Update
Update draw_polygons parameters
Calc normal vector for all polygons
Add shading mode option
Update rasterization
Update
Add saturate color
Update rasterizer
First gouraud shading
Refactor
Add phong shading
Update task
Merge branch 'gouraud' into develop
Refactoring
Refactor
Add Cython shader
Refactor
Refactor
Bugfix
Add Cython sample code