6.5. Summary

This chapter has applied the language concepts from previous chapters to the development of working shaders that create a procedurally defined brick pattern. The vertex shader is responsible for transforming the vertex position, passing along the modeling coordinate position of the vertex, and computing a light intensity value at each vertex, using a single simulated light source. The fragment shader is responsible for determining whether each fragment should be brick color or mortar color. Once this determination is made, the light intensity value is applied to the chosen color, and the final color value is passed from the fragment shader so that it can ultimately be written in the frame buffer. The source code for these two shaders was discussed line by line to explain clearly how they work. This pair of shaders illustrates many of the features of the OpenGL Shading Language and can be used as a springboard for doing bigger and better things with the language.