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Rotating a point_sprite texture

Started by DJHoltkamp Apr 7, 2009 at 2:48 AM 3 replies 2k views

Original Post

Apr 7, 2009 at 2:48 AM

Is there any way to rotate a point_sprite texture... I tried altering the texture matrix but everything went crazy leading me to believe that it is not possible. I am using OpenGL ES. Thanks. Here is my code: glPointSize(32.0f); glDisableClientState(GL_TEXTURE_COORD_ARRAY); glEnable(GL_POINT_SPRITE_OES); glTexEnvi(GL_POINT_SPRITE_OES, GL_COORD_REPLACE_OES, GL_TRUE); glMatrixMode(GL_TEXTURE); glRotatef(70, 0, 0, 1); float Intensity = 1.0f - TotalSeconds / 6.0f; glColor4f(Intensity, Intensity, Intensity, Intensity); glDrawElements(GL_POINTS, Count , GL_UNSIGNED_SHORT, GLIndicies); return false; glDisable(GL_POINT_SPRITE_OES); glLoadIdentity(); glMatrixMode(GL_MODELVIEW); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glTexEnvi(GL_POINT_SPRITE_OES, GL_COORD_REPLACE_OES, GL_FALSE);

DJHoltkamp

Apr 7, 2009 at 2:56 AM

ha ha, ok, this is what I get for programming at 4 in the morning... I totally missed the return false in the middle of my statement. Nonetheless, the texture matrix still doesnt seem to provide a way to rotate the texture. Suggestions?

AndyEsser

Apr 7, 2009 at 4:41 AM

I've never tried directly using the Texture matrix myself. But should you not be setting the matrix mode back to Modelview before doing you glDrawElements? So it should be:

glMatrixMode(GL_TEXTURE);glRotatef(70, 0, 0, 1);glLoadIdentity();glMatrixMode(GL_MODELVIEW);float Intensity = 1.0f - TotalSeconds / 6.0f;glColor4f(Intensity, Intensity, Intensity, Intensity);glDrawElements(GL_POINTS, Count , GL_UNSIGNED_SHORT, GLIndicies);

DJHoltkamp

Apr 7, 2009 at 9:52 AM

The currently selected matrix will not have any affect on the DrawElements (but i tried it just to make sure). Thanks for the guess! Anybody else?

zedz

Apr 7, 2009 at 1:20 PM

personally Ive neverused point sprites, lots of issues with them
perhpas u cant rotate texture coords (though u should be able to in a shader)

you might have to just do the points yourself

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