createTexture method

@override TextureHandle createTexture(TextureDescriptor descriptor)

A brand-new texture matching descriptor, with the single TextureHandle that will ever stand for it, contents undefined until written.

One creator since 1.0. A RenderTargetDescriptor — the 2D target the pool lends out, sampled, drawn into and copied either way — is what every allocator makes. Any other TextureDescriptor is the general form a GraphicsDevice makes beside it (it was createTextureWithDescriptor): a 2D array, a 3D texture, a cube or a cube array, with TextureDescriptor.mipLevelCount levels and the usages it names, gated by the feature the shape needs — textureArrays, texture3D, cubeTextures, cubeArrayTextures, and textureWrites for the general form itself; a TextureUsage.storage texture needs storageTextures and a format whose support says storage. A device without one throws UnsupportedCapabilityException, and a size past its limits an ArgumentError.

Implementation

@override
TextureHandle createTexture(TextureDescriptor descriptor) {
  if (descriptor is RenderTargetDescriptor) return _createTarget(descriptor);
  features.require(DeviceFeature.textureWrites, backend: _name);
  final shape = switch (descriptor.dimension) {
    TextureDimension.d2Array => DeviceFeature.textureArrays,
    TextureDimension.d3 => DeviceFeature.texture3D,
    TextureDimension.cube => DeviceFeature.cubeTextures,
    TextureDimension.cubeArray => DeviceFeature.cubeArrayTextures,
    TextureDimension.d1 => DeviceFeature.texture1D,
    TextureDimension.d2 => null,
    _ => throw UnsupportedError(
      'the fake backend cannot allocate a ${descriptor.dimension} texture',
    ),
  };
  if (shape != null) features.require(shape, backend: _name);
  if (descriptor.usage.contains(TextureUsage.storage)) {
    features.require(DeviceFeature.storageTextures, backend: _name);
  }
  calls.add(RecordedCall('createTexture', arguments: descriptor));
  return _born(
    wrapTexture(
      owner: this,
      backend: 'fake ${_serial++}',
      width: descriptor.width,
      height: descriptor.height,
      format: descriptor.format,
      sampleCount: descriptor.sampleCount,
      storageMode: descriptor.storageMode,
      dimension: descriptor.dimension,
      depthOrArrayLayers: descriptor.depthOrArrayLayers,
      mipLevelCount: descriptor.mipLevelCount,
      usage: descriptor.usage,
    ),
  );
}