git.mutantstargoat.com Git - cyberay/blob - src/mesh.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include "mesh.h"
   4
   5 static char *cleanline(char *s)
   6 {
   7         char *ptr;
   8
   9         if((ptr = strchr(s, '#'))) *ptr = 0;
  10
  11         while(*s && isspace(*s)) s++;
  12         ptr = s + strlen(s) - 1;
  13         while(ptr >= s && isspace(*s)) *ptr-- = 0;
  14
  15         return *s ? s : 0;
  16 }
  17
  18 #define APPEND(prefix)  \
  19         do { \
  20                 if(prefix##count >= prefix##max) { \
  21                         int newsz = prefix##max ? prefix##max * 2 : 8; \
  22                         void *ptr = realloc(prefix##arr, newsz * sizeof(cgm_vec3)); \
  23                         if(!ptr) { \
  24                                 fprintf(stderr, "load_mesh: failed to resize array to %d elements\n", newsz); \
  25                                 return -1; \
  26                         } \
  27                         prefix##arr = ptr; \
  28                         prefix##max = newsz; \
  29                 } \
  30         } while(0)
  31
  32
  33 int load_mesh(struct mesh *m, const char *fname)
  34 {
  35         int num, nline;
  36         FILE *fp;
  37         cgm_vec3 v;
  38         cgm_vec3 *varr, *narr, *tarr;
  39         int vcount, ncount, tcount, vmax, nmax, tmax;
  40         char linebuf[256], *line;
  41
  42         varr = narr = tarr = 0;
  43         vcount = ncount = tcount = vmax = nmax = tmax = 0;
  44
  45         if(!(fp = fopen(fname, "rb"))) {
  46                 fprintf(stderr, "load_mesh: failed to open: %s\n", fname);
  47                 return -1;
  48         }
  49
  50         nline = 0;
  51         while(fgets(linebuf, sizeof linebuf, fp)) {
  52                 nline++;
  53                 if(!(line = cleanline(linebuf))) {
  54                         continue;
  55                 }
  56
  57                 switch(line[0]) {
  58                 case 'v':
  59                         v.y = v.z = 0;
  60                         if((num = sscanf(line + 1, "%f %f %f", &v.x, &v.y, &v.z)) < 2) {
  61 verr:                   fprintf(stderr, "load_mesh: ignoring malformed attribute at %d: %s\n", nline, line);
  62                                 continue;
  63                         }
  64                         if(isspace(line[1])) {
  65                                 APPEND(v);
  66                                 varr[vcount++] = v;
  67                         } else if(line[1] == 'n') {
  68                                 APPEND(n);
  69                                 narr[ncount++] = v;
  70                         } else if(line[1] == 't') {
  71                                 APPEND(t);
  72                                 tarr[ncount].x = v.x;
  73                                 tarr[ncount++].y = v.y;
  74                         } else {
  75                                 goto verr;
  76                         }
  77                         break;
  78
  79                         /* TODO cont */
  80                 }
  81
  82         }
  83
  84         fclose(fp);
  85         return 0;
  86 }
  87
  88 void draw_mesh(struct mesh *m)
  89 {
  90         glEnableClientState(GL_VERTEX_ARRAY);
  91         glEnableClientState(GL_NORMAL_ARRAY);
  92         glEnableClientState(GL_TEXTURE_COORD_ARRAY);
  93
  94         glVertexPointer(3, GL_FLOAT, sizeof *m->faces, &m->faces->v[0].pos.x);
  95         glNormalPointer(GL_FLOAT, sizeof *m->faces, &m->faces->v[0].norm.x);
  96         glTexCoordPointer(2, GL_FLOAT, sizeof *m->faces, &m->faces->v[0].tex.x);
  97
  98         glDrawArrays(GL_TRIANGLES, 0, m->num_faces * 3);
  99
 100         glDisableClientState(GL_VERTEX_ARRAY);
 101         glDisableClientState(GL_NORMAL_ARRAY);
 102         glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 103 }