TOPIC:

Hi,

in OpenGLCanvas.pas  the Lazarus TCanvas is overwritten by a OpenGL Canvas.
In TOGLCanvas (starts at line 109) there's missing a function to overwrite the original Canvas function GetPixel()

add in line 116:
      function GetPixel(X, Y: Integer):TColor; override;


Then add in line 245:

function TOGLCanvas.GetPixel(X, Y: Integer):TColor;
begin
  glPointSize( 1);
  glReadPixels( X, Y, 1, 1, GL_RGB, GL_UNSIGNED_BYTE, @Result);
end;

Thanks,
Peter

We put your suggestion to pl_OpenGL pkg

Lazarus TCanvas ?


 

wrote:

We put your suggestion to pl_OpenGL pkg

Lazarus TCanvas ?
 

Yes, the Lazarus Canvas is replaced by the OpenGL Canvas

Please take a look at:
constructor TOpenGLCanvas.Create(AOwner: TComponent);
...
...
    FOldCanvas := Canvas;
    Canvas := TOGLCanvas.Create;

NO
it's Typhon TCanvas
Is that correct ?

wrote:

NO
it's Typhon TCanvas
Is that correct ?
 

The code I've sent (in my first post ..) is for unit OpenGLCanvas.pas
It adds missing function GetPixel()  to the Typhon's  TOGLCanvas, yes.