Development question regarding polygon rendering on PSX hardware

Dear all,

I'm hoping people can clear this up for me. I am developing a PSX emulator as part of my final university module, using a combination of Java and OpenGL 4 - there is a reason for using Java, as part of the module is investigating JIT techniques in Java bytecode. Anyhow, I am currently implementing the GPU using the excellent NOPSX documentation - it mentions that for GP0 polygon commands, the "Polygons are displayed up to <excluding> their lower-right coordinates.". This is what I would like more info on:

(1) Does this apply only to four pointed polygons? (I guess so as a triangle doesn't really have a bottom-right).
(2) Does it apply to the last vertex in the command stream, regardless of coordinates? (so even if in terms of coordinates, it isn't 'bottom-right').
(3) Does it modify the other vertices so that (for example) a rectangle is still a rectangle, just -1 px in width and height?

I can't seem to find definite answers so would appreciate any help. Thanks

Regards,
Phil

I'd try http://www.gamedev.net , although it is related to emulation, that question is most certainly related to 3d game dev. I have a lot go gaming development experiace and agree that it must refer to 4 point poly's but can not give you in-depth answers in confidence.

try read and find opengl bible its should help you
and book think like proggramer and pragmatic programmer those are about problem sloving

Thanks for the replies so far - I've read the OpenGL bible, and it was most helpful in explaining a lot of the math and other things. The issue is not the OpenGL API - I have been getting on ok with that. The problem is that I need to transform the vertices 'before' I send them (or modify them in a shader) in order that the bottom-right coordinate is rendered up to but not including. Just trying to think about the best way of doing that - I have a few ideas like calculating offsets with some basic cos/sin magic. With non-rotated rectangles it is easy because I can just minus one from each axis.