wrlib/save_png.c

   1 /* save_png.c - save PNG image
   2  *
   3  * Raster graphics library
   4  *
   5  * Copyright (c) 2023 Window Maker Team
   6  *
   7  *  This library is free software; you can redistribute it and/or
   8  *  modify it under the terms of the GNU Library General Public
   9  *  License as published by the Free Software Foundation; either
  10  *  version 2 of the License, or (at your option) any later version.
  11  *
  12  *  This library is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  *  Library General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU Library General Public
  18  *  License along with this library; if not, write to the Free
  19  *  Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  20  *  MA 02110-1301, USA.
  21  */
  22
  23 #include <config.h>
  24
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <assert.h>
  29 #include <errno.h>
  30 #include <png.h>
  31
  32 #include "wraster.h"
  33 #include "imgformat.h"
  34 #include "wr_i18n.h"
  35
  36 /*
  37  * Save RImage to PNG image
  38  */
  39 Bool RSavePNG(RImage *img, const char *filename, char *title)
  40 {
  41         FILE *file;
  42         png_structp png_ptr;
  43         png_infop png_info_ptr;
  44         png_bytep png_row;
  45         RColor pixel;
  46         int x, y;
  47         int width = img->width;
  48         int height = img->height;
  49
  50         file = fopen(filename, "wb");
  51         if (file == NULL) {
  52                 RErrorCode = RERR_OPEN;
  53                 return False;
  54         }
  55
  56         /* Initialize write structure */
  57         png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
  58         if (png_ptr == NULL) {
  59                 fclose(file);
  60                 RErrorCode = RERR_NOMEMORY;
  61                 return False;
  62         }
  63
  64         /* Initialize info structure */
  65         png_info_ptr = png_create_info_struct(png_ptr);
  66         if (png_info_ptr == NULL) {
  67                 fclose(file);
  68                 RErrorCode = RERR_NOMEMORY;
  69                 return False;
  70         }
  71
  72         /* Setup Exception handling */
  73         if (setjmp(png_jmpbuf (png_ptr))) {
  74                 fclose(file);
  75                 RErrorCode = RERR_INTERNAL;
  76                 return False;
  77         }
  78
  79         png_init_io(png_ptr, file);
  80
  81         /* Write header (8 bit colour depth) */
  82         png_set_IHDR(png_ptr, png_info_ptr, width, height, 8, PNG_COLOR_TYPE_RGB,
  83                         PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
  84                         PNG_FILTER_TYPE_BASE);
  85
  86         /* Set title if any */
  87         if (title) {
  88                 png_text title_text;
  89                 title_text.compression = PNG_TEXT_COMPRESSION_NONE;
  90                 title_text.key = "Title";
  91                 title_text.text = title;
  92                 png_set_text(png_ptr, png_info_ptr, &title_text, 1);
  93         }
  94
  95         png_write_info(png_ptr, png_info_ptr);
  96
  97         /* Allocate memory for one row (3 bytes per pixel - RGB) */
  98         png_row = (png_bytep) malloc(3 * width * sizeof(png_byte));
  99
 100         /* Write image data */
 101         for (y = 0; y < height; y++) {
 102                 for (x = 0; x < width; x++) {
 103                         png_byte *ptr;
 104
 105                         RGetPixel(img, x, y, &pixel);
 106                         ptr = &(png_row[x * 3]);
 107                         ptr[0] = pixel.red;
 108                         ptr[1] = pixel.green;
 109                         ptr[2] = pixel.blue;
 110                 }
 111                 png_write_row(png_ptr, png_row);
 112         }
 113
 114         /* End write */
 115         png_write_end(png_ptr, NULL);
 116
 117         /* Clean */
 118         fclose(file);
 119         if (png_info_ptr != NULL)
 120                 png_free_data(png_ptr, png_info_ptr, PNG_FREE_ALL, -1);
 121         if (png_ptr != NULL)
 122                 png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
 123         if (png_row != NULL)
 124                 free(png_row);
 125
 126         return True;
 127 }