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Austin Schuh3333ec72022-12-29 16:21:06 -08001/* Copyright (C) 2013-2016, The Regents of The University of Michigan.
2All rights reserved.
3This software was developed in the APRIL Robotics Lab under the
4direction of Edwin Olson, ebolson@umich.edu. This software may be
5available under alternative licensing terms; contact the address above.
6Redistribution and use in source and binary forms, with or without
7modification, are permitted provided that the following conditions are met:
81. Redistributions of source code must retain the above copyright notice, this
9 list of conditions and the following disclaimer.
102. Redistributions in binary form must reproduce the above copyright notice,
11 this list of conditions and the following disclaimer in the documentation
12 and/or other materials provided with the distribution.
13THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
14ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
17ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
20ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23The views and conclusions contained in the software and documentation are those
24of the authors and should not be interpreted as representing official policies,
25either expressed or implied, of the Regents of The University of Michigan.
26*/
27
28#include <assert.h>
29#include <stdio.h>
30#include <stdlib.h>
31
32#include "pnm.h"
33
34pnm_t *pnm_create_from_file(const char *path)
35{
36 FILE *f = fopen(path, "rb");
37 if (f == NULL)
38 return NULL;
39
40 pnm_t *pnm = calloc(1, sizeof(pnm_t));
41 pnm->format = -1;
42
43 char tmp[1024];
44 int nparams = 0; // will be 3 when we're all done.
45 int params[3];
46
47 while (nparams < 3 && !(pnm->format == PNM_FORMAT_BINARY && nparams == 2)) {
48 if (fgets(tmp, sizeof(tmp), f) == NULL)
49 goto error;
50
51 // skip comments
52 if (tmp[0]=='#')
53 continue;
54
55 char *p = tmp;
56
57 if (pnm->format == -1 && tmp[0]=='P') {
58 pnm->format = tmp[1]-'0';
59 assert(pnm->format == PNM_FORMAT_GRAY || pnm->format == PNM_FORMAT_RGB || pnm->format == PNM_FORMAT_BINARY);
60 p = &tmp[2];
61 }
62
63 // pull integers out of this line until there are no more.
64 while (nparams < 3 && *p!=0) {
65 while (*p==' ')
66 p++;
67
68 // encounter rubbish? (End of line?)
69 if (*p < '0' || *p > '9')
70 break;
71
72 int acc = 0;
73 while (*p >= '0' && *p <= '9') {
74 acc = acc*10 + *p - '0';
75 p++;
76 }
77
78 params[nparams++] = acc;
79 p++;
80 }
81 }
82
83 pnm->width = params[0];
84 pnm->height = params[1];
85 pnm->max = params[2];
86
87 switch (pnm->format) {
88 case PNM_FORMAT_BINARY: {
89 // files in the wild sometimes simply don't set max
90 pnm->max = 1;
91
92 pnm->buflen = pnm->height * ((pnm->width + 7) / 8);
93 pnm->buf = malloc(pnm->buflen);
94 size_t len = fread(pnm->buf, 1, pnm->buflen, f);
95 if (len != pnm->buflen)
96 goto error;
97
98 fclose(f);
99 return pnm;
100 }
101
102 case PNM_FORMAT_GRAY: {
103 if (pnm->max == 255)
104 pnm->buflen = pnm->width * pnm->height;
105 else if (pnm->max == 65535)
106 pnm->buflen = 2 * pnm->width * pnm->height;
107 else
108 assert(0);
109
110 pnm->buf = malloc(pnm->buflen);
111 size_t len = fread(pnm->buf, 1, pnm->buflen, f);
112 if (len != pnm->buflen)
113 goto error;
114
115 fclose(f);
116 return pnm;
117 }
118
119 case PNM_FORMAT_RGB: {
120 if (pnm->max == 255)
121 pnm->buflen = pnm->width * pnm->height * 3;
122 else if (pnm->max == 65535)
123 pnm->buflen = 2 * pnm->width * pnm->height * 3;
124 else
125 assert(0);
126
127 pnm->buf = malloc(pnm->buflen);
128 size_t len = fread(pnm->buf, 1, pnm->buflen, f);
129 if (len != pnm->buflen)
130 goto error;
131 fclose(f);
132 return pnm;
133 }
134 }
135
136error:
137 fclose(f);
138
139 if (pnm != NULL) {
140 free(pnm->buf);
141 free(pnm);
142 }
143
144 return NULL;
145}
146
147void pnm_destroy(pnm_t *pnm)
148{
149 if (pnm == NULL)
150 return;
151
152 free(pnm->buf);
153 free(pnm);
154}