git.mutantstargoat.com Git - dosdemo/blob - src/meshload.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <ctype.h>
   4 #include <assert.h>
   5 #include "mesh.h"
   6 #include "dynarr.h"
   7 #include "rbtree.h"
   8 #include "vmath.h"
   9 #include "3dgfx.h"
  10 #include "util.h"
  11
  12 struct vertex_pos_color {
  13         float x, y, z;
  14         float r, g, b, a;
  15 };
  16
  17 struct facevertex {
  18         int vidx, tidx, nidx;
  19 };
  20
  21 static char *clean_line(char *s);
  22 static char *parse_face_vert(char *ptr, struct facevertex *fv, int numv, int numt, int numn);
  23 static int cmp_facevert(const void *ap, const void *bp);
  24 static void free_rbnode_key(struct rbnode *n, void *cls);
  25
  26 /* merge of different indices per attribute happens during face processing.
  27  *
  28  * A triplet of (vertex index/texcoord index/normal index) is used as the key
  29  * to search in a balanced binary search tree for vertex buffer index assigned
  30  * to the same triplet if it has been encountered before. That index is
  31  * appended to the index buffer.
  32  *
  33  * If a particular triplet has not been encountered before, a new g3d_vertex is
  34  * appended to the vertex buffer. The index of this new vertex is appended to
  35  * the index buffer, and also inserted into the tree for future searches.
  36  */
  37 int load_mesh(struct g3d_mesh *mesh, const char *fname)
  38 {
  39         int i, line_num = 0, result = -1;
  40         int found_quad = 0;
  41         FILE *fp = 0;
  42         char buf[256];
  43         struct vertex_pos_color *varr = 0;
  44         vec3_t *narr = 0;
  45         vec2_t *tarr = 0;
  46         struct rbtree *rbtree = 0;
  47
  48         if(!(fp = fopen(fname, "rb"))) {
  49                 fprintf(stderr, "load_mesh: failed to open file: %s\n", fname);
  50                 goto err;
  51         }
  52
  53         if(!(rbtree = rb_create(cmp_facevert))) {
  54                 fprintf(stderr, "load_mesh: failed to create facevertex binary search tree\n");
  55                 goto err;
  56         }
  57         rb_set_delete_func(rbtree, free_rbnode_key, 0);
  58
  59         if(!(mesh->varr = dynarr_alloc(0, sizeof *mesh->varr)) ||
  60                         !(mesh->iarr = dynarr_alloc(0, sizeof *mesh->iarr))) {
  61                 fprintf(stderr, "load_mesh: failed to allocate resizable mesh arrays\n");
  62                 goto err;
  63         }
  64         if(!(varr = dynarr_alloc(0, sizeof *varr)) ||
  65                         !(narr = dynarr_alloc(0, sizeof *narr)) ||
  66                         !(tarr = dynarr_alloc(0, sizeof *tarr))) {
  67                 fprintf(stderr, "load_mesh: failed to allocate resizable vertex array\n");
  68                 goto err;
  69         }
  70
  71         while(fgets(buf, sizeof buf, fp)) {
  72                 char *line = clean_line(buf);
  73                 ++line_num;
  74
  75                 if(!*line) continue;
  76
  77                 switch(line[0]) {
  78                 case 'v':
  79                         if(isspace(line[1])) {
  80                                 /* vertex */
  81                                 struct vertex_pos_color v;
  82                                 int num;
  83
  84                                 num = sscanf(line + 2, "%f %f %f %f %f %f %f", &v.x, &v.y, &v.z, &v.r, &v.g, &v.b, &v.a);
  85                                 if(num < 3) {
  86                                         fprintf(stderr, "%s:%d: invalid vertex definition: \"%s\"\n", fname, line_num, line);
  87                                         goto err;
  88                                 }
  89                                 switch(num) {
  90                                 case 3:
  91                                         v.r = 1.0f;
  92                                 case 4:
  93                                         v.g = 1.0f;
  94                                 case 5:
  95                                         v.b = 1.0f;
  96                                 case 6:
  97                                         v.a = 1.0f;
  98                                 }
  99                                 if(!(varr = dynarr_push(varr, &v))) {
 100                                         fprintf(stderr, "load_mesh: failed to resize vertex buffer\n");
 101                                         goto err;
 102                                 }
 103
 104                         } else if(line[1] == 't' && isspace(line[2])) {
 105                                 /* texcoord */
 106                                 vec2_t tc;
 107                                 if(sscanf(line + 3, "%f %f", &tc.x, &tc.y) != 2) {
 108                                         fprintf(stderr, "%s:%d: invalid texcoord definition: \"%s\"\n", fname, line_num, line);
 109                                         goto err;
 110                                 }
 111                                 if(!(tarr = dynarr_push(tarr, &tc))) {
 112                                         fprintf(stderr, "load_mesh: failed to resize texcoord buffer\n");
 113                                         goto err;
 114                                 }
 115
 116                         } else if(line[1] == 'n' && isspace(line[2])) {
 117                                 /* normal */
 118                                 vec3_t norm;
 119                                 if(sscanf(line + 3, "%f %f %f", &norm.x, &norm.y, &norm.z) != 3) {
 120                                         fprintf(stderr, "%s:%d: invalid normal definition: \"%s\"\n", fname, line_num, line);
 121                                         goto err;
 122                                 }
 123                                 if(!(narr = dynarr_push(narr, &norm))) {
 124                                         fprintf(stderr, "load_mesh: failed to resize normal buffer\n");
 125                                         goto err;
 126                                 }
 127                         }
 128                         break;
 129
 130                 case 'f':
 131                         if(isspace(line[1])) {
 132                                 /* face */
 133                                 char *ptr = line + 2;
 134                                 struct facevertex fv;
 135                                 struct rbnode *node;
 136                                 int vsz = dynarr_size(varr);
 137                                 int tsz = dynarr_size(tarr);
 138                                 int nsz = dynarr_size(narr);
 139
 140                                 for(i=0; i<4; i++) {
 141                                         if(!(ptr = parse_face_vert(ptr, &fv, vsz, tsz, nsz))) {
 142                                                 if(i < 3 || found_quad) {
 143                                                         fprintf(stderr, "%s:%d: invalid face definition: \"%s\"\n", fname, line_num, line);
 144                                                         goto err;
 145                                                 } else {
 146                                                         break;
 147                                                 }
 148                                         }
 149
 150                                         if((node = rb_find(rbtree, &fv))) {
 151                                                 uint16_t idx = (int)(intptr_t)node->data;
 152                                                 if(!(mesh->iarr = dynarr_push(mesh->iarr, &idx))) {
 153                                                         fprintf(stderr, "load_mesh: failed to resize index array\n");
 154                                                         goto err;
 155                                                 }
 156                                         } else {
 157                                                 uint16_t newidx = dynarr_size(mesh->varr);
 158                                                 struct g3d_vertex v;
 159                                                 struct facevertex *newfv;
 160
 161                                                 v.x = varr[fv.vidx].x;
 162                                                 v.y = varr[fv.vidx].y;
 163                                                 v.z = varr[fv.vidx].z;
 164                                                 v.w = 1.0f;
 165                                                 v.r = cround64(varr[fv.vidx].r * 255.0);
 166                                                 v.g = cround64(varr[fv.vidx].g * 255.0);
 167                                                 v.b = cround64(varr[fv.vidx].b * 255.0);
 168                                                 v.a = cround64(varr[fv.vidx].a * 255.0);
 169                                                 if(fv.tidx >= 0) {
 170                                                         v.u = tarr[fv.tidx].x;
 171                                                         v.v = tarr[fv.tidx].y;
 172                                                 } else {
 173                                                         v.u = v.x;
 174                                                         v.v = v.y;
 175                                                 }
 176                                                 if(fv.nidx >= 0) {
 177                                                         v.nx = narr[fv.nidx].x;
 178                                                         v.ny = narr[fv.nidx].y;
 179                                                         v.nz = narr[fv.nidx].z;
 180                                                 } else {
 181                                                         v.nx = v.ny = 0.0f;
 182                                                         v.nz = 1.0f;
 183                                                 }
 184
 185                                                 if(!(mesh->varr = dynarr_push(mesh->varr, &v))) {
 186                                                         fprintf(stderr, "load_mesh: failed to resize combined vertex array\n");
 187                                                         goto err;
 188                                                 }
 189                                                 if(!(mesh->iarr = dynarr_push(mesh->iarr, &newidx))) {
 190                                                         fprintf(stderr, "load_mesh: failed to resize index array\n");
 191                                                         goto err;
 192                                                 }
 193
 194                                                 if((newfv = malloc(sizeof *newfv))) {
 195                                                         *newfv = fv;
 196                                                 }
 197                                                 if(!newfv || rb_insert(rbtree, newfv, (void*)(intptr_t)newidx) == -1) {
 198                                                         fprintf(stderr, "load_mesh: failed to insert facevertex to the binary search tree\n");
 199                                                         goto err;
 200                                                 }
 201                                         }
 202                                 }
 203                                 if(i > 3) found_quad = 1;
 204                         }
 205                         break;
 206
 207                 default:
 208                         break;
 209                 }
 210         }
 211
 212         mesh->prim = found_quad ? G3D_QUADS : G3D_TRIANGLES;
 213         mesh->vcount = dynarr_size(mesh->varr);
 214         mesh->icount = dynarr_size(mesh->iarr);
 215         mesh->varr = dynarr_finalize(mesh->varr);
 216         mesh->iarr = dynarr_finalize(mesh->iarr);
 217         result = 0;     /* success */
 218
 219         printf("loaded %s mesh: %s: %d vertices, %d faces\n", found_quad ? "quad" : "triangle",
 220                         fname, mesh->vcount, mesh->icount / mesh->prim);
 221
 222 err:
 223         if(fp) fclose(fp);
 224         dynarr_free(varr);
 225         dynarr_free(narr);
 226         dynarr_free(tarr);
 227         if(result == -1) {
 228                 dynarr_free(mesh->varr);
 229                 dynarr_free(mesh->iarr);
 230         }
 231         rb_free(rbtree);
 232         return result;
 233 }
 234
 235 int save_mesh(struct g3d_mesh *mesh, const char *fname)
 236 {
 237         int i, fvcount;
 238         FILE *fp;
 239
 240         if(!(fp = fopen(fname, "wb"))) {
 241                 fprintf(stderr, "save_mesh: failed to open %s for writing\n", fname);
 242                 return -1;
 243         }
 244         fprintf(fp, "# Wavefront OBJ file shoved in your FACE by Mindlapse. Deal with it\n");
 245
 246         for(i=0; i<mesh->vcount; i++) {
 247                 struct g3d_vertex *v = mesh->varr + i;
 248                 fprintf(fp, "v %f %f %f %f %f %f %f\n", v->x, v->y, v->z, v->r / 255.0f, v->g / 255.0f,
 249                                 v->b / 255.0f, v->a / 255.0f);
 250         }
 251         for(i=0; i<mesh->vcount; i++) {
 252                 fprintf(fp, "vn %f %f %f\n", mesh->varr[i].nx, mesh->varr[i].ny, mesh->varr[i].nz);
 253         }
 254         for(i=0; i<mesh->vcount; i++) {
 255                 fprintf(fp, "vt %f %f\n", mesh->varr[i].u, mesh->varr[i].v);
 256         }
 257
 258         fvcount = mesh->prim;
 259         for(i=0; i<mesh->icount; i++) {
 260                 int idx = mesh->iarr[i] + 1;
 261
 262                 if(fvcount == mesh->prim) {
 263                         fprintf(fp, "\nf");
 264                         fvcount = 0;
 265                 }
 266                 fprintf(fp, " %d/%d/%d", idx, idx, idx);
 267                 ++fvcount;
 268         }
 269         fprintf(fp, "\n");
 270
 271         fclose(fp);
 272         return 0;
 273 }
 274
 275 static char *clean_line(char *s)
 276 {
 277         char *end;
 278
 279         while(*s && isspace(*s)) ++s;
 280         if(!*s) return 0;
 281
 282         end = s;
 283         while(*end && *end != '#') ++end;
 284         *end = 0;
 285
 286         while(end > s && isspace(*end)) --end;
 287         *end = 0;
 288
 289         return s;
 290 }
 291
 292 static char *parse_idx(char *ptr, int *idx, int arrsz)
 293 {
 294         char *endp;
 295         int val = strtol(ptr, &endp, 10);
 296         if(endp == ptr) return 0;
 297
 298         if(val < 0) {   /* convert negative indices */
 299                 *idx = arrsz + val;
 300         } else {
 301                 *idx = val - 1; /* indices in obj are 1-based */
 302         }
 303         return endp;
 304 }
 305
 306 /* possible face-vertex definitions:
 307  * 1. vertex
 308  * 2. vertex/texcoord
 309  * 3. vertex//normal
 310  * 4. vertex/texcoord/normal
 311  */
 312 static char *parse_face_vert(char *ptr, struct facevertex *fv, int numv, int numt, int numn)
 313 {
 314         if(!(ptr = parse_idx(ptr, &fv->vidx, numv)))
 315                 return 0;
 316         if(*ptr != '/') return (!*ptr || isspace(*ptr)) ? ptr : 0;
 317
 318         if(*++ptr == '/') {     /* no texcoord */
 319                 fv->tidx = -1;
 320                 ++ptr;
 321         } else {
 322                 if(!(ptr = parse_idx(ptr, &fv->tidx, numt)))
 323                         return 0;
 324                 if(*ptr != '/') return (!*ptr || isspace(*ptr)) ? ptr : 0;
 325                 ++ptr;
 326         }
 327
 328         if(!(ptr = parse_idx(ptr, &fv->nidx, numn)))
 329                 return 0;
 330         return (!*ptr || isspace(*ptr)) ? ptr : 0;
 331 }
 332
 333 static int cmp_facevert(const void *ap, const void *bp)
 334 {
 335         const struct facevertex *a = ap;
 336         const struct facevertex *b = bp;
 337
 338         if(a->vidx == b->vidx) {
 339                 if(a->tidx == b->tidx) {
 340                         return a->nidx - b->nidx;
 341                 }
 342                 return a->tidx - b->tidx;
 343         }
 344         return a->vidx - b->vidx;
 345 }
 346
 347 static void free_rbnode_key(struct rbnode *n, void *cls)
 348 {
 349         free(n->key);
 350 }