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[cairo-png] Support generating CAIRO_FORMAT_RGB24 from PNGs.
If the PNG does not have an alpha channel, then create an opaque image.
This commit is contained in:
Chris Wilson
parent
06b375aee9
commit
11a2444ec8
4 changed files with 204 additions and 17 deletions
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@ -33,6 +33,7 @@
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* Contributor(s):
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* Carl D. Worth <cworth@cworth.org>
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* Kristian Høgsberg <krh@redhat.com>
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* Chris Wilson <chris@chris-wilson.co.uk>
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*/
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#include "cairoint.h"
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@ -304,7 +305,7 @@ cairo_surface_write_to_png (cairo_surface_t *surface,
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}
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struct png_write_closure_t {
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cairo_write_func_t write_func;
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cairo_write_func_t write_func;
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void *closure;
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};
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@ -368,21 +369,21 @@ premultiply_data (png_structp png,
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unsigned int i;
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for (i = 0; i < row_info->rowbytes; i += 4) {
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uint8_t *base = &data[i];
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uint8_t *base = &data[i];
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uint8_t alpha = base[3];
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uint32_t p;
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if (alpha == 0) {
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p = 0;
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} else {
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uint8_t red = base[0];
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uint8_t red = base[0];
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uint8_t green = base[1];
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uint8_t blue = base[2];
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uint8_t blue = base[2];
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if (alpha != 0xff) {
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red = multiply_alpha (alpha, red);
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red = multiply_alpha (alpha, red);
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green = multiply_alpha (alpha, green);
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blue = multiply_alpha (alpha, blue);
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blue = multiply_alpha (alpha, blue);
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}
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p = (alpha << 24) | (red << 16) | (green << 8) | (blue << 0);
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}
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@ -390,6 +391,24 @@ premultiply_data (png_structp png,
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}
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}
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/* Converts RGBx bytes to native endian xRGB */
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static void
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convert_bytes_to_data (png_structp png, png_row_infop row_info, png_bytep data)
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{
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unsigned int i;
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for (i = 0; i < row_info->rowbytes; i += 4) {
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uint8_t *base = &data[i];
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uint8_t red = base[0];
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uint8_t green = base[1];
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uint8_t blue = base[2];
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uint32_t pixel;
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pixel = (0xff << 24) | (red << 16) | (green << 8) | (blue << 0);
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memcpy (base, &pixel, sizeof (uint32_t));
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}
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}
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static cairo_surface_t *
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read_png (png_rw_ptr read_func,
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void *closure)
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@ -402,6 +421,7 @@ read_png (png_rw_ptr read_func,
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png_uint_32 png_width, png_height;
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int depth, color_type, interlace, stride;
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unsigned int i;
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cairo_format_t format;
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cairo_status_t status;
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/* XXX: Perhaps we'll want some other error handlers? */
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@ -445,7 +465,7 @@ read_png (png_rw_ptr read_func,
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png_set_palette_to_rgb (png);
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/* expand gray bit depth if needed */
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if (color_type == PNG_COLOR_TYPE_GRAY && depth < 8)
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if (color_type == PNG_COLOR_TYPE_GRAY && (depth > 1 && depth < 8))
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#if PNG_LIBPNG_VER >= 10209
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png_set_expand_gray_1_2_4_to_8 (png);
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#else
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@ -462,20 +482,35 @@ read_png (png_rw_ptr read_func,
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png_set_packing (png);
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/* convert grayscale to RGB */
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if (color_type == PNG_COLOR_TYPE_GRAY
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|| color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
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png_set_gray_to_rgb (png);
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if (color_type == PNG_COLOR_TYPE_GRAY ||
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color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
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{
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png_set_gray_to_rgb (png);
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}
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if (interlace != PNG_INTERLACE_NONE)
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png_set_interlace_handling (png);
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png_set_filler (png, 0xff, PNG_FILLER_AFTER);
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switch (color_type) {
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default:
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case PNG_COLOR_TYPE_GRAY_ALPHA:
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case PNG_COLOR_TYPE_RGB_ALPHA:
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format = CAIRO_FORMAT_ARGB32;
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png_set_read_user_transform_fn (png, premultiply_data);
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break;
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png_set_read_user_transform_fn (png, premultiply_data);
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case PNG_COLOR_TYPE_GRAY:
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case PNG_COLOR_TYPE_PALETTE:
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case PNG_COLOR_TYPE_RGB:
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format = CAIRO_FORMAT_RGB24;
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png_set_read_user_transform_fn (png, convert_bytes_to_data);
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png_set_filler (png, 0xff, PNG_FILLER_AFTER);
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break;
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}
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png_read_update_info (png, info);
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stride = cairo_format_stride_for_width (CAIRO_FORMAT_ARGB32, png_width);
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stride = cairo_format_stride_for_width (format, png_width);
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if (stride < 0) {
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surface = _cairo_surface_create_in_error (_cairo_error (CAIRO_STATUS_INVALID_STRIDE));
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goto BAIL;
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@ -504,9 +539,9 @@ read_png (png_rw_ptr read_func,
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goto BAIL;
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}
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surface = cairo_image_surface_create_for_data (data,
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CAIRO_FORMAT_ARGB32,
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png_width, png_height, stride);
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surface = cairo_image_surface_create_for_data (data, format,
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png_width, png_height,
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stride);
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if (surface->status)
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goto BAIL;
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@ -590,7 +625,7 @@ cairo_image_surface_create_from_png (const char *filename)
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}
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struct png_read_closure_t {
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cairo_read_func_t read_func;
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cairo_read_func_t read_func;
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void *closure;
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};
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1
test/.gitignore
vendored
1
test/.gitignore
vendored
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@ -123,6 +123,7 @@ pdf-features
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pdf-features.pdf
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pdf-surface-source
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pdf-surface-source.pdf
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png
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png-flatten
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ps-features
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ps-features.ps
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@ -96,6 +96,7 @@ paint-with-alpha$(EXEEXT) \
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pattern-get-type$(EXEEXT) \
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pattern-getters$(EXEEXT) \
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pixman-rotate$(EXEEXT) \
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png$(EXEEXT) \
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push-group$(EXEEXT) \
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radial-gradient$(EXEEXT) \
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random-intersections$(EXEEXT) \
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@ -623,6 +624,7 @@ fallback-resolution \
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font-options \
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multi-page \
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pdf-features \
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png \
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ps-features \
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svg-clip \
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svg-surface \
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149
test/png.c
Normal file
149
test/png.c
Normal file
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@ -0,0 +1,149 @@
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/*
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* Copyright © 2008 Chris Wilson
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*
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* Permission to use, copy, modify, distribute, and sell this software
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* and its documentation for any purpose is hereby granted without
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* fee, provided that the above copyright notice appear in all copies
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* and that both that copyright notice and this permission notice
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* appear in supporting documentation, and that the name of
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* Chris Wilson not be used in advertising or publicity pertaining to
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* distribution of the software without specific, written prior
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* permission. Chris Wilson makes no representations about the
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* suitability of this software for any purpose. It is provided "as
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* is" without express or implied warranty.
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*
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* CHRIS WILSON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
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* SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
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* FITNESS, IN NO EVENT SHALL CHRIS WILSON BE LIABLE FOR ANY SPECIAL,
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* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
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* RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
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* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
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* IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* Author: Chris Wilson <chris@chris-wilson.co.uk>
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "cairo-test.h"
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#include <cairo.h>
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#include <stdio.h>
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#include <stdint.h>
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#include <assert.h>
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/* Test the idempotency of write_png->read_png */
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#define RGB_MASK 0x00ffffff
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static cairo_bool_t
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image_surface_equals (cairo_surface_t *A, cairo_surface_t *B)
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{
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if (cairo_image_surface_get_format (A) !=
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cairo_image_surface_get_format (B))
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return 0;
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if (cairo_image_surface_get_width (A) !=
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cairo_image_surface_get_width (B))
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return 0;
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if (cairo_image_surface_get_height (A) !=
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cairo_image_surface_get_height (B))
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return 0;
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return 1;
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}
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static const char *
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format_to_string (cairo_format_t format)
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{
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switch (format) {
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case CAIRO_FORMAT_A1: return "a1";
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case CAIRO_FORMAT_A8: return "a8";
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case CAIRO_FORMAT_RGB24: return "rgb24";
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case CAIRO_FORMAT_ARGB32: return "argb32";
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default: return "???";
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}
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}
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static void
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print_surface (cairo_surface_t *surface)
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{
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printf ("%s (%dx%d)\n",
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format_to_string (cairo_image_surface_get_format (surface)),
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cairo_image_surface_get_width (surface),
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cairo_image_surface_get_height (surface));
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}
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int
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main (void)
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{
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cairo_surface_t *surface0, *surface1;
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cairo_status_t status;
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uint32_t argb32 = 0xdeadbede;
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surface0 = cairo_image_surface_create_for_data ((unsigned char *) &argb32,
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CAIRO_FORMAT_ARGB32,
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1, 1, 4);
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assert (cairo_surface_status (surface0) == CAIRO_STATUS_SUCCESS);
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status = cairo_surface_write_to_png (surface0, "png-test.png");
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if (status) {
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printf ("Error writing 'png-test.png': %s\n",
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cairo_status_to_string (status));
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return CAIRO_TEST_FAILURE;
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}
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surface1 = cairo_image_surface_create_from_png ("png-test.png");
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status = cairo_surface_status (surface1);
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if (status) {
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printf ("Error reading 'png-test.png': %s\n",
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cairo_status_to_string (status));
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return CAIRO_TEST_FAILURE;
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}
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if (! image_surface_equals (surface0, surface1)) {
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printf ("Error surface mismatch.\n");
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printf ("to png: "); print_surface (surface0);
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printf ("from png: "); print_surface (surface1);
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return CAIRO_TEST_FAILURE;
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}
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assert (*(uint32_t *) cairo_image_surface_get_data (surface1) == argb32);
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cairo_surface_destroy (surface0);
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cairo_surface_destroy (surface1);
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surface0 = cairo_image_surface_create_for_data ((unsigned char *) &argb32,
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CAIRO_FORMAT_RGB24,
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1, 1, 4);
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assert (cairo_surface_status (surface0) == CAIRO_STATUS_SUCCESS);
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status = cairo_surface_write_to_png (surface0, "png-test.png");
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if (status) {
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printf ("Error writing 'png-test.png': %s\n",
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cairo_status_to_string (status));
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return CAIRO_TEST_FAILURE;
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}
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surface1 = cairo_image_surface_create_from_png ("png-test.png");
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status = cairo_surface_status (surface1);
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if (status) {
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printf ("Error reading 'png-test.png': %s\n",
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cairo_status_to_string (status));
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return CAIRO_TEST_FAILURE;
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}
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if (! image_surface_equals (surface0, surface1)) {
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printf ("Error surface mismatch.\n");
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printf ("to png: "); print_surface (surface0);
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printf ("from png: "); print_surface (surface1);
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return CAIRO_TEST_FAILURE;
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}
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assert ((*(uint32_t *) cairo_image_surface_get_data (surface1) & RGB_MASK)
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== (argb32 & RGB_MASK));
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cairo_surface_destroy (surface0);
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cairo_surface_destroy (surface1);
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return CAIRO_TEST_SUCCESS;
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}
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