Hi all...

I gess this is kind of a newbie question, but here is my problem:

I am making a program that uses the result of another program (built by someone else, that I am adding to my one, copying the classes and changing it if I need) to draw pixels as a final result. The program (the one built by someone else) "sends me" only a texture id - actually, it originally displays this texture in a polygon - and I want to get the values of each pixel of this texture without display it (and without using vertex or fragment shaders).
If it makes more clear, I want to acsses this texture as if it was a matrix of bytes without display it... How can I do that?

thanks in advance

Leo

Try

glBindTexture(GL_TEXTURE_2D, texture);

//get texture size
GLint width, height, border;
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &width);
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &height);
glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_BORDER, &border);
width -= border; height -= border;

//get texture as rgba
char* buff = new char[width*height*4];
glGetTexImage(GL_TEXTURE_2D, 0, GL_RGBA, GL_UNSIGNED_BYTE, buff);

hope this works...

Leave the border stuff out, it is wrong...just get width and height (border is 0 for most cases anyway, so most of the time it won't matter :-|)

That should be
width += 2*border; height += 2*border;