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Diffstat (limited to 'src/cairo-png.c')
| -rw-r--r-- | src/cairo-png.c | 465 |
1 files changed, 465 insertions, 0 deletions
diff --git a/src/cairo-png.c b/src/cairo-png.c new file mode 100644 index 000000000..ecb23ca45 --- /dev/null +++ b/src/cairo-png.c @@ -0,0 +1,465 @@ +/* cairo - a vector graphics library with display and print output + * + * Copyright © 2003 University of Southern California + * + * This library is free software; you can redistribute it and/or + * modify it either under the terms of the GNU Lesser General Public + * License version 2.1 as published by the Free Software Foundation + * (the "LGPL") or, at your option, under the terms of the Mozilla + * Public License Version 1.1 (the "MPL"). If you do not alter this + * notice, a recipient may use your version of this file under either + * the MPL or the LGPL. + * + * You should have received a copy of the LGPL along with this library + * in the file COPYING-LGPL-2.1; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * You should have received a copy of the MPL along with this library + * in the file COPYING-MPL-1.1 + * + * The contents of this file are subject to the Mozilla Public License + * Version 1.1 (the "License"); you may not use this file except in + * compliance with the License. You may obtain a copy of the License at + * http://www.mozilla.org/MPL/ + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY + * OF ANY KIND, either express or implied. See the LGPL or the MPL for + * the specific language governing rights and limitations. + * + * The Original Code is the cairo graphics library. + * + * The Initial Developer of the Original Code is University of Southern + * California. + * + * Contributor(s): + * Carl D. Worth <cworth@cworth.org> + * Kristian Høgsberg <krh@redhat.com> + */ + +#include <png.h> +#include "cairoint.h" + +static void +unpremultiply_data (png_structp png, png_row_infop row_info, png_bytep data) +{ + int i; + + for (i = 0; i < row_info->rowbytes; i += 4) { + uint8_t *b = &data[i]; + uint32_t pixel; + uint8_t alpha; + + memcpy (&pixel, b, sizeof (uint32_t)); + alpha = (pixel & 0xff000000) >> 24; + if (alpha == 0) { + b[0] = b[1] = b[2] = b[3] = 0; + } else { + b[0] = (((pixel & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha; + b[1] = (((pixel & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha; + b[2] = (((pixel & 0xff0000) >> 16) * 255 + alpha / 2) / alpha; + b[3] = alpha; + } + } +} + +static cairo_status_t +write_png (cairo_surface_t *surface, + png_rw_ptr write_func, + void *closure) +{ + int i; + cairo_status_t status = CAIRO_STATUS_SUCCESS; + cairo_image_surface_t *image; + void *image_extra; + png_struct *png; + png_info *info; + png_time pt; + png_byte **rows; + png_color_16 white; + int png_color_type; + int depth; + + status = _cairo_surface_acquire_source_image (surface, + &image, + &image_extra); + + if (status == CAIRO_STATUS_NO_MEMORY) + return CAIRO_STATUS_NO_MEMORY; + else if (status != CAIRO_STATUS_SUCCESS) + return CAIRO_STATUS_SURFACE_TYPE_MISMATCH; + + rows = malloc (image->height * sizeof(png_byte*)); + if (rows == NULL) { + status = CAIRO_STATUS_NO_MEMORY; + goto BAIL1; + } + + for (i = 0; i < image->height; i++) + rows[i] = (png_byte *) image->data + i * image->stride; + + png = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); + if (png == NULL) { + status = CAIRO_STATUS_NO_MEMORY; + goto BAIL2; + } + + info = png_create_info_struct (png); + if (info == NULL) { + status = CAIRO_STATUS_NO_MEMORY; + goto BAIL3; + } + + if (setjmp (png_jmpbuf (png))) { + status = CAIRO_STATUS_NO_MEMORY; + goto BAIL3; + } + + png_set_write_fn (png, closure, write_func, NULL); + + switch (image->format) { + case CAIRO_FORMAT_ARGB32: + depth = 8; + png_color_type = PNG_COLOR_TYPE_RGB_ALPHA; + break; + case CAIRO_FORMAT_RGB24: + depth = 8; + png_color_type = PNG_COLOR_TYPE_RGB; + break; + case CAIRO_FORMAT_A8: + depth = 8; + png_color_type = PNG_COLOR_TYPE_GRAY; + break; + case CAIRO_FORMAT_A1: + depth = 1; + png_color_type = PNG_COLOR_TYPE_GRAY; + break; + default: + status = CAIRO_STATUS_NULL_POINTER; + goto BAIL3; + } + + png_set_IHDR (png, info, + image->width, + image->height, depth, + png_color_type, + PNG_INTERLACE_NONE, + PNG_COMPRESSION_TYPE_DEFAULT, + PNG_FILTER_TYPE_DEFAULT); + + white.red = 0xff; + white.blue = 0xff; + white.green = 0xff; + png_set_bKGD (png, info, &white); + + png_convert_from_time_t (&pt, time (NULL)); + png_set_tIME (png, info, &pt); + + png_set_write_user_transform_fn (png, unpremultiply_data); + if (image->format == CAIRO_FORMAT_ARGB32 || + image->format == CAIRO_FORMAT_RGB24) + png_set_bgr (png); + if (image->format == CAIRO_FORMAT_RGB24) + png_set_filler (png, 0, PNG_FILLER_AFTER); + + png_write_info (png, info); + png_write_image (png, rows); + png_write_end (png, info); + +BAIL3: + png_destroy_write_struct (&png, &info); +BAIL2: + free (rows); +BAIL1: + _cairo_surface_release_source_image (surface, image, image_extra); + + return status; +} + +static void +stdio_write_func (png_structp png, png_bytep data, png_size_t size) +{ + FILE *fp; + + fp = png_get_io_ptr (png); + if (fwrite (data, 1, size, fp) != size) + png_error(png, "Write Error"); +} + +/** + * cairo_surface_write_to_png: + * @surface: a #cairo_surface_t with pixel contents + * @filename: the name of a file to write to + * + * Writes the contents of @surface to a new file @filename as a PNG + * image. + * + * Return value: CAIRO_STATUS_SUCCESS if the PNG file was written + * successfully. Otherwise, CAIRO_STATUS_NO_MEMORY if memory could not + * be allocated for the operation or + * CAIRO_STATUS_SURFACE_TYPE_MISMATCH if the surface does not have + * pixel contents, or CAIRO_STATUS_WRITE_ERROR if an I/O error occurs + * while attempting to write the file. + **/ +cairo_status_t +cairo_surface_write_to_png (cairo_surface_t *surface, + const char *filename) +{ + FILE *fp; + cairo_status_t status; + + fp = fopen (filename, "wb"); + if (fp == NULL) + return CAIRO_STATUS_WRITE_ERROR; + + status = write_png (surface, stdio_write_func, fp); + + if (fclose (fp) && CAIRO_OK (status)) + status = CAIRO_STATUS_WRITE_ERROR; + + return status; +} + +struct png_write_closure_t { + cairo_write_func_t write_func; + void *closure; +}; + +static void +stream_write_func (png_structp png, png_bytep data, png_size_t size) +{ + struct png_write_closure_t *png_closure; + + png_closure = png_get_io_ptr (png); + if (!CAIRO_OK (png_closure->write_func (png_closure->closure, data, size))) + png_error(png, "Write Error"); +} + +/** + * cairo_surface_write_to_png_stream: + * @surface: a #cairo_surface_t with pixel contents + * @write_func: a #cairo_write_func_t + * @closure: closure data for the write function + * + * Writes the image surface to the write function. + * + * Return value: CAIRO_STATUS_SUCCESS if the PNG file was written + * successfully. Otherwise, CAIRO_STATUS_NO_MEMORY is returned if + * memory could not be allocated for the operation, + * CAIRO_STATUS_SURFACE_TYPE_MISMATCH if the surface does not have + * pixel contents. + **/ +cairo_status_t +cairo_surface_write_to_png_stream (cairo_surface_t *surface, + cairo_write_func_t write_func, + void *closure) +{ + struct png_write_closure_t png_closure; + + png_closure.write_func = write_func; + png_closure.closure = closure; + + return write_png (surface, stream_write_func, &png_closure); +} + +static void +premultiply_data (png_structp png, + png_row_infop row_info, + png_bytep data) +{ + int i; + + for (i = 0; i < row_info->rowbytes; i += 4) { + uint8_t *base = &data[i]; + uint8_t blue = base[0]; + uint8_t green = base[1]; + uint8_t red = base[2]; + uint8_t alpha = base[3]; + uint32_t p; + + red = ((unsigned) red * (unsigned) alpha + 127) / 255; + green = ((unsigned) green * (unsigned) alpha + 127) / 255; + blue = ((unsigned) blue * (unsigned) alpha + 127) / 255; + p = (alpha << 24) | (red << 16) | (green << 8) | (blue << 0); + memcpy (base, &p, sizeof (uint32_t)); + } +} + +static cairo_surface_t * +read_png (png_rw_ptr read_func, + void *closure) +{ + cairo_surface_t *surface; + png_byte *data; + int i; + png_struct *png; + png_info *info; + png_uint_32 png_width, png_height, stride; + int depth, color_type, interlace; + unsigned int pixel_size; + png_byte **row_pointers; + + surface = NULL; + data = NULL; + row_pointers = NULL; + + /* XXX: Perhaps we'll want some other error handlers? */ + png = png_create_read_struct (PNG_LIBPNG_VER_STRING, + NULL, + NULL, + NULL); + if (png == NULL) + return NULL; + + info = png_create_info_struct (png); + if (info == NULL) + goto BAIL; + + png_set_read_fn (png, closure, read_func); + + if (setjmp (png_jmpbuf (png))) + goto BAIL; + + png_read_info (png, info); + + png_get_IHDR (png, info, + &png_width, &png_height, &depth, + &color_type, &interlace, NULL, NULL); + stride = 4 * png_width; + + /* convert palette/gray image to rgb */ + if (color_type == PNG_COLOR_TYPE_PALETTE) + png_set_palette_to_rgb (png); + + /* expand gray bit depth if needed */ + if (color_type == PNG_COLOR_TYPE_GRAY && depth < 8) + png_set_gray_1_2_4_to_8 (png); + /* transform transparency to alpha */ + if (png_get_valid(png, info, PNG_INFO_tRNS)) + png_set_tRNS_to_alpha (png); + + if (depth == 16) + png_set_strip_16 (png); + + if (depth < 8) + png_set_packing (png); + + /* convert grayscale to RGB */ + if (color_type == PNG_COLOR_TYPE_GRAY + || color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb (png); + + if (interlace != PNG_INTERLACE_NONE) + png_set_interlace_handling (png); + + png_set_bgr (png); + png_set_filler (png, 0xff, PNG_FILLER_AFTER); + + png_set_read_user_transform_fn (png, premultiply_data); + + png_read_update_info (png, info); + + pixel_size = 4; + data = malloc (png_width * png_height * pixel_size); + if (data == NULL) + goto BAIL; + + row_pointers = malloc (png_height * sizeof(char *)); + if (row_pointers == NULL) + goto BAIL; + + for (i = 0; i < png_height; i++) + row_pointers[i] = &data[i * png_width * pixel_size]; + + png_read_image (png, row_pointers); + png_read_end (png, info); + + surface = cairo_image_surface_create_for_data (data, + CAIRO_FORMAT_ARGB32, + png_width, png_height, stride); + _cairo_image_surface_assume_ownership_of_data ((cairo_image_surface_t*)surface); + data = NULL; + + BAIL: + free (row_pointers); + free (data); + png_destroy_read_struct (&png, NULL, NULL); + + return surface; +} + +static void +stdio_read_func (png_structp png, png_bytep data, png_size_t size) +{ + FILE *fp; + + fp = png_get_io_ptr (png); + if (fread (data, 1, size, fp) != size) + png_error(png, "Read Error"); +} + +/** + * cairo_image_surface_create_from_png: + * @filename: name of PNG file to load + * + * Creates a new image surface and initializes the contents to the + * given PNG file. + * + * Return value: a new #cairo_surface_t initialized with the contents + * of the PNG file or %NULL if the file is not a valid PNG file or + * memory could not be allocated for the operation. + **/ +cairo_surface_t * +cairo_image_surface_create_from_png (const char *filename) +{ + FILE *fp; + cairo_surface_t *surface; + + fp = fopen (filename, "rb"); + if (fp == NULL) + return NULL; + + surface = read_png (stdio_read_func, fp); + + fclose (fp); + + return surface; +} + +struct png_read_closure_t { + cairo_read_func_t read_func; + void *closure; +}; + +static void +stream_read_func (png_structp png, png_bytep data, png_size_t size) +{ + struct png_read_closure_t *png_closure; + + png_closure = png_get_io_ptr (png); + if (!CAIRO_OK (png_closure->read_func (png_closure->closure, data, size))) + png_error(png, "Read Error"); +} + +/** + * cairo_image_surface_create_from_png_stream: + * @read_func: function called to read the data of the file + * @closure: data to pass to @read_func. + * + * Creates a new image surface from PNG data read incrementally + * via the @read_func function. + * + * Return value: a new #cairo_surface_t initialized with the contents + * of the PNG file or %NULL if the data read is not a valid PNG image or + * memory could not be allocated for the operation. + **/ +cairo_surface_t * +cairo_image_surface_create_from_png_stream (cairo_read_func_t read_func, + void *closure) +{ + struct png_read_closure_t png_closure; + + png_closure.read_func = read_func; + png_closure.closure = closure; + + return read_png (stream_read_func, &closure); +} + |