How to read a D3DFMT_A16B16G16R16 texture?

Hi,

I had a a D3DFMT_A16B16G16R16 format texture I want to read. I did sth like this:

float *dest = new float[size*size*4];

D3DLOCKED_RECT locked;

HRESULT hr = ptex->LockRect(0, &locked, NULL, 0);

assert(hr == S_OK);

WORD *fPointer=(WORD *)locked.pBits;

for (DWORD y=0; y<size; y++)

{

for (DWORD x=0; x<size; x++)

{

DWORD index=( x*4 + (y*(locked.Pitch/2)));

dest[y*size*4+x*4] = fPointer[index] ;

dest[y*size*4+x*4+1] = fPointer[index+1] ;

dest[y*size*4+x*4+2] = fPointer[index+2] ;

dest[y*size*4+x*4+3] = fPointer[index+3] ;

}

ptex->UnlockRect(0);

But it seems not working, does anyone know how to do it Thanks a lot,

Jianfeng

Craver84
Jianfeng Yin wrote:

float *dest = new float[size*size*4];
WORD *fPointer=(WORD *)locked.pBits
// ...
dest[y*size*4+x*4] = fPointer[index] ;

This should work, but looks unusual. Each component in a D3DFMT_A16B16G16R16 pixel is a 16-bit unsigned value ranging from 0 to 65535. When you convert this value to a float, the value remains the same. If you're expecting your float array to have values in the range of 0.0 to 1.0 then you need to divide by 65535.0:

dest[y*size*4+x*4] = fPointer[index] / 65535.0f;

Alternatively, your problem might instead be that you're trying to read a D3DFMT_A16B16G16R16F format texture, where each component is a 16-bit floating point value. In that case you'ld need to use D3DXFloat16To32Array() to convert the values.
Marcel de Vries
dividing by 65535.0f is not right, but D3DXFloat16To32Array() works. Thanks Ross.
How to read a D3DFMT_A16B16G16R16 texture?