unit fMeshExplosionD;

interface

uses
  Winapi.OpenGL,
  System.SysUtils,
  System.Classes,
  Vcl.Graphics,
  Vcl.Controls,
  Vcl.Forms,
  Vcl.Dialogs,
  Vcl.StdCtrls,
  Vcl.ComCtrls,
  Vcl.ExtCtrls,

  GLS.Scene,
  GLS.VectorFileObjects,
  GLS.SceneViewer,
  GLS.Cadencer,
  GLS.ExplosionFx,
  GLS.File3DS,
  GLS.Coordinates,
  Stage.Utils,
  GLS.BaseClasses;

type
  TFormMeshExplosion = class(TForm)
    Viewer: TGLSceneViewer;
    GLScene1: TGLScene;
    Camera1: TGLCamera;
    GLLightSource1: TGLLightSource;
    mesh: TGLFreeForm;
    GLCadencer1: TGLCadencer;
    Panel1: TPanel;
    CheckOn: TCheckBox;
    Button1: TButton;
    StepBar: TProgressBar;
    Label2: TLabel;
    MaxStepsBar: TTrackBar;
    Label1: TLabel;
    Label3: TLabel;
    SpeedBar: TTrackBar;
    procedure FormCreate(Sender: TObject);
    procedure CheckOnClick(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure ViewerMouseMove(Sender: TObject; Shift: TShiftState;
      X, Y: Integer);
    procedure ViewerMouseDown(Sender: TObject; Button: TMouseButton;
      Shift: TShiftState; X, Y: Integer);
    procedure GLCadencer1Progress(Sender: TObject;
      const deltaTime, newTime: Double);
    procedure SpeedBarChange(Sender: TObject);
    procedure MaxStepsBarChange(Sender: TObject);
  private

  public

  end;

var
  FormMeshExplosion: TFormMeshExplosion;
  vx, vy: Integer;
  Cache: TGLMeshObjectList;

implementation

{$R *.DFM}

procedure TFormMeshExplosion.FormCreate(Sender: TObject);
var
  expl: TGLBExplosionFx;
begin
  var Path: TFileName := GetCurrentAssetPath();
  SetCurrentDir(Path  + '\model');

  // load mesh
  mesh.LoadFromFile('mushroom.3ds');
  // cache information
  Cache := TGLMeshObjectList.Create;
  Cache.Assign(mesh.MeshObjects);
  // default settings
  expl := TGLBExplosionFx(mesh.Effects.Items[0]);
  expl.MaxSteps := 0;
  expl.Speed := 0.1;
end;

procedure TFormMeshExplosion.CheckOnClick(Sender: TObject);
begin
  // turn on/off
  TGLBExplosionFx(mesh.Effects.Items[0]).Enabled := CheckOn.checked;
end;

procedure TFormMeshExplosion.Button1Click(Sender: TObject);
begin
  // reset simulation
  TGLBExplosionFx(mesh.Effects.Items[0]).Reset;
  CheckOn.checked := false;
  // restore the mesh
  mesh.MeshObjects.Assign(Cache);
  mesh.StructureChanged;
end;

procedure TFormMeshExplosion.ViewerMouseMove(Sender: TObject;
  Shift: TShiftState; X, Y: Integer);
begin
  if Shift <> [ssLeft] then
    exit;

  Camera1.MoveAroundTarget(Y - vy, X - vx);
  vx := X;
  vy := Y;
end;

procedure TFormMeshExplosion.ViewerMouseDown(Sender: TObject;
  Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  vx := X;
  vy := Y;
end;

procedure TFormMeshExplosion.GLCadencer1Progress(Sender: TObject;
  const deltaTime, newTime: Double);
begin
  Viewer.Invalidate;
  StepBar.Position := TGLBExplosionFx(mesh.Effects.Items[0]).Step;
end;

procedure TFormMeshExplosion.SpeedBarChange(Sender: TObject);
begin
  TGLBExplosionFx(mesh.Effects.Items[0]).Speed := SpeedBar.Position / 10;
end;

procedure TFormMeshExplosion.MaxStepsBarChange(Sender: TObject);
begin
  TGLBExplosionFx(mesh.Effects.Items[0]).MaxSteps := MaxStepsBar.Position;
  StepBar.Max := MaxStepsBar.Position;
end;

end.