Fix for face colors on wrong faces by Christopher.

Tested by Isaak and Jan

closes #2028

git-svn-id: http://www.openflipper.org/svnrepo/OpenFlipper/branches/Free@18273 383ad7c9-94d9-4d36-a494-682f7c89f535

ACG/GL/DrawMesh.cc

@@ -564,7 +564,7 @@ DrawMeshT<Mesh>::rebuild()
     if (hh.is_valid())
     {
       vertices_[i].vcol = getVertexColor(mesh_.to_vertex_handle(hh));
-      vertices_[i].fcol = getFaceColor(mesh_.face_handle(hh));
+      vertices_[i].fcol = 0;
     }
     else
     {
@@ -576,6 +576,25 @@ DrawMeshT<Mesh>::rebuild()
     }
   }
 
+  // copy face colors to provoking id
+  
+  for (int i = 0; i < (int)numTris_; ++i)
+  {
+    const int provokingId = meshComp_->getProvokingVertex();
+
+    assert(provokingId >= 0 && provokingId < 3);
+    
+    int idx = meshComp_->getIndex(i*3+provokingId);
+
+    int faceId = meshComp_->mapToOriginalFaceID(i);
+    unsigned int fcolor = getFaceColor(mesh_.face_handle(faceId));
+
+    // debug check
+    assert(vertices_[idx].fcol == 0 || vertices_[idx].fcol == fcolor);
+
+    vertices_[idx].fcol = fcolor;
+  }
+
   //////////////////////////////////////////////////////////////////////////
   // copy to GPU
 

ACG/GL/DrawMesh.hh

@@ -174,6 +174,9 @@ public:
   */
   GLuint getIBO();
 
+  /** \brief get mesh compiler used to create the draw mesh
+  */
+  MeshCompiler* getMeshCompiler() {return meshComp_;}
 
   /** \brief get vertex declaration used for per-vertex color rendering
   */

ACG/GL/MeshCompiler.cc

@@ -3202,6 +3202,56 @@ int MeshCompiler::getAdjVertexFace( int _vertexID, int _k ) const
   return adjacencyVert_.num ? adjacencyVert_.getAdj(_vertexID, _k) : faceInput_->getVertexAdjFace(_vertexID, _k);
 }
 
+bool MeshCompiler::isTriangleMesh() const
+{
+  return maxFaceSize_ == 3;
+}
+
+bool MeshCompiler::isFaceEdge( const int _triID, const int _edge ) const
+{
+  assert(_edge >= 0);
+  assert(_edge < 3);
+
+  if (maxFaceSize_ <= 3) return true;
+
+  // brute force: search for triangle edge in input face
+
+  const int faceID = mapToOriginalFaceID(_triID);
+  const int fsize = getFaceSize(faceID);
+
+  // get all draw vertices of face
+  std::vector<int> FaceVerts(fsize);
+
+  for (int i = 0; i < fsize; ++i)
+    FaceVerts[i] = mapToDrawVertexID(faceID, i);
+
+  int edgeStart = -1;
+  int edgeEnd = -1;
+
+  switch (_edge)
+  {
+  case 0: edgeStart = 0; edgeEnd = 1; break;
+  case 1: edgeStart = 1; edgeEnd = 2; break;
+  case 2: edgeStart = 2; edgeEnd = 0; break;
+  default: break;
+  }
+
+  // access index buffer of triangle
+  edgeStart = getIndex(_triID * 3 + edgeStart);
+  edgeEnd = getIndex(_triID * 3 + edgeEnd);
+
+  // search for edge in face vertices
+  for (int e = 0; e < fsize; ++e)
+  {
+    if (FaceVerts[e] == edgeStart && FaceVerts[(e+1)%fsize] == edgeEnd)
+      return true;
+    if (FaceVerts[e] == edgeEnd && FaceVerts[(e+1)%fsize] == edgeStart)
+      return true;
+  }
+
+  return false;
+}
+
 void MeshCompilerDefaultFaceInput::dbgWriteToObjFile(FILE* _file, int _posAttrID, int _normalAttrID, int _texcAttrID)
 {
   for (int i = 0; i < numFaces_; ++i)

ACG/GL/MeshCompiler.hh

@@ -467,6 +467,12 @@ public:
    */
   void setProvokingVertex(int _v);
 
+  /** See glProvokingVertex()
+   *
+   * @return provoking vertex id
+   */
+  int getProvokingVertex() const {return provokingVertex_;}
+
 
   /** \brief Get vertex buffer ready for rendering.
    * 
@@ -562,6 +568,27 @@ public:
 /** @} */  
 
 
+//===========================================================================
+/** @name Triangulation properties
+* @{ */
+//===========================================================================  
+
+  /** Test if the input mesh consists of triangles only.
+  */
+  bool isTriangleMesh() const;
+
+  /** Test if a triangle edge is a face edge from the input buffer.
+   *
+   * When a convex n-poly is subdivided into (n-2) triangles, new edges are created which do not exist in the input mesh.
+   * This function identifies if an edge was already existant in the input mesh or added during triangulation.
+   * @param _triID triangle ID in draw buffer
+   * @param _edge edge of triangle, edge ordering: v0-v1, v1-v2, v2-v0
+   * @return true if the edge is an edge from an input face, false otherwise
+  */
+  bool isFaceEdge(const int _triID, const int _edge) const;
+
+
+/** @} */