ID3D12GraphicsCommandList::DiscardResource method (d3d12.h)

Indicates that the contents of a resource don't need to be preserved. The function may re-initialize resource metadata in some cases.

Syntax

void DiscardResource(
  ID3D12Resource             *pResource,
  const D3D12_DISCARD_REGION *pRegion
);

pResource

A pointer to the ID3D12Resource interface for the resource to discard.

pRegion

Type: [in, optional] const D3D12_DISCARD_REGION*

A pointer to a D3D12_DISCARD_REGION structure that describes details for the discard-resource operation.

None

The semantics of DiscardResource change based on the command list type.

For D3D12_COMMAND_LIST_TYPE_DIRECT, the following two rules apply:

When a resource has the D3D12_RESOURCE_FLAG_ALLOW_RENDER_TARGET flag, DiscardResource must be called when the discarded subresource regions are in the D3D12_RESOURCE_STATE_RENDER_TARGET resource barrier state.
When a resource has the D3D12_RESOURCE_FLAG _ALLOW_DEPTH_STENCIL flag, DiscardResource must be called when the discarded subresource regions are in the D3D12_RESOURCE_STATE_DEPTH_WRITE.

For D3D12_COMMAND_LIST_TYPE_COMPUTE, the following rule applies:

The resource must have the D3D12_RESOURCE_FLAG_ALLOW_UNORDERED_ACCESS flag, and DiscardResource must be called when the discarded subresource regions are in the D3D12_RESOURCE_STATE_UNORDERED_ACCESS resource barrier state.

DiscardResource is not supported on command lists with either D3D12_COMMAND_LIST_TYPE_BUNDLE nor D3D12_COMMAND_LIST_TYPE_COPY.