setBlendColor method

  1. @override
void setBlendColor(
  1. Vector4 color
)

Refused, and the refusal is the promise supportsBlendColor makes.

WebGPU has setBlendConstant and two of the four constant-reading BlendFactor values map straight onto "constant" and "one-minus-constant". The other two are OpenGL's CONSTANT_ALPHA, which this API cannot form in a colour equation at all — so a backend answering true would promise four factors and honour two. The capability is one answer for all four, so the honest answer loses the two it could have had.

Implementation

@override
void setBlendColor(Vector4 color) => throw UnsupportedError(
  'this backend answers false to supportsBlendColor: WebGPU has "constant" '
  'and "one-minus-constant" and no equivalent of CONSTANT_ALPHA, so two of '
  'the four factors BlendFactor names cannot be formed',
);