Copies buffer's contents into a tightly packed ArrayBuffer —
copyBufferToBuffer + mapAsync, readTexturePixels' shape for a buffer
instead of a texture, with the same discipline: the staging buffer is
created per call and destroyed before resolving.
Resolves null when the device surface lacks the entry points
(copyBufferToBuffer, the mapping trio — presence is the capability); the
caller turns that into UNSUPPORTED_GPU_FEATURE. Throws
INVALID_APPLICATION_STATE for a disposed buffer (§83) — a validation
fact, not a capability one.
Copies
buffer's contents into a tightly packedArrayBuffer—copyBufferToBuffer+mapAsync,readTexturePixels' shape for a buffer instead of a texture, with the same discipline: the staging buffer is created per call and destroyed before resolving.Resolves
nullwhen the device surface lacks the entry points (copyBufferToBuffer, the mapping trio — presence is the capability); the caller turns that intoUNSUPPORTED_GPU_FEATURE. ThrowsINVALID_APPLICATION_STATEfor a disposed buffer (§83) — a validation fact, not a capability one.