Converting DirectX to OpenGL

Graphics and GPU Programming Programming OpenGL

Started by HappyDude January 03, 2003 06:27 PM

2 comments, last by HappyDude 21 years, 3 months ago

122

Author

January 03, 2003 06:27 PM

I wrote a small program in DirectX and am now trying to write an equivalent one in OpenGL... I converted everything, and it works... kinda... my problem is that my OpenGL version seems to have flipped all my textures horizontally and vertically, and my left-right movement seems to have been inverted as well... it looks like my vertex coordinates are flipped horizontally when they''re displayed, but their vertical components seem to be the same. Is there a difference in the coordinate systems of OpenGL & DirectX that I''m missing which is causing these problems?

GarlandIX

212

January 03, 2003 10:02 PM

Since OpenGL uses a right handed system, the z-coordinate goes in the opposite direction. You also have to define triangle vertices in a counter-clockwise order instead of clockwise so they face the right way.

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BASIC programmers don''t die, they just GOSUB and don''t return.

------------------------------BASIC programmers don't die, they just GOSUB and don't return.

zedzeek

529

January 03, 2003 11:10 PM

for textures d3d uses 0,0 as topleft, gl uses 0,0 as bottom left

Captain Courgette, eat more veg

HappyDude

122

Author

January 03, 2003 11:59 PM

Exactly what I needed, thanks.