[PATCH v2] gdiplus: Scale widened dashes to the pen width.

[Zebediah Figura]

v2: more correct approach
Signed-off-by: Zebediah Figura <zfigura at codeweavers.com>
---
 dlls/gdiplus/graphicspath.c       | 14 ++++++++++----
 dlls/gdiplus/tests/graphicspath.c | 27 +++++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/dlls/gdiplus/graphicspath.c b/dlls/gdiplus/graphicspath.c
index 5fedd07e4ea..5d82a770f7f 100644
--- a/dlls/gdiplus/graphicspath.c
+++ b/dlls/gdiplus/graphicspath.c
@@ -2063,6 +2063,7 @@ static void widen_dashed_figure(GpPath *path, GpPen *pen, int start, int end,
     REAL dash_pos=0.0;
     int dash_index=0;
     const REAL *dash_pattern;
+    REAL *dash_pattern_scaled;
     int dash_count;
     GpPointF *tmp_points;
     REAL segment_dy;
@@ -2101,6 +2102,12 @@ static void widen_dashed_figure(GpPath *path, GpPen *pen, int start, int end,
         break;
     }
 
+    dash_pattern_scaled = heap_alloc(dash_count * sizeof(REAL));
+    if (!dash_pattern_scaled) return;
+
+    for (i = 0; i < dash_count; i++)
+        dash_pattern_scaled[i] = pen->width * dash_pattern[i];
+
     tmp_points = heap_alloc_zero((end - start + 2) * sizeof(GpPoint));
     if (!tmp_points) return; /* FIXME */
 
@@ -2149,7 +2156,7 @@ static void widen_dashed_figure(GpPath *path, GpPen *pen, int start, int end,
                 }
             }
 
-            if (dash_pattern[dash_index] - dash_pos > segment_length - segment_pos)
+            if (dash_pattern_scaled[dash_index] - dash_pos > segment_length - segment_pos)
             {
                 /* advance to next segment */
                 if ((dash_index % 2) == 0)
@@ -2163,7 +2170,7 @@ static void widen_dashed_figure(GpPath *path, GpPen *pen, int start, int end,
             else
             {
                 /* advance to next dash in pattern */
-                segment_pos += dash_pattern[dash_index] - dash_pos;
+                segment_pos += dash_pattern_scaled[dash_index] - dash_pos;
                 dash_pos = 0.0;
                 if (++dash_index == dash_count)
                     dash_index = 0;
@@ -2175,8 +2182,7 @@ static void widen_dashed_figure(GpPath *path, GpPen *pen, int start, int end,
     if (dash_index % 2 == 0 && num_tmp_points != 0)
     {
         /* last dash overflows last segment */
-        tmp_points[num_tmp_points] = path->pathdata.Points[end];
-        widen_open_figure(tmp_points, pen, 0, num_tmp_points,
+        widen_open_figure(tmp_points, pen, 0, num_tmp_points-1,
             draw_start_cap ? pen->startcap : LineCapFlat, pen->customstart,
             closed ? LineCapFlat : pen->endcap, pen->customend, last_point);
     }
diff --git a/dlls/gdiplus/tests/graphicspath.c b/dlls/gdiplus/tests/graphicspath.c
index c44ed5e4240..2a94e845c92 100644
--- a/dlls/gdiplus/tests/graphicspath.c
+++ b/dlls/gdiplus/tests/graphicspath.c
@@ -1065,6 +1065,17 @@ static path_test_t widenline_wide_path[] = {
     {5.0, 20.0,  PathPointTypeLine|PathPointTypeCloseSubpath,  0, 0} /*3*/
     };
 
+static path_test_t widenline_dash_path[] = {
+    {5.0, 0.0,   PathPointTypeStart, 0, 0}, /*0*/
+    {35.0, 0.0,  PathPointTypeLine,  0, 0}, /*1*/
+    {35.0, 10.0, PathPointTypeLine,  0, 0}, /*2*/
+    {5.0, 10.0,  PathPointTypeLine|PathPointTypeCloseSubpath,  0, 0}, /*3*/
+    {45.0, 0.0,   PathPointTypeStart, 0, 0}, /*4*/
+    {50.0, 0.0,  PathPointTypeLine,  0, 0}, /*5*/
+    {50.0, 10.0, PathPointTypeLine,  0, 0}, /*6*/
+    {45.0, 10.0,  PathPointTypeLine|PathPointTypeCloseSubpath,  0, 0}, /*7*/
+    };
+
 static void test_widen(void)
 {
     GpStatus status;
@@ -1139,6 +1150,22 @@ static void test_widen(void)
     status = GdipScaleMatrix(m, 1.0, 0.5, MatrixOrderAppend);
     expect(Ok, status);
 
+    /* dashed line */
+    status = GdipResetPath(path);
+    expect(Ok, status);
+    status = GdipAddPathLine(path, 5.0, 5.0, 50.0, 5.0);
+    expect(Ok, status);
+
+    status = GdipSetPenDashStyle(pen, DashStyleDash);
+    expect(Ok, status);
+
+    status = GdipWidenPath(path, pen, m, 1.0);
+    expect(Ok, status);
+    ok_path(path, widenline_dash_path, sizeof(widenline_dash_path)/sizeof(path_test_t), FALSE);
+
+    status = GdipSetPenDashStyle(pen, DashStyleSolid);
+    expect(Ok, status);
+
     /* pen width in UnitWorld */
     GdipDeletePen(pen);
     status = GdipCreatePen1(0xffffffff, 10.0, UnitWorld, &pen);
-- 
2.13.1