Updated meshoptimizer.

3rdparty/meshoptimizer/src/meshoptimizer.h

@@ -312,6 +312,15 @@ MESHOPTIMIZER_EXPERIMENTAL void meshopt_encodeFilterOct(void* destination, size_
 MESHOPTIMIZER_EXPERIMENTAL void meshopt_encodeFilterQuat(void* destination, size_t count, size_t stride, int bits, const float* data);
 MESHOPTIMIZER_EXPERIMENTAL void meshopt_encodeFilterExp(void* destination, size_t count, size_t stride, int bits, const float* data);
 
+/**
+ * Simplification options
+ */
+enum
+{
+    /* Do not move vertices that are located on the topological border (vertices on triangle edges that don't have a paired triangle). Useful for simplifying portions of the larger mesh. */
+    meshopt_SimplifyLockBorder = 1 << 0,
+};
+
 /**
  * Experimental: Mesh simplifier
  * Reduces the number of triangles in the mesh, attempting to preserve mesh appearance as much as possible
@@ -324,9 +333,10 @@ MESHOPTIMIZER_EXPERIMENTAL void meshopt_encodeFilterExp(void* destination, size_
  * destination must contain enough space for the target index buffer, worst case is index_count elements (*not* target_index_count)!
  * vertex_positions should have float3 position in the first 12 bytes of each vertex - similar to glVertexPointer
  * target_error represents the error relative to mesh extents that can be tolerated, e.g. 0.01 = 1% deformation
+ * options must be a bitmask composed of meshopt_SimplifyX options; 0 is a safe default
  * result_error can be NULL; when it's not NULL, it will contain the resulting (relative) error after simplification
  */
-MESHOPTIMIZER_EXPERIMENTAL size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices, size_t index_count, const float* vertex_positions, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, float* result_error);
+MESHOPTIMIZER_EXPERIMENTAL size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices, size_t index_count, const float* vertex_positions, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, unsigned int options, float* result_error);
 
 /**
  * Experimental: Mesh simplifier (sloppy)
@@ -605,7 +615,7 @@ inline size_t meshopt_encodeIndexSequence(unsigned char* buffer, size_t buffer_s
 template <typename T>
 inline int meshopt_decodeIndexSequence(T* destination, size_t index_count, const unsigned char* buffer, size_t buffer_size);
 template <typename T>
-inline size_t meshopt_simplify(T* destination, const T* indices, size_t index_count, const float* vertex_positions, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, float* result_error = 0);
+inline size_t meshopt_simplify(T* destination, const T* indices, size_t index_count, const float* vertex_positions, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, unsigned int options = 0, float* result_error = 0);
 template <typename T>
 inline size_t meshopt_simplifySloppy(T* destination, const T* indices, size_t index_count, const float* vertex_positions, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, float* result_error = 0);
 template <typename T>
@@ -940,12 +950,12 @@ inline int meshopt_decodeIndexSequence(T* destination, size_t index_count, const
 }
 
 template <typename T>
-inline size_t meshopt_simplify(T* destination, const T* indices, size_t index_count, const float* vertex_positions, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, float* result_error)
+inline size_t meshopt_simplify(T* destination, const T* indices, size_t index_count, const float* vertex_positions, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, unsigned int options, float* result_error)
 {
 	meshopt_IndexAdapter<T> in(0, indices, index_count);
 	meshopt_IndexAdapter<T> out(destination, 0, index_count);
 
-	return meshopt_simplify(out.data, in.data, index_count, vertex_positions, vertex_count, vertex_positions_stride, target_index_count, target_error, result_error);
+	return meshopt_simplify(out.data, in.data, index_count, vertex_positions, vertex_count, vertex_positions_stride, target_index_count, target_error, options, result_error);
 }
 
 template <typename T>

3rdparty/meshoptimizer/src/simplifier.cpp

@@ -252,7 +252,7 @@ static bool hasEdge(const EdgeAdjacency& adjacency, unsigned int a, unsigned int
 	return false;
 }
 
-static void classifyVertices(unsigned char* result, unsigned int* loop, unsigned int* loopback, size_t vertex_count, const EdgeAdjacency& adjacency, const unsigned int* remap, const unsigned int* wedge)
+static void classifyVertices(unsigned char* result, unsigned int* loop, unsigned int* loopback, size_t vertex_count, const EdgeAdjacency& adjacency, const unsigned int* remap, const unsigned int* wedge, unsigned int options)
 {
 	memset(loop, -1, vertex_count * sizeof(unsigned int));
 	memset(loopback, -1, vertex_count * sizeof(unsigned int));
@@ -274,7 +274,15 @@ static void classifyVertices(unsigned char* result, unsigned int* loop, unsigned
 		{
 			unsigned int target = edges[j].next;
 
-			if (!hasEdge(adjacency, target, vertex))
+			if (target == vertex)
+			{
+				// degenerate triangles have two distinct edges instead of three, and the self edge
+				// is bi-directional by definition; this can break border/seam classification by "closing"
+				// the open edge from another triangle and falsely marking the vertex as manifold
+				// instead we mark the vertex as having >1 open edges which turns it into locked/complex
+				openinc[vertex] = openout[vertex] = vertex;
+			}
+			else if (!hasEdge(adjacency, target, vertex))
 			{
 				openinc[target] = (openinc[target] == ~0u) ? vertex : target;
 				openout[vertex] = (openout[vertex] == ~0u) ? target : vertex;
@@ -354,6 +362,11 @@ static void classifyVertices(unsigned char* result, unsigned int* loop, unsigned
 		}
 	}
 
+	if (options & meshopt_SimplifyLockBorder)
+		for (size_t i = 0; i < vertex_count; ++i)
+			if (result[i] == Kind_Border)
+				result[i] = Kind_Locked;
+
 #if TRACE
 	printf("locked: many open edges %d, disconnected seam %d, many seam edges %d, many wedges %d\n",
 	    int(stats[0]), int(stats[1]), int(stats[2]), int(stats[3]));
@@ -1264,7 +1277,7 @@ MESHOPTIMIZER_API unsigned int* meshopt_simplifyDebugLoop = 0;
 MESHOPTIMIZER_API unsigned int* meshopt_simplifyDebugLoopBack = 0;
 #endif
 
-size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices, size_t index_count, const float* vertex_positions_data, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, float* out_result_error)
+size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices, size_t index_count, const float* vertex_positions_data, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, unsigned int options, float* out_result_error)
 {
 	using namespace meshopt;
 
@@ -1272,6 +1285,7 @@ size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices,
 	assert(vertex_positions_stride > 0 && vertex_positions_stride <= 256);
 	assert(vertex_positions_stride % sizeof(float) == 0);
 	assert(target_index_count <= index_count);
+	assert((options & ~(meshopt_SimplifyLockBorder)) == 0);
 
 	meshopt_Allocator allocator;
 
@@ -1291,7 +1305,7 @@ size_t meshopt_simplify(unsigned int* destination, const unsigned int* indices,
 	unsigned char* vertex_kind = allocator.allocate<unsigned char>(vertex_count);
 	unsigned int* loop = allocator.allocate<unsigned int>(vertex_count);
 	unsigned int* loopback = allocator.allocate<unsigned int>(vertex_count);
-	classifyVertices(vertex_kind, loop, loopback, vertex_count, adjacency, remap, wedge);
+	classifyVertices(vertex_kind, loop, loopback, vertex_count, adjacency, remap, wedge, options);
 
 #if TRACE
 	size_t unique_positions = 0;