summaryrefslogtreecommitdiffstats
path: root/src/pngenc.cpp
blob: 79a83ac6f9b674c6f8a0147e5c916fee76e480be (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
/******************************************************************************
 *
 * 
 *
 *
 * Copyright (C) 1997-2006 by Dimitri van Heesch.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation under the terms of the GNU General Public License is hereby 
 * granted. No representations are made about the suitability of this software 
 * for any purpose. It is provided "as is" without express or implied warranty.
 * See the GNU General Public License for more details.
 *
 * Documents produced by Doxygen are derivative works derived from the
 * input used in their production; they are not affected by this license.
 *
 * ---------------------------------------------------------------------------
 *
 * The Portable Network Graphic format is an ISO Standard.
 * Most of the code below was donated by Bernhard Ristow.
 */

#ifndef png_jmpbuf
#  define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
#endif

#define ALL_STATIC
#include <../libpng/png.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "pngenc.h"
#include "message.h"

#undef jmpbuf

static void user_error_fn(png_structp, png_const_charp error_msg)
{
    err("%s\n", error_msg);
}

static void user_warning_fn(png_structp, png_const_charp warning_msg)
{
    err("%s\n", warning_msg);
}

PngEncoder::PngEncoder(Byte *rawBytes, Color *p, int w, int h, Byte d, int t) : 
     data(rawBytes), palette(p), width(w), height(h), depth(d), transIndex(t)
{
   numPixels = w*h;
   dataPtr   = data;
}

PngEncoder::~PngEncoder()
{
}

void PngEncoder::write(const char *name)
{
   FILE           * file               = NULL;
   unsigned char ** rows               = 0;
   unsigned char  * cmap               = 0;
   short            numOfColors        = (1<<depth);
   short            bit_depth          = 4;
   long             i                  = 0;
   long             j                  = 0;
   png_structp      png_ptr;
   png_infop        info_ptr;
   char             user_error_ptr[]   = "PngEncoder";
   png_colorp       png_palette;
   png_byte         ti[1];

   png_ptr = png_create_write_struct
             ( PNG_LIBPNG_VER_STRING, (png_voidp)user_error_ptr,
               user_error_fn, user_warning_fn);
   if (!png_ptr) 
   {
      err("Can not allocate writing structure!\n");
      return;
   }

   info_ptr = png_create_info_struct(png_ptr);
   if (!info_ptr) 
   {
      png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
      err("Can not allocate writing structure!\n");
      return;
   }

   if (setjmp(png_jmpbuf(png_ptr))) 
   {
     png_destroy_write_struct(&png_ptr, &info_ptr);
     return;
   }
   else
   {
     png_palette = (png_colorp) png_malloc(png_ptr,
         PNG_MAX_PALETTE_LENGTH*sizeof(png_color));
     memset(png_palette,0,PNG_MAX_PALETTE_LENGTH*sizeof(png_color));
     for (i=0; i<numOfColors; i++) 
     {
       png_palette[i].red   = palette[i].red;
       png_palette[i].green = palette[i].green;
       png_palette[i].blue  = palette[i].blue;
     }
     png_set_PLTE(png_ptr, info_ptr, png_palette, numOfColors);
     png_set_IHDR( png_ptr, info_ptr, width, height, bit_depth,
         PNG_COLOR_TYPE_PALETTE, PNG_INTERLACE_NONE,
         PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE
                 );
     free(png_palette);
     ti[0] = transIndex;
     png_set_tRNS(png_ptr,info_ptr,ti,1,NULL);
     rows    = (unsigned char **) calloc(sizeof(unsigned char*),height);
     rows[0] = (unsigned char  *) calloc(sizeof(unsigned char),height*width);
     for (i=1; i<height; i++) 
     {
       rows[i] = rows[i-1] + width;
     }
     for (i=0, dataPtr=data; i<height; i++) 
     {
       for (j=0; j<width; j++) 
       {
         if (j%2)
         {
           rows[i][j/2] = ( rows[i][j/2] | *dataPtr );
         }
         else
         {
           rows[i][j/2] = (*dataPtr) << 4;
         }
         dataPtr++;
       }
     }
     png_set_rows(png_ptr,info_ptr,rows);

     file = fopen(name,"wb");
     if (file==0)
     {
       err("Error opening png file %s for writing: %s!\n",name,strerror(errno));
     }
     else
     {
       png_init_io(png_ptr,file);
       png_write_png(png_ptr,info_ptr,PNG_TRANSFORM_IDENTITY,NULL);
     }
   }

   png_destroy_write_struct(&png_ptr, &info_ptr);

   if (file)
   {
      fclose (file);
   }
   if (cmap)
   {
      free(cmap);
   }
   if (rows) 
   {
      if (rows[0])
      {
         free(rows[0]);
      }
      free(rows);
   }
   return;
}