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
|
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <png.h>
#include "log.h"
#include "image.h"
#define HEADER_BYTES 8
void image_load(struct image *image, const char *filename)
{
log_debug("Loading image '%s'\n", filename);
FILE *fp = fopen(filename, "rb");
uint8_t header[HEADER_BYTES];
if (!fp) {
log_error("Couldn't open '%s': %s.\n",
filename, strerror(errno));
return;
}
if (fread(header, 1, HEADER_BYTES, fp) != HEADER_BYTES) {
log_error("Failed to read '%s': %s.\n",
filename, strerror(errno));
fclose(fp);
return;
}
if (png_sig_cmp(header, 0, HEADER_BYTES)) {
log_error("'%s' isn't a PNG file.\n", filename);
fclose(fp);
return;
}
png_structp png_ptr = png_create_read_struct(
PNG_LIBPNG_VER_STRING,
NULL, NULL, NULL);
if (!png_ptr) {
log_error("Couldn't create PNG read struct.\n");
fclose(fp);
return;
}
png_infop info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
png_destroy_read_struct(&png_ptr, NULL, NULL);
fclose(fp);
log_error("Couldn't create PNG info struct.\n");
return;
}
if (setjmp(png_jmpbuf(png_ptr)) != 0) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
fclose(fp);
log_error("Couldn't setjmp for libpng.\n");
return;
}
png_init_io(png_ptr, fp);
png_set_sig_bytes(png_ptr, HEADER_BYTES);
png_read_info(png_ptr, info_ptr);
uint32_t width = png_get_image_width(png_ptr, info_ptr);
uint32_t height = png_get_image_height(png_ptr, info_ptr);
//uint8_t color_type = png_get_color_type(png_ptr, info_ptr);
//uint8_t bit_depth = png_get_bit_depth(png_ptr, info_ptr);
png_set_expand(png_ptr);
png_set_gray_to_rgb(png_ptr);
png_set_filler(png_ptr, 0xFFu, PNG_FILLER_AFTER);
png_read_update_info(png_ptr, info_ptr);
uint32_t row_bytes = png_get_rowbytes(png_ptr, info_ptr);
/* Guard against integer overflow */
if (height > PNG_SIZE_MAX / row_bytes) {
png_error(png_ptr, "image_data buffer would be too large");
}
png_bytep buffer = malloc(height * row_bytes);
png_bytepp row_pointers = calloc(height, sizeof(png_bytep));
for (uint32_t y = 0; y < height; y++) {
row_pointers[y] = &buffer[y * row_bytes];
}
png_read_image(png_ptr, row_pointers);
png_read_end(png_ptr, NULL);
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
free(row_pointers);
fclose(fp);
image->width = width;
image->height = height;
image->buffer = buffer;
log_debug("Image loaded.\n");
}
|
