Multi Draw Indirect (MDI)

API for dispatching multiple instanced draw commands. The multi draw indirect extensions allow multiple sets of DrawInstancedIndirect to be submitted in one API call. The draw calls are issued on the GPU's command processor (CP), potentially saving the significant CPU overheads incurred by submitting the equivalent draw calls on the CPU. More...

Functions
AMD_AGS_API AGSReturnCode	agsDriverExtensionsDX11_MultiDrawInstancedIndirect (AGSContext *context, ID3D11DeviceContext *dxContext, unsigned int drawCount, ID3D11Buffer *pBufferForArgs, unsigned int alignedByteOffsetForArgs, unsigned int byteStrideForArgs)
	Function used to submit a batch of draws via MultiDrawIndirect. More...
AMD_AGS_API AGSReturnCode	agsDriverExtensionsDX11_MultiDrawIndexedInstancedIndirect (AGSContext *context, ID3D11DeviceContext *dxContext, unsigned int drawCount, ID3D11Buffer *pBufferForArgs, unsigned int alignedByteOffsetForArgs, unsigned int byteStrideForArgs)
	Function used to submit a batch of draws via MultiDrawIndirect. More...
AMD_AGS_API AGSReturnCode	agsDriverExtensionsDX11_MultiDrawInstancedIndirectCountIndirect (AGSContext *context, ID3D11DeviceContext *dxContext, ID3D11Buffer *pBufferForDrawCount, unsigned int alignedByteOffsetForDrawCount, ID3D11Buffer *pBufferForArgs, unsigned int alignedByteOffsetForArgs, unsigned int byteStrideForArgs)
	Function used to submit a batch of draws via MultiDrawIndirect. More...
AMD_AGS_API AGSReturnCode	agsDriverExtensionsDX11_MultiDrawIndexedInstancedIndirectCountIndirect (AGSContext *context, ID3D11DeviceContext *dxContext, ID3D11Buffer *pBufferForDrawCount, unsigned int alignedByteOffsetForDrawCount, ID3D11Buffer *pBufferForArgs, unsigned int alignedByteOffsetForArgs, unsigned int byteStrideForArgs)
	Function used to submit a batch of draws via MultiDrawIndirect. More...

Detailed Description

API for dispatching multiple instanced draw commands. The multi draw indirect extensions allow multiple sets of DrawInstancedIndirect to be submitted in one API call. The draw calls are issued on the GPU's command processor (CP), potentially saving the significant CPU overheads incurred by submitting the equivalent draw calls on the CPU.

The extension allows the following code:

// Submit n batches of DrawIndirect calls
for ( int i = 0; i < n; i++ )
    deviceContext->DrawIndexedInstancedIndirect( buffer, i * sizeof( cmd ) );

To be replaced by the following call:

// Submit all n batches in one call
agsDriverExtensionsDX11_MultiDrawIndexedInstancedIndirect( m_agsContext, deviceContext, n, buffer, 0, sizeof( cmd ) );

The buffer used for the indirect args must be of the following formats:

// Buffer layout for agsDriverExtensions_MultiDrawInstancedIndirect
struct DrawInstancedIndirectArgs
{
    UINT VertexCountPerInstance;
    UINT InstanceCount;
    UINT StartVertexLocation;
    UINT StartInstanceLocation;
};
 
// Buffer layout for agsDriverExtensions_MultiDrawIndexedInstancedIndirect
struct DrawIndexedInstancedIndirectArgs
{
    UINT IndexCountPerInstance;
    UINT InstanceCount;
    UINT StartIndexLocation;
    UINT BaseVertexLocation;
    UINT StartInstanceLocation;
};

Example usage can be seen in AMD's GeometryFX (https://github.com/GPUOpen-Effects/GeometryFX). In particular, in this file: https://github.com/GPUOpen-Effects/GeometryFX/blob/master/amd_geometryfx/src/AMD_GeometryFX_Filtering.cpp

Function Documentation

agsDriverExtensionsDX11_MultiDrawIndexedInstancedIndirect()

AMD_AGS_API AGSReturnCode agsDriverExtensionsDX11_MultiDrawIndexedInstancedIndirect	(	AGSContext *	context,
		ID3D11DeviceContext *	dxContext,
		unsigned int	drawCount,
		ID3D11Buffer *	pBufferForArgs,
		unsigned int	alignedByteOffsetForArgs,
		unsigned int	byteStrideForArgs
	)

Function used to submit a batch of draws via MultiDrawIndirect.

Parameters

[in]	context	Pointer to a context.
[in]	dxContext	Pointer to the DirectX device context. If this is to work using the non-immediate context, then you need to check support. If nullptr is specified, then the immediate context is assumed.
[in]	drawCount	The number of draws.
[in]	pBufferForArgs	The args buffer.
[in]	alignedByteOffsetForArgs	The offset into the args buffer.
[in]	byteStrideForArgs	The per element stride of the args buffer.

agsDriverExtensionsDX11_MultiDrawIndexedInstancedIndirectCountIndirect()

AMD_AGS_API AGSReturnCode agsDriverExtensionsDX11_MultiDrawIndexedInstancedIndirectCountIndirect	(	AGSContext *	context,
		ID3D11DeviceContext *	dxContext,
		ID3D11Buffer *	pBufferForDrawCount,
		unsigned int	alignedByteOffsetForDrawCount,
		ID3D11Buffer *	pBufferForArgs,
		unsigned int	alignedByteOffsetForArgs,
		unsigned int	byteStrideForArgs
	)

Function used to submit a batch of draws via MultiDrawIndirect.

Parameters

[in]	context	Pointer to a context.
[in]	dxContext	Pointer to the DirectX device context. If this is to work using the non-immediate context, then you need to check support. If nullptr is specified, then the immediate context is assumed.
[in]	pBufferForDrawCount	The draw count buffer.
[in]	alignedByteOffsetForDrawCount	The offset into the draw count buffer.
[in]	pBufferForArgs	The args buffer.
[in]	alignedByteOffsetForArgs	The offset into the args buffer.
[in]	byteStrideForArgs	The per element stride of the args buffer.

agsDriverExtensionsDX11_MultiDrawInstancedIndirect()

AMD_AGS_API AGSReturnCode agsDriverExtensionsDX11_MultiDrawInstancedIndirect	(	AGSContext *	context,
		ID3D11DeviceContext *	dxContext,
		unsigned int	drawCount,
		ID3D11Buffer *	pBufferForArgs,
		unsigned int	alignedByteOffsetForArgs,
		unsigned int	byteStrideForArgs
	)

Function used to submit a batch of draws via MultiDrawIndirect.

Parameters

[in]	context	Pointer to a context.
[in]	dxContext	Pointer to the DirectX device context. If this is to work using the non-immediate context, then you need to check support. If nullptr is specified, then the immediate context is assumed.
[in]	drawCount	The number of draws.
[in]	pBufferForArgs	The args buffer.
[in]	alignedByteOffsetForArgs	The offset into the args buffer.
[in]	byteStrideForArgs	The per element stride of the args buffer.

agsDriverExtensionsDX11_MultiDrawInstancedIndirectCountIndirect()

AMD_AGS_API AGSReturnCode agsDriverExtensionsDX11_MultiDrawInstancedIndirectCountIndirect	(	AGSContext *	context,
		ID3D11DeviceContext *	dxContext,
		ID3D11Buffer *	pBufferForDrawCount,
		unsigned int	alignedByteOffsetForDrawCount,
		ID3D11Buffer *	pBufferForArgs,
		unsigned int	alignedByteOffsetForArgs,
		unsigned int	byteStrideForArgs
	)

Function used to submit a batch of draws via MultiDrawIndirect.

Parameters

[in]	context	Pointer to a context.
[in]	dxContext	Pointer to the DirectX device context. If this is to work using the non-immediate context, then you need to check support. If nullptr is specified, then the immediate context is assumed.
[in]	pBufferForDrawCount	The draw count buffer.
[in]	alignedByteOffsetForDrawCount	The offset into the draw count buffer.
[in]	pBufferForArgs	The args buffer.
[in]	alignedByteOffsetForArgs	The offset into the args buffer.
[in]	byteStrideForArgs	The per element stride of the args buffer.