D3DXSHMultiply4 function
Note
The D3DX (D3DX 9, D3DX 10, and D3DX 11) utility library is deprecated and is not supported for Windows Store apps.
Note
Instead of using this function, we recommend that you use the Spherical Harmonics Math library function XMSHMultiply4.
Computes the product of two spherical harmonics functions (f and g). Both functions are of order N = 4.
Syntax
FLOAT* D3DXSHMultiply4(
_In_ FLOAT *pOut,
_In_ const FLOAT *pF,
_In_ const FLOAT *pG
);
Parameters
-
pOut [in]
-
Type: FLOAT*
Pointer to the output SH coefficients — basis function Yₗₘ is stored at l² + m + l. The order N determines the length of the array, where there should always be N² coefficients.
-
pF [in]
-
Type: const FLOAT*
Input SH coefficients for first function.
-
pG [in]
-
Type: const FLOAT*
Second set of input SH coefficients.
Return value
Type: FLOAT*
Pointer to SH output coefficients.
Remarks
The product of two SH functions of order N = 4 generates an SH function of order 2 × N - 1 = 7, but the results are truncated. This means that the product commutes ( f × g = g × f ) but doesn't associate ( f × ( g × h ) ≠ ( f × g ) × h ).
This function uses the following equation:
pOut[i] = int(y_i(s) * f(s) * g(s))
where y_i(s) is the ith SH basis function, and where f(s) and g(s) use the following SH function:
sum_i(y_i(s)*c_i)
Requirements
| Requirement | Value |
|---|---|
| Header |
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| Library |
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See also