MTXMultVecArraySR

Syntax

#include <revolution/mtx.h>

void C_MTXMultVecArraySR (
    const Mtx  m,
    const Vec* srcBase,
          Vec* dstBase,
          u32  count );
void PSMTXMultVecArraySR (
    const Mtx  m,
    const Vec* srcBase,
          Vec* dstBase,
          u32  count );

#define MTXMultVecArraySR  C_MTXMultVecArraySR // for debug build
#define MTXMultVecArraySR  PSMTXMultVecArraySR // for nondebug build

Arguments

m	Source matrix to multiply. m is not altered by this function. The type of m may be either `Mtx` or `MtxPtr`.
srcBase	Pointer to the first `Vec` type of the source vector array. The type of srcBase may be either `VecPtr` or `Point3dPtr`.
dstBase	Pointer to the first `Vec` type of the calculated vector array. The type of dstBase may be either `VecPtr` or `Point3dPtr`.
count	Number of contiguous array elements to multiply. Acceptable if srcBase=dstBase. However, the condition srcBase < dstBase < (srcBase + count - 1) must be avoided.

Return Values

None.

Description

Post-multiplies an array of count 3D vectors by a 3x3 sub-matrix (Scale and Rotate component of 3x4 matrix m).

For arrays of vectors, this function is more efficient than calling the MTXMultVecSR function in a loop because it saves the overhead of repeated function calls.

Note: Vectors are transformed one array element at a time through a single temporary vector, so it is acceptable if srcBase = dstBase. However, problems will result if the dstBase pointer is within the range (srcBase + count - 1). In this case, resultant vectors will overwrite part of the srcBase array before it can be used as a source value.

During a debug build, the MTXMultVecArraySR function is parsed as C_MTXMultVecArraySR, which is a normal C language version. During a non-debug build for a Broadway processor, the paired-singles equivalent of this function, PSMTXMultVecArraySR, will be automatically substituted. You can also call C_MTXMultVecArraySR and PSMTXMultVecArraySR explicitly.

Revision History

2008/05/26 Corrected errors.
2006/03/01 Initial version.