Initial commit

Torque/SDK/engine/terrain/bvQuadTree.cc

@@ -0,0 +1,166 @@
+//-----------------------------------------------------------------------------
+// Torque Game Engine
+// Copyright (C) GarageGames.com, Inc.
+//-----------------------------------------------------------------------------
+
+#include "terrain/bvQuadTree.h"
+#include "console/console.h"
+
+BVQuadTree::BVQuadTree(BitVector *bv)
+{
+   if (bv != NULL)
+      init(*bv);
+   else
+   {
+      BitVector localBV;
+      localBV.setSize(4);
+      localBV.set();
+      init(localBV);
+   }
+}
+
+BVQuadTree::~BVQuadTree()
+{
+   while (mQTHierarchy.size() > 0)
+   {
+      delete mQTHierarchy.last();
+      mQTHierarchy.pop_back();
+   }
+}
+
+bool BVQuadTree::isSet(const Point2F &pos, S32 level) const
+{
+   AssertFatal(pos.x >= 0. && pos.x <= 1., "BVQuadTree::isSet: x must be in range [0,1]");
+   AssertFatal(pos.y >= 0. && pos.y <= 1., "BVQuadTree::isSet: y must be in range [0,1]");
+   AssertFatal(level >= 0, "BVQuadTree:isSet: level must be greater than or equal to zero");
+
+   if (level >= mQTHierarchy.size())
+      // force to be within resolution of QT
+      level = mQTHierarchy.size() - 1;
+   if (level < 0)
+      level = 0;
+
+   F32 dimension = F32(1 << level);
+   U32 offset = U32((F32(U32(pos.y * dimension)) + pos.x) * dimension);
+   return(mQTHierarchy[level]->test(offset));
+}
+
+bool BVQuadTree::isClear(const Point2F &pos, S32 level) const
+{
+   AssertFatal(pos.x >= 0. && pos.x <= 1., "BVQuadTree::isClear: x must be in range [0,1]");
+   AssertFatal(pos.y >= 0. && pos.y <= 1., "BVQuadTree::isClear: y must be in range [0,1]");
+   AssertFatal(level >= 0, "BVQuadTree:isClear: level must be greater than or equal to zero");
+
+   if (level >= mQTHierarchy.size())
+      // force to be within resolution of QT
+      level = mQTHierarchy.size() - 1;
+   if (level < 0)
+      level = 0;
+
+   F32 dimension = F32(1 << level);
+   U32 offset = U32((F32(U32(pos.y * dimension)) + pos.x) * dimension);
+   return(mQTHierarchy[level]->test(offset) == false);
+}
+
+/* Initialize the quadtree with the provided bit vector. Note that the bit vector
+ * denotes data at each corner of the quadtree cell. Hence the dimension for the
+ * deepest quadtree level must be 1 less than that of the bit vector.
+ */
+void BVQuadTree::init(const BitVector &bv)
+{
+   while (mQTHierarchy.size() > 0)
+   {
+      delete mQTHierarchy.last();
+      mQTHierarchy.pop_back();
+   }
+
+   // get the width/height of the square bit vector
+   U32 bvDim = (U32)mSqrt((F32)bv.getSize());
+   U32 qtDim = bvDim - 1;                                // here's where we correct dimension...
+
+   AssertFatal(((mSqrt((F32)bv.getSize()) - 1) == (F32)qtDim) && (isPow2(qtDim) == true), "BVQuadTree::init: bit vector size must be power of 4");
+
+   // find the power of two we're starting at
+   mResolution = qtDim;
+   U32 level = 0;
+   while ((1 << (level + 1)) <= qtDim)
+      level++;
+   BitVector *initBV = new BitVector;
+
+   AssertFatal(initBV != NULL, "BVQuadTree::init: failed to allocate highest detail bit vector");
+
+   initBV->setSize(qtDim * qtDim);
+   initBV->clear();
+   for (S32 i = 0; i < qtDim; i++)
+      for (S32 j = 0; j < qtDim; j++)
+      {
+         S32 k = i * bvDim + j;
+         if (bv.test(k) || bv.test(k + 1) || bv.test(k + bvDim) || bv.test(k + bvDim + 1))
+            initBV->set(i * qtDim + j);
+      }
+   mQTHierarchy.push_back(initBV);
+   if (level > 0)
+      buildHierarchy(level - 1);
+}
+
+#ifdef BV_QUADTREE_DEBUG
+void BVQuadTree::dump() const
+{
+   char str[256];
+   U32 strlen;
+   for (U32 i = 0; i < mQTHierarchy.size(); i++)
+   {
+      U32 dimension = 1 << i;
+      Con::printf("level %d:", i);
+      for (U32 y = 0; y < dimension; y++)
+      {
+         U32 yOffset = y * dimension;
+         str[0] = '\0';
+         for (U32 x = 0; x < dimension; x++)
+         {
+            U32 offset = yOffset + x;
+            strlen = dStrlen(str);
+            if (strlen < 252)
+               dSprintf(str + strlen, 256 - strlen, mQTHierarchy[i]->isSet(offset) ? "1  " : "0  ");
+            else
+            {
+               dSprintf(str + strlen, 256 - strlen, "...");
+               break;
+            }
+         }
+         Con::printf("%s", str);
+      }
+   }
+}
+#endif
+
+void BVQuadTree::buildHierarchy(U32 level)
+{
+   BitVector *priorBV = mQTHierarchy.first();
+   BitVector *levelBV = new BitVector;
+
+   AssertFatal(levelBV != NULL, "BVQuadTree::buildHierarchy: failed to allocate bit vector");
+
+   U32 levelDim = (1 << level);
+   levelBV->setSize(levelDim * levelDim);
+   levelBV->clear();
+   U32 yOffset, offset, yPriorOffset, priorOffset;
+   // COULD THIS BE DONE WITH A SINGLE LOOP?
+   for (U32 y = 0; y < levelDim; y++)
+   {
+      yOffset = y * levelDim;
+      yPriorOffset = yOffset << 2;
+      for (U32 x = 0; x < levelDim; x++)
+      {
+         offset = yOffset + x;
+         priorOffset = yPriorOffset + (x << 1);
+         if (priorBV->test(priorOffset) || priorBV->test(priorOffset + 1) ||
+             priorBV->test(priorOffset + (levelDim << 1)) ||
+             priorBV->test(priorOffset + (levelDim << 1) + 1))
+            levelBV->set(offset);
+      }
+   }
+   mQTHierarchy.push_front(levelBV);
+   if (level > 0)
+      buildHierarchy(level - 1);
+}