checkFeatures method

void checkFeatures(DeviceFeatures features, { required String backend, })

Throws UnsupportedCapabilityException when this buffer needs a feature features lacks: a storage usage (compute or renderStageStorage, either one), an indirect usage (indirectDraw or indirectDispatch, either one) or general buffers at all (buffers), in that order.

Where either of two features takes a usage, the refusal names the one the buffer was shaped for: the copy usages of BufferUsage.standardStorage are a compute pass's buffer, a bare storage usage a render stage's. For a backend's createBuffer, so that a usage a minor adds with its feature is refused by a backend written before it rather than ignored. backend names the backend as a person would.

Implementation

void checkFeatures(DeviceFeatures features, {required String backend}) {
  // The usages first: a storage or indirect buffer is refused by what it
  // was made for, which says more than `buffers` would.
  if (usage.contains(BufferUsage.storage) &&
      !features.has(DeviceFeature.compute) &&
      !features.has(DeviceFeature.renderStageStorage)) {
    features.require(
      usage.contains(BufferUsage.standardStorage)
          ? DeviceFeature.compute
          : DeviceFeature.renderStageStorage,
      backend: backend,
      reason: 'a storage buffer needs compute or render-stage storage',
    );
  }
  if (usage.contains(BufferUsage.indirect) &&
      !features.has(DeviceFeature.indirectDraw) &&
      !features.has(DeviceFeature.indirectDispatch)) {
    features.require(
      DeviceFeature.indirectDraw,
      backend: backend,
      reason: 'an indirect buffer needs indirect draws or dispatches',
    );
  }
  features.require(DeviceFeature.buffers, backend: backend);
}