[test] Exercise caps and joins under reflection.

The nature of the joins depends critically upon whether the joint is
clockwise or counter-clockwise, so extend the basic caps-joins test to
exercise both conditions i.e. repeat the test under a reflection.

1 files changed, 28 insertions, 12 deletions

diff --git a/test/caps-joins.c b/test/caps-joins.c
index 5ec6a8175..9d1c2a889 100644
--- a/test/caps-joins.c
+++ b/test/caps-joins.c
@@ -37,21 +37,15 @@ make_path (cairo_t *cr)
     cairo_rel_line_to (cr, SIZE, 0.);
     cairo_close_path (cr);
 
-    cairo_move_to (cr, 2 * LINE_WIDTH, 0.);
-    cairo_rel_line_to (cr, 3 * LINE_WIDTH, 0.);
-    cairo_rel_line_to (cr, 0., 3 * LINE_WIDTH);
+    cairo_move_to (cr, 5 * LINE_WIDTH, 3 * LINE_WIDTH);
+    cairo_rel_line_to (cr, 0., -3 * LINE_WIDTH);
+    cairo_rel_line_to (cr, -3 * LINE_WIDTH, 0.);
 }
 
-static cairo_test_status_t
-draw (cairo_t *cr, int width, int height)
+static void
+draw_caps_joins (cairo_t *cr)
 {
-    /* We draw in the default black, so paint white first. */
     cairo_save (cr);
-    cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
-    cairo_paint (cr);
-    cairo_restore (cr);
-
-    cairo_set_line_width (cr, LINE_WIDTH);
 
     cairo_translate (cr, PAD, PAD);
 
@@ -74,6 +68,28 @@ draw (cairo_t *cr, int width, int height)
     cairo_set_line_join (cr, CAIRO_LINE_JOIN_MITER);
     cairo_stroke (cr);
 
+    cairo_restore (cr);
+}
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    /* We draw in the default black, so paint white first. */
+    cairo_save (cr);
+    cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
+    cairo_paint (cr);
+    cairo_restore (cr);
+
+    cairo_set_line_width (cr, LINE_WIDTH);
+
+    draw_caps_joins (cr);
+
+    /* and reflect to generate the opposite vertex ordering */
+    cairo_translate (cr, 0, height);
+    cairo_scale (cr, 1, -1);
+
+    draw_caps_joins (cr);
+
     return CAIRO_TEST_SUCCESS;
 }
 
@@ -82,6 +98,6 @@ CAIRO_TEST (caps_joins,
 	    "stroke", /* keywords */
 	    NULL, /* requirements */
 	    3 * (PAD + SIZE) + PAD,
-	    PAD + SIZE + PAD,
+	    2 * (PAD + SIZE) + PAD,
 	    NULL, draw)