* updated glBitmap

[LazOpenGLCore.git] / examples / simple / uMainForm.pas

diff --git a/examples/simple/uMainForm.pas b/examples/simple/uMainForm.pas
new file mode 100644 (file)
index 0000000..1179a67
--- /dev/null
+++ b/examples/simple/uMainForm.pas
@@ -0,0 +1,122 @@
+unit uMainForm;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, ExtCtrls, StdCtrls,
+  uglcContext, uglcShader, uglcArrayBuffer, uglcTypes;
+
+type
+  TMainForm = class(TForm)
+    ApplicationProperties: TApplicationProperties;
+    LogLB: TListBox;
+    RenderPanel: TPanel;
+    procedure ApplicationPropertiesIdle(Sender: TObject; var Done: Boolean);
+    procedure FormCreate(Sender: TObject);
+    procedure FormDestroy(Sender: TObject);
+    procedure RenderPanelResize(Sender: TObject);
+  private
+    fContext: TglcContext;
+    fShader: TglcShaderProgram;
+    fVBO: TglcArrayBuffer;
+    procedure Log(aSender: TObject; const aMsg: String);
+    procedure Render;
+  public
+    { public declarations }
+  end;
+
+var
+  MainForm: TMainForm;
+
+implementation
+
+{$R *.lfm}
+
+uses
+  dglOpenGL, ugluVector;
+
+const
+  SHADER_FILE  = 'shader.glsl';
+
+  LAYOUT_LOCATION_POS = 0;
+
+procedure TMainForm.FormCreate(Sender: TObject);
+type
+  TVertex = packed record
+    pos: TgluVector3f;
+  end;
+  PVertex = ^TVertex;
+var
+  pf: TglcContextPixelFormatSettings;
+  p: PVertex;
+begin
+  pf := TglcContext.MakePF();
+  fContext := TglcContext.GetPlatformClass.Create(RenderPanel, pf);
+  fContext.BuildContext;
+
+  fShader := TglcShaderProgram.Create(@Log);
+  fShader.LoadFromFile(ExtractFilePath(Application.ExeName) + SHADER_FILE);
+  fShader.Compile;
+
+  fVBO := TglcArrayBuffer.Create(TglcBufferTarget.btArrayBuffer);
+  fVBO.BufferData(4, sizeof(TVertex), TglcBufferUsage.buStaticDraw, nil);
+  p := fVBO.MapBuffer(TglcBufferAccess.baWriteOnly);
+  try
+    p^.pos := gluVector3f(-0.5, -0.5, 0); inc(p);
+    p^.pos := gluVector3f( 0.5, -0.5, 0); inc(p);
+    p^.pos := gluVector3f( 0.5,  0.5, 0); inc(p);
+    p^.pos := gluVector3f(-0.5,  0.5, 0); inc(p);
+  finally
+    fVBO.UnmapBuffer;
+  end;
+end;
+
+procedure TMainForm.ApplicationPropertiesIdle(Sender: TObject; var Done: Boolean);
+begin
+  Render;
+  Done := false;
+end;
+
+procedure TMainForm.FormDestroy(Sender: TObject);
+begin
+  FreeAndNil(fVBO);
+  FreeAndNil(fShader);
+  FreeAndNil(fContext);
+end;
+
+procedure TMainForm.RenderPanelResize(Sender: TObject);
+begin
+  if Assigned(fContext) then begin
+    glViewport(0, 0, RenderPanel.ClientWidth, RenderPanel.ClientHeight);
+  end;
+end;
+
+procedure TMainForm.Log(aSender: TObject; const aMsg: String);
+begin
+  LogLB.Items.Add(aMsg);
+end;
+
+procedure TMainForm.Render;
+begin
+  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
+
+  fVBO.Bind;
+  fShader.Enable;
+
+  glEnableVertexAttribArray(LAYOUT_LOCATION_POS);
+  glVertexAttribPointer(LAYOUT_LOCATION_POS, 3, GL_FLOAT, False, 0, nil);
+
+  glDrawArrays(GL_QUADS, 0, fVBO.DataCount);
+
+  glDisableVertexAttribArray(LAYOUT_LOCATION_POS);
+
+  fShader.Disable;
+  fVBO.Unbind;
+
+  fContext.SwapBuffers;
+end;
+
+end.
+