Simple Image Loading LibrarY 0.1.0
SILLYPNGImageLoader.cpp
1/***********************************************************************
2 filename: SILLYPNGImageLoader.cpp
3 created: 11 Jun 2006
4 author: Olivier Delannoy
5
6 purpose: Definition of the PNGImageLoader methods
7*************************************************************************/
8/***************************************************************************
9 * Copyright (C) 2004 - 2006 Paul D Turner & The CEGUI Development Team
10 *
11 * Permission is hereby granted, free of charge, to any person obtaining
12 * a copy of this software and associated documentation files (the
13 * "Software"), to deal in the Software without restriction, including
14 * without limitation the rights to use, copy, modify, merge, publish,
15 * distribute, sublicense, and/or sell copies of the Software, and to
16 * permit persons to whom the Software is furnished to do so, subject to
17 * the following conditions:
18 *
19 * The above copyright notice and this permission notice shall be
20 * included in all copies or substantial portions of the Software.
21 *
22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
25 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
26 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
27 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28 * OTHER DEALINGS IN THE SOFTWARE.
29 ***************************************************************************/
30#ifdef HAVE_CONFIG_H
31#include <config.h>
32#include <string.h>
33#endif
34
35#include "loaders/SILLYPNGImageLoader.h"
36
37#ifndef SILLY_OPT_INLINE
38#define inline
39#include "loaders/SILLYPNGImageLoader.icpp"
40#undef inline
41#endif
42
43#include "loaders/SILLYPNGImageContext.h"
44#include <png.h>
45// Start section of namespace SILLY
46namespace SILLY
47{
48void PNG_read_function(png_structp png_ptr, png_bytep data, png_size_t length)
49{
50 PNGImageContext* png = reinterpret_cast<PNGImageContext*>(png_get_io_ptr(png_ptr));
51 int readed = png->read(data, length);
52 if (readed != (int)length)
53 {
54 png_error(png_ptr, "PNG_read_function error");
55 }
56}
57
58void PNG_warning_function(png_structp png_ptr,
59 png_const_charp error)
60{
61// printf("PNG Warning: %s\n", error);
62}
63
64void PNG_error_function(png_structp png_ptr,
65 png_const_charp error)
66{
67 // printf("PNG Error: %s\n", error);
68 // copied from libpng's pngerror.cpp
69 jmp_buf buf;
70#if PNG_LIBPNG_VER_MAJOR >= 1 && PNG_LIBPNG_VER_MINOR >= 4
71 memcpy(buf, png_jmpbuf((png_ptr)), sizeof(jmp_buf));
72#else
73 memcpy(buf, png_ptr->jmpbuf, sizeof(jmp_buf));
74#endif
75 longjmp(buf, 1);
76}
77
78
79PNGImageLoader::PNGImageLoader()
80 : ImageLoader("PNG Image Loader based on libpng")
81{
82}
83PNGImageLoader::~PNGImageLoader()
84{
85}
86
87
88ImageContext* PNGImageLoader::loadHeader(PixelFormat& formatSource, DataSource* data)
89{
90 PNGImageContext* png = new PNGImageContext(data);
91 if (!png)
92 {
93 return 0;
94
95 }
96 // Prepare png loading
97 png->d_png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
98 if (png->d_png_ptr == 0)
99 {
100 delete png;
101 return 0;
102 }
103 png->d_info_ptr = png_create_info_struct(png->d_png_ptr);
104 if (png->d_info_ptr == 0)
105 {
106 delete png;
107 return 0;
108 }
109 if (setjmp(png_jmpbuf(png->d_png_ptr)))
110 {
111 delete png;
112 return 0;
113 }
114 png_set_error_fn(png->d_png_ptr, 0, PNG_error_function, PNG_warning_function);
115 png_set_read_fn(png->d_png_ptr, png, PNG_read_function);
116 //png_set_sig_bytes(png->d_png_ptr, 8);
117
118
119
120 // Read header Check whether PNG can depaletize transparently or not
121 int png_transform = PNG_TRANSFORM_STRIP_16 | PNG_TRANSFORM_EXPAND;
122 //printf("Start reading png\n");
123 png_read_png(png->d_png_ptr, png->d_info_ptr, png_transform, 0);
124 png->setImageSize();
125 png->d_bit_depth = png_get_bit_depth(png->d_png_ptr, png->d_info_ptr);
126 png->d_num_channels = png_get_channels(png->d_png_ptr, png->d_info_ptr);
127 //printf("PNG Info: width: %d height: %d bpp: %d channels: %d\n", png->getWidth(), png->getHeight(), png->d_bit_depth, png->d_num_channels);
128 if (png->d_bit_depth == 8)
129 {
130 if (png->d_num_channels == 4)
131 {
132 formatSource = PF_RGBA;
133 }
134 else if (png->d_num_channels == 3)
135 {
136 formatSource = PF_RGB;
137 }
138 else
139 {
140 delete png;
141 return 0;
142 }
143 }
144 // Paletized or grayscale not yet handled
145 else
146 {
147 delete png;
148 return 0;
149 }
150 return png;
151}
152
153
154bool PNGImageLoader::loadImageData(PixelOrigin origin,
155 DataSource* data,
156 ImageContext* context)
157{
158 PNGImageContext* png = static_cast<PNGImageContext*>(context);
159 byte red;
160 byte green;
161 byte blue;
162 byte alpha;
163 size_t width = png->getWidth();
164 size_t height = png->getHeight();
165 png_bytepp row_pointers = png_get_rows(png->d_png_ptr, png->d_info_ptr);
166 if (png->d_bit_depth == 8)
167 {
168 // Read RGBA
169 if (png->d_num_channels == 4)
170 {
171 for (size_t j = 0 ; j < height ; ++j)
172 {
173 for(size_t i = 0 ; i < width ; ++i)
174 {
175 size_t pixel_offset = 4 * i;
176 red = *(row_pointers[j] + pixel_offset);
177 green = *(row_pointers[j] + pixel_offset + 1);
178 blue = *(row_pointers[j] + pixel_offset + 2);
179 alpha = *(row_pointers[j] + pixel_offset + 3);
180 png->setNextPixel(red, green, blue, alpha);
181 }
182 }
183 }
184 else if (png->d_num_channels == 3)
185 {
186 alpha = 0xff;
187 for (size_t j = 0 ; j < height ; ++j)
188 {
189 for(size_t i = 0 ; i < width ; ++i)
190 {
191 size_t pixel_offset = 3 * i;
192 red = *(row_pointers[j] + pixel_offset);
193 green = *(row_pointers[j] + pixel_offset + 1);
194 blue = *(row_pointers[j] + pixel_offset + 2);
195 png->setNextPixel(red, green, blue, alpha);
196 }
197 }
198
199 }
200 }
201 if (origin == PO_BOTTOM_LEFT)
202 return png->flipVertically();
203
204 return true;
205}
206
207} // End section of namespace SILLY
Simple Image Loading LibrarY namespace.
PixelFormat
List all pixel format supported.
Definition SILLYBase.h:60
PixelOrigin
List all pixel origin supported.
Definition SILLYBase.h:71
Image Context for PNG Image Loader.
This is an abstract class used to provide data to the loader.
Store the data needed by an ImageLoader object during the parsing of an image.
void setNextPixel(byte red, byte green, byte bleu, byte alpha)
Set the next pixel of the image.
bool flipVertically()
Flip pixel ordering.