The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 1 | /*--------------------------------------------------------------------------- |
| 2 | |
| 3 | rpng - simple PNG display program readppm.c |
| 4 | |
| 5 | --------------------------------------------------------------------------- |
| 6 | |
| 7 | This is a special-purpose replacement for readpng.c that allows binary |
| 8 | PPM files to be used in place of PNG images. |
| 9 | |
| 10 | --------------------------------------------------------------------------- |
| 11 | |
| 12 | Copyright (c) 1998-2007 Greg Roelofs. All rights reserved. |
| 13 | |
| 14 | This software is provided "as is," without warranty of any kind, |
| 15 | express or implied. In no event shall the author or contributors |
| 16 | be held liable for any damages arising in any way from the use of |
| 17 | this software. |
| 18 | |
| 19 | The contents of this file are DUAL-LICENSED. You may modify and/or |
| 20 | redistribute this software according to the terms of one of the |
| 21 | following two licenses (at your option): |
| 22 | |
| 23 | |
| 24 | LICENSE 1 ("BSD-like with advertising clause"): |
| 25 | |
| 26 | Permission is granted to anyone to use this software for any purpose, |
| 27 | including commercial applications, and to alter it and redistribute |
| 28 | it freely, subject to the following restrictions: |
| 29 | |
| 30 | 1. Redistributions of source code must retain the above copyright |
| 31 | notice, disclaimer, and this list of conditions. |
| 32 | 2. Redistributions in binary form must reproduce the above copyright |
| 33 | notice, disclaimer, and this list of conditions in the documenta- |
| 34 | tion and/or other materials provided with the distribution. |
| 35 | 3. All advertising materials mentioning features or use of this |
| 36 | software must display the following acknowledgment: |
| 37 | |
| 38 | This product includes software developed by Greg Roelofs |
| 39 | and contributors for the book, "PNG: The Definitive Guide," |
| 40 | published by O'Reilly and Associates. |
| 41 | |
| 42 | |
| 43 | LICENSE 2 (GNU GPL v2 or later): |
| 44 | |
| 45 | This program is free software; you can redistribute it and/or modify |
| 46 | it under the terms of the GNU General Public License as published by |
| 47 | the Free Software Foundation; either version 2 of the License, or |
| 48 | (at your option) any later version. |
| 49 | |
| 50 | This program is distributed in the hope that it will be useful, |
| 51 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 52 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 53 | GNU General Public License for more details. |
| 54 | |
| 55 | You should have received a copy of the GNU General Public License |
| 56 | along with this program; if not, write to the Free Software Foundation, |
| 57 | Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 58 | |
| 59 | ---------------------------------------------------------------------------*/ |
| 60 | |
| 61 | #include <stdio.h> |
| 62 | #include <stdlib.h> |
| 63 | |
| 64 | #include "readpng.h" /* typedefs, common macros, public prototypes */ |
| 65 | |
| 66 | |
| 67 | ulg width, height; |
| 68 | int bit_depth, color_type, channels; |
| 69 | uch *image_data = NULL; |
| 70 | FILE *saved_infile; |
| 71 | |
| 72 | |
| 73 | void readpng_version_info() |
| 74 | { |
| 75 | fprintf(stderr, " Compiled without libpng, zlib or PBMPLUS/NetPBM.\n"); |
| 76 | } |
| 77 | |
| 78 | |
| 79 | /* return value = 0 for success, 1 for bad sig, 2 for bad IHDR, 4 for no mem */ |
| 80 | |
| 81 | int readpng_init(FILE *infile, ulg *pWidth, ulg *pHeight) |
| 82 | { |
| 83 | static uch ppmline[256]; |
| 84 | int maxval; |
| 85 | |
| 86 | |
| 87 | saved_infile = infile; |
| 88 | |
| 89 | fgets(ppmline, 256, infile); |
| 90 | if (ppmline[0] != 'P' || ppmline[1] != '6') { |
| 91 | fprintf(stderr, "ERROR: not a PPM file\n"); |
| 92 | return 1; |
| 93 | } |
| 94 | /* possible color types: P5 = grayscale (0), P6 = RGB (2), P8 = RGBA (6) */ |
| 95 | if (ppmline[1] == '6') { |
| 96 | color_type = 2; |
| 97 | channels = 3; |
| 98 | } else if (ppmline[1] == '8') { |
| 99 | color_type = 6; |
| 100 | channels = 4; |
| 101 | } else /* if (ppmline[1] == '5') */ { |
| 102 | color_type = 0; |
| 103 | channels = 1; |
| 104 | } |
| 105 | |
| 106 | do { |
| 107 | fgets(ppmline, 256, infile); |
| 108 | } while (ppmline[0] == '#'); |
| 109 | sscanf(ppmline, "%lu %lu", &width, &height); |
| 110 | |
| 111 | do { |
| 112 | fgets(ppmline, 256, infile); |
| 113 | } while (ppmline[0] == '#'); |
| 114 | sscanf(ppmline, "%d", &maxval); |
| 115 | if (maxval != 255) { |
| 116 | fprintf(stderr, "ERROR: maxval = %d\n", maxval); |
| 117 | return 2; |
| 118 | } |
| 119 | bit_depth = 8; |
| 120 | |
| 121 | *pWidth = width; |
| 122 | *pHeight = height; |
| 123 | |
| 124 | return 0; |
| 125 | } |
| 126 | |
| 127 | |
| 128 | |
| 129 | |
| 130 | /* returns 0 if succeeds, 1 if fails due to no bKGD chunk, 2 if libpng error; |
| 131 | * scales values to 8-bit if necessary */ |
| 132 | |
| 133 | int readpng_get_bgcolor(uch *red, uch *green, uch *blue) |
| 134 | { |
| 135 | return 1; |
| 136 | } |
| 137 | |
| 138 | |
| 139 | |
| 140 | |
| 141 | /* display_exponent == LUT_exponent * CRT_exponent */ |
| 142 | |
| 143 | uch *readpng_get_image(double display_exponent, int *pChannels, ulg *pRowbytes) |
| 144 | { |
| 145 | ulg rowbytes; |
| 146 | |
| 147 | |
| 148 | /* expand palette images to RGB, low-bit-depth grayscale images to 8 bits, |
| 149 | * transparency chunks to full alpha channel; strip 16-bit-per-sample |
| 150 | * images to 8 bits per sample; and convert grayscale to RGB[A] */ |
| 151 | |
| 152 | /* GRR WARNING: grayscale needs to be expanded and channels reset! */ |
| 153 | |
| 154 | *pRowbytes = rowbytes = channels*width; |
| 155 | *pChannels = channels; |
| 156 | |
| 157 | if ((image_data = (uch *)malloc(rowbytes*height)) == NULL) { |
| 158 | return NULL; |
| 159 | } |
| 160 | |
| 161 | Trace((stderr, "readpng_get_image: rowbytes = %ld, height = %ld\n", rowbytes, height)); |
| 162 | |
| 163 | |
| 164 | /* now we can go ahead and just read the whole image */ |
| 165 | |
Matt Sarett | 96be908 | 2016-05-03 13:29:54 -0400 | [diff] [blame^] | 166 | if (fread(image_data, 1L, rowbytes*height, saved_infile) < |
| 167 | rowbytes*height) { |
| 168 | free (image_data); |
| 169 | image_data = NULL; |
| 170 | return NULL; |
| 171 | } |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 172 | |
| 173 | return image_data; |
| 174 | } |
| 175 | |
| 176 | |
| 177 | void readpng_cleanup(int free_image_data) |
| 178 | { |
| 179 | if (free_image_data && image_data) { |
| 180 | free(image_data); |
| 181 | image_data = NULL; |
| 182 | } |
| 183 | } |