From 98315c0a86e2d8157e3aec73d532bb4c87860ed2 Mon Sep 17 00:00:00 2001
From: taw27 <taw27@84d2e878-0bd5-11dd-ad15-13eda11d74c5>
Date: Sun, 10 Aug 2008 19:14:39 +0000
Subject: obj2model: parse .mtl files

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@245 84d2e878-0bd5-11dd-ad15-13eda11d74c5
---
 src/obj2model.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 96 insertions(+), 13 deletions(-)

diff --git a/src/obj2model.c b/src/obj2model.c
index d58786e..a720273 100644
--- a/src/obj2model.c
+++ b/src/obj2model.c
@@ -16,11 +16,78 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#include <libgen.h>
 
 #include "utils.c"
 
 #define MAX_VERTICES 65536
 
+static void do_material(const char *mtllib, const char *mtlname, FILE *out, char *infilename) {
+
+	FILE *fh;
+	char tmp[1024];
+	char *infilename_dup;
+	
+	infilename_dup = strdup(infilename);
+	snprintf(tmp, 1023, "%s/%s", dirname(infilename_dup), mtllib);
+	free(infilename_dup);
+	fh = fopen(tmp, "r");
+	if ( fh == NULL ) {
+		fprintf(stderr, "Couldn't open material library '%s'\n", tmp);
+		return;
+	}
+	
+	while ( !feof(fh) ) {
+		
+		char line[1024];
+		char **bits;
+		int n, i;
+		
+		fgets(line, 1023, fh);
+		n = assplode(line, " \t\r\n", &bits, ASSPLODE_NONE);
+		
+		if ( n > 1 ) {
+			if ( (strcmp(bits[0], "newmtl") == 0) && (strcmp(bits[1], mtlname) == 0) ) {
+				/* Found the right material */
+				while ( !feof(fh) ) {
+		
+					char line[1024];
+					char **bits;
+					int n, i;
+		
+					fgets(line, 1023, fh);
+					n = assplode(line, " \t\r\n", &bits, ASSPLODE_NONE);
+		
+					if ( n > 1 ) {
+						
+						if ( strcmp(bits[0], "newmtl") == 0 ) {
+							return;
+						}
+						if ( strcmp(bits[0], "Kd") == 0 ) {
+							fprintf(out, "colour %s %s %s\n", bits[1], bits[2], bits[3]);
+						}
+						if ( strcmp(bits[0], "Ns") == 0 ) {
+							fprintf(out, "shiny %s\n", bits[1]);
+						}
+					}
+		
+					for ( i=0; i<n; i++ ) free(bits[i]);
+					free(bits);
+		
+				}
+	
+			}
+		}
+		
+		for ( i=0; i<n; i++ ) free(bits[i]);
+		free(bits);
+		
+	}
+	
+	fclose(fh);
+	
+}
+
 int main(int argc, char *argv[]) {
 
 	FILE *fh;
@@ -32,8 +99,10 @@ int main(int argc, char *argv[]) {
 	int vn_used[MAX_VERTICES];
 	int tex_used[MAX_VERTICES];
 	int n_vtmp, n_vntmp, n_textmp;
-	int nprev;
+	int new_prim, n_prev;
 	int i, v_unused, vn_unused, tex_unused;
+	char mtllib[64];
+	char *cur_material = NULL;
 	
 	fh = fopen(argv[1], "r");
 	if ( fh == NULL ) {
@@ -92,6 +161,11 @@ int main(int argc, char *argv[]) {
 			n_textmp++;
 			continue;
 		}
+		
+		if ( sscanf(line+s, "mtllib %63s\n", mtllib) == 1 ) {
+			printf("Material library '%s'\n", mtllib);
+			continue;
+		}
 	
 	}
 	
@@ -100,7 +174,8 @@ int main(int argc, char *argv[]) {
 	out = fopen(argv[2], "w");
 	fprintf(out, "# %s\n", argv[1]);
 	fprintf(out, "\n");
-	nprev = 0;
+	new_prim = 1;
+	n_prev = 0;
 	while ( !feof(fh) ) {
 	
 		char line[1024];
@@ -112,23 +187,24 @@ int main(int argc, char *argv[]) {
 		
 		/* 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 ) {
+			int n_this = n-1;
+			if ( new_prim || (n_this != n_prev) ) {
+				if ( n_this != n_prev ) {
+					fprintf(out, "\n");
+				}
+				if ( n_this == 4 ) {
 					fprintf(out, "QUADS\n");
-				} else if ( nthis == 3 ) {
+				} else if ( n_this == 3 ) {
 					fprintf(out, "TRIANGLES\n");
 				} else {
 					fprintf(out, "POLYGONS\n");
 				}
-				nprev = nthis;
-			} else {
-				//fprintf(out, "#\n");
+				new_prim = 0;
+				n_prev = n_this;
+				if ( cur_material != NULL ) {
+					do_material(mtllib, cur_material, out, argv[1]);
+				}
 			}
 			
 			/* For each vertex... */
@@ -186,6 +262,13 @@ int main(int argc, char *argv[]) {
 				
 			}
 			
+		} else if ( strcmp(bits[0], "usemtl") == 0 ) {
+			cur_material = strdup(bits[1]);
+		} else if ( strcmp(bits[0], "v") == 0 ) {
+			if ( !new_prim ) {
+				fprintf(out, "\n");
+			}
+			new_prim = 1;
 		}
 		
 		for ( i=0; i<n; i++ ) free(bits[i]);
-- 
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