Using RAW RGBA texture files

Shields · December 13, 2000, 9:50am

I’ve got a problem. I am using PhotoShop to add an Alpha channel to a bitmap and saving as RAW ( 0 size header, including alpha, interleaved.). This all works OK but when I load and texture stuff with it in Delphi, I just get a garbled image. I’ve checked the image dimensions, and they are OK.

Below is the relevant code I’m using.

PTexture = ^TgloveTexture ;
TTexture = record
width, height, bytes : integer ;
data : Pointer ;
end ;

function LoadTextureRaw ( filename : string ; w,h : integer ) : Cardinal ;
var
ptr : PTexture ;
tex : GLUint ;
fp : FILE of BYTE ;
resultInt : Integer ;
begin

 tex := -1 ;

 NEW ( ptr ) ;
 if ( ptr &lt;&gt; nil ) then
 begin

      ptr ^. width := w ;
      ptr ^. height := h ;
      ptr ^. bytes := 4 ;             // R,G,B & A componants
      ptr ^. data := nil ;
      GetMem ( ptr ^. data, ( w*h*4) ) ;

      if ( ptr^.data &lt;&gt; nil ) then
      begin

           AssignFile ( fp, filename ) ;
           Reset ( fp ) ;
           BlockRead ( fp, ptr ^. data, ( w*h*4 ) , resultInt ) ;
           CloseFile ( fp ) ;

        glGenTextures(1, tex);
        glBindTexture(GL_TEXTURE_2D, tex);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
        glTexImage2D(GL_TEXTURE_2D, 0, ptr^.bytes, ptr ^. width, ptr^.height, 0, GL_RGBA, GL_UNSIGNED_BYTE, ptr^.data );

      end ;
 end ;

 LoadTextureRaw := tex ;

end ;

I then use the return texture variable (tex) to texture my polygons. BTW, the code for texturing the polys has not changed from when it works using a normal load of a bitmap (using the GLAUX routine).

Any ideas?

Thanks.