Book excerpt: Because graphics systems for video games and game console hardware have become more complex, graphics applications must also advance. This is where programmable vertex and pixel shaders come in. This book shows how to write assembly language for programming the vertex shader and pixel shader hardware using DirectX 9 and covers the fundamentals of programming vectors using SIMD methodology in conjunction with the Direct3D 9 application interfaces. Features: Find out about the valid vertex shader and pixel shader instruction sets; Learn how branching and branchless code can be used for flow control; Understand the vertex shader instructions that support matrices; Discover how to use quaternions to accurately represent rotating objects; Use texturing with both vertex and pixel shaders, including bump mapping.