1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/objfile.c	Thu Jan 15 14:59:38 2015 +0200
     1.3 @@ -0,0 +1,308 @@
     1.4 +/* version 2: does not crash when there are no texture coordinates or normals */
     1.5 +#include <stdio.h>
     1.6 +#include <stdlib.h>
     1.7 +#include <string.h>
     1.8 +#include <errno.h>
     1.9 +#include <limits.h>
    1.10 +#include <ctype.h>
    1.11 +#include "objfile.h"
    1.12 +
    1.13 +#define INVALID_IDX		INT_MIN
    1.14 +
    1.15 +struct objfile {
    1.16 +	float *verts, *normals, *texcoords;
    1.17 +	int num_faces;
    1.18 +};
    1.19 +
    1.20 +struct vec3 {
    1.21 +	float x, y, z;
    1.22 +};
    1.23 +
    1.24 +struct face {
    1.25 +	int vidx[4];
    1.26 +	int nidx[4];
    1.27 +	int tidx[4];
    1.28 +};
    1.29 +
    1.30 +static int objf_read(struct objfile *obj, FILE *fp, const char *fname);
    1.31 +static int count_elem(FILE *fp, const char *elem);
    1.32 +static char *strip(char *s);
    1.33 +static int mkface(char *line, struct face *face);
    1.34 +static int parse_face(char *s, int *vidx, int *nidx, int *tidx);
    1.35 +static int is_int(const char *str);
    1.36 +
    1.37 +
    1.38 +struct objfile *objf_load(const char *fname)
    1.39 +{
    1.40 +	FILE *fp;
    1.41 +	struct objfile *obj;
    1.42 +
    1.43 +	if(!(fp = fopen(fname, "rb"))) {
    1.44 +		fprintf(stderr, "objf_load: failed to open file: %s: %s\n", fname, strerror(errno));
    1.45 +		return 0;
    1.46 +	}
    1.47 +
    1.48 +	if(!(obj = malloc(sizeof *obj))) {
    1.49 +		perror("failed to allocate objfile structure\n");
    1.50 +		fclose(fp);
    1.51 +		return 0;
    1.52 +	}
    1.53 +
    1.54 +	if(objf_read(obj, fp, fname) == -1) {
    1.55 +		free(obj);
    1.56 +		obj = 0;
    1.57 +	}
    1.58 +	fclose(fp);
    1.59 +	return obj;
    1.60 +}
    1.61 +
    1.62 +void objf_free(struct objfile *obj)
    1.63 +{
    1.64 +	if(obj) {
    1.65 +		free(obj->verts);
    1.66 +		free(obj->normals);
    1.67 +		free(obj->texcoords);
    1.68 +		free(obj);
    1.69 +	}
    1.70 +}
    1.71 +
    1.72 +int objf_vertex_count(struct objfile *obj)
    1.73 +{
    1.74 +	return obj->num_faces * 3;
    1.75 +}
    1.76 +
    1.77 +int objf_face_count(struct objfile *obj)
    1.78 +{
    1.79 +	return obj->num_faces;
    1.80 +}
    1.81 +
    1.82 +float *objf_vertices(struct objfile *obj)
    1.83 +{
    1.84 +	return obj->verts;
    1.85 +}
    1.86 +
    1.87 +float *objf_normals(struct objfile *obj)
    1.88 +{
    1.89 +	return obj->normals;
    1.90 +}
    1.91 +
    1.92 +float *objf_texcoords(struct objfile *obj)
    1.93 +{
    1.94 +	return obj->texcoords;
    1.95 +}
    1.96 +
    1.97 +
    1.98 +float *objf_vertex(struct objfile *obj, int idx)
    1.99 +{
   1.100 +	return obj->verts + idx * 3;
   1.101 +}
   1.102 +
   1.103 +float *objf_normal(struct objfile *obj, int idx)
   1.104 +{
   1.105 +	return obj->normals + idx * 3;
   1.106 +}
   1.107 +
   1.108 +float *objf_texcoord(struct objfile *obj, int idx)
   1.109 +{
   1.110 +	return obj->texcoords + idx * 2;
   1.111 +}
   1.112 +
   1.113 +static int objf_read(struct objfile *obj, FILE *fp, const char *fname)
   1.114 +{
   1.115 +	int i, j, res = -1;
   1.116 +	int vcount, ncount, tcount, fcount;
   1.117 +	int num_verts;
   1.118 +	struct vec3 *varr, *narr, *tarr;
   1.119 +	struct vec3 *vptr, *nptr, *tptr;
   1.120 +	struct vec3 dummy_vec = {0, 0, 0};
   1.121 +	struct face *faces, *fptr;
   1.122 +	float *vdest, *ndest, *tdest;
   1.123 +	char buf[512];
   1.124 +
   1.125 +	vcount = count_elem(fp, "v");
   1.126 +	rewind(fp);
   1.127 +	ncount = count_elem(fp, "vn");
   1.128 +	rewind(fp);
   1.129 +	tcount = count_elem(fp, "vt");
   1.130 +	rewind(fp);
   1.131 +	fcount = count_elem(fp, "f");
   1.132 +	rewind(fp);
   1.133 +
   1.134 +	obj->num_faces = fcount;
   1.135 +
   1.136 +	if(!vcount || !fcount) {
   1.137 +		fprintf(stderr, "invalid or corrupted obj file: %s\n", fname);
   1.138 +		return -1;
   1.139 +	}
   1.140 +
   1.141 +	printf("Reading obj file: %s (%d vertices, %d faces)\n", fname, vcount, fcount);
   1.142 +
   1.143 +	vptr = varr = malloc(vcount * sizeof *varr);
   1.144 +	nptr = narr = ncount ? malloc(ncount * sizeof *narr) : &dummy_vec;
   1.145 +	tptr = tarr = tcount ? malloc(tcount * sizeof *tarr) : &dummy_vec;
   1.146 +	fptr = faces = malloc(fcount * sizeof *faces);
   1.147 +
   1.148 +	if(!varr || !narr || !tarr || !faces) {
   1.149 +		perror("can't allocate enough memory for the geometry");
   1.150 +		goto cleanup;
   1.151 +	}
   1.152 +
   1.153 +	while(fgets(buf, sizeof buf, fp)) {
   1.154 +		char *line;
   1.155 +
   1.156 +		if(!(line = strip(buf)) || *line == '#') {
   1.157 +			continue;	/* ignore empty lines and comments */
   1.158 +		}
   1.159 +
   1.160 +		if(sscanf(line, "v %f %f %f", &vptr->x, &vptr->y, &vptr->z) == 3) {
   1.161 +			vptr++;
   1.162 +		} else if(sscanf(line, "vn %f %f %f", &nptr->x, &nptr->y, &nptr->z) == 3) {
   1.163 +			nptr++;
   1.164 +		} else if(sscanf(line, "vt %f %f", &tptr->x, &tptr->y) == 2) {
   1.165 +			tptr++;
   1.166 +		} else if(mkface(line, fptr) == 0) {
   1.167 +			fptr++;
   1.168 +		}
   1.169 +	}
   1.170 +
   1.171 +	/* now go forth and create the straight-up 3-vert-per-face vertex arrays */
   1.172 +	num_verts = obj->num_faces * 3;
   1.173 +
   1.174 +	vdest = obj->verts = malloc(num_verts * 3 * sizeof *obj->verts);
   1.175 +	ndest = obj->normals = malloc(num_verts * 3 * sizeof *obj->normals);
   1.176 +	tdest = obj->texcoords = malloc(num_verts * 2 * sizeof *obj->texcoords);
   1.177 +
   1.178 +	if(!obj->verts || !obj->normals || !obj->texcoords) {
   1.179 +		free(obj->verts);
   1.180 +		free(obj->normals);
   1.181 +		goto cleanup;
   1.182 +	}
   1.183 +
   1.184 +	/* for all faces */
   1.185 +	for(i=0; i<fcount; i++) {
   1.186 +		/* for the 3 vertices of each face */
   1.187 +		for(j=0; j<3; j++) {
   1.188 +			*vdest++ = varr[faces[i].vidx[j]].x;
   1.189 +			*vdest++ = varr[faces[i].vidx[j]].y;
   1.190 +			*vdest++ = varr[faces[i].vidx[j]].z;
   1.191 +
   1.192 +			*ndest++ = narr[faces[i].nidx[j]].x;
   1.193 +			*ndest++ = narr[faces[i].nidx[j]].y;
   1.194 +			*ndest++ = narr[faces[i].nidx[j]].z;
   1.195 +
   1.196 +			*tdest++ = tarr[faces[i].tidx[j]].x;
   1.197 +			*tdest++ = tarr[faces[i].tidx[j]].y;
   1.198 +		}
   1.199 +	}
   1.200 +	res = 0;	/* success */
   1.201 +
   1.202 +cleanup:
   1.203 +	free(varr);
   1.204 +	if(narr != &dummy_vec) {
   1.205 +		free(narr);
   1.206 +	}
   1.207 +	if(tarr != &dummy_vec) {
   1.208 +		free(tarr);
   1.209 +	}
   1.210 +	free(faces);
   1.211 +	return res;
   1.212 +}
   1.213 +
   1.214 +static int count_elem(FILE *fp, const char *elem)
   1.215 +{
   1.216 +	int count = 0;
   1.217 +	char buf[512];
   1.218 +
   1.219 +	while(fgets(buf, sizeof buf, fp)) {
   1.220 +		if(buf[0] == elem[0] && (!elem[1] || buf[1] == elem[1])) {
   1.221 +			count++;
   1.222 +		}
   1.223 +	}
   1.224 +	return count;
   1.225 +}
   1.226 +
   1.227 +
   1.228 +static char *strip(char *s)
   1.229 +{
   1.230 +	while(*s && isspace(*s)) {
   1.231 +		s++;
   1.232 +	}
   1.233 +	return s;
   1.234 +}
   1.235 +
   1.236 +static int mkface(char *s, struct face *face)
   1.237 +{
   1.238 +	int nverts;
   1.239 +
   1.240 +	if(s[0] != 'f') {
   1.241 +		return -1;
   1.242 +	}
   1.243 +
   1.244 +	if((nverts = parse_face(s + 2, face->vidx, face->nidx, face->tidx)) == -1) {
   1.245 +		return -1;
   1.246 +	}
   1.247 +	if(nverts > 3) {
   1.248 +		fprintf(stderr, "warning face with more than 3 vertices found\n");
   1.249 +	}
   1.250 +	return 0;
   1.251 +}
   1.252 +
   1.253 +#define SEP	" \t\v\n\r"
   1.254 +/* returns the number of vertices on this face, or -1 on error. */
   1.255 +static int parse_face(char *s, int *vidx, int *nidx, int *tidx)
   1.256 +{
   1.257 +	int i, num_verts = 0;
   1.258 +	char *tok[] = {0, 0, 0, 0};
   1.259 +	char *subtok;
   1.260 +
   1.261 +	for(i=0; i<4; i++) {
   1.262 +		if((!(tok[i] = strtok(i == 0 ? s : 0, SEP)) || !is_int(tok[i]))) {
   1.263 +			if(i < 3) return -1;
   1.264 +		} else {
   1.265 +			num_verts++;
   1.266 +		}
   1.267 +	}
   1.268 +
   1.269 +	for(i=0; i<4; i++) {
   1.270 +		subtok = tok[i];
   1.271 +		if(!subtok || !*subtok || !is_int(subtok)) {
   1.272 +			if(i < 3) {
   1.273 +				return -1;
   1.274 +			}
   1.275 +			vidx[i] = INVALID_IDX;
   1.276 +		} else {
   1.277 +			vidx[i] = atoi(subtok);
   1.278 +			if(vidx[i] > 0) vidx[i]--;	/* convert to 0-based */
   1.279 +		}
   1.280 +
   1.281 +		while(subtok && *subtok && *subtok != '/') {
   1.282 +			subtok++;
   1.283 +		}
   1.284 +		if(subtok && *subtok && *++subtok && is_int(subtok)) {
   1.285 +			tidx[i] = atoi(subtok);
   1.286 +			if(tidx[i] > 0) tidx[i]--;	/* convert to 0-based */
   1.287 +		} else {
   1.288 +			tidx[i] = 0;
   1.289 +		}
   1.290 +
   1.291 +		while(subtok && *subtok && *subtok != '/') {
   1.292 +			subtok++;
   1.293 +		}
   1.294 +		if(subtok && *subtok && *++subtok && is_int(subtok)) {
   1.295 +			nidx[i] = atoi(subtok);
   1.296 +			if(nidx[i] > 0) nidx[i]--;	/* convert to 0-based */
   1.297 +		} else {
   1.298 +			nidx[i] = 0;
   1.299 +		}
   1.300 +	}
   1.301 +
   1.302 +	return num_verts;
   1.303 +}
   1.304 +
   1.305 +
   1.306 +static int is_int(const char *str)
   1.307 +{
   1.308 +	return isdigit(str[0]) ||
   1.309 +		(str[0] == '-' && isdigit(str[1])) ||
   1.310 +		(str[0] == '+' && isdigit(str[1]));
   1.311 +}