[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.

test/Makefile.am

@@ -16,6 +16,7 @@ test_sources = \
 	caps.c						\
 	caps-joins.c					\
 	caps-joins-alpha.c				\
+	caps-joins-curve.c				\
 	caps-sub-paths.c				\
 	clip-all.c					\
 	clip-empty.c					\
@@ -333,9 +334,10 @@ REFERENCE_IMAGES = \
 	caps-joins-alpha.ref.png	\
 	caps-joins-alpha.svg12.ref.png	\
 	caps-joins-alpha.svg11.ref.png	\
+	caps-joins-curve.ref.png	\
+	caps-joins-curve.ps.ref.png	\
 	caps-joins.ref.png	\
-	caps-joins.ps2.ref.png	\
-	caps-joins.ps3.ref.png	\
+	caps-joins.ps.ref.png	\
 	caps-sub-paths.ref.png	\
 	clip-all.ref.png	\
 	clip-empty.ref.png	\

test/caps-joins-curve.c

@@ -0,0 +1,111 @@
+/*
+ * Copyright © 2008 Chris Wilson
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Chris Wilson not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Chris Wilson makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * CHRIS WILSON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL CHRIS WILSON BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Author: Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+#include "cairo-test.h"
+
+#define LINE_WIDTH	10.
+#define SIZE		(5 * LINE_WIDTH)
+#define PAD		(3 * LINE_WIDTH)
+
+static void
+make_path (cairo_t *cr)
+{
+    cairo_move_to (cr, 0, 0);
+    cairo_rel_curve_to (cr,
+			-SIZE/4, SIZE/3,
+			-SIZE/4, SIZE/3,
+			0, SIZE);
+    cairo_rel_curve_to (cr,
+			SIZE/3, -SIZE/4,
+			SIZE/3, -SIZE/4,
+			SIZE, 0);
+    cairo_close_path (cr);
+
+    cairo_move_to (cr, 5 * LINE_WIDTH, 3 * LINE_WIDTH);
+    cairo_rel_curve_to (cr,
+			0, -3 * LINE_WIDTH,
+			0, -3 * LINE_WIDTH,
+			-3 * LINE_WIDTH, -3 * LINE_WIDTH);
+}
+
+static void
+draw_caps_joins (cairo_t *cr)
+{
+    cairo_save (cr);
+
+    cairo_translate (cr, PAD, PAD);
+
+    make_path (cr);
+    cairo_set_line_cap (cr, CAIRO_LINE_CAP_BUTT);
+    cairo_set_line_join (cr, CAIRO_LINE_JOIN_BEVEL);
+    cairo_stroke (cr);
+
+    cairo_translate (cr, SIZE + PAD, 0.);
+
+    make_path (cr);
+    cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
+    cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+    cairo_stroke (cr);
+
+    cairo_translate (cr, SIZE + PAD, 0.);
+
+    make_path (cr);
+    cairo_set_line_cap (cr, CAIRO_LINE_CAP_SQUARE);
+    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;
+}
+
+CAIRO_TEST (caps_joins_curve,
+	    "Test caps and joins on curves",
+	    "stroke cap join", /* keywords */
+	    NULL, /* requirements */
+	    3 * (PAD + SIZE) + PAD,
+	    2 * (PAD + SIZE) + PAD,
+	    NULL, draw)
+

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)