In a GLSL fragment shader, how to access to texel at a specific mipmap level?

Question

I am using OpenGL to do some GPGPU computations through the combination of one vertex shader and one fragment shader. I need to do computations on a image at different scale

Answer 1

try:

glGenerateMipmapEXT(GL_TEXTURE_2D);

after you bind the texture. (And before doing the rendering of course)

The glTexParameteri-GL_GENERATE_MIPMAP is deprecated I think... MfG Digi