More concerns about using opengl for all graphical applications
Isn't there something about graphics cards not supporting images of a certain size in opengl? So I coudn't use opengl for high quality processing of images because the quality would be degraded. Am I correct?
Old cards can only support power-of-two sized textures. Newer cards can do any reasonable sized image with an extension.
Oh, so it does not matter what size the image is, even on older cards. They could be (provided memory could handle it) 998001 X 998001?
There is absolutely no reason you can't just put your non power of 2 texture on a power of 2 'canvas'. Say you have a 130x200 texture. Copy it to a 256x256 texture, and colour all the unused pixels black with 0 alpha. Now rework your texture coords to use only the part 130x200 part of the image.
Alternatively you could pack multiple non power of 2 textures into 1 power of 2 texture. Google 'texture packing' for some more ideas.
So no, you are not correct.
Alternatively you could pack multiple non power of 2 textures into 1 power of 2 texture. Google 'texture packing' for some more ideas.
So no, you are not correct.
Quote:Original post by aewarnick
Oh, so it does not matter what size the image is, even on older cards. They could be (provided memory could handle it) 998001 X 998001?
No. You can query the driver for the maximum texture size. I forget the exact token to use, so either check around the back of the gl spec, or have a look here. 2048x2048 is a common maximum.
The number I posted above is a power of 2. That is why I chose it. I think all of you are misunderstanding my question. I read somewhere that opengl can only support textures up to a certain size like 1024 x 1024. Any image bigger than that would be degraded because it would have to be scaled down. That is my question.
for the record, ATI has a max of 2048*2048 and NV max is 4096*4096.
and 998001 cant be a power of two texture size because it has a '1' in it [smile]
and 998001 cant be a power of two texture size because it has a '1' in it [smile]
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