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
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/*
* TransFig: Facility for Translating Fig code
* Parts Copyright (c) 1989-2002 by Brian V. Smith
*
* Any party obtaining a copy of these files is granted, free of charge, a
* full and unrestricted irrevocable, world-wide, paid up, royalty-free,
* nonexclusive right and license to deal in this software and
* documentation files (the "Software"), including without limitation the
* rights to use, copy, modify, merge, publish and/or distribute copies of
* the Software, and to permit persons who receive copies from any such
* party to do so, with the only requirement being that this copyright
* notice remain intact.
*
*/
#include "fig2dev.h"
#include "object.h"
#include <png.h>
/* return codes: 1 : success
0 : invalid file
*/
int
read_png(file,filetype,pic,llx,lly)
FILE *file;
int filetype;
F_pic *pic;
int *llx, *lly;
{
register int i, j;
png_structp png_ptr;
png_infop info_ptr;
png_infop end_info;
png_uint_32 w, h, rowsize;
int bit_depth, color_type, interlace_type;
int compression_type, filter_type;
png_bytep *row_pointers;
unsigned char *ptr;
int num_palette;
png_colorp palette;
double gamma;
png_color_16p file_background;
png_color_16 png_background;
*llx = *lly = 0;
/* read the png file here */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
(png_voidp) NULL, NULL, NULL);
if (!png_ptr)
return 0;
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
png_destroy_read_struct(&png_ptr, (png_infopp) NULL, (png_infopp) NULL);
return 0;
}
end_info = png_create_info_struct(png_ptr);
if (!end_info) {
png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp) NULL);
return 0;
}
/* set long jump here */
if (setjmp(png_jmpbuf(png_ptr))) {
/* if we get here there was a problem reading the file */
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
return 0;
}
/* set up the input code */
png_init_io(png_ptr, file);
/* now read the file info */
png_read_info(png_ptr, info_ptr);
/* get width, height etc */
png_get_IHDR(png_ptr, info_ptr, &w, &h, &bit_depth, &color_type,
&interlace_type, &compression_type, &filter_type);
if (png_get_gAMA(png_ptr, info_ptr, &gamma))
png_set_gamma(png_ptr, 2.2, gamma);
else
png_set_gamma(png_ptr, 2.2, 0.45);
if (png_get_bKGD(png_ptr, info_ptr, &file_background))
/* set the background to the one supplied */
png_set_background(png_ptr, file_background,
PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
else {
/* blend the canvas background using the alpha channel */
if (bgspec) {
png_background.red = background.red >> 8;
png_background.green = background.green >> 8;
png_background.blue = background.blue >> 8;
png_background.gray = 0;
} else {
/* no background specified by user, use white */
png_background.red = png_background.green =
png_background.blue = png_background.gray = 255;
}
png_set_background(png_ptr, &png_background, PNG_BACKGROUND_GAMMA_SCREEN, 0, 2.2);
}
/* set order to BGR (default is RGB) */
if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA)
png_set_bgr(png_ptr);
/* if user wants grayscale (-N) then map to gray */
if (grayonly &&
(color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA))
png_set_rgb_to_gray(png_ptr, 1, 0.3, 0.59);
/* strip 16-bit RGB values down to 8-bit */
if (bit_depth == 16)
png_set_strip_16(png_ptr);
/* force to 8-bits per pixel if less than 8 */
if (bit_depth < 8)
png_set_packing(png_ptr);
/* dither rgb files down to 8 bit palette */
num_palette = 0;
pic->transp = -1;
if (color_type & PNG_COLOR_MASK_COLOR) {
png_uint_16p histogram;
if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette)) {
png_get_hIST(png_ptr, info_ptr, &histogram);
#if (PNG_LIBPNG_VER_MAJOR > 1 || (PNG_LIBPNG_VER_MAJOR == 1 && (PNG_LIBPNG_VER_MINOR > 4))) || defined(png_set_quantize)
png_set_quantize(png_ptr, palette, num_palette, 256, histogram, 0);
#else
png_set_dither(png_ptr, palette, num_palette, 256, histogram, 0);
#endif
}
}
if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
/* expand to full range */
png_set_expand(png_ptr);
/* make a gray colormap */
num_palette = 256;
for (i = 0; i < num_palette; i++)
pic->cmap[RED][i] = pic->cmap[GREEN][i] = pic->cmap[BLUE][i] = i;
} else {
/* transfer the palette to the object's colormap */
for (i=0; i<num_palette; i++) {
pic->cmap[RED][i] = palette[i].red;
pic->cmap[GREEN][i] = palette[i].green;
pic->cmap[BLUE][i] = palette[i].blue;
/* if user wants grayscale (-N) then map to gray */
if (grayonly)
pic->cmap[RED][i] = pic->cmap[GREEN][i] = pic->cmap[BLUE][i] =
(int) (rgb2luminance(pic->cmap[RED][i]/255.0,
pic->cmap[GREEN][i]/255.0,
pic->cmap[BLUE][i]/255.0)*255.0);
}
}
rowsize = w;
if (color_type == PNG_COLOR_TYPE_RGB ||
color_type == PNG_COLOR_TYPE_RGB_ALPHA)
rowsize = w*3;
/* allocate the row pointers and rows */
row_pointers = (png_bytep *) malloc(h*sizeof(png_bytep));
for (i=0; i<h; i++) {
if ((row_pointers[i] = malloc(rowsize)) == NULL) {
for (j=0; j<i; j++)
free(row_pointers[j]);
return 0;
}
}
/* finally, read the file */
png_read_image(png_ptr, row_pointers);
/* allocate the bitmap */
if ((pic->bitmap=malloc(rowsize*h))==NULL)
return 0;
/* copy it to our bitmap */
ptr = pic->bitmap;
for (i=0; i<h; i++) {
bcopy(row_pointers[i], ptr, rowsize);
ptr += rowsize;
}
/* put in width, height */
pic->bit_size.x = w;
pic->bit_size.y = h;
if (color_type == PNG_COLOR_TYPE_RGB || color_type == PNG_COLOR_TYPE_RGB_ALPHA) {
/* no palette */
pic->numcols = 2<<16;
} else {
pic->numcols = num_palette;
}
/* clean up */
png_read_end(png_ptr, end_info);
png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
for (i=0; i<h; i++)
free(row_pointers[i]);
pic->subtype = P_PNG;
pic->hw_ratio = (float) pic->bit_size.y / pic->bit_size.x;
/* success */
return 1;
}
|
