Rendering Passes?

Paging through my copy of the mighty Red Book and strolling through these forums, I’ve heard many references to first pass, second pass, etc. I understand the idea, but how is it done?

I understand how multiple textures can be used, but if your card does not have enough texturing capability, you have to use these multiple passes to get the same effect–how’s that done?

check out …
http://nehe.gamedev.net/tutorials/lesson22.asp

and be sure to look at the other tutorials on that site! Good luck

Simply.

glDepthTest (GL_LEQUAL);

// First pass
glBindTexture (GL_TEXTURE_2D, base_tex_id);
DrawPolygon (FIRST_TEXCOORD_SET);

glEnable (GL_BLEND);
glBlendFunc (GL_ZERO, GL_ONE);

// second pass
glBindTexture (GL_TEXTURE_2D, second_tex_id);
DrawPolygon (GL_SECOND_TEXCOORD_SET);

glDisable (GL_BLEND);

where GL_XXXXX_TEXCOORD_SET are constants for DrawPolygon indicating which texture coord set to use.

Sorry For Bad English