Class description
The blend-state controls how alpha blending between the current framebuffer contents and newly drawn pixels.
The constant-color slot contains an optional four-float sequence that specifies a constant parameter to the func-*constant* blend-functions. If constant blend functions are not used, the slot can be f.
The rgb-mode and alpha-mode slots both contain blend-mode values that determine the blending equation used between RGB and alpha channel values, respectively. If both slots are f, blending is disabled.

See also
<blend-state>, get-blend-state