perf: Add box_outline test case.

This test shows that drawing a 100x100 single-pixel wide box outline is
currently 5 to 16 times slower when using the natural cairo_stroke() as
compared to a rather awkward cairo_fill() of two rectangles.

[ # ]  backend-content                    test-size min(ticks)  min(ms) median(ms) stddev. iterations
[  0]    image-rgba         box-outline-stroke-100     301321    0.218    0.219  0.39%   5
[  1]    image-rgba           box-outline-fill-100      18178    0.013    0.013  0.43%   5
[  0]     xlib-rgba         box-outline-stroke-100     379177    0.275    0.276  1.39%   6
[  1]     xlib-rgba           box-outline-fill-100      83355    0.060    0.060  0.17%   5

perf/Makefile.am

@@ -18,6 +18,7 @@ cairo_perf_SOURCES =		\
 	cairo-perf-cover.c	\
 	cairo-stats.c		\
 	cairo-stats.h		\
+	box-outline.c		\
 	fill.c			\
 	paint.c			\
 	stroke.c		\

perf/box-outline.c

@@ -0,0 +1,93 @@
+/*
+ * Copyright © 2006 Red Hat, Inc.
+ *
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Author: Carl D. Worth <cworth@cworth.org>
+ */
+
+#include "cairo-perf.h"
+
+/* This test case is designed to illustrate a performance bug that
+ * exists in cairo in which using cairo_stroke is much slower than
+ * cairo_fill to draw an identical figure, (and in particular a figure
+ * that is much more natural to draw with cairo_stroke). The figure is
+ * a 100x100 square outline 1-pixel wide, nicely pixel aligned.
+ *
+ * The performance bug should affect any path whose resulting contour
+ * consists only of pixel-aligned horizontal and vertical elements.
+ *
+ * Initial testing on on machine shows stroke as 5x slower than fill
+ * for the xlib backend and 16x slower for the image backend.
+ */
+
+static cairo_perf_ticks_t
+box_outline_stroke (cairo_t *cr, int width, int height)
+{
+    cairo_set_source_rgb (cr, 0, 0, 1); /* blue */
+    cairo_paint (cr);
+
+    cairo_rectangle (cr,
+		     1.5, 1.5,
+		     width - 3, height - 3);
+    cairo_set_line_width (cr, 1.0);
+    cairo_set_source_rgb (cr, 1, 0, 0); /* red */
+
+    cairo_perf_timer_start ();
+
+    cairo_stroke (cr);
+
+    cairo_perf_timer_stop ();
+
+    return cairo_perf_timer_elapsed ();
+}
+
+static cairo_perf_ticks_t
+box_outline_fill (cairo_t *cr, int width, int height)
+{
+    cairo_set_source_rgb (cr, 0, 0, 1); /* blue */
+    cairo_paint (cr);
+
+    cairo_rectangle (cr,
+		     1.0, 1.0,
+		     width - 2, height - 2);
+    cairo_rectangle (cr,
+		     2.0, 2.0,
+		     width - 4, height - 4);
+    cairo_set_fill_rule (cr, CAIRO_FILL_RULE_EVEN_ODD);
+    cairo_set_source_rgb (cr, 0, 1, 0); /* green */
+
+    cairo_perf_timer_start ();
+
+    cairo_fill (cr);
+
+    cairo_perf_timer_stop ();
+
+    return cairo_perf_timer_elapsed ();
+}
+
+void
+box_outline (cairo_perf_t *perf, cairo_t *cr, int width, int height)
+{
+    cairo_perf_run (perf, "box-outline-stroke", box_outline_stroke);
+    cairo_perf_run (perf, "box-outline-fill", box_outline_fill);
+}

perf/cairo-perf.c

@@ -325,5 +325,6 @@ cairo_perf_case_t perf_cases[] = {
     { pattern_create_radial, 16, 16},
     { zrusin, 415, 415},
     { world_map, 800, 800},
+    { box_outline, 100, 100},
     { NULL }
 };

perf/cairo-perf.h

@@ -64,6 +64,7 @@ cairo_perf_yield (void);
 typedef struct _cairo_perf {
     /* Options from command-line */
     unsigned int iterations;
+    cairo_bool_t exact_iterations;
     cairo_bool_t raw;
     cairo_bool_t list_only;
     char **names;
@@ -100,5 +101,6 @@ CAIRO_PERF_DECL (text);
 CAIRO_PERF_DECL (pattern_create_radial);
 CAIRO_PERF_DECL (zrusin);
 CAIRO_PERF_DECL (world_map);
+CAIRO_PERF_DECL (box_outline);
 
 #endif