a/Занимательное программирование/3/3_random/geometry.pas b/Занимательное программирование/3/3_random/geometry.pas
new file mode 100644
index 0000000..cc00fd7
--- /dev/null
+++ b/Занимательное программирование/3/3_random/geometry.pas
@@ -0,0 +1,302 @@
+unit Geometry;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils;
+
+type
+  { Вершины }
+  Vertex = record
+    x, y, z: Real; { Координаты вершины }
+  end;
+  { Ребра }
+  Edge = record
+    src, dest: Integer; { Индексы соединяемых вершин }
+  end;
+
+  Object3D = record
+    vertices: array of Vertex; { вершины }
+    edges: array of Edge; { ребра }
+    xc, yc, zc: Real; { координаты центра объекта }
+  end;
+
+  Matrix = array[1..4, 1..4] of Real; { матрица 4x4 }
+  Column = array[1..4] of Real; { столбец }
+
+function LoadObject3D(filename: String): Object3D;
+function CopyObject3D(Shape: Object3D): Object3D;
+
+{ умножение матрицы на матрицу }
+function MMMult(lhs, rhs: Matrix): Matrix;
+{ умножение матрицы на столбец }
+function MCMult(lhs: Matrix; rhs: Column): Column;
+{ матрица поворота модели }
+function RotateMatrix(xa, ya, za: Real): Matrix;
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+procedure RotateShape(var Shape: Object3D; xa, ya, za: Real);
+procedure MoveShape(var Shape: Object3D; tx, ty, tz: Real);
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+
+implementation
+
+function LoadObject3D(filename: String): Object3D;
+var
+  F: TextFile; { исходный файл }
+  NV, NE: Integer; { количество вершин, количество ребер }
+  Shape: Object3D; { модель }
+  i: Integer; { счетчик цикла }
+begin
+  AssignFile(F, filename); { открываем  исходный файл }
+  FileMode := 0; { в режиме "только чтение" }
+  Reset(F);
+
+  ReadLn(F, NV); { считываем количество вершин }
+  SetLength(Shape.vertices, NV); { и корректируем размер массива }
+  for i := 0 to NV - 1 do { считываем каждую вершину }
+    ReadLn(F, Shape.vertices[i].x, Shape.vertices[i].y, Shape.vertices[i].z);
+
+  ReadLn(F, NE); { то же для ребер }
+  SetLength(Shape.edges, NE);
+  for i := 0 to NE - 1 do
+    ReadLn(F, Shape.edges[i].src, Shape.edges[i].dest);
+
+  CloseFile(F);
+  LoadObject3D := Shape;
+end;
+
+function CopyObject3D(Shape: Object3D): Object3D;
+begin
+  CopyObject3D.vertices := Copy(Shape.vertices, 0);
+  CopyObject3D.edges := Copy(Shape.edges, 0);
+
+  CopyObject3D.xc := Shape.xc;
+  CopyObject3D.yc := Shape.yc;
+  CopyObject3D.zc := Shape.zc
+end;
+
+function MMMult(lhs, rhs: Matrix): Matrix;
+var
+   i, j, k: Integer;
+   r: Matrix;
+   s: Real;
+begin
+  for i := 1 to 4 do
+    for j := 1 to 4 do
+    begin
+      s := 0;
+      for k := 1 to 4 do
+        s := s + lhs[i, k] * rhs[k, j];
+      r[i, j] := s;
+    end;
+  MMMult := r;
+end;
+
+function MCMult(lhs: Matrix; rhs: Column): Column;
+var
+  k, i: Integer;
+  s: Real;
+  r: Column;
+begin
+  for i := 1 to 4 do { аналогично MMMult }
+  begin
+    s := 0;
+
+    for k := 1 to 4 do
+      s := s + lhs[i, k] * rhs[k];
+    r[i] := s;
+  end;
+
+  MCMult := r;
+end;
+
+function RotateMatrix(xa, ya, za: Real): Matrix;
+var
+  xr, yr, zr: Matrix;
+begin
+  { матрица поворота вокруг оси Ox }
+  xr[1, 1] := 1;
+  xr[1, 2] := 0;
+  xr[1, 3] := 0;
+  xr[1, 4] := 0;
+
+  xr[2, 1] := 0;
+  xr[2, 2] := Cos(xa);
+  xr[2, 3] := -Sin(xa);
+  xr[2, 4] := 0;
+
+  xr[3, 1] := 0;
+  xr[3, 2] := Sin(xa);
+  xr[3, 3] := Cos(xa);
+  xr[3, 4] := 0;
+
+  xr[4, 1] := 0;
+  xr[4, 2] := 0;
+  xr[4, 3] := 0;
+  xr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oy }
+  yr[1, 1] := Cos(ya);
+  yr[1, 2] := 0;
+  yr[1, 3] := Sin(ya);
+  yr[1, 4] := 0;
+
+  yr[2, 1] := 0;
+  yr[2, 2] := 1;
+  yr[2, 3] := 0;
+  yr[2, 4] := 0;
+
+  yr[3, 1] := -Sin(ya);
+  yr[3, 2] := 0;
+  yr[3, 3] := Cos(ya);
+  yr[3, 4] := 0;
+
+  yr[4, 1] := 0;
+  yr[4, 2] := 0;
+  yr[4, 3] := 0;
+  yr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oz }
+  zr[1, 1] := Cos(za);
+  zr[1, 2] := -Sin(za);
+  zr[1, 3] := 0;
+  zr[1, 4] := 0;
+
+  zr[2, 1] := Sin(za);
+  zr[2, 2] := Cos(za);
+  zr[2, 3] := 0;
+  zr[2, 4] := 0;
+
+  zr[3, 1] := 0;
+  zr[3, 2] := 0;
+  zr[3, 3] := 1;
+  zr[3, 4] := 0;
+
+  zr[4, 1] := 0;
+  zr[4, 2] := 0;
+  zr[4, 3] := 0;
+  zr[4, 4] := 1;
+
+  RotateMatrix := MMMult(MMMult(xr, yr), zr)
+end;
+
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+begin
+  MoveMatrix[1, 1] := 1;
+  MoveMatrix[1, 2] := 0;
+  MoveMatrix[1, 3] := 0;
+  MoveMatrix[1, 4] := tx;
+
+  MoveMatrix[2, 1] := 0;
+  MoveMatrix[2, 2] := 1;
+  MoveMatrix[2, 3] := 0;
+  MoveMatrix[2, 4] := ty;
+
+  MoveMatrix[3, 1] := 0;
+  MoveMatrix[3, 2] := 0;
+  MoveMatrix[3, 3] := 1;
+  MoveMatrix[3, 4] := tz;
+
+  MoveMatrix[4, 1] := 0;
+  MoveMatrix[4, 2] := 0;
+  MoveMatrix[4, 3] := 0;
+  MoveMatrix[4, 4] := 1
+end;
+
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+begin
+  ResizeMatrix[1, 1] := sx;
+  ResizeMatrix[1, 2] := 0;
+  ResizeMatrix[1, 3] := 0;
+  ResizeMatrix[1, 4] := 0;
+
+  ResizeMatrix[2, 1] := 0;
+  ResizeMatrix[2, 2] := sy;
+  ResizeMatrix[2, 3] := 0;
+  ResizeMatrix[2, 4] := 0;
+
+  ResizeMatrix[3, 1] := 0;
+  ResizeMatrix[3, 2] := 0;
+  ResizeMatrix[3, 3] := sz;
+  ResizeMatrix[3, 4] := 0;
+
+  ResizeMatrix[4, 1] := 0;
+  ResizeMatrix[4, 2] := 0;
+  ResizeMatrix[4, 3] := 0;
+  ResizeMatrix[4, 4] := 1
+end;
+
+procedure RotateShape(var Shape: Object3D; xa, ya, za: Real);
+var
+  rm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  rm := RotateMatrix(xa, ya, za); { сгенерировать матрицу вращения }
+  c[4] := 1; { последний элемент столбца всегда равен единице }
+
+  for i := 0 to High(Shape.vertices) do { цикл по всем вершинам }
+  begin { High(a) возвращает верхний индекс массива a }
+    c[1] := Shape.vertices[i].x; { инициализация столбца }
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(rm, c); { вызов преобразования }
+
+    Shape.vertices[i].x := c[1]; { внесение изменений в модель }
+    Shape.vertices[i].y := c[2]; { в соответствии с полученным }
+    Shape.vertices[i].z := c[3] { результатом преобразования }
+  end
+end;
+
+procedure MoveShape(var Shape: Object3D; tx, ty, tz: Real);
+var
+  mm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  mm := MoveMatrix(tx, ty, tz);
+  c[4] := 1;
+
+  for i := 0 to High(Shape.vertices) do
+  begin
+    c[1] := Shape.vertices[i].x;
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(mm, c);
+
+    Shape.vertices[i].x := c[1];
+    Shape.vertices[i].y := c[2];
+    Shape.vertices[i].z := c[3]
+  end
+end;
+
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+var
+  mm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  mm := ResizeMatrix(sx, sy, sz);
+  c[4] := 1;
+
+  for i := 0 to High(Shape.vertices) do
+  begin
+    c[1] := Shape.vertices[i].x;
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(mm, c);
+
+    Shape.vertices[i].x := c[1];
+    Shape.vertices[i].y := c[2];
+    Shape.vertices[i].z := c[3]
+  end
+end;
+
+end.
+
diff --git a/Занимательное программирование/3/3_random/graphics_3d.lpi b/Занимательное программирование/3/3_random/graphics_3d.lpi
new file mode 100644
index 0000000..67fa0db
--- /dev/null
+++ b/Занимательное программирование/3/3_random/graphics_3d.lpi
@@ -0,0 +1,90 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectOptions>
+    <Version Value="12"/>
+    <PathDelim Value="\"/>
+    <General>
+      <SessionStorage Value="InProjectDir"/>
+      <Title Value="graphics_3d"/>
+      <Scaled Value="True"/>
+      <ResourceType Value="res"/>
+      <UseXPManifest Value="True"/>
+      <XPManifest>
+        <DpiAware Value="True"/>
+      </XPManifest>
+      <Icon Value="0"/>
+    </General>
+    <BuildModes>
+      <Item Name="Default" Default="True"/>
+    </BuildModes>
+    <PublishOptions>
+      <Version Value="2"/>
+      <UseFileFilters Value="True"/>
+    </PublishOptions>
+    <RunParams>
+      <FormatVersion Value="2"/>
+    </RunParams>
+    <RequiredPackages>
+      <Item>
+        <PackageName Value="LCL"/>
+      </Item>
+    </RequiredPackages>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+    </Units>
+  </ProjectOptions>
+  <CompilerOptions>
+    <Version Value="11"/>
+    <PathDelim Value="\"/>
+    <Target>
+      <Filename Value="graphics_3d"/>
+    </Target>
+    <SearchPaths>
+      <IncludeFiles Value="$(ProjOutDir)"/>
+      <UnitOutputDirectory Value="lib\$(TargetCPU)-$(TargetOS)"/>
+    </SearchPaths>
+    <Linking>
+      <Debugging>
+        <DebugInfoType Value="dsDwarf3"/>
+      </Debugging>
+      <Options>
+        <Win32>
+          <GraphicApplication Value="True"/>
+        </Win32>
+      </Options>
+    </Linking>
+  </CompilerOptions>
+  <Debugging>
+    <Exceptions>
+      <Item>
+        <Name Value="EAbort"/>
+      </Item>
+      <Item>
+        <Name Value="ECodetoolError"/>
+      </Item>
+      <Item>
+        <Name Value="EFOpenError"/>
+      </Item>
+    </Exceptions>
+  </Debugging>
+</CONFIG>
diff --git a/Занимательное программирование/3/3_random/graphics_3d.lpr b/Занимательное программирование/3/3_random/graphics_3d.lpr
new file mode 100644
index 0000000..3778580
--- /dev/null
+++ b/Занимательное программирование/3/3_random/graphics_3d.lpr
@@ -0,0 +1,29 @@
+program graphics_3d;
+
+{$mode objfpc}{$H+}
+
+uses
+  {$IFDEF UNIX}
+  cthreads,
+  {$ENDIF}
+  {$IFDEF HASAMIGA}
+  athreads,
+  {$ENDIF}
+  Interfaces, // this includes the LCL widgetset
+  Forms, Octahedron, geometry
+  { you can add units after this };
+
+{$R *.res}
+
+begin
+  Randomize;
+  RequireDerivedFormResource:=True;
+  Application.Scaled:=True;
+  {$PUSH}{$WARN 5044 OFF}
+  Application.MainFormOnTaskbar:=True;
+  {$POP}
+  Application.Initialize;
+  Application.CreateForm(TForm1, Form1);
+  Application.Run;
+end.
+
diff --git a/Занимательное программирование/3/3_random/graphics_3d.lps b/Занимательное программирование/3/3_random/graphics_3d.lps
new file mode 100644
index 0000000..9c5a149
--- /dev/null
+++ b/Занимательное программирование/3/3_random/graphics_3d.lps
@@ -0,0 +1,180 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectSession>
+    <PathDelim Value="\"/>
+    <Version Value="12"/>
+    <BuildModes Active="Default"/>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="1"/>
+        <CursorPos X="13" Y="19"/>
+        <UsageCount Value="53"/>
+        <Loaded Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+        <IsVisibleTab Value="True"/>
+        <TopLine Value="62"/>
+        <CursorPos X="18" Y="79"/>
+        <UsageCount Value="53"/>
+        <Bookmarks Count="1">
+          <Item0 X="17" Y="48" Left="1" Top="84" ID="3"/>
+        </Bookmarks>
+        <Loaded Value="True"/>
+        <LoadedDesigner Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+        <EditorIndex Value="3"/>
+        <TopLine Value="238"/>
+        <CursorPos X="20" Y="183"/>
+        <UsageCount Value="53"/>
+        <Loaded Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="2"/>
+        <CursorPos X="4" Y="20"/>
+        <UsageCount Value="53"/>
+        <Loaded Value="True"/>
+        <DefaultSyntaxHighlighter Value="Text"/>
+      </Unit>
+    </Units>
+    <JumpHistory HistoryIndex="29">
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="257" Column="18" TopLine="247"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="134" Column="7" TopLine="126"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="137" Column="14" TopLine="126"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="146" Column="23" TopLine="130"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="70" Column="19" TopLine="60"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="93" Column="12" TopLine="77"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="137" Column="14" TopLine="121"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="27" Column="45" TopLine="11"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="266" TopLine="248"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="31" Column="11" TopLine="19"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="73" Column="23" TopLine="58"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="77" Column="27" TopLine="63"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="143" Column="37" TopLine="132"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="146" Column="37" TopLine="136"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="18" Column="23" TopLine="18"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="106" Column="23" TopLine="96"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="19" Column="23" TopLine="18"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="20" Column="23" TopLine="7"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="19" Column="23" TopLine="7"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="143" Column="10" TopLine="128"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="63" Column="37" TopLine="39"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="61" Column="18" TopLine="40"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="46" Column="38" TopLine="32"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="42" TopLine="40"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="175" Column="32" TopLine="166"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="95" Column="28" TopLine="85"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="18" Column="5" TopLine="7"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="17" Column="5" TopLine="7"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="78" Column="25" TopLine="66"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="72" Column="20" TopLine="61"/>
+      </Position>
+    </JumpHistory>
+    <RunParams>
+      <FormatVersion Value="2"/>
+      <Modes ActiveMode=""/>
+    </RunParams>
+  </ProjectSession>
+</CONFIG>
diff --git a/Занимательное программирование/3/3_random/octahedron.lfm b/Занимательное программирование/3/3_random/octahedron.lfm
new file mode 100644
index 0000000..c020ad3
--- /dev/null
+++ b/Занимательное программирование/3/3_random/octahedron.lfm
@@ -0,0 +1,53 @@
+object Form1: TForm1
+  Left = 352
+  Height = 673
+  Top = 32
+  Width = 600
+  Caption = 'Form1'
+  ClientHeight = 673
+  ClientWidth = 600
+  DesignTimePPI = 120
+  object BackScreen: TImage
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object Screen: TPaintBox
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object StartStopBtn: TButton
+    AnchorSideLeft.Control = Owner
+    AnchorSideLeft.Side = asrCenter
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrCenter
+    AnchorSideBottom.Control = Owner
+    AnchorSideBottom.Side = asrBottom
+    Left = 241
+    Height = 48
+    Top = 615
+    Width = 118
+    Anchors = [akLeft, akBottom]
+    BorderSpacing.Bottom = 10
+    Caption = 'Пуск'
+    TabOrder = 0
+    OnClick = StartStopBtnClick
+  end
+end
diff --git a/Занимательное программирование/3/3_random/octahedron.pas b/Занимательное программирование/3/3_random/octahedron.pas
new file mode 100644
index 0000000..7bb06e1
--- /dev/null
+++ b/Занимательное программирование/3/3_random/octahedron.pas
@@ -0,0 +1,157 @@
+unit Octahedron;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, ExtCtrls, StdCtrls,
+  Spin, Geometry;
+
+type
+
+  { TForm1 }
+
+  TForm1 = class(TForm)
+    BackScreen: TImage;
+    StartStopBtn: TButton;
+    Screen: TPaintBox;
+    procedure StartStopBtnClick(Sender: TObject);
+  private
+
+  public
+
+  end;
+
+var
+  Form1: TForm1;
+  IsRunning: Boolean = false;
+
+implementation
+
+{$R *.lfm}
+
+procedure ShowShape(Shape: Object3D); { нарисовать объект }
+var
+  i, Xs, Ys: Integer;
+  x, y, z: Real;
+const
+  N = 300; { "глубина" экрана }
+begin
+  for i := 0 to High(Shape.edges) do { цикл по всем ребрам }
+  begin { координаты первой точки ребра }
+    x := Shape.vertices[Shape.edges[i].src].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].src].y + Shape.yc;
+    z := Shape.vertices[Shape.edges[i].src].z + Shape.zc;
+    if Abs(z) < 0.01 then z := 0.01; { избегаем деления на нуль }
+                                     { вычисляем экранные координаты }
+    Xs := Round(Form1.Screen.Width div 2 + N * x / z);
+    Ys := Round(Form1.Screen.Height div 2 + N * y / z);
+
+    Form1.BackScreen.Canvas.MoveTo(Xs, Ys);
+                                       { координаты второй точки зрения }
+    x := Shape.vertices[Shape.edges[i].dest].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].dest].y + Shape.yc;
+    z := Shape.vertices[Shape.edges[i].dest].z + Shape.zc;
+    if Abs(z) < 0.01 then z := 0.01; { избегаем деления на нуль }
+                                     { и ее экранные координаты }
+    Xs := Round(Form1.Screen.Width div 2 + N * x / z);
+    Ys := Round(Form1.Screen.Height div 2 + N * y / z);
+
+    Form1.BackScreen.Canvas.LineTo(Xs, Ys); { рисуем ребро }
+  end;
+end;
+
+{ TForm1 }
+
+procedure TForm1.StartStopBtnClick(Sender: TObject); { главная процедура }
+var
+  oldtime: TDateTime;
+  Model: Object3D; { трехмерный объект }
+  Vx, Vy, Vz: Real; { значения составляющих его скорости }
+  xa, ya, za: Real;
+  pause: Integer;
+const
+  MSecsPerFrame = 25; { скорость работы (кадров в секунду) }
+begin
+  xa := Random(10) / 100; { скорость вращения вокруг оси Ox }
+  ya := Random(10) / 100; { скорость вращения вокруг оси Oy }
+  za := Random(10) / 100; { скорость вращения вокруг оси Oz }
+
+  if IsRunning then
+  begin
+    IsRunning := false;
+    StartStopBtn.Caption := 'Пуск';
+    Exit;
+  end;
+  StartStopBtn.Caption := 'Стоп';
+  IsRunning := true;
+
+  Model := LoadObject3D('octahedron.txt'); { загрузить объект }
+
+  Model.xc := (Screen.Width div 2) - Random(Screen.Width); { начальное положение }
+  Model.yc := (Screen.Height div 2) - Random(Screen.Height); { объекта }
+  Model.zc := 200;
+  Vx := 10 - Random(20); { и составляющие }
+  Vy := 15 - Random(30); { скорости }
+  Vz := 20 - Random(40);
+
+  while IsRunning do
+  begin
+    oldtime := Now;
+
+    { отразить от стена (3D-аналог "молекулы в закрытом сосуде") }
+    if Model.xc > BackScreen.Width div 2 then
+    begin
+      Model.xc := BackScreen.Width div 2;
+      Vx := -Vx;
+    end;
+    if Model.xc < -BackScreen.Width div 2 then
+    begin
+      Model.xc := -BackScreen.Width div 2;
+      Vx := -Vx;
+    end;
+
+    if Model.yc > BackScreen.Height div 2 then
+    begin
+      Model.yc := BackScreen.Height div 2;
+      Vy := -Vy;
+    end;
+    if Model.yc < -BackScreen.Height div 2 then
+    begin
+      Model.yc := -BackScreen.Height div 2;
+      Vy := -Vy;
+    end;
+
+    if Model.zc > 1000 then
+    begin
+      Model.zc := 1000;
+      Vz := -Vz;
+    end;
+    if Model.zc < 200 then
+    begin
+      Model.zc := 200;
+      Vz := -Vz;
+    end;
+
+    RotateShape(Model, xa, ya, za); { поворот модели }
+    BackScreen.Canvas.FillRect(Rect(0, 0, Screen.Width, Screen.Height));
+    ShowShape(Model); { очистить экран и нарисовать объект }
+                      { отобразить объект на основном экране }
+    Screen.Canvas.CopyRect(Rect(0, 0, Screen.Width, Screen.Height),
+        BackScreen.Canvas, Rect(0, 0, Screen.Width, Screen.Height));
+
+    Model.xc := Model.xc + Vx;
+    Model.yc := Model.yc + Vy;
+    Model.zc := Model.zc + Vz;
+
+    Application.ProcessMessages;
+    pause := Round(MSecsPerFrame - (Now - oldtime) * MSecsPerDay);
+    if pause > 0 then Sleep(pause); { задержка }
+
+    if Application.Terminated then Exit;
+  end;
+end;
+
+end.
+
diff --git a/Занимательное программирование/3/3_random/octahedron.txt b/Занимательное программирование/3/3_random/octahedron.txt
new file mode 100644
index 0000000..770d229
--- /dev/null
+++ b/Занимательное программирование/3/3_random/octahedron.txt
@@ -0,0 +1,20 @@
+6
+-100 -100 0
+-100 100 0
+100 100 0
+100 -100 0
+0 0 -141.42
+0 0 141.42
+12
+0 1
+1 2
+2 3
+3 0
+4 0
+4 1
+4 2
+4 3
+5 0
+5 1
+5 2
+5 3
diff --git a/Занимательное программирование/3/4_cube/geometry.pas b/Занимательное программирование/3/4_cube/geometry.pas
new file mode 100644
index 0000000..cc00fd7
--- /dev/null
+++ b/Занимательное программирование/3/4_cube/geometry.pas
@@ -0,0 +1,302 @@
+unit Geometry;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils;
+
+type
+  { Вершины }
+  Vertex = record
+    x, y, z: Real; { Координаты вершины }
+  end;
+  { Ребра }
+  Edge = record
+    src, dest: Integer; { Индексы соединяемых вершин }
+  end;
+
+  Object3D = record
+    vertices: array of Vertex; { вершины }
+    edges: array of Edge; { ребра }
+    xc, yc, zc: Real; { координаты центра объекта }
+  end;
+
+  Matrix = array[1..4, 1..4] of Real; { матрица 4x4 }
+  Column = array[1..4] of Real; { столбец }
+
+function LoadObject3D(filename: String): Object3D;
+function CopyObject3D(Shape: Object3D): Object3D;
+
+{ умножение матрицы на матрицу }
+function MMMult(lhs, rhs: Matrix): Matrix;
+{ умножение матрицы на столбец }
+function MCMult(lhs: Matrix; rhs: Column): Column;
+{ матрица поворота модели }
+function RotateMatrix(xa, ya, za: Real): Matrix;
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+procedure RotateShape(var Shape: Object3D; xa, ya, za: Real);
+procedure MoveShape(var Shape: Object3D; tx, ty, tz: Real);
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+
+implementation
+
+function LoadObject3D(filename: String): Object3D;
+var
+  F: TextFile; { исходный файл }
+  NV, NE: Integer; { количество вершин, количество ребер }
+  Shape: Object3D; { модель }
+  i: Integer; { счетчик цикла }
+begin
+  AssignFile(F, filename); { открываем  исходный файл }
+  FileMode := 0; { в режиме "только чтение" }
+  Reset(F);
+
+  ReadLn(F, NV); { считываем количество вершин }
+  SetLength(Shape.vertices, NV); { и корректируем размер массива }
+  for i := 0 to NV - 1 do { считываем каждую вершину }
+    ReadLn(F, Shape.vertices[i].x, Shape.vertices[i].y, Shape.vertices[i].z);
+
+  ReadLn(F, NE); { то же для ребер }
+  SetLength(Shape.edges, NE);
+  for i := 0 to NE - 1 do
+    ReadLn(F, Shape.edges[i].src, Shape.edges[i].dest);
+
+  CloseFile(F);
+  LoadObject3D := Shape;
+end;
+
+function CopyObject3D(Shape: Object3D): Object3D;
+begin
+  CopyObject3D.vertices := Copy(Shape.vertices, 0);
+  CopyObject3D.edges := Copy(Shape.edges, 0);
+
+  CopyObject3D.xc := Shape.xc;
+  CopyObject3D.yc := Shape.yc;
+  CopyObject3D.zc := Shape.zc
+end;
+
+function MMMult(lhs, rhs: Matrix): Matrix;
+var
+   i, j, k: Integer;
+   r: Matrix;
+   s: Real;
+begin
+  for i := 1 to 4 do
+    for j := 1 to 4 do
+    begin
+      s := 0;
+      for k := 1 to 4 do
+        s := s + lhs[i, k] * rhs[k, j];
+      r[i, j] := s;
+    end;
+  MMMult := r;
+end;
+
+function MCMult(lhs: Matrix; rhs: Column): Column;
+var
+  k, i: Integer;
+  s: Real;
+  r: Column;
+begin
+  for i := 1 to 4 do { аналогично MMMult }
+  begin
+    s := 0;
+
+    for k := 1 to 4 do
+      s := s + lhs[i, k] * rhs[k];
+    r[i] := s;
+  end;
+
+  MCMult := r;
+end;
+
+function RotateMatrix(xa, ya, za: Real): Matrix;
+var
+  xr, yr, zr: Matrix;
+begin
+  { матрица поворота вокруг оси Ox }
+  xr[1, 1] := 1;
+  xr[1, 2] := 0;
+  xr[1, 3] := 0;
+  xr[1, 4] := 0;
+
+  xr[2, 1] := 0;
+  xr[2, 2] := Cos(xa);
+  xr[2, 3] := -Sin(xa);
+  xr[2, 4] := 0;
+
+  xr[3, 1] := 0;
+  xr[3, 2] := Sin(xa);
+  xr[3, 3] := Cos(xa);
+  xr[3, 4] := 0;
+
+  xr[4, 1] := 0;
+  xr[4, 2] := 0;
+  xr[4, 3] := 0;
+  xr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oy }
+  yr[1, 1] := Cos(ya);
+  yr[1, 2] := 0;
+  yr[1, 3] := Sin(ya);
+  yr[1, 4] := 0;
+
+  yr[2, 1] := 0;
+  yr[2, 2] := 1;
+  yr[2, 3] := 0;
+  yr[2, 4] := 0;
+
+  yr[3, 1] := -Sin(ya);
+  yr[3, 2] := 0;
+  yr[3, 3] := Cos(ya);
+  yr[3, 4] := 0;
+
+  yr[4, 1] := 0;
+  yr[4, 2] := 0;
+  yr[4, 3] := 0;
+  yr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oz }
+  zr[1, 1] := Cos(za);
+  zr[1, 2] := -Sin(za);
+  zr[1, 3] := 0;
+  zr[1, 4] := 0;
+
+  zr[2, 1] := Sin(za);
+  zr[2, 2] := Cos(za);
+  zr[2, 3] := 0;
+  zr[2, 4] := 0;
+
+  zr[3, 1] := 0;
+  zr[3, 2] := 0;
+  zr[3, 3] := 1;
+  zr[3, 4] := 0;
+
+  zr[4, 1] := 0;
+  zr[4, 2] := 0;
+  zr[4, 3] := 0;
+  zr[4, 4] := 1;
+
+  RotateMatrix := MMMult(MMMult(xr, yr), zr)
+end;
+
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+begin
+  MoveMatrix[1, 1] := 1;
+  MoveMatrix[1, 2] := 0;
+  MoveMatrix[1, 3] := 0;
+  MoveMatrix[1, 4] := tx;
+
+  MoveMatrix[2, 1] := 0;
+  MoveMatrix[2, 2] := 1;
+  MoveMatrix[2, 3] := 0;
+  MoveMatrix[2, 4] := ty;
+
+  MoveMatrix[3, 1] := 0;
+  MoveMatrix[3, 2] := 0;
+  MoveMatrix[3, 3] := 1;
+  MoveMatrix[3, 4] := tz;
+
+  MoveMatrix[4, 1] := 0;
+  MoveMatrix[4, 2] := 0;
+  MoveMatrix[4, 3] := 0;
+  MoveMatrix[4, 4] := 1
+end;
+
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+begin
+  ResizeMatrix[1, 1] := sx;
+  ResizeMatrix[1, 2] := 0;
+  ResizeMatrix[1, 3] := 0;
+  ResizeMatrix[1, 4] := 0;
+
+  ResizeMatrix[2, 1] := 0;
+  ResizeMatrix[2, 2] := sy;
+  ResizeMatrix[2, 3] := 0;
+  ResizeMatrix[2, 4] := 0;
+
+  ResizeMatrix[3, 1] := 0;
+  ResizeMatrix[3, 2] := 0;
+  ResizeMatrix[3, 3] := sz;
+  ResizeMatrix[3, 4] := 0;
+
+  ResizeMatrix[4, 1] := 0;
+  ResizeMatrix[4, 2] := 0;
+  ResizeMatrix[4, 3] := 0;
+  ResizeMatrix[4, 4] := 1
+end;
+
+procedure RotateShape(var Shape: Object3D; xa, ya, za: Real);
+var
+  rm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  rm := RotateMatrix(xa, ya, za); { сгенерировать матрицу вращения }
+  c[4] := 1; { последний элемент столбца всегда равен единице }
+
+  for i := 0 to High(Shape.vertices) do { цикл по всем вершинам }
+  begin { High(a) возвращает верхний индекс массива a }
+    c[1] := Shape.vertices[i].x; { инициализация столбца }
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(rm, c); { вызов преобразования }
+
+    Shape.vertices[i].x := c[1]; { внесение изменений в модель }
+    Shape.vertices[i].y := c[2]; { в соответствии с полученным }
+    Shape.vertices[i].z := c[3] { результатом преобразования }
+  end
+end;
+
+procedure MoveShape(var Shape: Object3D; tx, ty, tz: Real);
+var
+  mm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  mm := MoveMatrix(tx, ty, tz);
+  c[4] := 1;
+
+  for i := 0 to High(Shape.vertices) do
+  begin
+    c[1] := Shape.vertices[i].x;
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(mm, c);
+
+    Shape.vertices[i].x := c[1];
+    Shape.vertices[i].y := c[2];
+    Shape.vertices[i].z := c[3]
+  end
+end;
+
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+var
+  mm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  mm := ResizeMatrix(sx, sy, sz);
+  c[4] := 1;
+
+  for i := 0 to High(Shape.vertices) do
+  begin
+    c[1] := Shape.vertices[i].x;
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(mm, c);
+
+    Shape.vertices[i].x := c[1];
+    Shape.vertices[i].y := c[2];
+    Shape.vertices[i].z := c[3]
+  end
+end;
+
+end.
+
diff --git a/Занимательное программирование/3/4_cube/graphics_3d.lpi b/Занимательное программирование/3/4_cube/graphics_3d.lpi
new file mode 100644
index 0000000..67fa0db
--- /dev/null
+++ b/Занимательное программирование/3/4_cube/graphics_3d.lpi
@@ -0,0 +1,90 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectOptions>
+    <Version Value="12"/>
+    <PathDelim Value="\"/>
+    <General>
+      <SessionStorage Value="InProjectDir"/>
+      <Title Value="graphics_3d"/>
+      <Scaled Value="True"/>
+      <ResourceType Value="res"/>
+      <UseXPManifest Value="True"/>
+      <XPManifest>
+        <DpiAware Value="True"/>
+      </XPManifest>
+      <Icon Value="0"/>
+    </General>
+    <BuildModes>
+      <Item Name="Default" Default="True"/>
+    </BuildModes>
+    <PublishOptions>
+      <Version Value="2"/>
+      <UseFileFilters Value="True"/>
+    </PublishOptions>
+    <RunParams>
+      <FormatVersion Value="2"/>
+    </RunParams>
+    <RequiredPackages>
+      <Item>
+        <PackageName Value="LCL"/>
+      </Item>
+    </RequiredPackages>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+    </Units>
+  </ProjectOptions>
+  <CompilerOptions>
+    <Version Value="11"/>
+    <PathDelim Value="\"/>
+    <Target>
+      <Filename Value="graphics_3d"/>
+    </Target>
+    <SearchPaths>
+      <IncludeFiles Value="$(ProjOutDir)"/>
+      <UnitOutputDirectory Value="lib\$(TargetCPU)-$(TargetOS)"/>
+    </SearchPaths>
+    <Linking>
+      <Debugging>
+        <DebugInfoType Value="dsDwarf3"/>
+      </Debugging>
+      <Options>
+        <Win32>
+          <GraphicApplication Value="True"/>
+        </Win32>
+      </Options>
+    </Linking>
+  </CompilerOptions>
+  <Debugging>
+    <Exceptions>
+      <Item>
+        <Name Value="EAbort"/>
+      </Item>
+      <Item>
+        <Name Value="ECodetoolError"/>
+      </Item>
+      <Item>
+        <Name Value="EFOpenError"/>
+      </Item>
+    </Exceptions>
+  </Debugging>
+</CONFIG>
diff --git a/Занимательное программирование/3/4_cube/graphics_3d.lpr b/Занимательное программирование/3/4_cube/graphics_3d.lpr
new file mode 100644
index 0000000..3778580
--- /dev/null
+++ b/Занимательное программирование/3/4_cube/graphics_3d.lpr
@@ -0,0 +1,29 @@
+program graphics_3d;
+
+{$mode objfpc}{$H+}
+
+uses
+  {$IFDEF UNIX}
+  cthreads,
+  {$ENDIF}
+  {$IFDEF HASAMIGA}
+  athreads,
+  {$ENDIF}
+  Interfaces, // this includes the LCL widgetset
+  Forms, Octahedron, geometry
+  { you can add units after this };
+
+{$R *.res}
+
+begin
+  Randomize;
+  RequireDerivedFormResource:=True;
+  Application.Scaled:=True;
+  {$PUSH}{$WARN 5044 OFF}
+  Application.MainFormOnTaskbar:=True;
+  {$POP}
+  Application.Initialize;
+  Application.CreateForm(TForm1, Form1);
+  Application.Run;
+end.
+
diff --git a/Занимательное программирование/3/4_cube/graphics_3d.lps b/Занимательное программирование/3/4_cube/graphics_3d.lps
new file mode 100644
index 0000000..d92f2c8
--- /dev/null
+++ b/Занимательное программирование/3/4_cube/graphics_3d.lps
@@ -0,0 +1,180 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectSession>
+    <PathDelim Value="\"/>
+    <Version Value="12"/>
+    <BuildModes Active="Default"/>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="1"/>
+        <CursorPos X="13" Y="19"/>
+        <UsageCount Value="54"/>
+        <Loaded Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+        <IsVisibleTab Value="True"/>
+        <TopLine Value="112"/>
+        <CursorPos X="18" Y="79"/>
+        <UsageCount Value="54"/>
+        <Bookmarks Count="1">
+          <Item0 X="17" Y="48" Left="1" Top="84" ID="3"/>
+        </Bookmarks>
+        <Loaded Value="True"/>
+        <LoadedDesigner Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+        <EditorIndex Value="3"/>
+        <TopLine Value="238"/>
+        <CursorPos X="20" Y="183"/>
+        <UsageCount Value="54"/>
+        <Loaded Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="2"/>
+        <CursorPos X="13" Y="9"/>
+        <UsageCount Value="54"/>
+        <Loaded Value="True"/>
+        <DefaultSyntaxHighlighter Value="Text"/>
+      </Unit>
+    </Units>
+    <JumpHistory HistoryIndex="29">
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="257" Column="18" TopLine="247"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="134" Column="7" TopLine="126"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="137" Column="14" TopLine="126"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="146" Column="23" TopLine="130"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="70" Column="19" TopLine="60"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="93" Column="12" TopLine="77"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="137" Column="14" TopLine="121"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="27" Column="45" TopLine="11"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="266" TopLine="248"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="31" Column="11" TopLine="19"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="73" Column="23" TopLine="58"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="77" Column="27" TopLine="63"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="143" Column="37" TopLine="132"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="146" Column="37" TopLine="136"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="18" Column="23" TopLine="18"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="106" Column="23" TopLine="96"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="19" Column="23" TopLine="18"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="20" Column="23" TopLine="7"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="19" Column="23" TopLine="7"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="143" Column="10" TopLine="128"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="63" Column="37" TopLine="39"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="61" Column="18" TopLine="40"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="46" Column="38" TopLine="32"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="42" TopLine="40"/>
+      </Position>
+      <Position>
+        <Filename Value="geometry.pas"/>
+        <Caret Line="175" Column="32" TopLine="166"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="95" Column="28" TopLine="85"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="18" Column="5" TopLine="7"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="17" Column="5" TopLine="7"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="78" Column="25" TopLine="66"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="72" Column="20" TopLine="61"/>
+      </Position>
+    </JumpHistory>
+    <RunParams>
+      <FormatVersion Value="2"/>
+      <Modes ActiveMode=""/>
+    </RunParams>
+  </ProjectSession>
+</CONFIG>
diff --git a/Занимательное программирование/3/4_cube/octahedron.lfm b/Занимательное программирование/3/4_cube/octahedron.lfm
new file mode 100644
index 0000000..c020ad3
--- /dev/null
+++ b/Занимательное программирование/3/4_cube/octahedron.lfm
@@ -0,0 +1,53 @@
+object Form1: TForm1
+  Left = 352
+  Height = 673
+  Top = 32
+  Width = 600
+  Caption = 'Form1'
+  ClientHeight = 673
+  ClientWidth = 600
+  DesignTimePPI = 120
+  object BackScreen: TImage
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object Screen: TPaintBox
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object StartStopBtn: TButton
+    AnchorSideLeft.Control = Owner
+    AnchorSideLeft.Side = asrCenter
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrCenter
+    AnchorSideBottom.Control = Owner
+    AnchorSideBottom.Side = asrBottom
+    Left = 241
+    Height = 48
+    Top = 615
+    Width = 118
+    Anchors = [akLeft, akBottom]
+    BorderSpacing.Bottom = 10
+    Caption = 'Пуск'
+    TabOrder = 0
+    OnClick = StartStopBtnClick
+  end
+end
diff --git a/Занимательное программирование/3/4_cube/octahedron.pas b/Занимательное программирование/3/4_cube/octahedron.pas
new file mode 100644
index 0000000..7bb06e1
--- /dev/null
+++ b/Занимательное программирование/3/4_cube/octahedron.pas
@@ -0,0 +1,157 @@
+unit Octahedron;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, ExtCtrls, StdCtrls,
+  Spin, Geometry;
+
+type
+
+  { TForm1 }
+
+  TForm1 = class(TForm)
+    BackScreen: TImage;
+    StartStopBtn: TButton;
+    Screen: TPaintBox;
+    procedure StartStopBtnClick(Sender: TObject);
+  private
+
+  public
+
+  end;
+
+var
+  Form1: TForm1;
+  IsRunning: Boolean = false;
+
+implementation
+
+{$R *.lfm}
+
+procedure ShowShape(Shape: Object3D); { нарисовать объект }
+var
+  i, Xs, Ys: Integer;
+  x, y, z: Real;
+const
+  N = 300; { "глубина" экрана }
+begin
+  for i := 0 to High(Shape.edges) do { цикл по всем ребрам }
+  begin { координаты первой точки ребра }
+    x := Shape.vertices[Shape.edges[i].src].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].src].y + Shape.yc;
+    z := Shape.vertices[Shape.edges[i].src].z + Shape.zc;
+    if Abs(z) < 0.01 then z := 0.01; { избегаем деления на нуль }
+                                     { вычисляем экранные координаты }
+    Xs := Round(Form1.Screen.Width div 2 + N * x / z);
+    Ys := Round(Form1.Screen.Height div 2 + N * y / z);
+
+    Form1.BackScreen.Canvas.MoveTo(Xs, Ys);
+                                       { координаты второй точки зрения }
+    x := Shape.vertices[Shape.edges[i].dest].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].dest].y + Shape.yc;
+    z := Shape.vertices[Shape.edges[i].dest].z + Shape.zc;
+    if Abs(z) < 0.01 then z := 0.01; { избегаем деления на нуль }
+                                     { и ее экранные координаты }
+    Xs := Round(Form1.Screen.Width div 2 + N * x / z);
+    Ys := Round(Form1.Screen.Height div 2 + N * y / z);
+
+    Form1.BackScreen.Canvas.LineTo(Xs, Ys); { рисуем ребро }
+  end;
+end;
+
+{ TForm1 }
+
+procedure TForm1.StartStopBtnClick(Sender: TObject); { главная процедура }
+var
+  oldtime: TDateTime;
+  Model: Object3D; { трехмерный объект }
+  Vx, Vy, Vz: Real; { значения составляющих его скорости }
+  xa, ya, za: Real;
+  pause: Integer;
+const
+  MSecsPerFrame = 25; { скорость работы (кадров в секунду) }
+begin
+  xa := Random(10) / 100; { скорость вращения вокруг оси Ox }
+  ya := Random(10) / 100; { скорость вращения вокруг оси Oy }
+  za := Random(10) / 100; { скорость вращения вокруг оси Oz }
+
+  if IsRunning then
+  begin
+    IsRunning := false;
+    StartStopBtn.Caption := 'Пуск';
+    Exit;
+  end;
+  StartStopBtn.Caption := 'Стоп';
+  IsRunning := true;
+
+  Model := LoadObject3D('octahedron.txt'); { загрузить объект }
+
+  Model.xc := (Screen.Width div 2) - Random(Screen.Width); { начальное положение }
+  Model.yc := (Screen.Height div 2) - Random(Screen.Height); { объекта }
+  Model.zc := 200;
+  Vx := 10 - Random(20); { и составляющие }
+  Vy := 15 - Random(30); { скорости }
+  Vz := 20 - Random(40);
+
+  while IsRunning do
+  begin
+    oldtime := Now;
+
+    { отразить от стена (3D-аналог "молекулы в закрытом сосуде") }
+    if Model.xc > BackScreen.Width div 2 then
+    begin
+      Model.xc := BackScreen.Width div 2;
+      Vx := -Vx;
+    end;
+    if Model.xc < -BackScreen.Width div 2 then
+    begin
+      Model.xc := -BackScreen.Width div 2;
+      Vx := -Vx;
+    end;
+
+    if Model.yc > BackScreen.Height div 2 then
+    begin
+      Model.yc := BackScreen.Height div 2;
+      Vy := -Vy;
+    end;
+    if Model.yc < -BackScreen.Height div 2 then
+    begin
+      Model.yc := -BackScreen.Height div 2;
+      Vy := -Vy;
+    end;
+
+    if Model.zc > 1000 then
+    begin
+      Model.zc := 1000;
+      Vz := -Vz;
+    end;
+    if Model.zc < 200 then
+    begin
+      Model.zc := 200;
+      Vz := -Vz;
+    end;
+
+    RotateShape(Model, xa, ya, za); { поворот модели }
+    BackScreen.Canvas.FillRect(Rect(0, 0, Screen.Width, Screen.Height));
+    ShowShape(Model); { очистить экран и нарисовать объект }
+                      { отобразить объект на основном экране }
+    Screen.Canvas.CopyRect(Rect(0, 0, Screen.Width, Screen.Height),
+        BackScreen.Canvas, Rect(0, 0, Screen.Width, Screen.Height));
+
+    Model.xc := Model.xc + Vx;
+    Model.yc := Model.yc + Vy;
+    Model.zc := Model.zc + Vz;
+
+    Application.ProcessMessages;
+    pause := Round(MSecsPerFrame - (Now - oldtime) * MSecsPerDay);
+    if pause > 0 then Sleep(pause); { задержка }
+
+    if Application.Terminated then Exit;
+  end;
+end;
+
+end.
+
diff --git a/Занимательное программирование/3/4_cube/octahedron.txt b/Занимательное программирование/3/4_cube/octahedron.txt
new file mode 100644
index 0000000..c47a3b7
--- /dev/null
+++ b/Занимательное программирование/3/4_cube/octahedron.txt
@@ -0,0 +1,22 @@
+8
+-100 -100 -100
+-100 100 -100
+100 100 -100
+100 -100 -100
+-100 -100 100
+-100 100 100
+100 100 100
+100 -100 100
+12
+0 1
+1 2
+2 3
+3 0
+4 5
+5 6
+6 7
+7 4
+0 4
+1 5
+2 6
+3 7
diff --git a/Занимательное программирование/3/5_ideal_gas/geometry.pas b/Занимательное программирование/3/5_ideal_gas/geometry.pas
new file mode 100644
index 0000000..cbbff5d
--- /dev/null
+++ b/Занимательное программирование/3/5_ideal_gas/geometry.pas
@@ -0,0 +1,344 @@
+unit Geometry;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils;
+
+type
+  { Вершины }
+  Vertex = record
+    x, y, z: Real; { Координаты вершины }
+  end;
+  { Ребра }
+  Edge = record
+    src, dest: Integer; { Индексы соединяемых вершин }
+  end;
+
+  Object3D = class
+  public
+    vertices: array of Vertex; { вершины }
+    edges: array of Edge; { ребра }
+    xc, yc, zc: Real; { координаты центра объекта }
+    vx, vy, vz: Real; { значения составляющих его скорости }
+    xa, ya, za: Real; { скорость вращения вокруг оси }
+
+    constructor Create(var center, velocity, axis: Vertex);
+
+    procedure MoveCenter();
+  end;
+
+  Matrix = array[1..4, 1..4] of Real; { матрица 4x4 }
+  Column = array[1..4] of Real; { столбец }
+
+function CopyObject3D(Shape: Object3D): Object3D;
+
+{ умножение матрицы на матрицу }
+function MMMult(lhs, rhs: Matrix): Matrix;
+{ умножение матрицы на столбец }
+function MCMult(lhs: Matrix; rhs: Column): Column;
+{ матрица поворота модели }
+function RotateMatrix(xa, ya, za: Real): Matrix;
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+procedure RotateShape(Shape: Object3D);
+procedure MoveShape(Shape: Object3D; Width, Height: Real);
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+
+implementation
+
+constructor Object3D.Create(var center, velocity, axis: Vertex);
+const
+  size = 10;
+  cubeVertices: array of Vertex = (
+    (x: -size; y: -size; z: -size),
+    (x: -size; y: size; z: -size),
+    (x: size; y: size; z: -size),
+    (x: size; y: -size; z: -size),
+    (x: -size; y: -size; z: size),
+    (x: -size; y: size; z: size),
+    (x: size; y: size; z: size),
+    (x: size; y: -size; z: size)
+  );
+  cubeEdges: array of Edge = (
+    (src: 0; dest: 1),
+    (src: 1; dest: 2),
+    (src: 2; dest: 3),
+    (src: 3; dest: 0),
+    (src: 4; dest: 5),
+    (src: 5; dest: 6),
+    (src: 6; dest: 7),
+    (src: 7; dest: 4),
+    (src: 0; dest: 4),
+    (src: 1; dest: 5),
+    (src: 2; dest: 6),
+    (src: 3; dest: 7)
+  );
+begin
+  vertices := cubeVertices;
+  edges := cubeEdges;
+  xc := center.x;
+  yc := center.y;
+  zc := center.z;
+  vx := velocity.x;
+  vy := velocity.y;
+  vz := velocity.z;
+  xa := axis.x;
+  ya := axis.y;
+  za := axis.z
+end;
+
+procedure Object3D.MoveCenter();
+begin
+  xc := xc + Vx;
+  yc := yc + Vy;
+  zc := zc + Vz
+end;
+
+function CopyObject3D(Shape: Object3D): Object3D;
+begin
+  CopyObject3D.vertices := Copy(Shape.vertices, 0);
+  CopyObject3D.edges := Copy(Shape.edges, 0);
+
+  CopyObject3D.xc := Shape.xc;
+  CopyObject3D.yc := Shape.yc;
+  CopyObject3D.zc := Shape.zc
+end;
+
+function MMMult(lhs, rhs: Matrix): Matrix;
+var
+   i, j, k: Integer;
+   r: Matrix;
+   s: Real;
+begin
+  for i := 1 to 4 do
+    for j := 1 to 4 do
+    begin
+      s := 0;
+      for k := 1 to 4 do
+        s := s + lhs[i, k] * rhs[k, j];
+      r[i, j] := s;
+    end;
+  MMMult := r;
+end;
+
+function MCMult(lhs: Matrix; rhs: Column): Column;
+var
+  k, i: Integer;
+  s: Real;
+  r: Column;
+begin
+  for i := 1 to 4 do { аналогично MMMult }
+  begin
+    s := 0;
+
+    for k := 1 to 4 do
+      s := s + lhs[i, k] * rhs[k];
+    r[i] := s;
+  end;
+
+  MCMult := r;
+end;
+
+function RotateMatrix(xa, ya, za: Real): Matrix;
+var
+  xr, yr, zr: Matrix;
+begin
+  { матрица поворота вокруг оси Ox }
+  xr[1, 1] := 1;
+  xr[1, 2] := 0;
+  xr[1, 3] := 0;
+  xr[1, 4] := 0;
+
+  xr[2, 1] := 0;
+  xr[2, 2] := Cos(xa);
+  xr[2, 3] := -Sin(xa);
+  xr[2, 4] := 0;
+
+  xr[3, 1] := 0;
+  xr[3, 2] := Sin(xa);
+  xr[3, 3] := Cos(xa);
+  xr[3, 4] := 0;
+
+  xr[4, 1] := 0;
+  xr[4, 2] := 0;
+  xr[4, 3] := 0;
+  xr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oy }
+  yr[1, 1] := Cos(ya);
+  yr[1, 2] := 0;
+  yr[1, 3] := Sin(ya);
+  yr[1, 4] := 0;
+
+  yr[2, 1] := 0;
+  yr[2, 2] := 1;
+  yr[2, 3] := 0;
+  yr[2, 4] := 0;
+
+  yr[3, 1] := -Sin(ya);
+  yr[3, 2] := 0;
+  yr[3, 3] := Cos(ya);
+  yr[3, 4] := 0;
+
+  yr[4, 1] := 0;
+  yr[4, 2] := 0;
+  yr[4, 3] := 0;
+  yr[4, 4] := 1;
+
+  { матрица поворота вокруг оси Oz }
+  zr[1, 1] := Cos(za);
+  zr[1, 2] := -Sin(za);
+  zr[1, 3] := 0;
+  zr[1, 4] := 0;
+
+  zr[2, 1] := Sin(za);
+  zr[2, 2] := Cos(za);
+  zr[2, 3] := 0;
+  zr[2, 4] := 0;
+
+  zr[3, 1] := 0;
+  zr[3, 2] := 0;
+  zr[3, 3] := 1;
+  zr[3, 4] := 0;
+
+  zr[4, 1] := 0;
+  zr[4, 2] := 0;
+  zr[4, 3] := 0;
+  zr[4, 4] := 1;
+
+  RotateMatrix := MMMult(MMMult(xr, yr), zr)
+end;
+
+function MoveMatrix(tx, ty, tz: Real): Matrix;
+begin
+  MoveMatrix[1, 1] := 1;
+  MoveMatrix[1, 2] := 0;
+  MoveMatrix[1, 3] := 0;
+  MoveMatrix[1, 4] := tx;
+
+  MoveMatrix[2, 1] := 0;
+  MoveMatrix[2, 2] := 1;
+  MoveMatrix[2, 3] := 0;
+  MoveMatrix[2, 4] := ty;
+
+  MoveMatrix[3, 1] := 0;
+  MoveMatrix[3, 2] := 0;
+  MoveMatrix[3, 3] := 1;
+  MoveMatrix[3, 4] := tz;
+
+  MoveMatrix[4, 1] := 0;
+  MoveMatrix[4, 2] := 0;
+  MoveMatrix[4, 3] := 0;
+  MoveMatrix[4, 4] := 1
+end;
+
+function ResizeMatrix(sx, sy, sz: Real): Matrix;
+begin
+  ResizeMatrix[1, 1] := sx;
+  ResizeMatrix[1, 2] := 0;
+  ResizeMatrix[1, 3] := 0;
+  ResizeMatrix[1, 4] := 0;
+
+  ResizeMatrix[2, 1] := 0;
+  ResizeMatrix[2, 2] := sy;
+  ResizeMatrix[2, 3] := 0;
+  ResizeMatrix[2, 4] := 0;
+
+  ResizeMatrix[3, 1] := 0;
+  ResizeMatrix[3, 2] := 0;
+  ResizeMatrix[3, 3] := sz;
+  ResizeMatrix[3, 4] := 0;
+
+  ResizeMatrix[4, 1] := 0;
+  ResizeMatrix[4, 2] := 0;
+  ResizeMatrix[4, 3] := 0;
+  ResizeMatrix[4, 4] := 1
+end;
+
+procedure RotateShape(Shape: Object3D);
+var
+  rm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  rm := RotateMatrix(Shape.xa, Shape.ya, Shape.za); { сгенерировать матрицу вращения }
+  c[4] := 1; { последний элемент столбца всегда равен единице }
+
+  for i := 0 to High(Shape.vertices) do { цикл по всем вершинам }
+  begin { High(a) возвращает верхний индекс массива a }
+    c[1] := Shape.vertices[i].x; { инициализация столбца }
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(rm, c); { вызов преобразования }
+
+    Shape.vertices[i].x := c[1]; { внесение изменений в модель }
+    Shape.vertices[i].y := c[2]; { в соответствии с полученным }
+    Shape.vertices[i].z := c[3] { результатом преобразования }
+  end
+end;
+
+procedure MoveShape(Shape: Object3D; Width, Height: Real);
+begin
+  if Shape.xc > Width then
+  begin
+    Shape.xc := Width;
+    Shape.Vx := -Shape.Vx
+  end;
+  if Shape.xc < -Width then
+  begin
+    Shape.xc := -Width;
+    Shape.Vx := -Shape.Vx
+  end;
+
+  if Shape.yc > Height then
+  begin
+    Shape.yc := Height;
+    Shape.Vy := -Shape.Vy
+  end;
+  if Shape.yc < -Height then
+  begin
+    Shape.yc := -Height;
+    Shape.Vy := -Shape.Vy
+  end;
+
+  if Shape.zc > 500 then
+  begin
+    Shape.zc := 500;
+    Shape.Vz := -Shape.Vz
+  end;
+  if Shape.zc < 200 then
+  begin
+    Shape.zc := 200;
+    Shape.Vz := -Shape.Vz
+  end;
+end;
+
+procedure ResizeShape(var Shape: Object3D; sx, sy, sz: Real);
+var
+  mm: Matrix;
+  i: Integer;
+  c: Column;
+begin
+  mm := ResizeMatrix(sx, sy, sz);
+  c[4] := 1;
+
+  for i := 0 to High(Shape.vertices) do
+  begin
+    c[1] := Shape.vertices[i].x;
+    c[2] := Shape.vertices[i].y;
+    c[3] := Shape.vertices[i].z;
+
+    c := MCMult(mm, c);
+
+    Shape.vertices[i].x := c[1];
+    Shape.vertices[i].y := c[2];
+    Shape.vertices[i].z := c[3]
+  end
+end;
+
+end.
+
diff --git a/Занимательное программирование/3/5_ideal_gas/graphics_3d.lpi b/Занимательное программирование/3/5_ideal_gas/graphics_3d.lpi
new file mode 100644
index 0000000..67fa0db
--- /dev/null
+++ b/Занимательное программирование/3/5_ideal_gas/graphics_3d.lpi
@@ -0,0 +1,90 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectOptions>
+    <Version Value="12"/>
+    <PathDelim Value="\"/>
+    <General>
+      <SessionStorage Value="InProjectDir"/>
+      <Title Value="graphics_3d"/>
+      <Scaled Value="True"/>
+      <ResourceType Value="res"/>
+      <UseXPManifest Value="True"/>
+      <XPManifest>
+        <DpiAware Value="True"/>
+      </XPManifest>
+      <Icon Value="0"/>
+    </General>
+    <BuildModes>
+      <Item Name="Default" Default="True"/>
+    </BuildModes>
+    <PublishOptions>
+      <Version Value="2"/>
+      <UseFileFilters Value="True"/>
+    </PublishOptions>
+    <RunParams>
+      <FormatVersion Value="2"/>
+    </RunParams>
+    <RequiredPackages>
+      <Item>
+        <PackageName Value="LCL"/>
+      </Item>
+    </RequiredPackages>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
+    </Units>
+  </ProjectOptions>
+  <CompilerOptions>
+    <Version Value="11"/>
+    <PathDelim Value="\"/>
+    <Target>
+      <Filename Value="graphics_3d"/>
+    </Target>
+    <SearchPaths>
+      <IncludeFiles Value="$(ProjOutDir)"/>
+      <UnitOutputDirectory Value="lib\$(TargetCPU)-$(TargetOS)"/>
+    </SearchPaths>
+    <Linking>
+      <Debugging>
+        <DebugInfoType Value="dsDwarf3"/>
+      </Debugging>
+      <Options>
+        <Win32>
+          <GraphicApplication Value="True"/>
+        </Win32>
+      </Options>
+    </Linking>
+  </CompilerOptions>
+  <Debugging>
+    <Exceptions>
+      <Item>
+        <Name Value="EAbort"/>
+      </Item>
+      <Item>
+        <Name Value="ECodetoolError"/>
+      </Item>
+      <Item>
+        <Name Value="EFOpenError"/>
+      </Item>
+    </Exceptions>
+  </Debugging>
+</CONFIG>
diff --git a/Занимательное программирование/3/5_ideal_gas/graphics_3d.lpr b/Занимательное программирование/3/5_ideal_gas/graphics_3d.lpr
new file mode 100644
index 0000000..3778580
--- /dev/null
+++ b/Занимательное программирование/3/5_ideal_gas/graphics_3d.lpr
@@ -0,0 +1,29 @@
+program graphics_3d;
+
+{$mode objfpc}{$H+}
+
+uses
+  {$IFDEF UNIX}
+  cthreads,
+  {$ENDIF}
+  {$IFDEF HASAMIGA}
+  athreads,
+  {$ENDIF}
+  Interfaces, // this includes the LCL widgetset
+  Forms, Octahedron, geometry
+  { you can add units after this };
+
+{$R *.res}
+
+begin
+  Randomize;
+  RequireDerivedFormResource:=True;
+  Application.Scaled:=True;
+  {$PUSH}{$WARN 5044 OFF}
+  Application.MainFormOnTaskbar:=True;
+  {$POP}
+  Application.Initialize;
+  Application.CreateForm(TForm1, Form1);
+  Application.Run;
+end.
+
diff --git a/Занимательное программирование/3/5_ideal_gas/graphics_3d.lps b/Занимательное программирование/3/5_ideal_gas/graphics_3d.lps
new file mode 100644
index 0000000..d227996
--- /dev/null
+++ b/Занимательное программирование/3/5_ideal_gas/graphics_3d.lps
@@ -0,0 +1,179 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<CONFIG>
+  <ProjectSession>
+    <PathDelim Value="\"/>
+    <Version Value="12"/>
+    <BuildModes Active="Default"/>
+    <Units>
+      <Unit>
+        <Filename Value="graphics_3d.lpr"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="1"/>
+        <CursorPos X="20"/>
+        <UsageCount Value="58"/>
+        <Loaded Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.pas"/>
+        <IsPartOfProject Value="True"/>
+        <ComponentName Value="Form1"/>
+        <HasResources Value="True"/>
+        <ResourceBaseClass Value="Form"/>
+        <UnitName Value="Octahedron"/>
+        <IsVisibleTab Value="True"/>
+        <TopLine Value="13"/>
+        <CursorPos X="23" Y="21"/>
+        <UsageCount Value="58"/>
+        <Bookmarks Count="1">
+          <Item0 X="17" Y="48" Left="1" Top="79" ID="3"/>
+        </Bookmarks>
+        <Loaded Value="True"/>
+        <LoadedDesigner Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="geometry.pas"/>
+        <IsPartOfProject Value="True"/>
+        <UnitName Value="Geometry"/>
+        <EditorIndex Value="2"/>
+        <TopLine Value="50"/>
+        <CursorPos X="29" Y="52"/>
+        <UsageCount Value="58"/>
+        <Loaded Value="True"/>
+      </Unit>
+      <Unit>
+        <Filename Value="octahedron.txt"/>
+        <IsPartOfProject Value="True"/>
+        <EditorIndex Value="-1"/>
+        <CursorPos X="15" Y="13"/>
+        <UsageCount Value="58"/>
+        <DefaultSyntaxHighlighter Value="Text"/>
+      </Unit>
+    </Units>
+    <JumpHistory HistoryIndex="29">
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="81" Column="24" TopLine="56"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="96" Column="10" TopLine="72"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="103" Column="22" TopLine="79"/>
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+      <Position>
+        <Filename Value="octahedron.pas"/>
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+      <Position>
+        <Filename Value="octahedron.pas"/>
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+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="112" Column="12" TopLine="88"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="15" Column="11" TopLine="8"/>
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+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="81" Column="24" TopLine="56"/>
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+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="87" Column="19" TopLine="76"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="98" Column="11" TopLine="76"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="106" Column="21" TopLine="82"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="108" Column="23" TopLine="84"/>
+      </Position>
+      <Position>
+        <Filename Value="octahedron.pas"/>
+        <Caret Line="110" Column="21" TopLine="86"/>
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diff --git a/Занимательное программирование/3/5_ideal_gas/octahedron.lfm b/Занимательное программирование/3/5_ideal_gas/octahedron.lfm
new file mode 100644
index 0000000..8db0965
--- /dev/null
+++ b/Занимательное программирование/3/5_ideal_gas/octahedron.lfm
@@ -0,0 +1,54 @@
+object Form1: TForm1
+  Left = 352
+  Height = 673
+  Top = 32
+  Width = 600
+  Caption = 'Form1'
+  ClientHeight = 673
+  ClientWidth = 600
+  DesignTimePPI = 120
+  LCLVersion = '4.2.0.0'
+  object BackScreen: TImage
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object Screen: TPaintBox
+    AnchorSideLeft.Control = Owner
+    AnchorSideTop.Control = Owner
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrBottom
+    AnchorSideBottom.Control = StartStopBtn
+    Left = 0
+    Height = 600
+    Top = 0
+    Width = 600
+    Anchors = [akTop, akLeft, akRight, akBottom]
+    BorderSpacing.Bottom = 15
+  end
+  object StartStopBtn: TButton
+    AnchorSideLeft.Control = Owner
+    AnchorSideLeft.Side = asrCenter
+    AnchorSideRight.Control = Owner
+    AnchorSideRight.Side = asrCenter
+    AnchorSideBottom.Control = Owner
+    AnchorSideBottom.Side = asrBottom
+    Left = 241
+    Height = 48
+    Top = 615
+    Width = 118
+    Anchors = [akLeft, akBottom]
+    BorderSpacing.Bottom = 10
+    Caption = 'Пуск'
+    TabOrder = 0
+    OnClick = StartStopBtnClick
+  end
+end
diff --git a/Занимательное программирование/3/5_ideal_gas/octahedron.pas b/Занимательное программирование/3/5_ideal_gas/octahedron.pas
new file mode 100644
index 0000000..31fe970
--- /dev/null
+++ b/Занимательное программирование/3/5_ideal_gas/octahedron.pas
@@ -0,0 +1,129 @@
+unit Octahedron;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, Forms, Controls, Graphics, Dialogs, ExtCtrls, StdCtrls,
+  Geometry;
+
+type
+
+  { TForm1 }
+
+  TForm1 = class(TForm)
+    BackScreen: TImage;
+    StartStopBtn: TButton;
+    Screen: TPaintBox;
+    procedure StartStopBtnClick(Sender: TObject);
+  private
+    Model: array[1..10] of Object3D; { трехмерный объект }
+  public
+
+  end;
+
+var
+  Form1: TForm1;
+  IsRunning: Boolean = false;
+
+implementation
+
+{$R *.lfm}
+
+procedure ShowShape(Shape: Object3D); { нарисовать объект }
+var
+  i, Xs, Ys: Integer;
+  x, y, z: Real;
+const
+  N = 300; { "глубина" экрана }
+begin
+  for i := 0 to High(Shape.edges) do { цикл по всем ребрам }
+  begin { координаты первой точки ребра }
+    x := Shape.vertices[Shape.edges[i].src].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].src].y + Shape.yc;
+    z := Shape.vertices[Shape.edges[i].src].z + Shape.zc;
+    if Abs(z) < 0.01 then z := 0.01; { избегаем деления на нуль }
+                                     { вычисляем экранные координаты }
+    Xs := Round(Form1.Screen.Width div 2 + N * x / z);
+    Ys := Round(Form1.Screen.Height div 2 + N * y / z);
+
+    Form1.BackScreen.Canvas.MoveTo(Xs, Ys);
+                                       { координаты второй точки зрения }
+    x := Shape.vertices[Shape.edges[i].dest].x + Shape.xc;
+    y := Shape.vertices[Shape.edges[i].dest].y + Shape.yc;
+    z := Shape.vertices[Shape.edges[i].dest].z + Shape.zc;
+    if Abs(z) < 0.01 then z := 0.01; { избегаем деления на нуль }
+                                     { и ее экранные координаты }
+    Xs := Round(Form1.Screen.Width div 2 + N * x / z);
+    Ys := Round(Form1.Screen.Height div 2 + N * y / z);
+
+    Form1.BackScreen.Canvas.LineTo(Xs, Ys); { рисуем ребро }
+  end;
+end;
+
+{ TForm1 }
+
+procedure TForm1.StartStopBtnClick(Sender: TObject); { главная процедура }
+var
+  oldtime: TDateTime;
+  pause: Integer;
+  center, velocity, axis: Vertex;
+  i: Integer;
+const
+  MSecsPerFrame = 25; { скорость работы (кадров в секунду) }
+begin
+  if IsRunning then
+  begin
+    IsRunning := false;
+    StartStopBtn.Caption := 'Пуск';
+    for i := 1 to Length(Model) do
+      FreeAndNil(Model[i]);
+    Exit;
+  end;
+  StartStopBtn.Caption := 'Стоп';
+  IsRunning := true;
+
+  for i := 1 to Length(Model) do
+  begin
+    axis.x := Random(10) / 100; { скорость вращения вокруг оси Ox }
+    axis.y := Random(10) / 100; { скорость вращения вокруг оси Oy }
+    axis.z := Random(10) / 100; { скорость вращения вокруг оси Oz }
+    velocity.x := 10 - Random(20); { и составляющие }
+    velocity.y := 15 - Random(30); { скорости }
+    velocity.z := 20 - Random(40);
+    center.x := (Screen.Width div 2) - Random(Screen.Width); { начальное положение }
+    center.y := (Screen.Width div 2) - Random(Screen.Width); { начальное положение }
+    center.z := Random(300) + 200;
+    Model[i] := Object3D.Create(center, velocity, axis) { загрузить объект }
+  end;
+
+  while IsRunning do
+  begin
+    oldtime := Now;
+    BackScreen.Canvas.FillRect(Rect(0, 0, Screen.Width, Screen.Height));
+
+    for i := 1 to Length(Model) do
+    begin
+      { отразить от стена (3D-аналог "молекулы в закрытом сосуде") }
+      MoveShape(Model[i], BackScreen.Width div 2, BackScreen.Height div 2);
+
+      RotateShape(Model[i]); { поворот модели }
+      ShowShape(Model[i]); { очистить экран и нарисовать объект }
+      Model[i].MoveCenter()
+    end;
+    { отобразить объект на основном экране }
+    Screen.Canvas.CopyRect(Rect(0, 0, Screen.Width, Screen.Height),
+        BackScreen.Canvas, Rect(0, 0, Screen.Width, Screen.Height));
+
+
+    Application.ProcessMessages;
+    pause := Round(MSecsPerFrame - (Now - oldtime) * MSecsPerDay);
+    if pause > 0 then Sleep(pause); { задержка }
+
+    if Application.Terminated then Exit;
+  end;
+end;
+
+end.
+
author	Eugen Wissner <belka@caraus.de>	2025-12-17 12:12:16 +0100
committer	Eugen Wissner <belka@caraus.de>	2025-12-17 12:13:15 +0100
commit	6d7c43c85f8852ed3b3fa9cefc742bc87e941842 (patch)
tree	20da65c403c17b962027469897500de626a958f4
parent	2878f1e34c2c2e19d5b7f6fd368dbf9ec0c6277f (diff)
download	book-exercises-6d7c43c85f8852ed3b3fa9cefc742bc87e941842.tar.gz