As I understand it:
When you want to use Gouraud shading, the color of a fragment is determined by interpolating the per-vertex colors. Thus all computation is contained within the vertex shader. However if we want to use a diffuse map to granularly define the color of an object, then we wouldn't be able to determine the color of a fragment until the fragment shader, since we'd need to sample the correct texel using the texture coordinates of the fragment.
So is Gouraud shading with a diffuse map not possible?
Or would "Gouraud shading" with a diffuse map involve only calculating the per-vertex light intensity and then using that in our fragment shader to calculate the fragment's color?
