D3D10_MAPPED_TEXTURE2D structure (d3d10.h)
Provides access to subresource data in a 2D texture.
Syntax
typedef struct D3D10_MAPPED_TEXTURE2D {
void *pData;
UINT RowPitch;
} D3D10_MAPPED_TEXTURE2D;
Members
pData
Type: void*
Pointer to the data.
RowPitch
Type: UINT
The pitch, or width, or physical size (in bytes), of one row of an uncompressed texture. A block-compressed texture is encoded in 4x4 blocks (see virtual size vs physical size) ; therefore, RowPitch is the number of bytes in a block of 4x4 texels.
Remarks
This structure is used in a call to Map.
To illustrate the row pitch, assume an uncompressed 2D texture with mipmap levels, as shown in the following illustration.
![Illustration of an uncompressed 2D texture with mipmap levels](images/d3d10_resource_texture2d.png)
Visualize the top-level texture drawn in a single plane like the following illustration.
![Illustration of a single plane](images/d3d10_2d_texture_conceptual.png)
However, the actual layout of each element in memory looks more like the following illustration.
![Illustration of the row pitch in memory](images/d3d10_2d_texture_memory.png)
For this example, the row pitch encompasses 5 elements (one row), whose size would be five times the number of bytes per element.
Use row pitch to advance a pointer between rows within a single 2D texture plane.
Example
To access data in, say, the third mipmap level, you must cast the pData pointer as demonstrated in the following example for a floating-point texture.
D3D10_MAPPED_TEXTURE2D mappedTexture;
if( SUCCEEDED( pTexture->Map( D3D10CalcSubresource(2, 0, 3), D3D10_MAP_WRITE_DISCARD, 0, &mappedTexture )))
{
D3D10_TEXTURE2D_DESC desc;
pTexture->GetDesc( &desc );
// Compute the width and height of the third mipmap level
const UINT WIDTH = desc.Width >> 2;
const UINT HEIGHT = desc.Height >> 2;
FLOAT* pTexels = (FLOAT*)mappedTexture.pData;
for( UINT row = 0; row < HEIGHT; row++ )
{
UINT rowStart = row * mappedTexture.RowPitch/4;
for( UINT col = 0; col < WIDTH; col++ )
{
pTexels[rowStart + col*4 + 0]; // Red
pTexels[rowStart + col*4 + 1]; // Green
pTexels[rowStart + col*4 + 2]; // Blue
pTexels[rowStart + col*4 + 3]; // Alpha
}
}
pTexture->Unmap(D3D10CalcSubresource(2, 0, 3));
}
Requirements
Requirement | Value |
---|---|
Header | d3d10.h |