drawPlatform
Adds one opaque platform draw command at a local half-open rectangle.
Core retains command by reference, translates localBounds into tree coordinates, and preserves the command among portable draw and clip commands. Only a matching platform backend may interpret the payload; portable backends reject it before producing output.
Parameters
command
immutable platform-owned payload.
localBounds
nonempty local bounds used for translation, clipping, and backend placement.
Throws
when localBounds is empty.
when the scope is no longer valid.