cairo/perf/intersections.c

/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
/* cairo - a vector graphics library with display and print output
 *
 * Copyright (c) 2008  M Joonas Pihlaja
 *
 * 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.
 */
#include "cairo-perf.h"

#define NUM_SEGMENTS 256

static unsigned state;
static double
uniform_random (double minval, double maxval)
{
    static unsigned const poly = 0x9a795537U;
    unsigned n = 32;
    while (n-->0)
	state = 2*state < state ? (2*state ^ poly) : 2*state;
    return minval + state * (maxval - minval) / 4294967296.0;
}

static cairo_perf_ticks_t
draw_random (cairo_t *cr, cairo_fill_rule_t fill_rule,
	     int width, int height, int loops)
{
    int i;
    double x[NUM_SEGMENTS];
    double y[NUM_SEGMENTS];

    cairo_save (cr);
    cairo_set_source_rgb (cr, 0, 0, 0);
    cairo_paint (cr);

    for (i = 0; i < NUM_SEGMENTS; i++) {
         x[i] = uniform_random (0, width);
         y[i] = uniform_random (0, height);
    }

    state = 0x12345678;
    cairo_translate (cr, 1, 1);
    cairo_set_fill_rule (cr, fill_rule);
    cairo_set_source_rgb (cr, 1, 0, 0);

    cairo_move_to (cr, 0, 0);
    for (i = 0; i < NUM_SEGMENTS; i++)
	cairo_line_to (cr, x[i], y[i]);
    cairo_close_path (cr);

    cairo_perf_timer_start ();
    while (loops--)
        cairo_fill_preserve (cr);
    cairo_perf_timer_stop ();

    cairo_restore (cr);

    return cairo_perf_timer_elapsed ();
}

static cairo_perf_ticks_t
random_eo (cairo_t *cr, int width, int height, int loops)
{
    return draw_random (cr, CAIRO_FILL_RULE_EVEN_ODD, width, height, loops);
}

static cairo_perf_ticks_t
random_nz (cairo_t *cr, int width, int height, int loops)
{
    return draw_random (cr, CAIRO_FILL_RULE_WINDING, width, height, loops);
}

void
intersections (cairo_perf_t *perf, cairo_t *cr, int width, int height)
{
    if (! cairo_perf_can_run (perf, "intersections"))
	return;

    cairo_perf_run (perf, "intersections-nz-fill", random_nz);
    cairo_perf_run (perf, "intersections-eo-fill", random_eo);
}