basegfx/source/matrix/b2dhommatrix.cxx | 56 ++++++++++++++++++++++++++------- 1 file changed, 45 insertions(+), 11 deletions(-)
New commits: commit a78a9ea3a5f935bf364f59426b22e9039d2c1784 Author: Noel Grandin <[email protected]> AuthorDate: Tue May 16 13:02:47 2023 +0200 Commit: Noel Grandin <[email protected]> CommitDate: Wed May 17 15:26:04 2023 +0200 tdf#63130 use a simpler, SIMD-friendly algorithm for matrix invert which is 10% faster loading this document Algorithm copied from https://github.com/niswegmann/small-matrix-inverse/blob/master/invert3x3_c.h, which is CC0-1.0 licensed. Change-Id: I7aa272cae90b1aee30eb6b3e8e5acb260b92ceef Reviewed-on: https://gerrit.libreoffice.org/c/core/+/151830 Tested-by: Jenkins Reviewed-by: Noel Grandin <[email protected]> diff --git a/basegfx/source/matrix/b2dhommatrix.cxx b/basegfx/source/matrix/b2dhommatrix.cxx index 565be5c68b1c..4222c7a351c2 100644 --- a/basegfx/source/matrix/b2dhommatrix.cxx +++ b/basegfx/source/matrix/b2dhommatrix.cxx @@ -75,21 +75,55 @@ namespace basegfx bool B2DHomMatrix::invert() { if(isIdentity()) - { return true; - } - Impl2DHomMatrix aWork(maImpl); - sal_uInt16* pIndex = static_cast<sal_uInt16*>(alloca( sizeof(sal_uInt16) * Impl2DHomMatrix::getEdgeLength() )); - sal_Int16 nParity; - if(aWork.ludcmp(pIndex, nParity)) - { - maImpl.doInvert(aWork, pIndex); - return true; - } + double dst[9]; + + /* Compute adjoint: */ - return false; + dst[0] = + get(1, 1) * get(2, 2) - get(1, 2) * get(2, 1); + dst[1] = - get(0, 1) * get(2, 2) + get(0, 2) * get(2, 1); + dst[2] = + get(0, 1) * get(1, 2) - get(0, 2) * get(1, 1); + dst[3] = - get(1, 0) * get(2, 2) + get(1, 2) * get(2, 0); + dst[4] = + get(0, 0) * get(2, 2) - get(0, 2) * get(2, 0); + dst[5] = - get(0, 0) * get(1, 2) + get(0, 2) * get(1, 0); + dst[6] = + get(1, 0) * get(2, 1) - get(1, 1) * get(2, 0); + dst[7] = - get(0, 0) * get(2, 1) + get(0, 1) * get(2, 0); + dst[8] = + get(0, 0) * get(1, 1) - get(0, 1) * get(1, 0); + + /* Compute determinant: */ + + double det = get(0, 0) * dst[0] + get(0, 1) * dst[3] + get(0, 2) * dst[6]; + if (fTools::equalZero(det)) + return false; + + /* Multiply adjoint with reciprocal of determinant: */ + + det = 1.0 / det; + + maImpl.set(0, 0, dst[0] * det); + maImpl.set(0, 1, dst[1] * det); + maImpl.set(0, 2, dst[2] * det); + maImpl.set(1, 0, dst[3] * det); + maImpl.set(1, 1, dst[4] * det); + maImpl.set(1, 2, dst[5] * det); + maImpl.set(2, 0, dst[6] * det); + maImpl.set(2, 1, dst[7] * det); + maImpl.set(2, 2, dst[8] * det); + + // The above algorithm is very slightly less accurate then the old one, so + // we need to round the last row to make sure that functions like decompose + // still do the same thing with existing data, otherwise testTdf109143 + // in CppunitTest_vcl_pdfexport will fail. + if (fTools::equalZero(maImpl.get(2, 0))) + maImpl.set(2, 0, 0); + if (fTools::equalZero(maImpl.get(2, 1))) + maImpl.set(2, 1, 0); + if (fTools::equal(1.0, maImpl.get(2, 2))) + maImpl.set(2, 2, 1); + + return true; } B2DHomMatrix& B2DHomMatrix::operator+=(const B2DHomMatrix& rMat)
