Hi. I´m trying to create some examples of glReadPixels and glCopyPixels but I´m having some problems.
After rendering a scene I use glReadPixels to read a section of the screen and then I pass that pointer to glDrawPixels so I can draw it in a new rastre location. The thing is that it only draws a black square with two gray lines. Also glCopyPixels does´t draw any thing when I try to use it.
I don´t know if it is some driver problem or what am I doing wrong.
I also have problem with glReadPixels() and glDrawPixels() - nothing happens even after a bunch of disable : GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_FOG, GL_LIGHTING, GL_DITHER, GL.GL_BLEND
I see that you gave for glReadPixels negative values. After testing, it seem that at least the first 2 parameters of glReadPixels must be in the range of the frame buffer size otherwise I get artifacts.
oumind: I also have problem with glReadPixels() and glDrawPixels() …
if you have problems with a function, why not reading the documentation on it first? f.e. glDrawPixels requires a raster position to be set before drawing any pixels. If not done you won’t see anything in the worst case. Now this is something you can read in the documentation.