satya - Mon Sep 03 2012 12:04:27 GMT-0400 (Eastern Daylight Time)

Let's look at the meaningful stages for a beginer

Vertex Processing
   model transformations: scaling, positioning, rotation etc
   View transformations: fixing the eye coords
   Projection transformations: viewing volume or frustum
   texture coordinates calculated/transformed
   lighting impact on colors
   Also called T&L (Transformation and lighting stage)
   (done by vertex shaders)
Graphics Primitive assembly
   gather enough vertices for a primitive: lines or triangles etc
   pass them to the next stage where the following happens
     figure out front/back faces
     cull if needed
   (done not by a shader but like a fixed functionality)
Rasterization
   Convert geometric primitives to fragments (or pixels)
   anti-aliasing
Fragment processing
   a fragment has attributes at each pixel: color, texture etc
   these values are intepolated
   texture mapping
   fog
   color sum
   done by (fragment shader)
Per fragment operations
   fragment testing: ownership, depth, etc
   blending
   dithering
Framebuffer transfer
   pixels sent to the frame buffer for display
   fragment tests
       ownership, depth, stencil etc