ID2D1Transform::MapOutputRectToInputRects method (d2d1effectauthor.h)

Allows a transform to state how it would map a rectangle requested on its output to a set of sample rectangles on its input.

Syntax

HRESULT MapOutputRectToInputRects(
        const D2D1_RECT_L *outputRect,
  [out] D2D1_RECT_L       *inputRects,
        UINT32            inputRectsCount
);

Parameters

outputRect

Type: const D2D1_RECT_L*

The output rectangle from which the inputs must be mapped.

[out] inputRects

Type: D2D1_RECT_L*

The corresponding set of inputs. The inputs will directly correspond to the transform inputs.

inputRectsCount

Type: UINT32

The number of inputs specified. Direct2D guarantees that this is equal to the number of inputs specified on the transform.

Return value

Type: HRESULT

If the method succeeds, it returns S_OK. If it fails, it returns an HRESULT error code.

Remarks

The transform implementation must ensure that any pixel shader or software callback implementation it provides honors this calculation.

The transform implementation must regard this method as purely functional. It can base the mapped input and output rectangles on its current state as specified by the encapsulating effect properties. However, it must not change its own state in response to this method being invoked. The Direct2D renderer implementation reserves the right to call this method at any time and in any sequence.

Requirements

See also

ID2D1EffectImpl

ID2D1Transform