What is rasterizer in AmanithVG?

Hi,
I am trying to port “rasterizer” Amanith code for a project. I am not sure what the purpose of this code is? Does anyone know what this code actually tests?

main: http://www.amanithvg.com/testsuite/aman … rizer.html

code: http://www.amanithvg.com/testsuite/aman … erizer.inc

Thanks!