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/* -*- Mode: c; c-basic-offset: 4; indent-tabs-mode: t; tab-width: 8; -*- */
/*
* Copyright 2009 Andrea Canciani
*
* 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: Andrea Canciani <ranma42@gmail.com>
*/
#include "cairo-test.h"
/* Lengths of the dashes of the dash patterns */
static const double dashes[] = { 2, 2, 4, 4 };
/* Dash offset in userspace units
* They always grow by 2, so the dash pattern is
* should be shifted by the same amount each time */
static const double frac_offset[] = { 0, 2, 4, 6 };
/* Dash offset relative to the whole dash pattern
* This corresponds to the non-inverted part only if
* the dash pattern has odd length, so the expected result
* is the same for every int_offset if the pattern has
* even lenght, and inverted each time (or shifted by half
* period, which is the same) if the pattern has odd length. */
static const double int_offset[] = { -2, -1, 0, 1, 2 };
#define PAD 6
#define STROKE_LENGTH 32
#define IMAGE_WIDTH (PAD + (STROKE_LENGTH + PAD) * ARRAY_LENGTH (dashes))
#define IMAGE_HEIGHT (PAD + PAD * ARRAY_LENGTH (int_offset) + PAD * ARRAY_LENGTH (frac_offset) * ARRAY_LENGTH (int_offset))
static cairo_test_status_t
draw (cairo_t *cr, int width, int height)
{
double total;
size_t i, j, k;
cairo_set_source_rgb (cr, 1, 1, 1);
cairo_paint (cr);
cairo_set_source_rgb (cr, 0, 0, 0);
cairo_set_line_width (cr, 2);
total = 0.0;
for (k = 0; k < ARRAY_LENGTH (dashes); ++k) {
total += dashes[k];
for (i = 0; i < ARRAY_LENGTH (frac_offset); ++i) {
for (j = 0; j < ARRAY_LENGTH (int_offset); ++j) {
cairo_set_dash (cr, dashes, k + 1, frac_offset[i] + total * int_offset[j]);
cairo_move_to (cr, (STROKE_LENGTH + PAD) * k + PAD, PAD * (i + j + ARRAY_LENGTH (frac_offset) * j + 1));
cairo_line_to (cr, (STROKE_LENGTH + PAD) * (k + 1), PAD * (i + j + ARRAY_LENGTH (frac_offset) * j + 1));
cairo_stroke (cr);
}
}
}
return CAIRO_TEST_SUCCESS;
}
CAIRO_TEST (dash_offset,
"Tests dashes of different length with various offsets",
"stroke, dash", /* keywords */
NULL, /* requirements */
IMAGE_WIDTH, IMAGE_HEIGHT,
NULL, draw)
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