OpenGL 4 Shading Language Cookbook - Third Edition

How it works...

Within the main function of the fragment shader, we access the alpha map texture and store the result in alphaMap. If the alpha component of alphaMap is less than a certain value (0.15, in this example), then we discard the fragment using the discard keyword.

Otherwise, we compute the Blinn-Phong lighting model using the normal vector oriented appropriately, depending on whether or not the fragment is a front facing fragment.