X-Git-Url: https://git.delphigl.com/?p=LazOpenGLCore.git;a=blobdiff_plain;f=examples%2Fvertexarrayobject%2FuMainForm.pas;fp=examples%2Fvertexarrayobject%2FuMainForm.pas;h=02887d3a67fd6bab7e7fe54d2abcef61fc950c3b;hp=0000000000000000000000000000000000000000;hb=f6ca47eeb2c217505d9c1babe79d46b6668d3881;hpb=dfa7064d827360dd9a3ce0467fadb3f1c32a36c1

diff --git a/examples/vertexarrayobject/uMainForm.pas b/examples/vertexarrayobject/uMainForm.pas
new file mode 100644
index 0000000..02887d3
--- /dev/null
+++ b/examples/vertexarrayobject/uMainForm.pas
@@ -0,0 +1,170 @@
+unit uMainForm;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, FileUtil, Forms, Controls, Graphics, Dialogs, ExtCtrls, StdCtrls,
+  uglcContext, uglcShader, uglcArrayBuffer, uglcTypes, uglcBitmap, uglcVertexArrayObject;
+
+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;
+    fVAO: TglcVertexArrayObject;
+    fTexture: TglcBitmap2D;
+    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';
+  TEXTURE_FILE = 'data\texture.png';
+
+  LAYOUT_LOCATION_POS = 0;
+  LAYOUT_LOCATION_TEX = 1;
+
+  UNIFORM_NAME_TEXTURE = 'uTexture';
+
+type
+  TVertex = packed record
+    pos: TgluVector3f;
+    tex: TgluVector2f;
+  end;
+  PVertex = ^TVertex;
+
+procedure CheckGlError;
+var
+  err: GLenum;
+begin
+  err := glGetError();
+  if (err <> 0) then begin
+    ShowMessage('ERROR: 0x' + IntToHex(err, 16));
+    halt;
+  end;
+end;
+
+procedure TMainForm.FormCreate(Sender: TObject);
+var
+  pf: TglcContextPixelFormatSettings;
+  p: PVertex;
+  texData: TglcBitmapData;
+  vbo: TglcArrayBuffer;
+begin
+  pf := TglcContext.MakePF();
+  fContext := TglcContext.GetPlatformClass.Create(RenderPanel, pf);
+  fContext.BuildContext;
+
+  Log(self, glGetString(GL_VERSION));
+
+  fShader := TglcShaderProgram.Create(@Log);
+  fShader.LoadFromFile(ExtractFilePath(Application.ExeName) + SHADER_FILE);
+  fShader.Compile;
+  fShader.Uniform1i(UNIFORM_NAME_TEXTURE, 0);
+
+  vbo := TglcArrayBuffer.Create(TglcBufferTarget.btArrayBuffer);
+  vbo.BufferData(4, sizeof(TVertex), TglcBufferUsage.buStaticDraw, nil);
+  p := vbo.MapBuffer(TglcBufferAccess.baWriteOnly);
+  try
+    p^.pos := gluVector3f(-0.5, -0.5, 0);
+    p^.tex := gluVector2f( 0.0,  1.0);
+    inc(p);
+
+    p^.pos := gluVector3f( 0.5, -0.5, 0);
+    p^.tex := gluVector2f( 1.0,  1.0);
+    inc(p);
+
+    p^.pos := gluVector3f( 0.5,  0.5, 0);
+    p^.tex := gluVector2f( 1.0,  0.0);
+    inc(p);
+
+    p^.pos := gluVector3f(-0.5,  0.5, 0);
+    p^.tex := gluVector2f( 0.0,  0.0);
+    inc(p);
+  finally
+    vbo.UnmapBuffer;
+  end;
+
+  fVAO := TglcVertexArrayObject.Create;
+  fVAO.BindArrayBuffer(vbo, true);
+  fVAO.VertexAttribPointer(LAYOUT_LOCATION_POS, 3, GL_FLOAT, False, SizeOf(TVertex), GLint(@PVertex(nil)^.pos));
+  fVAO.VertexAttribPointer(LAYOUT_LOCATION_TEX, 2, GL_FLOAT, False, SizeOf(TVertex), GLint(@PVertex(nil)^.tex));
+
+  fTexture := TglcBitmap2D.Create;
+  texData := TglcBitmapData.Create;
+  try
+    texData.LoadFromFile(ExtractFilePath(Application.ExeName) + TEXTURE_FILE);
+    fTexture.UploadData(texData);
+  finally
+    FreeAndNil(texData);
+  end;
+end;
+
+procedure TMainForm.ApplicationPropertiesIdle(Sender: TObject; var Done: Boolean);
+begin
+  Render;
+  Done := false;
+end;
+
+procedure TMainForm.FormDestroy(Sender: TObject);
+begin
+  FreeAndNil(fTexture);
+  FreeAndNil(fVAO);
+  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
+  CheckGlError;
+
+  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
+
+  fTexture.Bind;
+  fShader.Enable;
+  fVAO.Bind;
+
+  glDrawArrays(GL_QUADS, 0, 4);
+
+  fVAO.Unbind;
+  fShader.Disable;
+  fTexture.Unbind;
+
+  fContext.SwapBuffers;
+end;
+
+end.
+