Fix T81484: Weight/Vertex paint with mirror and viewport clipping does not update stroke on initial side

Issue introduced in rB4f616c93f7cb.

Issue here is that the the `StrokeCache` `mirror_symmetry_pass` is still
in its previous state when entering
`wpaint_do_symmetrical_brush_actions`.
For the initial stroke this means that the (wrong) cache
`mirror_symmetry_pass` ends up in SculptBrushTest `mirror_symmetry_pass`
as well and thus the clipping test in `sculpt_brush_test_clipping` will
fail.
[ This one flips the coords to test against clipping according to (now
wrong) `mirror_symmetry_pass` ]

Solution seems simple: just ensure we start of with a
`mirror_symmetry_pass` of zero in `wpaint_do_symmetrical_brush_actions`
for the initial stroke.
Same thing is done for vertex paint as well.

Maniphest Tasks: T81484

Differential Revision: https://developer.blender.org/D9268

1 files changed, 2 insertions, 0 deletions

diff --git a/source/blender/editors/sculpt_paint/paint_vertex.c b/source/blender/editors/sculpt_paint/paint_vertex.c
index 6472da48f40..2876670a8d2 100644
--- a/source/blender/editors/sculpt_paint/paint_vertex.c
+++ b/source/blender/editors/sculpt_paint/paint_vertex.c
@@ -2296,6 +2296,7 @@ static void wpaint_do_symmetrical_brush_actions(
   int i = 0;
 
   /* initial stroke */
+  cache->mirror_symmetry_pass = 0;
   wpaint_do_paint(C, ob, wp, sd, wpd, wpi, me, brush, 0, 'X', 0, 0);
   wpaint_do_radial_symmetry(C, ob, wp, sd, wpd, wpi, me, brush, 0, 'X');
   wpaint_do_radial_symmetry(C, ob, wp, sd, wpd, wpi, me, brush, 0, 'Y');
@@ -3316,6 +3317,7 @@ static void vpaint_do_symmetrical_brush_actions(
   int i = 0;
 
   /* initial stroke */
+  cache->mirror_symmetry_pass = 0;
   vpaint_do_paint(C, sd, vp, vpd, ob, me, brush, i, 'X', 0, 0);
   vpaint_do_radial_symmetry(C, sd, vp, vpd, ob, me, brush, i, 'X');
   vpaint_do_radial_symmetry(C, sd, vp, vpd, ob, me, brush, i, 'Y');