Understanding Shader Concepts

In the days before standalone GPUs were commonplace, drawing pixels to the screen was a lot different than it is today. Kids these days just don’t know how good things have gotten with their programmable shaders! Back then, you would write pixel color values directly into a buffer in memory that becomes the next frame sent to the display. The advent and proliferation of the dedicated graphics processor as an add-on came in the late 1990s, and it changed the landscape completely. Access to display pixels was abstracted around two major Application Programming Interfaces (APIs): DirectX and OpenGL. There’s an incredibly rich history of the evolution of those interfaces but this isn’t a book on graphics hardware interfaces and their history – it’s a book on present 3D graphics development, so let’s just leave the details to those tomes and summarize them in short.

To avoid the need for developers and end user software...