Class TBGLFrameBuffer

Unit

BGRAOpenGL

Declaration

type TBGLFrameBuffer = class(TBGLCustomFrameBuffer)

Description

Frame buffer in OpenGL.

A frame buffer is a texture that can be used as a drawing surface in OpenGL.

Example of drawing on a framebuffer and then drawing it on the OpenGL control:

uses ..., BGRABitmapTypes, BGRAOpenGL;

procedure TForm1.OpenGLControlPaint(Sender: TObject);
var
  mousePos: TPoint;
  buf: TBGLFrameBuffer;
begin
  // Draw Background
  BGLViewPort(OpenGLControl.Width, OpenGLControl.Height, BGRAWhite);
  // Create framebuffer
  buf := TBGLFrameBuffer.Create(256,256);
  // Use it
  BGLCanvas.ActiveFrameBuffer := buf;

  BGLCanvas.Fill(CSSYellow);
  BGLCanvas.Line(0,0,128,128, BGRABlack);
  mousePos := ScreenToClient(Mouse.CursorPos);
  BGLCanvas.FillRect(mousePos.x - 50, mousePos.y - 50, mousePos.x + 50, mousePos.y + 50, CSSRed, False);

  // Render framebuffer on the control
  BGLCanvas.ActiveFrameBuffer := nil;
  BGLCanvas.PutImage(0,0, buf.Texture);
  // Free framebuffer
  buf.Free;

  // Update
  OpenGLControl.SwapBuffers;
end;

Hierarchy

• TObject
• TBGLCustomFrameBuffer
• TBGLFrameBuffer

Overview

Fields

	FFrameBufferId: GLuint;
	FHeight: integer;
	FMatrix: TAffineMatrix;
	FProjectionMatrix: TMatrix4D;
	FRenderBufferId: GLuint;
	FSettingMatrices: boolean;
	FTexture: IBGLTexture;
	FWidth: integer;

Methods

	constructor Create(AWidth,AHeight: integer);
	destructor Destroy; override;
	function MakeTextureAndFree: IBGLTexture; override;
	function GetHandle: pointer; override;
	function GetHeight: integer; override;
	function GetMatrix: TAffineMatrix; override;
	function GetProjectionMatrix: TMatrix4D; override;
	function GetTexture: IBGLTexture; override;
	function GetWidth: integer; override;
	procedure SetMatrix(AValue: TAffineMatrix); override;
	procedure SetProjectionMatrix(AValue: TMatrix4D); override;

Description

Fields

	FFrameBufferId: GLuint;
This item has no description.

	FHeight: integer;
This item has no description.

	FMatrix: TAffineMatrix;
This item has no description.

	FProjectionMatrix: TMatrix4D;
This item has no description.

	FRenderBufferId: GLuint;
This item has no description.

	FSettingMatrices: boolean;
This item has no description.

	FTexture: IBGLTexture;
This item has no description.

	FWidth: integer;
This item has no description.

Methods

	constructor Create(AWidth,AHeight: integer);
This item has no description.

	destructor Destroy; override;
This item has no description.

	function MakeTextureAndFree: IBGLTexture; override;
This item has no description.

	function GetHandle: pointer; override;
This item has no description.

	function GetHeight: integer; override;
This item has no description.

	function GetMatrix: TAffineMatrix; override;
This item has no description.

	function GetProjectionMatrix: TMatrix4D; override;
This item has no description.

	function GetTexture: IBGLTexture; override;
This item has no description.

	function GetWidth: integer; override;
This item has no description.

	procedure SetMatrix(AValue: TAffineMatrix); override;
This item has no description.

	procedure SetProjectionMatrix(AValue: TMatrix4D); override;
This item has no description.