/*
 * obj2model.c
 *
 * Turn Wavefront OBJ files into Thrust3D models
 *
 * (c) 2008 Thomas White <taw27@cam.ac.uk>
 *
 *  thrust3d - a silly game
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "utils.c"

#define MAX_VERTICES 65536

int main(int argc, char *argv[]) {

	FILE *fh;
	FILE *out;
	float vtmp[3*MAX_VERTICES];
	float vntmp[3*MAX_VERTICES];
	float textmp[2*MAX_VERTICES];
	int v_used[MAX_VERTICES];
	int vn_used[MAX_VERTICES];
	int tex_used[MAX_VERTICES];
	int n_vtmp, n_vntmp, n_textmp;
	int nprev;
	int i, v_unused, vn_unused, tex_unused;
	
	fh = fopen(argv[1], "r");
	if ( fh == NULL ) {
		fprintf(stderr, "Couldn't open '%s'\n", argv[1]);
		return 1;
	}
	
	for ( i=0; i<MAX_VERTICES; i++ ) {
		v_used[i] = 5;
		vn_used[i] = 5;
		tex_used[i] = 5;
	}
	
	/* Zip through and find all the vertices */
	n_vtmp = 0;
	n_textmp = 0;
	n_vntmp = 0;
	while ( !feof(fh) ) {
		
		char line[1024];
		float x, y, z;
		size_t s;
		
		fgets(line, 1023, fh);
		s = 0;
		for ( ; s<strlen(line); s++ ) {
			if ( line[s] != ' ' ) break;
		}
			
		if ( line[s] == '#' ) {
			continue;
		}
		
		if ( sscanf(line+s, "v %f %f %f\n", &x, &y, &z) == 3 ) {
			vtmp[3*n_vtmp+0] = x;
			vtmp[3*n_vtmp+1] = y;
			vtmp[3*n_vtmp+2] = z;
			v_used[n_vtmp] = 0;
			n_vtmp++;
			continue;
		}
		
		if ( sscanf(line+s, "vn %f %f %f\n", &x, &y, &z) == 3 ) {
			vntmp[3*n_vntmp+0] = x;
			vntmp[3*n_vntmp+1] = y;
			vntmp[3*n_vntmp+2] = z;
			vn_used[n_vntmp] = 0;
			n_vntmp++;
			continue;
		}
		
		if ( sscanf(line+s, "vt %f %f %f\n", &x, &y, &z) == 3 ) {
			textmp[2*n_textmp+0] = x;
			textmp[2*n_textmp+1] = y;
			tex_used[n_textmp] = 0;
			n_textmp++;
			continue;
		}
	
	}
	
	/* Go through again and look for faces */
	rewind(fh);
	out = fopen(argv[2], "w");
	fprintf(out, "# %s\n", argv[1]);
	fprintf(out, "\n");
	nprev = 0;
	while ( !feof(fh) ) {
	
		char line[1024];
		char **bits;
		int n, i;
		
		fgets(line, 1023, fh);
		n = assplode(line, " \t\r\n", &bits, ASSPLODE_NONE);
		
		/* Read in a face */
		if ( strcmp(bits[0], "f") == 0 ) {
		
			int nthis;
			
			/* Change primitive type if this face has a different number of vertices */
			nthis = n-1;
			if ( nthis != nprev ) {
				if ( nprev != 0 ) fprintf(out, "\n");
				if ( nthis == 4 ) {
					fprintf(out, "QUADS\n");
				} else if ( nthis == 3 ) {
					fprintf(out, "TRIANGLES\n");
				} else {
					fprintf(out, "POLYGONS\n");
				}
				nprev = nthis;
			} else {
				//fprintf(out, "#\n");
			}
			
			/* For each vertex... */
			for ( i=1; i<n; i++ ) {
			
				char **sp;
				int np, j, nslash;
				
				nslash = 0;
				for ( j=0; j<strlen(bits[i]); j++ ) {
					if ( bits[i][j] == '/' ) nslash++;
				}
				if ( nslash == 2 ) {
				
					int vnum, tnum, nnum;
				
					np = assplode(bits[i], "/", &sp, ASSPLODE_DUPS);
					if ( np != 3 ) {
						printf("Error!\n");
						continue;
					}
					vnum = atoi(sp[0])-1;
					tnum = atoi(sp[1])-1;
					nnum = atoi(sp[2])-1;
					if ( vnum >= n_vtmp ) {
						fprintf(stderr, "Vertex index is too high (%i/%i)\n", vnum, n_vtmp);
						continue;
					}
					if ( nnum >= n_vntmp ) {
						fprintf(stderr, "Normal index is too high (%i/%i)\n", nnum, n_vntmp);
						continue;
					}
					fprintf(out, "%+8.3f %+8.3f %+8.3f      %8.3f %8.3f     %+8.3f %+8.3f %+8.3f\n",
							vtmp[3*vnum+0], vtmp[3*vnum+1], vtmp[3*vnum+2],
							textmp[2*tnum+0], textmp[2*tnum+1],
							vntmp[3*nnum+0], vntmp[3*nnum+1], vntmp[3*nnum+2]);
					v_used[vnum] = 1;
					vn_used[nnum] = 1;
					tex_used[tnum] = 1;
					free(sp[0]);
					free(sp[1]);
					free(sp[2]);
					free(sp);
				
				} else if ( nslash == 0 ) {
					
					int vnum;
					vnum = atoi(bits[i])-1;
					fprintf(out, "%+8.3f %+8.3f %+8.3f      %8.3f %8.3f\n",
							vtmp[3*vnum+0], vtmp[3*vnum+1], vtmp[3*vnum+2],
							0.0, 0.0);
					v_used[vnum] = 1;
				
				}
				
			}
			
		}
		
		for ( i=0; i<n; i++ ) free(bits[i]);
		free(bits);
		
	}
	fprintf(out, "\n");
	
	fclose(fh);
	fclose(out);
	
	v_unused = 0;
	vn_unused = 0;
	tex_unused = 0;
	for ( i=0; i<MAX_VERTICES; i++ ) {
		if ( v_used[i] == 0 ) {
			v_unused++;
		}
		if ( vn_used[i] == 0 ) {
			vn_unused++;
		}
		if ( tex_used[i] == 0 ) {
			tex_unused++;
		}
	}
	printf("%i vertices (%i unused)\n", n_vtmp, v_unused);
	printf("%i normals (%i unused)\n", n_vntmp, vn_unused);
	printf("%i texcoords (%i unused)\n", n_textmp, tex_unused);
	
	return 0;
	
}