texture question

OpenGL OpenGL: Basic Coding
21

my program works even on drivers with that bug
I see your point, but if you want to make sure your program works fine with all drivers, it can get complex.

I have never seen this TexEnv bug probably because I tend to use MODULATE or COMBINE and seems to work perfectly and also I’m on Windows.

i’m running this on ubuntu linux with an nvidia 6600gt (76.67 driver).
I’m sure you are seeing a bug.
Tried the new drivers? 87.62

I do however unbind the texture (bind 0), could this maybe reset the texture environment?
You can try

int myTexEnv;
glGetTexEnviv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE , &myTexEnv);

but even this might return GL_REPLACE, while on the GPU, it may be GL_MODULATE.

22

I see your point, but if you want to make sure your program works fine with all drivers, it can get complex.

Before I started to work with GLSL, most of the problems I had were relatively simple to work around once I have found what the problem is. Ussualy I only work around issues in drivers that are relatively new at time I hit the bug. I mostly do not try to fix issues with the older drivers.


I have never seen this TexEnv bug probably because I tend to use MODULATE or COMBINE and seems to work perfectly and also I’m on Windows.

I have seen two issues relating to this on ATI cards. Fortunatelly the “set again” workaround for the first issue I have hit (TexEnv mode change after immediate mode rendering) worked also with the second one (incorrect sampling of EXT_texture_rectangle textures) which appeared in some newer drivers. Actually I found the second issue only when I disabled the workaround to check current state of the first issue.

23

In my own code, I make a workaround branch code until it gets solved. For other people, I inform them before doing anything. I think that both companies (NV + ATI) listen but often do not reply.

I haven’t been using immediate mode.
I think this is a good example why “OpenGL: What’s Next” is a good idea.
http://www.opengl.org/discussion_boards/ubb/ultimatebb.php?ubb=get_topic;f=2;t=020408

OpenGL Lean and Mean (LM) if it becomes real, will be close to the hw. They will cut out most of the ancient API from GL, thus companies can concentrate on perfecting that.