[PATCH] d2d1: Fix arc center translation to use center.y in _31 update.

[Giang Nguyen]

In d2d_arc_to_bezier(), when computing the affine transform that maps
the canonical unit-arc parameter space to the actual arc, the
translation contribution from the arc center is meant to be the linear
matrix-vector product M * center, i.e.:

    (_31, _32) += (M11*cx + M12*cy, M21*cx + M22*cy)

The first line of the update used center.x in both terms, which yields
M11*cx + M12*cx instead of M11*cx + M12*cy.  Effect is invisible when
M12 == 0 (i.e. arc->rotationAngle == 0), which is the common case for
unrotated arcs in UI rendering.  Becomes visible for arcs with a
non-zero rotationAngle, where the arc center ends up displaced along
the rotation axis.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=59718
Signed-off-by: Giang Nguyen <[e-mail]>
---
 dlls/d2d1/geometry.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dlls/d2d1/geometry.c b/dlls/d2d1/geometry.c
index 68de4c2193c..b7dc2b7b55e 100644
--- a/dlls/d2d1/geometry.c
+++ b/dlls/d2d1/geometry.c
@@ -1311,7 +1311,7 @@ static int d2d_arc_to_bezier(const D2D_POINT_2F *start_point, const D2D1_ARC_SEG
     m._32 = 0.5f * (arc->point.y + start_point->y);
     if (!zero_center)
     {
-        m._31 += (m._11 * center.x + m._12 * center.x);
+        m._31 += (m._11 * center.x + m._12 * center.y);
         m._32 += (m._21 * center.x + m._22 * center.y);
     }
 
-- 
2.43.0

[Nikolay Sivov]

Hi,

Patches should be submitted through gitlab.winehq.org, see
https://gitlab.winehq.org/wine/wine/-/wikis/Submitting-Patches.