Coverage values in [0, 1], row-major, at any resolution (bilinear, clamped to the edge). Treat as immutable: GPU textures are cached per object, so create a new one for every change.
Readonly
Coverage values in [0, 1], row-major, at any resolution (bilinear, clamped to the edge). Treat as immutable: GPU textures are cached per object, so create a new one for every change.