[Csgl-users] Loading Textures without PreTexture2D

[Ben H. <be...@ex...>]

Hi all,

Here is a really straight forward way of loading OpenGL textures.  It
seems simpler than how it is currently being done in the various
examples and such.

-----
// convert bitmap to be square because OpenGL likes that
Bitmap bitmapSquare = new Bitmap( bitmap, 256, 256 );
			
// get the size of the bitmap
//   in this case it will be (0,0,256,256)
Rectangle rect = new Rectangle(
	0, 0, bitmapSquare.Width, bitmapSquare.Height );

// request the bitmap's data in a particular pixel format.
//   this function is nice because it will automatically
//   convert the bitmap data into whatever format you request.
//   (in this case 32bit RGBA data)
BitmapData bitmapdata = bitmapSquare.LockBits(
	rect,
	ImageLockMode.ReadOnly,
	PixelFormat.Format32bppArgb );

// set the OpenGL texture map data
GL.glTexImage2D(
	GL.GL_TEXTURE_2D,
	0,
	(int) GL.GL_RGB8,
	bitmapdata.Width,
	bitmapdata.Height,
	0,
	GL.GL_BGRA_EXT,
	GL.GL_UNSIGNED_BYTE,
	bitmapdata.Scan0 );

// unlock the bitmap since we are done with it
bitmapSquare.UnlockBits( bitmapdata );
-----

I recommend doing away with the class 'PreTexture2D' since I don't think
that it is really needed.

All the best,
-ben houston
4th Year Cognitive Science/Neuroscience
Carleton University, Ottawa, Canada
( be...@ex... / 613-266-0637 )