In reference to yesterday's post I continued a bit and implemented the following

1. Line drawing via DDA and Bresenham
   
2. Basic Cohen-Southerland Clipping in 2D

These routines may not be the fastet but this actually not the point since the code is written in managed C# and makes no use of any optimizations. It's sole purpose is learning. The next things that need to be done are

• drawing of triangles (including basic fill)
  
• a Z-Buffer (at least I have already set up the basics)
  
• clipping in homogenous clip space
• simple scene-graph

If anyone is interested in some sources - I can either post them here or put them online on my website. I also thought about making the whole engine a bit more flexible. So I thought I could
divide all the pipeline elements into pipeline stages. Each stage has access to some renderstate and does only execute on some defined input. As a consequence one would get something similar to vertex and fragment programs and a non-fixed function pipeline. But of course this is only some thinking and I should better get things set up before reasoning about making it most flexible.