Henri Verbeet : d2d1: Properly handle collinear edges in d2d_cdt_insert_segment().

[Alexandre Julliard]

Module: wine
Branch: master
Commit: a84658f928c27b94fa0e9ba7c50d84a7813d566b
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=a84658f928c27b94fa0e9ba7c50d84a7813d566b

Author: Henri Verbeet <hverbeet at codeweavers.com>
Date:   Fri Oct 23 13:46:24 2015 +0200

d2d1: Properly handle collinear edges in d2d_cdt_insert_segment().

Signed-off-by: Henri Verbeet <hverbeet at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 dlls/d2d1/geometry.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/dlls/d2d1/geometry.c b/dlls/d2d1/geometry.c
index 198e5d6..ed69a1e 100644
--- a/dlls/d2d1/geometry.c
+++ b/dlls/d2d1/geometry.c
@@ -1342,17 +1342,30 @@ static BOOL d2d_cdt_insert_segment(struct d2d_cdt *cdt, struct d2d_geometry *geo
         const struct d2d_cdt_edge_ref *origin, struct d2d_cdt_edge_ref *edge, size_t end_vertex)
 {
     struct d2d_cdt_edge_ref base_edge, current, new_origin, next, target;
+    size_t current_destination, current_origin;
 
     for (current = *origin;; current = next)
     {
         d2d_cdt_edge_next_origin(cdt, &next, &current);
 
-        if (d2d_cdt_edge_destination(cdt, &current) == end_vertex)
+        current_destination = d2d_cdt_edge_destination(cdt, &current);
+        if (current_destination == end_vertex)
         {
             d2d_cdt_edge_sym(edge, &current);
             return TRUE;
         }
 
+        current_origin = d2d_cdt_edge_origin(cdt, &current);
+        if (d2d_cdt_ccw(cdt, end_vertex, current_origin, current_destination) == 0.0f
+                && (cdt->vertices[current_destination].x > cdt->vertices[current_origin].x)
+                == (cdt->vertices[end_vertex].x > cdt->vertices[current_origin].x)
+                && (cdt->vertices[current_destination].y > cdt->vertices[current_origin].y)
+                == (cdt->vertices[end_vertex].y > cdt->vertices[current_origin].y))
+        {
+            d2d_cdt_edge_sym(&new_origin, &current);
+            return d2d_cdt_insert_segment(cdt, geometry, &new_origin, edge, end_vertex);
+        }
+
         if (d2d_cdt_rightof(cdt, end_vertex, &next) && d2d_cdt_leftof(cdt, end_vertex, &current))
         {
             d2d_cdt_edge_next_left(cdt, &base_edge, &current);