GL_ARB_point_sprite problem

Hi, i’m new here.
I have i little(or big) problem with the ARB_point_sprite extension.
I just bought a new graphics card (an ati radeon 9600xt) and when i ran my program with that new card and a point-sprite came into my view the whole texture coords of all the other textured primitives were “damaged”(it looked like that). With my old card i did not have that bug. I searched the net for that problem … no success. Might i have overlooked something? I also tried a point-sprite tutorial program. The same problems appeared.

Any suggestions?


Try loading an identity matrix onto the texture matrix stack when you’re done with the sprites. It shouldn’t be required but there may be a bug. Texgen may be the other potential culprit so maybe try disabling that. Again none of this should be broken so it’s a long shot. That’s the kind of state that can stuff up your texture.

I have also experienced this problem. I filed a bug with ATI about a month ago and discussed it with one of their developer relations people, but they have yet to acknowledge it as the fault of their driver.

Thanks for the information. I hope that they are working on it.
Did they tell you how to fix the problem temporarily?


No. As far as I know, the only way to fix the problem is to disable point sprites.

few details:

-enabling ps and/or texcoord generation doesnt hurt… until you actually draw a sprite.
-restoring the texture matrix and pretty much all attributes opengl has to offer doesnt help.
-using point sprites with va or vbo in my case didnt generate correct tex coords (or none at all, hard to tell)
-using vertex pointer and color pointer (or other vertex attrib pointers) caused vpu to crash

personal result:
-ps support on ati is a bad joke that looks like it never was touched by qa

good news:
-according to a post on gamedev the texture warping will be fixed in cat 4.6 (any maybe some of the other problems if im really lucky)

until then i use this vertex program:
-normal is actually the sprite position
-texcoord is the x,y size for the sprite
-position are signs (-.5 | 5) that specify the corner


PARAM ModProj[4] = {state.matrix.mvp};

TEMP pos, res;
MOV pos, vertex.normal;
MOV pos.w, 1;
DP4 res.x, ModProj[0], pos;
DP4 res.y, ModProj[1], pos;
DP4 res.z, ModProj[2], pos;
DP4 res.w, ModProj[3], pos;

MOV result.position, res;
MAD result.position.xy, vertex.position, vertex.texcoord[0], res;
ADD result.texcoord[0], vertex.position, {.5,.5,0,0};
MOV result.color, vertex.color;


to render:

only half the speed of point sprites (but allows for non square particles). basically its simply avoiding a lot of math by doing the work after the projection instead of fooling around with camera up and right vectors.

Thank you very much! I’ll try your code.
ATI, what are you doing? I am really disappointed.