Engine directory for ticket #1

Engine/source/gfx/util/triListOpt.h

@@ -0,0 +1,100 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2012 GarageGames, LLC
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//-----------------------------------------------------------------------------
+
+#ifndef _TRI_LIST_OPT_H_
+#define _TRI_LIST_OPT_H_
+
+#include "core/util/tVector.h"
+
+namespace TriListOpt
+{
+   typedef U32 IndexType;
+
+   const U32 MaxSizeVertexCache = 32;
+
+   struct VertData
+   {
+      S32 cachePosition;
+      F32 score;
+      U32 numReferences;
+      U32 numUnaddedReferences;
+      S32 *triIndex;
+
+      VertData() : cachePosition(-1), score(0.0f), numReferences(0), numUnaddedReferences(0), triIndex(NULL) {}
+      ~VertData() { if(triIndex != NULL) delete [] triIndex; triIndex = NULL; }
+   };
+
+   struct TriData
+   {
+      bool isInList;
+      F32 score;
+      U32 vertIdx[3];
+
+      TriData() : isInList(false), score(0.0f) { dMemset(vertIdx, 0, sizeof(vertIdx)); }
+   };
+
+   class LRUCacheModel
+   {
+      struct LRUCacheEntry
+      {
+         LRUCacheEntry *next;
+         U32 vIdx;
+         VertData *vData;
+
+         LRUCacheEntry() : next(NULL), vIdx(0), vData(NULL) {}
+      };
+
+      LRUCacheEntry *mCacheHead;
+
+   public:
+      LRUCacheModel() : mCacheHead(NULL) {}
+      ~LRUCacheModel();
+      void enforceSize(const dsize_t maxSize, Vector<U32> &outTrisToUpdate);
+      void useVertex(const U32 vIdx, VertData *vData);
+      S32 getCachePosition(const U32 vIdx);
+   };
+
+
+   /// This method will look at the index buffer for a triangle list, and generate
+   /// a new index buffer which is optimized using Tom Forsyth's paper:
+   /// "Linear-Speed Vertex Cache Optimization" 
+   /// http://home.comcast.net/~tom_forsyth/papers/fast_vert_cache_opt.html
+   /// @param   numVerts Number of vertices indexed by the 'indices'
+   /// @param numIndices Number of elements in both 'indices' and 'outIndices'
+   /// @param    indices Input index buffer
+   /// @param outIndices Output index buffer
+   ///
+   /// @note Both 'indices' and 'outIndices' can point to the same memory.
+   void OptimizeTriangleOrdering(const dsize_t numVerts, const dsize_t numIndices, const U32 *indices, IndexType *outIndices);
+
+   namespace FindVertexScore
+   {
+      const F32 CacheDecayPower = 1.5f;
+      const F32 LastTriScore = 0.75f;
+      const F32 ValenceBoostScale = 2.0f;
+      const F32 ValenceBoostPower = 0.5f;
+
+      F32 score(const VertData &vertexData);
+   };
+};
+
+#endif