Re: [PATCH 4/5] d3dx9_36: Implemented ID3DXConstantTable_SetMatrix and ID3DXConstantTable_SetMatrixArray

[Michael Stefaniuc]

On 01/21/2011 06:56 AM, Travis Athougies wrote:
> Uh no. If I were to do that, matrix->m[1] would be the second row, not
> the second matrix. I'm trying to get at the second matrix. To
> illustrate this, suppose the matrix were at 0x8000 (not going to
> happen, but just pretend). matrix->m[1] would be at 0x8010, since
> floats are 4 bytes. However, the next matrix is actually at 0x8040
> (since sizeof(float) * 16 [the number of elements in the matrix] =
> 64).

So you want a pointer to the first element of the "i"th matrix, right?
     &matrix[i]._11
No cast, no explicit pointer arithmetic.
> On Thu, Jan 20, 2011 at 7:27 AM, Matteo Bruni  wrote:
> > 2011/1/20 Travis Athougies:
> > > -
> > >        /* D3DXMATRIX is a union, one of whose elements is an array, so it can be cast to a float pointer */
> > > -
> > >       if (is_vertex_shader(This->desc.Version))
> > > -
> > >           IDirect3DDevice9_SetVertexShaderConstantF(device, desc.RegisterIndex + i, (float *)(matrix + i),
> > > -
> > >                    desc.RegisterCount);
> > > -
> > >       else
> > > -
> > >           IDirect3DDevice9_SetPixelShaderConstantF(device, desc.RegisterIndex + i, (float *)(matrix + i),
> > > -
> > >                    desc.RegisterCount);
> >
> > Can't you just pass matrix->m[i] as parameter, instead of that cast?

bye
    michael