Add long-lines perf case

This shows some very bad slowness for lines that are mostly
offscreen (like 100x slower than just drawing the visible
portion).

perf/Makefile.am

@@ -21,6 +21,7 @@ cairo_perf_SOURCES =		\
 	cairo-stats.h		\
 	box-outline.c		\
 	fill.c			\
+	long-lines.c		\
 	paint.c			\
 	stroke.c		\
 	subimage_copy.c		\

perf/cairo-perf.c

@@ -327,5 +327,6 @@ cairo_perf_case_t perf_cases[] = {
     { world_map, 800, 800},
     { box_outline, 100, 100},
     { mosaic, 800, 800 },
+    { long_lines, 100, 100},
     { NULL }
 };

perf/cairo-perf.h

@@ -103,5 +103,6 @@ CAIRO_PERF_DECL (zrusin);
 CAIRO_PERF_DECL (world_map);
 CAIRO_PERF_DECL (box_outline);
 CAIRO_PERF_DECL (mosaic);
+CAIRO_PERF_DECL (long_lines);
 
 #endif

perf/long-lines.c

@@ -0,0 +1,117 @@
+/*
+ * 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 in
+ * drawing very long lines, where most of the line is out of bounds of
+ * the destination surface, (but some portion of the line is
+ * visibile). These results are in the "long-lines-uncropped" report.
+ *
+ * For comparison, this test also renders the visible portions of the
+ * same lines, (this is the "long-lines-cropped" report).
+ */
+
+typedef enum { LONG_LINES_UNCROPPED, LONG_LINES_CROPPED } long_lines_crop_t;
+#define NUM_LINES    20
+#define LONG_FACTOR  50.0
+
+static cairo_perf_ticks_t
+do_long_lines (cairo_t *cr, int width, int height, long_lines_crop_t crop)
+{
+    int i;
+    double x, y, dx, dy, min_x, min_y, max_x, max_y;
+    double outer_width, outer_height;
+
+    cairo_save (cr);
+
+    cairo_translate (cr, width / 2, height / 2);
+
+    if (crop == LONG_LINES_UNCROPPED) {
+	outer_width = LONG_FACTOR * width;
+	outer_height = LONG_FACTOR * height;
+	cairo_set_source_rgb (cr, 1.0, 0.0, 0.0); /* red */
+    } else {
+	outer_width = width;
+	outer_height = height;
+	cairo_set_source_rgb (cr, 0.0, 1.0, 0.0); /* green */
+    }
+
+    min_x = x = - outer_width / 2.0;
+    min_y = y = - outer_height / 2.0;
+    max_x = outer_width / 2.0;
+    max_y = outer_width / 2.0;
+    dx = outer_width / NUM_LINES;
+    dy = outer_height / NUM_LINES;
+
+    cairo_perf_timer_start ();
+
+    for (i = 0; i < NUM_LINES; i++) {
+	cairo_move_to (cr, 0, 0);
+	cairo_line_to (cr, x, min_y);
+	cairo_stroke (cr);
+
+	cairo_move_to (cr, 0, 0);
+	cairo_line_to (cr, x, max_y);
+	cairo_stroke (cr);
+
+	cairo_move_to (cr, 0, 0);
+	cairo_line_to (cr, min_x, y);
+	cairo_stroke (cr);
+
+	cairo_move_to (cr, 0, 0);
+	cairo_line_to (cr, max_x, y);
+	cairo_stroke (cr);
+
+	x += dx;
+	y += dy;
+    }
+
+    cairo_perf_timer_stop ();
+
+    cairo_restore (cr);
+
+    return cairo_perf_timer_elapsed ();
+}
+
+static cairo_perf_ticks_t
+long_lines_uncropped (cairo_t *cr, int width, int height)
+{
+    return do_long_lines (cr, width, height, LONG_LINES_UNCROPPED);
+}
+
+static cairo_perf_ticks_t
+long_lines_cropped (cairo_t *cr, int width, int height)
+{
+    return do_long_lines (cr, width, height, LONG_LINES_CROPPED);
+}
+
+void
+long_lines (cairo_perf_t *perf, cairo_t *cr, int width, int height)
+{
+    cairo_perf_run (perf, "long-lines-uncropped", long_lines_uncropped);
+    cairo_perf_run (perf, "long-lines-cropped", long_lines_cropped);
+}