[Libreoffice-commits] core.git: Branch 'distro/collabora/cp-6.4' - include/basegfx

[Tomaž Vajngerl (via logerrit)]

 include/basegfx/matrix/Matrix.hxx |   25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

New commits:
commit 560bfab85e0bd91a820c8c7dbe744628d807c1e6
Author:     Tomaž Vajngerl <tomaz.vajngerl at collabora.co.uk>
AuthorDate: Sat Mar 28 20:21:12 2020 +0100
Commit:     Tomaž Vajngerl <quikee at gmail.com>
CommitDate: Sat Jun 6 19:28:48 2020 +0200

    basegfx: Fix the problem with Matrix Concatinate and Transform
    
    In Concatinate and Transform methods we change the instance
    variables during calculation (matrix multiplication), which leads
    to the wrong result. This change fixes both calculations.
    
    Change-Id: I9f7ef7323707df1ab4a764f97f9bae8593c42940
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/91311
    Tested-by: Jenkins
    Reviewed-by: Tomaž Vajngerl <quikee at gmail.com>
    (cherry picked from commit d088b243cad18777f785abf704b0310f057f740b)
    Reviewed-on: https://gerrit.libreoffice.org/c/core/+/95639
    Tested-by: Tomaž Vajngerl <quikee at gmail.com>

diff --git a/include/basegfx/matrix/Matrix.hxx b/include/basegfx/matrix/Matrix.hxx
index 9224e2784b60..e690216a3824 100644
--- a/include/basegfx/matrix/Matrix.hxx
+++ b/include/basegfx/matrix/Matrix.hxx
@@ -86,19 +86,28 @@ public:
     /// Multiply this * other.
     void Concatinate(const Matrix& other)
     {
-        ma = ma * other.ma + mb * other.mc;
-        mb = ma * other.mb + mb * other.md;
-        mc = mc * other.ma + md * other.mc;
-        md = mc * other.mb + md * other.md;
-        me = me * other.ma + mf * other.mc + other.me;
-        mf = me * other.mb + mf * other.md + other.mf;
+        double newA = ma * other.ma + mb * other.mc;
+        double newB = ma * other.mb + mb * other.md;
+        double newC = mc * other.ma + md * other.mc;
+        double newD = mc * other.mb + md * other.md;
+        double newE = me * other.ma + mf * other.mc + other.me;
+        double newF = me * other.mb + mf * other.md + other.mf;
+
+        ma = newA;
+        mb = newB;
+        mc = newC;
+        md = newD;
+        me = newE;
+        mf = newF;
     }
 
     /// Transform the point (x, y) by this Matrix.
     template <typename T> void Transform(T& x, T& y)
     {
-        x = ma * x + mc * y + me;
-        y = mb * x + md * y + mf;
+        T newX = v00 * x + v01 * y + v02;
+        T newY = v10 * x + v11 * y + v12;
+        x = newX;
+        y = newY;
     }
 
     /// Transform the rectangle (left, right, top, bottom) by this Matrix.