//  3D Object Viewer
//  1998 Spring Geometric Modeling Term Project
//  Professor : Genji Shimada
//  Programmed by Joonhong Lim

unit Main;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  ExtCtrls, Menus, UrickGL, U3Dpolys, StdCtrls, Buttons, gl, ColorGrd,
  ComCtrls, Spin, Unit2;

type

  TVdata = array[0..11,0..2] of single;
  TIndices = array[0..19,0..2] of integer;
  TVector = array[0..2] of single;
                                     
  TForm1 = class(TForm)
    Panel1: TPanel;
    Panel2: TPanel;
    Panel3: TPanel;
    MainMenu1: TMainMenu;
    N1: TMenuItem;
    Timer1: TTimer;
    Panel5: TPanel;
    Panel4: TPanel;
    Panel7: TPanel;
    GroupBox2: TGroupBox;
    Cube: TBitBtn;
    Sphere: TBitBtn;
    Panel6: TPanel;
    GroupBox4: TGroupBox;
    Panel8: TPanel;
    GroupBox5: TGroupBox;
    Back: TBitBtn;
    Panel9: TPanel;
    MouseMove: TBitBtn;
    GroupBox6: TGroupBox;
    ColorGrid1: TColorGrid;
    GroupBox3: TGroupBox;
    GroupBox7: TGroupBox;
    Up: TBitBtn;
    Down: TBitBtn;
    Go: TBitBtn;
    MoveLeft: TBitBtn;
    MoveRight: TBitBtn;
    BitBtn7: TBitBtn;
    MoveDown: TBitBtn;
    GroupBox8: TGroupBox;
    ZAxisRight: TBitBtn;
    ZAxisLeft: TBitBtn;
    RotateLeft: TBitBtn;
    RotateRight: TBitBtn;
    Panel11: TPanel;
    GroupBox1: TGroupBox;
    Label1: TLabel;
    label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    Label6: TLabel;
    Panel12: TPanel;
    BitBtn3: TBitBtn;
    ColorDialog1: TColorDialog;
    SpinEdit1: TSpinEdit;
    Delete: TBitBtn;
    Label7: TLabel;
    Label8: TLabel;
    StatusBar1: TStatusBar;
    Panel10: TPanel;
    BitBtn2: TBitBtn;
    Corn: TBitBtn;
    Tube: TBitBtn;
    Panel13: TPanel;
    GroupBox9: TGroupBox;
    Spin: TBitBtn;
    procedure N1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure CubeClick(Sender: TObject);
    procedure Panel2MouseMove(Sender: TObject; Shift: TShiftState; X,
      Y: Integer);
    procedure MouseMoveClick(Sender: TObject);
    procedure FormResize(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure SphereClick(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure BackMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure BackMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure ZAxisLeftMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure ZAxisLeftMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure GoMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure GoMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure ZAxisRightMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure ZAxisRightMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure UpMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure UpMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure DownMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure DownMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure RotateLeftMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure RotateLeftMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure RotateRightMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure RotateRightMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure BitBtn7MouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure BitBtn7MouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure MoveDownMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure MoveDownMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure ColorGrid1Click(Sender: TObject);
    procedure BitBtn3Click(Sender: TObject);
    procedure MoveLeftMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure MoveLeftMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure MoveRightMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure MoveRightMouseUp(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure SpinEdit1Change(Sender: TObject);
    procedure DeleteClick(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
    procedure CornClick(Sender: TObject);
    procedure TubeClick(Sender: TObject);
    procedure SpinClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    Scene: TSceneGL;
    light: Tlight;
    num_entity: Integer;
    mouse: T3DMouse;
    mouse_mode: Integer;
    go_move: boolean;
    Back_move: boolean;
    z_axis_left: boolean;
    z_axis_right: boolean;
    rotate_right: boolean;
    rotate_left: boolean;
    rotate_up: boolean;
    rotate_down: boolean;
    move_up: boolean;
    move_down: boolean;
    move_left: boolean;
    move_right: boolean;
    spin_on: boolean;
    angle_z: single;
    bR, bG, bB: byte;   // RGB color
    primitive_num: integer;
    procedure LabelMark;
  end;

  procedure Normalize(var v: TVector);
  procedure Subdivide(var v1, v2, v3: TVector; depth: integer; sphere: TEntity);
  procedure Drawtriangle(v1, v2, v3: TVector; sphere: TEntity);
  procedure CalcNormal(v1, v2, v3: TVector; var nx, ny, nz: single);

const

// This declaration came from P.84 of OpenGL Programming Guide
  X = 0.525731112119133606;
  Z = 0.850650808352039932;
  vdata: TVdata = ((-X,0,Z),(X,0,Z),(-X,0,-Z),(X,0,-Z),(0,Z,X)
   ,(0,Z,-X),(0,-Z,X),(0,-Z,-X),(Z,X,0),(-Z,X,0),(Z,-X,0),(-Z,-X,0));
  indices: TIndices = ((0,4,1),(0,9,4),(9,5,4),(4,5,8),(4,8,1)
                      ,(8,10,1),(8,3,10),(5,3,8),(5,2,3),(2,7,3)
                      ,(7,10,3),(7,6,10),(7,11,6),(11,0,6),(0,1,6)
                      ,(6,1,10),(9,0,11),(9,11,2),(9,2,5),(7,2,11));
var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.N1Click(Sender: TObject);
begin
  Close;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Scene := TSceneGL.create;
  light:=Tlight.create(1);  {create a white light}
  Scene.lights.add(light);   {add light to scene}
  Scene.InitRC(panel2.handle);    {initialice Rendering context}
  Scene.UpdateArea(panel2.width,panel2.height);
  Scene.Redraw;
  num_entity := -1;
  mouse := nil;
  mouse_mode := 1;
  go_move:= false;
  back_move := false;
  z_axis_left := false;
  z_axis_right := false;
  rotate_left := false;
  rotate_right := false;
  rotate_up := false;
  rotate_down := false;
  move_up := false;
  move_down := false;
  move_left := false;
  move_right := false;
  spin_on := false;
  bR := $FF; bG := $FF; bB := $FF;
  panel12.Color := clWhite;
  primitive_num := -1;
end;

procedure TForm1.CornClick(Sender: TObject);
var
  Corn: TEntity;
  Face: TFace;
  i: integer;
  px, pz, xx, zz, r, theta, dtheta: single;
  nx, ny, nz: single;  // normal vector
  v1, v2, v3: TVector;
  vv: array[1..25] of TVector;
begin
  if(mouse <> nil) then
  begin
    mouse.Free;
    mouse := nil;
  end;

  num_entity := num_entity + 1;
  SpinEdit1.MaxValue := SpinEdit1.MaxValue + 1;
  primitive_num := num_entity;
  Corn := TEntity.Create;
  Corn.SetColor(bR,bG,bB);

  r := 0.8; px := r; pz := 0;
  theta := 0; dtheta := pi/12;
  v1[0] := 0; v1[1] := 1.5; v1[2] := 0;
  for i := 1 to 24 do begin
    Face := Corn.AddFace;
    theta := theta + dtheta;
    xx := r*cos(theta); zz := r*sin(theta);
    v2[0] := px; v2[1] := -0.5; v2[2] := pz;
    v3[0] := xx; v3[1] := -0.5; v3[2] := zz;
    vv[i,0] := xx; vv[i,1] := -0.5; vv[i,2] := zz;
    CalcNormal(v1,v3,v2,nx,ny,nz);
    Face.AddVertex(px, -0.5, pz, nx, ny, nz);
    Face.AddVertex(0, 1.5, 0, nx, ny, nz);
    if i = 24 then
      Face.AddVertex(r, -0.5, 0, nx, ny, nz)
    else
      Face.AddVertex(xx, -0.5, zz, nx, ny, nz);
    px := xx; pz := zz;
  end;

  vv[25,0] := r; vv[25,1] := -0.5; vv[25,2] := 0;

  Face := Corn.AddFace;
  for i := 1 to 25 do begin
    Face.AddVertex(vv[i,0],vv[i,1],vv[i,2],0,-1,0);
  end;

  corn.Move(0, 0, -10);

  Scene.Entities.Add(corn);

  SpinEdit1.Value := num_entity;
  SpinEdit1.MinValue := 0;

  Scene.Redraw;
  labelmark;

end;

procedure TForm1.TubeClick(Sender: TObject);
var
  Tube: TEntity;
  Face: TFace;
  r, px, pz: single;
  theta, dtheta: single;
  xx, zz, nx, ny, nz: single;
  vv: array[1..24] of TVector;
  v1, v2, v3: TVector;
  i, i1: integer;
begin
  if(mouse <> nil) then
  begin
    mouse.Free;
    mouse := nil;
  end;

  num_entity := num_entity + 1;
  SpinEdit1.MaxValue := SpinEdit1.MaxValue + 1;
  primitive_num := num_entity;
  Tube := TEntity.Create;
  Tube.SetColor(bR,bG,bB);

  r := 0.8; px := r; pz := 0;
  theta := 0; dtheta := pi/12;
  for i := 1 to 24 do begin
    Face := Tube.AddFace;
    theta := theta + dtheta;
    xx := r*cos(theta); zz := r*sin(theta);
    v1[0] := px; v1[1] := -1.0; v1[2] := pz;
    v2[0] := px; v2[1] := 1.0;  v2[2] := pz;
    v3[0] := xx; v3[1] := -1.0; v3[2] := zz;
    vv[i,0] := xx; vv[i,2] := zz;
    CalcNormal(v1,v2,v3,nx,ny,nz);
    Face.AddVertex(px, -1, pz, nx, ny, nz);
    Face.AddVertex(px, 1,  pz, nx, ny, nz);
    if i = 24 then begin
      Face.AddVertex(r, 1, 0, nx, ny, nz);
      Face.AddVertex(r, -1,  0, nx, ny, nz);
    end else begin
      Face.AddVertex(xx, 1, zz, nx, ny, nz);
      Face.AddVertex(xx, -1, zz, nx, ny, nz);
    end;
    px := xx; pz := zz;
  end;

  Face := Tube.AddFace;
  for i := 1 to 24 do
    Face.AddVertex(vv[i,0],-1.0,vv[i,2],0,-1,0);

  i1 := 24;
  Face := Tube.AddFace;
  for i := 1 to 24 do begin
    Face.AddVertex(vv[i1,0],1.0,vv[i1,2],0,1,0);
    i1 := i1 - 1;  // We have to maintain Count Clock Wise..
  end;

  Tube.Move(0, 0, -10);

  Scene.Entities.Add(Tube);

  SpinEdit1.Value := num_entity;
  SpinEdit1.MinValue := 0;

  Scene.Redraw;
  labelmark;

end;

procedure TForm1.CubeClick(Sender: TObject);
var
  Cube: TEntity;
  Face: TFace;
begin
  if(mouse <> nil) then
  begin
    mouse.Free;
    mouse := nil;
  end;

  num_entity := num_entity + 1;
  SpinEdit1.MaxValue := SpinEdit1.MaxValue + 1;
  primitive_num := num_entity;
  Cube := TEntity.Create;
  Cube.SetColor(bR,bG,bB);

  Face:=cube.addFace;          {create the first face of the cube}
    Face.AddVertex(1, 1.0, 1.0,0.0, 0.0, 1.0);     {add the 1st vertex}
    Face.AddVertex(-1, 1.0, 1.0,0.0, 0.0, 1.0);    {add the 2nd vertex}
    Face.AddVertex(-1, -1.0, 1.0,0.0, 0.0, 1.0);   {add the 3th vertex}
    Face.AddVertex(1, -1.0, 1.0,0.0, 0.0, 1.0);    {add the 4th vertex}

  Face:=cube.addFace;
    Face.AddVertex(1, 1.0, -1.0,0.0, 0.0, -1.0);
    Face.AddVertex(1, -1.0, -1.0,0.0, 0.0, -1.0);
    Face.AddVertex(-1, -1.0, -1.0,0.0, 0.0, -1.0);
    Face.AddVertex(-1, 1.0, -1.0,0.0, 0.0, -1.0);

  Face:=cube.addFace;
    Face.AddVertex(-1, 1.0, 1.0,-1.0, 0.0, 0.0);
    Face.AddVertex(-1, 1.0, -1.0,-1.0, 0.0, 0.0);
    Face.AddVertex(-1, -1.0, -1.0,-1.0, 0.0, 0.0);
    Face.AddVertex(-1, -1.0, 1.0,-1.0, 0.0, 0.0);

  Face:=cube.addFace;
    Face.AddVertex(1, 1.0, 1.0,1.0, 0.0, 0.0);
    Face.AddVertex(1, -1.0, 1.0,1.0, 0.0, 0.0);
    Face.AddVertex(1, -1.0, -1.0,1.0, 0.0, 0.0);
    Face.AddVertex(1, 1.0, -1.0,1.0, 0.0, 0.0);

  Face:=cube.addFace;
    Face.AddVertex(-1, 1.0, -1.0,0.0, 1.0, 0.0);
    Face.AddVertex(-1, 1.0, 1.0,0.0, 1.0, 0.0);
    Face.AddVertex(1, 1.0, 1.0,0.0, 1.0, 0.0);
    Face.AddVertex(1, 1.0, -1.0,0.0, 1.0, 0.0);

  Face:=cube.addFace;
    Face.AddVertex(-1, -1.0, -1.0,0.0, -1.0, 0.0);
    Face.AddVertex(1, -1.0, -1.0,0.0, -1.0, 0.0);
    Face.AddVertex(1, -1.0, 1.0,0.0, -1.0, 0.0);
    Face.AddVertex(-1, -1.0, 1.0,0.0, -1.0, 0.0);

  cube.Move(0, 0, -10);

  Scene.Entities.Add(cube);

  SpinEdit1.Value := num_entity;
  SpinEdit1.MinValue := 0;

  Scene.Redraw;
  labelmark;

end;

procedure TForm1.SphereClick(Sender: TObject);
type
  T3Vector = array[0..2] of TVector;
var
  sphere: TEntity;
  i, j: Integer;
  xx, yy, zz : single;
  v33: T3Vector;
  v1, v2, v3: TVector;
begin
  if(mouse <> nil) then
  begin
    mouse.Free;
    mouse := nil;
  end;

  num_entity := num_entity + 1;
  SpinEdit1.MaxValue := SpinEdit1.MaxValue + 1;
  primitive_num := num_entity;
  sphere := TEntity.Create;
  sphere.SetColor(bR,bG,bB);

  for i := 0 to 19 do begin
    for j := 0 to 2 do begin
      xx := vdata[indices[i,j], 0];
      yy := vdata[indices[i,j], 1];
      zz := vdata[indices[i,j], 2];
      v33[j,0] := xx;
      v33[j,1] := yy;
      v33[j,2] := zz;
    end;
    v1[0] := v33[0,0]; v1[1] := v33[0,1]; v1[2] := v33[0,2];
    v2[0] := v33[1,0]; v2[1] := v33[1,1]; v2[2] := v33[1,2];
    v3[0] := v33[2,0]; v3[1] := v33[2,1]; v3[2] := v33[2,2];
    Subdivide(v1, v2, v3, 2, sphere);
  end;


  sphere.Move(0, 0, -10);

  Scene.Entities.Add(sphere);

  SpinEdit1.Value := num_entity;
  SpinEdit1.MinValue := 0;

  Scene.Redraw;
  Labelmark;
end;

procedure Subdivide(var v1, v2, v3: TVector; depth: integer; sphere: TEntity);
var
  v12, v23, v31: TVector;
  i : integer;
begin
  if( depth = 0 ) then
  begin
    Drawtriangle(v1, v2, v3, sphere)
  end else begin
    for i := 0 to 2 do begin
      v12[i] := v1[i] + v2[i];
      v23[i] := v2[i] + v3[i];
      v31[i] := v3[i] + v1[i];
    end;
    Normalize(v12);
    Normalize(v23);
    Normalize(v31);
    Subdivide(v1, v12, v31, depth - 1, sphere);
    Subdivide(v2, v23, v12, depth - 1, sphere);
    Subdivide(v3, v31, v23, depth - 1, sphere);
    Subdivide(v12, v23, v31, depth - 1, sphere);
  end;
end;

procedure Normalize(var v: TVector);
var
  f: single;
begin
  f := sqrt( v[0]*v[0] + v[1]*v[1] + v[2]*v[2] );
  v[0] := v[0] / f;
  v[1] := v[1] / f;
  v[2] := v[2] / f;
end;

procedure Drawtriangle(v1, v2, v3: TVector; sphere: TEntity);
var
  face: TFace;
  nx, ny, nz: single;
begin
  face := sphere.AddFace;
  CalcNormal(v1, v3, v2, nx, ny, nz);

  face.AddVertex(v2[0], v2[1], v2[2], nx, ny, nz);
  face.AddVertex(v1[0], v1[1], v1[2], nx, ny, nz);
  face.AddVertex(v3[0], v3[1], v3[2], nx, ny, nz);

end;


procedure CalcNormal(v1, v2, v3: TVector; var nx, ny, nz: single);
var
  dv1, dv2: TVector;
  f : single;
begin

// Generate direction vector dv1, dv2.

  dv1[0] := v2[0]-v1[0]; dv1[1] := v2[1]-v1[1]; dv1[2] := v2[2]-v1[2];
  dv2[0] := v3[0]-v1[0]; dv2[1] := v3[1]-v1[1]; dv2[2] := v3[2]-v1[2];

// Cross Product for normal vector. Here I reuse v3 as a normal vector

  v3[0] := dv1[1]*dv2[2] - dv1[2]*dv2[1];
  v3[1] := dv1[2]*dv2[0] - dv1[0]*dv2[2];
  v3[2] := dv1[0]*dv2[1] - dv1[1]*dv2[0];

// Normalization

  f := sqrt(v3[0]*v3[0] + v3[1]*v3[1] + v3[2]*v3[2]);
  nx := v3[0] / f;
  ny := v3[1] / f;
  nz := v3[2] / f;

end;


procedure TForm1.Panel2MouseMove(Sender: TObject; Shift: TShiftState; X,
  Y: Integer);
begin
  if mouse <> nil then
  begin
    mouse.Move(x,y,Shift);
    Scene.Redraw;
    Labelmark;
  end;
end;

procedure TForm1.MouseMoveClick(Sender: TObject);
begin
  if mouse <> nil then
  begin
    If mouse.mode=1 then
    begin
      mouse.mode:=3;
      mouse_mode := 3;
      MouseMove.caption:='Rotation';
    end
      else
    begin
      mouse.mode:=1;
      mouse_mode := 1;
      MouseMove.caption:='Move';
    end;
  end;
end;

procedure TForm1.Labelmark;
begin
  if num_entity <> -1 then begin
    Label8.Caption := Format('%d',[primitive_num]);
    label4.Caption := Format('%4.2f',
                  [Tentity(Scene.Entities.Items[primitive_num]).position[1]]);
    label5.Caption := Format('%4.2f',
                  [Tentity(Scene.Entities.Items[primitive_num]).position[2]]);
    label6.Caption := Format('%4.2f',
                  [Tentity(Scene.Entities.Items[primitive_num]).position[3]]);
  end;
end;


procedure TForm1.FormResize(Sender: TObject);
begin
  panel2.Width := panel1.Width - 246;
  Scene.UpdateArea(panel2.width,panel2.height);
  if num_entity <> -1 then
    Scene.Redraw;
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
var
  i: Integer;
begin
  Tlight(Scene.Lights.Items[0]).free;
  for i:=0 to num_entity do
    TEntity(Scene.Entities.Items[i]).Free;
  Scene.Free;
  mouse.Free;
end;


procedure TForm1.Timer1Timer(Sender: TObject);
const
  da: single = pi/18;  // The changing rate of angle. radian.
var
  i: integer;
  xx, yy, zz: single;
  R, theta: single;  // theta is radian.
begin
  if back_move then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      Tentity(Scene.Entities.Items[i]).move(xx, yy, zz - 1);

    end;
  Scene.Redraw;
  labelmark;
  end;

  if go_move then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      Tentity(Scene.Entities.Items[i]).move(xx, yy, zz + 1);
    end;
  Scene.Redraw;
  labelmark;
  end;

  if move_up then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      Tentity(Scene.Entities.Items[i]).move(xx, yy+1, zz);
    end;
  Scene.Redraw;
  labelmark;
  end;

  if move_down then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      Tentity(Scene.Entities.Items[i]).move(xx, yy-1, zz);
    end;
  Scene.Redraw;
  labelmark;
  end;

  if move_left then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      Tentity(Scene.Entities.Items[i]).move(xx-1, yy, zz);
    end;
  Scene.Redraw;
  labelmark;
  end;

  if move_right then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      Tentity(Scene.Entities.Items[i]).move(xx+1, yy, zz);
    end;
  Scene.Redraw;
  labelmark;
  end;

  if z_axis_left then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      if xx <> 0 then
        theta := Arctan(yy / xx)
      else if yy < 0 then
        theta := 1.5*pi
      else
        theta := 0.5*pi;

      r := sqrt(xx*xx + yy*yy);

      if (xx > 0) then
        theta := theta + da
      else if (xx < 0) then
        theta := theta + da + pi;

      xx := r*cos(theta);
      yy := r*sin(theta);

      Tentity(Scene.Entities.Items[i]).move(xx, yy, zz);
    end;
    Scene.Redraw;
    labelmark;
  end;

  if z_axis_right then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      if xx <> 0 then
        theta := Arctan(yy / xx)
      else if yy < 0 then
        theta := 1.5*pi
      else
        theta := 0.5*pi;

      r := sqrt(xx*xx + yy*yy);

      if (xx > 0) then
        theta := theta - da
      else if (xx < 0) then
        theta := theta - da - pi;

      xx := r*cos(theta);
      yy := r*sin(theta);

      Tentity(Scene.Entities.Items[i]).move(xx, yy, zz);
    end;
    Scene.Redraw;
    labelmark;
  end;

  if rotate_up then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      if zz <> 0 then
        theta := Arctan(yy / zz)
      else if yy < 0 then
        theta := 1.5*pi
      else
        theta := 0.5*pi;

      r := sqrt(zz*zz + yy*yy);

      if (zz > 0) then
        theta := theta + da / 2
      else if (zz < 0) then
        theta := theta + da/2 + pi;

      zz := r*cos(theta);
      yy := r*sin(theta);

      Tentity(Scene.Entities.Items[i]).move(xx, yy, zz);
    end;
    Scene.Redraw;
    labelmark;
  end;

  if rotate_down then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      if zz <> 0 then
        theta := Arctan(yy / zz)
      else if yy < 0 then
        theta := 1.5*pi
      else
        theta := 0.5*pi;

      r := sqrt(zz*zz + yy*yy);

      if (zz > 0) then
        theta := theta - da / 2
      else if (zz < 0) then
        theta := theta - da/2 - pi;

      zz := r*cos(theta);
      yy := r*sin(theta);

      Tentity(Scene.Entities.Items[i]).move(xx, yy, zz);
    end;
    Scene.Redraw;
    labelmark;
  end;

  if rotate_left then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      if zz <> 0 then
        theta := Arctan(xx / zz)
      else if xx < 0 then
        theta := 1.5*pi
      else
        theta := 0.5*pi;

      r := sqrt(xx*xx + zz*zz);

      if (zz > 0) then
        theta := theta + da/2
      else if (zz < 0) then
        theta := theta + da/2 + pi;

      zz := r*cos(theta);
      xx := r*sin(theta);

      Tentity(Scene.Entities.Items[i]).move(xx, yy, zz);
    end;
    Scene.Redraw;
    labelmark;
  end;

  if rotate_right then
  begin
    for i := 0 to num_entity do
    begin
      xx := Tentity(Scene.Entities.Items[i]).position[1];
      yy := Tentity(Scene.Entities.Items[i]).position[2];
      zz := Tentity(Scene.Entities.Items[i]).position[3];

      if zz <> 0 then
        theta := Arctan(xx / zz)
      else if xx < 0 then
        theta := 1.5*pi
      else
        theta := 0.5*pi;

      r := sqrt(xx*xx + zz*zz);

      if (zz > 0) then
        theta := theta - da/2
      else if (zz < 0) then
        theta := theta - da/2 - pi;

      zz := r*cos(theta);
      xx := r*sin(theta);

      Tentity(Scene.Entities.Items[i]).move(xx, yy, zz);
    end;
    Scene.Redraw;
    labelmark;
  end;

  if spin_on then begin
    for i := 0 to num_entity do begin
      xx := Tentity(Scene.Entities.Items[i]).rotation[1];
      yy := Tentity(Scene.Entities.Items[i]).rotation[2];
      zz := Tentity(Scene.Entities.Items[i]).rotation[3];

      Tentity(Scene.Entities.Items[i]).rotate(xx+3, yy+3, zz+3 );
    end;
    Scene.Redraw;
    labelmark;
  end;


end;

procedure TForm1.BackMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  back_move := True;
  Timer1.Enabled := True;
end;

procedure TForm1.BackMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  back_move := False;
  Timer1.Enabled := False;
end;

procedure TForm1.ZAxisLeftMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  z_axis_left := TRUE;
  timer1.Enabled := TRUE;
end;

procedure TForm1.ZAxisLeftMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  z_axis_left := FALSE;
  timer1.Enabled := FALSE;
end;

procedure TForm1.GoMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  go_move := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.GoMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  go_move := FALSE;
  Timer1.Enabled := FALSE;
end;

procedure TForm1.ZAxisRightMouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  z_axis_right := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.ZAxisRightMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  z_axis_right := FALSE;
  Timer1.Enabled := FALSE;
end;

procedure TForm1.UpMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  rotate_down := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.UpMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  rotate_down := FALSE;
  Timer1.Enabled := FALSE;
end;

procedure TForm1.DownMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  rotate_up := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.DownMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  rotate_up := FALSE;
  Timer1.Enabled := FALSE;
end;


procedure TForm1.RotateLeftMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  rotate_left := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.RotateLeftMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  rotate_left := FALSE;
  Timer1.Enabled := FALSE;
end;

procedure TForm1.RotateRightMouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  rotate_right := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.RotateRightMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  rotate_right := FALSE;
  Timer1.Enabled := FALSE;
end;


procedure TForm1.BitBtn7MouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  move_up := FALSE;
  Timer1.Enabled := FALSE;

end;

procedure TForm1.BitBtn7MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  move_up := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.MoveDownMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  move_down := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.MoveDownMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  move_down := FALSE;
  Timer1.Enabled := FALSE;
end;

procedure TForm1.ColorGrid1Click(Sender: TObject);
var
  p: PByteArray;
begin
  Panel12.Color := ColorGrid1.ForegroundColor;
  p := @Panel12.Color;
  bR := p[0]; bG := p[1]; bB := p[2];
end;

procedure TForm1.BitBtn3Click(Sender: TObject);
var
  p: PByteArray;
begin
  if ColorDialog1.Execute then
  begin
    Panel12.Color := ColorDialog1.Color;
    p := @Panel12.Color;
    bR := p[0]; bG := p[1]; bB := p[2];
  end;
end;

procedure TForm1.MoveLeftMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  move_left := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.MoveLeftMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  move_left := FALSE;
  Timer1.Enabled := FALSE;
end;

procedure TForm1.MoveRightMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  move_right := TRUE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.MoveRightMouseUp(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  move_right := FALSE;
  Timer1.Enabled := TRUE;
end;

procedure TForm1.SpinEdit1Change(Sender: TObject);
begin
  if (num_entity <> -1) and (SpinEdit1.Value > -1)
     and (SpinEdit1.Value <= SpinEdit1.MaxValue) then
  begin
    primitive_num := SpinEdit1.Value;
    if primitive_num > num_entity then primitive_num := num_entity;
    if (mouse <> nil) then
      mouse.Free;
    mouse := T3dMouse.Create(TEntity(Scene.Entities.Items[primitive_num]));
    mouse.scale(0.1,-0.1,0.1,1,1,1);
    mouse.Mode := mouse_mode;
  end;
end;

procedure TForm1.DeleteClick(Sender: TObject);
begin
  if (num_entity <> -1) and (SpinEdit1.Value > -1)
     and (SpinEdit1.Value <= SpinEdit1.MaxValue) then
  begin
    TEntity(Scene.Entities.Items[SpinEdit1.Value]).Free;  // Free the memory
    Scene.Entities.Delete(SpinEdit1.Value);  // Remove the item from List
    num_entity := num_entity - 1;
    SpinEdit1.MaxValue := num_entity;
    if SpinEdit1.Value > num_entity then
      SpinEdit1.Value := num_entity
    else if num_entity <> -1 then
    begin
      primitive_num := SpinEdit1.Value;
      if (mouse <> nil) then
        mouse.Free;
      mouse := T3dMouse.Create(TEntity(Scene.Entities.Items[primitive_num]));
      mouse.scale(0.1,-0.1,0.1,1,1,1);
      mouse.Mode := mouse_mode;
    end;

    Scene.Redraw;
  end;
end;

procedure TForm1.BitBtn2Click(Sender: TObject);
begin
  Form2.ShowModal;
end;

procedure TForm1.SpinClick(Sender: TObject);
begin
  if Spin_on then begin
    Spin_on := FALSE;
    Timer1.Enabled := FALSE;
    Spin.Caption := 'Auto Spin'
  end else begin
    Spin_on := TRUE;
    Timer1.Enabled := TRUE;
    Spin.Caption := 'Stop';
  end;
end;

end.