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/*
* Copyright © 2006 Red Hat, Inc.
*
* 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
* Red Hat, Inc. not be used in advertising or publicity pertaining to
* distribution of the software without specific, written prior
* permission. Red Hat, Inc. makes no representations about the
* suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS, IN NO EVENT SHALL RED HAT, INC. 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: Carl D. Worth <cworth@cworth.org>
*/
#include "cairo-test.h"
#include <string.h>
/* Bug history
*
* 2006-01-07 Jon Hellan <hellan@acm.org>
*
* Jon opened the following bug report:
*
* _XError from XRenderCompositeText8
* https://bugs.freedesktop.org/show_bug.cgi?id=5528
*
* 2006-03-02 Carl Worth <cworth@cworth.org>
*
* I wrote this test case to demonstrate the bug.
*
* Approach:
*
* Draw 65535 glyphs white-on-white all on top of each other.
*
* Rationale:
*
* The number 65535 comes from the original bug report.
*
* I would use cairo_show_text with a long string of 'x's say,
* but then the surface would need to be enormous to contain
* them. A smaller surface could be used, but I fear that at some
* point the off-surface glyph drawing would be optimized away
* and not exercise the bug.
*
* So, to keep the surface size under control, I use
* cairo_show_glyphs which allows me to place the glyphs all on
* top of each other. But, since cairo doesn't provide any
* character-to-glyphs mapping, I can't get a reliable glyph
* index (for character 'x' for example). So I just "guess" a
* glyph index and use white-on-white drawing to ignore the
* result. (I don't care what's drawn---I just want to ensure
* that things don't crash.)
*
* Status: I replicated bug. The largest value of NUM_GLYPHS for
* which I saw success is 21842.
*/
#define TEXT_SIZE 12
#define NUM_GLYPHS 65535
/* This is the index into the font for what glyph we'll draw. Since we
* don't guarantee we'll get any particular font, we can't relibably
* get any particular glyph. But we don't care what we draw anyway,
* (see discussion of white-on-white drawing above). For what it's
* worth, this appears to be giving me 'M' with Bitstream Vera
* Sans Mono. */
#define GLYPH_INDEX 48
static cairo_test_draw_function_t draw;
cairo_test_t test = {
"show-glyphs-many",
"Test that cairo_show_glyps works when handed 'many' glyphs",
9, 11,
draw
};
static cairo_test_status_t
draw (cairo_t *cr, int width, int height)
{
cairo_glyph_t glyphs[NUM_GLYPHS];
int i;
/* Initialize our giant array of glyphs. */
for (i=0; i < NUM_GLYPHS; i++) {
glyphs[i].index = GLYPH_INDEX;
glyphs[i].x = 1.0;
glyphs[i].y = height - 1;
}
/* Paint white background. */
cairo_set_source_rgb (cr, 1.0, 1.0, 1.0); /* white */
cairo_paint (cr);
cairo_select_font_face (cr, "Bitstream Vera Sans Mono",
CAIRO_FONT_SLANT_NORMAL,
CAIRO_FONT_WEIGHT_NORMAL);
cairo_set_font_size (cr, TEXT_SIZE);
cairo_show_glyphs (cr, glyphs, NUM_GLYPHS);
return CAIRO_TEST_SUCCESS;
}
int
main (void)
{
return cairo_test (&test);
}
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