3da46a8d8d
Move the weight paint drawing to the fragment shader. The shader uses a texture that uses the U.coba_weight custom color band, or an internal color band. In addition to actual weights, the shader has to display two alert colors: missing vertex group, and zero weight. The zero weight alert has to be blended with regular weight colors, so that a single alert vertex surrounded by weighted ones is still visible. Reviewers: campbellbarton, fclem Differential Revision: https://developer.blender.org/D3675