OpenGl Shader for Brightness

I am new user of OpenGl Shader, Iam creating shader for brightness I have done with creation of shader also I draw the image on QGlWidget but After that Iam not able to apply gl_fragColor value to Image.

Please Help me. Its Realy Very Urgent…


I’m confused. You’re done with the creation of the shader, but changing gl_fragColor doesn’t change the image? You mean you’ve written it, but it doesn’t do anything? How do you know the shader is even turned on? Can you post your drawing code?