[Mesa-users] questions about glDrawPixels

[Brian Paul]

On 6/16/21 10:08 PM, 张银霞 wrote:
> Is it necessary to do glUseProgram(0) before use glDrawPixels?I found 
> that if I just call glDrawPixels,Pixels I got are all about background 
> color .but if i do glUseProgram(0) before glDrawPixels I will get 
> correct pixels.

IIRC, glDrawPixels should bypass the vertex/fragment shader stages so 
glUseProgram(0) should not be needed.  So this looks like it may be a 
bug.  You could open an issue to report it at 
https://gitlab.freedesktop.org/mesa/mesa/-/issues

-Brian