Freya Holmér on Twitter: "making a drawing app was a sobering reminder that "alpha blending" in games is such a lie~ it ignores the destination alpha channel! so if you want to
CanvasBlend Enumeration
What is alpha blending
Alpha Blending using GDI+ - CodeProject
r - Control alpha blending / opacity of n overlapping areas - Stack Overflow
DirectX10 Tutorial 6: Blending and Alpha Blending | Taking Initiative