ABSTRACT
The vertices processed by the vertex program enter a hard-wired stage. First of all, they are assembled to build primitives such as triangles, using the connectivity information that accompanies the input stream of vertices. (Not only a triangle but also a line segment or a point can be a primitive. A primitive is processed as an independent entity in the rendering pipeline.) Each primitive is further processed to determine its 2D form appearing on the screen, and is rasterized into a set of fragments. The per-vertex data such as the vertex normals are interpolated across each primitive, and each fragment is assigned the interpolated data. The hard-wired stage is generally named primitive assembly and rasterization. Direct3D simply calls this stage rasterization or rasterizer, and this book follows it just for the sake of simplicity.
