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
46 namespace SILLY
47 {
48 void 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 
58 void PNG_warning_function(png_structp png_ptr,
59  png_const_charp error)
60 {
61 // printf("PNG Warning: %s\n", error);
62 }
63 
64 void 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 
79 PNGImageLoader::PNGImageLoader()
80  : ImageLoader("PNG Image Loader based on libpng")
81 {
82 }
83 PNGImageLoader::~PNGImageLoader()
84 {
85 }
86 
87 
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 
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
PixelOrigin
List all pixel origin supported.
Definition: SILLYBase.h:70
unsigned char byte
Typename for a byte.
Definition: SILLYBase.h:80
This is an abstract class used to provide data to the loader.
ImageContext * loadHeader(PixelFormat &formatSource, DataSource *data)
Parse the header of the image and fill the header struct.
void setNextPixel(byte red, byte green, byte bleu, byte alpha)
Set the next pixel of the image.
PixelFormat
List all pixel format supported.
Definition: SILLYBase.h:59
bool flipVertically()
Flip pixel ordering.
Simple Image Loading LibrarY namespace.
Store the data needed by an ImageLoader object during the parsing of an image.
bool loadImageData(PixelOrigin origin, DataSource *data, ImageContext *context)
Parse the pixels data of the image and fill the header struct.
Image Context for PNG Image Loader.