87 lines
2.9 KiB
C++
Executable File
87 lines
2.9 KiB
C++
Executable File
//-----------------------------------------------------------------------------
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// Torque Shader Engine
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// Copyright (C) GarageGames.com, Inc.
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//-----------------------------------------------------------------------------
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#ifndef _QUADTREETRACER_H_
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#define _QUADTREETRACER_H_
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#include "platform/platform.h"
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#include "math/mPoint.h"
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#include "sim/sceneObject.h"
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/// Helper class to perform a fast, recursive ray cast against a set of
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/// hierarchical bounding boxes.
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///
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/// This class assumes that it is working on a unit quadtree (ie, one that
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/// extends from 0..1 in the XY dimensions. Z scale is unaffected).
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///
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/// Node indexing is done TGE Terrain style - 0 is the largest level of the
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/// quadtree, while coordinates are always in the full range of the quadtree
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/// (in a 6 deep tree, 0..63, for instance). This allows the quadtree descent
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/// to be very fast!
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class QuadTreeTracer
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{
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protected:
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struct StackNode
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{
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Point2I squarePos;
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U32 level;
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};
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struct RayStackNode : StackNode
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{
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F32 startT;
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F32 endT;
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};
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U32 mTreeDepth;
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QuadTreeTracer(U32 treeDepth)
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: mTreeDepth(treeDepth)
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{
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}
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/// Children better implement these! They return min/max height bounds
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/// of the specified square.
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virtual const F32 getSquareMin(const U32 &level, const Point2I &pos) const = 0;
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virtual const F32 getSquareMax(const U32 &level, const Point2I &pos) const = 0;
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/// And this does checks on leaf nodes.
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virtual bool castLeafRay(const Point2I pos, const Point3F &start, const Point3F &end, const F32 &startT, const F32 &endT, RayInfo *info) = 0;
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/// Helper function to calculate intercepts.
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inline const F32 calcIntercept(const F32 vStart, const F32 invDeltaV, const F32 intercept) const
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{
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return (intercept - vStart) * invDeltaV;
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}
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public:
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/// Size of a quadtree of depth.
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static inline const U32 getNodeCount(const U32 depth)
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{
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return 0x55555555 & ((1 << depth*2) - 1);
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}
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/// Index of a node at given position in a quadtree.
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static inline const U32 getNodeIndex(const U32 level, const Point2I pos)
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{
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//AssertFatal(level < mTreeDepth, "QuadTreeTracer::getNodeIndex - out of range level!)
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AssertFatal(pos.x < BIT(level) && pos.x >= 0 , "QuadTreeTracer::getNodeIndex - out of range x for level!");
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AssertFatal(pos.y < BIT(level) && pos.y >= 0 , "QuadTreeTracer::getNodeIndex - out of range y for level!");
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const U32 base = getNodeCount(level);
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return base + (pos.x << level) + pos.y;
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}
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/// Cast a ray against a quadtree of hierarchical bounding boxes.
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///
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/// This method assumes the quadtree extends from (0..1) along the
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/// X and Y axes. Z is unscaled. You may need to adjust the points
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/// you pass into this method to get the proper results.
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bool castRay(const Point3F &start, const Point3F &end, RayInfo *info);
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};
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#endif |