save obj with UVs

include/cinolib/io/write_OBJ.cpp

@@ -340,4 +340,42 @@ void write_OBJ(const char                           *filename,
     fclose(f_mtl);
 }
 
+//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+
+CINO_INLINE
+void write_OBJ(const char                * filename,
+               const std::vector<double> & xyz,
+               const std::vector<double> & uv,
+               const std::vector<uint>   & tri)
+{
+    setlocale(LC_NUMERIC, "en_US.UTF-8"); // makes sure "." is the decimal separator
+
+    FILE *fp = fopen(filename, "w");
+
+    if(!fp)
+    {
+        std::cerr << "ERROR : " << __FILE__ << ", line " << __LINE__ << " : save_OBJ() : couldn't open input file " << filename << std::endl;
+        exit(-1);
+    }
+
+    for(size_t i=0; i<xyz.size(); i+=3)
+    {
+        // http://stackoverflow.com/questions/16839658/printf-width-specifier-to-maintain-precision-of-floating-point-value
+        //
+        fprintf(fp, "v %.17g %.17g %.17g\n", xyz[i], xyz[i+1], xyz[i+2]);
+    }
+
+    for(size_t i=0; i<uv.size(); i+=2)
+    {
+        fprintf(fp, "vt %.17g %.17g\n", uv[i], uv[i+1]);
+    }
+
+    for(size_t i=0; i<tri.size(); i+=3)
+    {
+        fprintf(fp, "f %d %d %d\n", tri[i] + 1, tri[i+1] + 1, tri[i+2] + 1);
+    }
+
+    fclose(fp);
+}
+
 }

include/cinolib/io/write_OBJ.h

@@ -91,6 +91,14 @@ void write_OBJ(const char                           * filename,
                const std::vector<std::vector<uint>> & poly,
                const std::vector<int>               & labels);
 
+//::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
+
+CINO_INLINE
+void write_OBJ(const char                * filename,
+               const std::vector<double> & xyz,
+               const std::vector<double> & uv,
+               const std::vector<uint>   & tri);
+
 }
 
 #ifndef  CINO_STATIC_LIB