From 3edca81a75eb74950beba4bd8368d90c2b95acbb Mon Sep 17 00:00:00 2001
From: Holden Green <awesomeholdengreen@gmail.com>
Date: Wed, 4 Jul 2018 21:21:56 -0700
Subject: [PATCH] Added line paths.

---
 tiny_obj_loader.h | 70 +++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 61 insertions(+), 9 deletions(-)

diff --git a/tiny_obj_loader.h b/tiny_obj_loader.h
index 9e43a7d..4045404 100644
--- a/tiny_obj_loader.h
+++ b/tiny_obj_loader.h
@@ -236,9 +236,14 @@ typedef struct {
   std::vector<tag_t> tags;                        // SubD tag
 } mesh_t;
 
+typedef struct {
+    std::vector<int> indices; // pairs of indices for lines
+} path_t;
+
 typedef struct {
   std::string name;
   mesh_t mesh;
+  path_t path;
 } shape_t;
 
 // Vertex attributes
@@ -401,6 +406,11 @@ struct face_t {
   face_t() : smoothing_group_id(0) {}
 };
 
+struct line_t {
+    int idx0;
+    int idx1;
+};
+
 struct tag_sizes {
   tag_sizes() : num_ints(0), num_reals(0), num_strings(0) {}
   int num_ints;
@@ -1015,15 +1025,17 @@ static int pnpoly(int nvert, T *vertx, T *verty, T testx,
 }
 
 // TODO(syoyo): refactor function.
-static bool exportFaceGroupToShape(shape_t *shape,
+static bool exportGroupsToShape(shape_t *shape,
                                    const std::vector<face_t> &faceGroup,
+                                   const std::vector<int> &lineGroup,
                                    const std::vector<tag_t> &tags,
                                    const int material_id,
                                    const std::string &name, bool triangulate,
                                    const std::vector<real_t> &v) {
-  if (faceGroup.empty()) {
-    return false;
-  }
+
+
+
+  if (!faceGroup.empty()) {
 
   // Flatten vertices and indices
   for (size_t i = 0; i < faceGroup.size(); i++) {
@@ -1031,10 +1043,11 @@ static bool exportFaceGroupToShape(shape_t *shape,
 
     size_t npolys = face.vertex_indices.size();
 
+    /*
     if (npolys < 3) {
       // Face must have 3+ vertices.
       continue;
-    }
+    }*/
 
     vertex_index_t i0 = face.vertex_indices[0];
     vertex_index_t i1(-1);
@@ -1254,6 +1267,12 @@ static bool exportFaceGroupToShape(shape_t *shape,
 
   shape->name = name;
   shape->mesh.tags = tags;
+  }
+
+
+  if(!lineGroup.empty()){
+      shape->path.indices = std::move(lineGroup);
+  }
 
   return true;
 }
@@ -1765,6 +1784,7 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
   std::vector<real_t> vc;
   std::vector<tag_t> tags;
   std::vector<face_t> faceGroup;
+  std::vector<int> lineGroup;
   std::string name;
 
   // material
@@ -1842,6 +1862,32 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
       continue;
     }
 
+    // line
+    if (token[0] == 'l' && IS_SPACE((token[1]))){
+        token += 2;
+
+        line_t line_cache;
+        bool end_line_bit = 0;
+        while(!IS_NEW_LINE(token[0])){
+            //get index from string
+            int idx;
+            fixIndex(parseInt(&token), 0, &idx);
+            // move to next space or end of string (\0 / \n)
+            token += strcspn(token, " \t\r")+1;
+
+            if(!end_line_bit){
+                line_cache.idx0 = idx;
+            } else {
+                line_cache.idx1 = idx;
+                lineGroup.push_back(line_cache.idx0);
+                lineGroup.push_back(line_cache.idx1);
+                line_cache = line_t();
+            }
+            end_line_bit = !end_line_bit;
+        }
+
+        continue;
+    }
     // face
     if (token[0] == 'f' && IS_SPACE((token[1]))) {
       token += 2;
@@ -1892,7 +1938,7 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
         // Create per-face material. Thus we don't add `shape` to `shapes` at
         // this time.
         // just clear `faceGroup` after `exportFaceGroupToShape()` call.
-        exportFaceGroupToShape(&shape, faceGroup, tags, material, name,
+        exportGroupsToShape(&shape, faceGroup, lineGroup, tags, material, name,
                                triangulate, v);
         faceGroup.clear();
         material = newMaterialId;
@@ -1947,7 +1993,7 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
     // group name
     if (token[0] == 'g' && IS_SPACE((token[1]))) {
       // flush previous face group.
-      bool ret = exportFaceGroupToShape(&shape, faceGroup, tags, material, name,
+      bool ret = exportGroupsToShape(&shape, faceGroup, lineGroup, tags, material, name,
                                         triangulate, v);
       (void)ret;  // return value not used.
 
@@ -1984,7 +2030,7 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
     // object name
     if (token[0] == 'o' && IS_SPACE((token[1]))) {
       // flush previous face group.
-      bool ret = exportFaceGroupToShape(&shape, faceGroup, tags, material, name,
+      bool ret = exportGroupsToShape(&shape, faceGroup, lineGroup, tags, material, name,
                                         triangulate, v);
       if (ret) {
         shapes->push_back(shape);
@@ -2092,7 +2138,7 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
     // Ignore unknown command.
   }
 
-  bool ret = exportFaceGroupToShape(&shape, faceGroup, tags, material, name,
+  bool ret = exportGroupsToShape(&shape, faceGroup, lineGroup, tags, material, name,
                                     triangulate, v);
   // exportFaceGroupToShape return false when `usemtl` is called in the last
   // line.
@@ -2103,6 +2149,12 @@ bool LoadObj(attrib_t *attrib, std::vector<shape_t> *shapes,
   }
   faceGroup.clear();  // for safety
 
+
+        for(int i=0;i<lineGroup.size();i++){
+            //printf("facegroup indices size: %i\n", faceGroup[i].vertex_indices.size());
+            printf("linegroup[%i]: %i\n", i, lineGroup[i]);
+        }
+
   if (err) {
     (*err) += errss.str();
   }