Torque3D/Engine/source/util/quadTreeTracer.h
2012-09-19 11:15:01 -04:00

104 lines
3.9 KiB
C++

//-----------------------------------------------------------------------------
// 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 _QUADTREETRACER_H_
#define _QUADTREETRACER_H_
#include "platform/platform.h"
#include "math/mPoint3.h"
#include "scene/sceneObject.h"
/// Helper class to perform a fast, recursive ray cast against a set of
/// hierarchical bounding boxes.
///
/// This class assumes that it is working on a unit quadtree (ie, one that
/// extends from 0..1 in the XY dimensions. Z scale is unaffected).
///
/// Node indexing is done TGE Terrain style - 0 is the largest level of the
/// quadtree, while coordinates are always in the full range of the quadtree
/// (in a 6 deep tree, 0..63, for instance). This allows the quadtree descent
/// to be very fast!
class QuadTreeTracer
{
protected:
struct StackNode
{
Point2I squarePos;
U32 level;
};
struct RayStackNode : StackNode
{
F32 startT;
F32 endT;
};
U32 mTreeDepth;
QuadTreeTracer(U32 treeDepth)
: mTreeDepth(treeDepth)
{
}
/// Children better implement these! They return min/max height bounds
/// of the specified square.
virtual const F32 getSquareMin(const U32 &level, const Point2I &pos) const = 0;
virtual const F32 getSquareMax(const U32 &level, const Point2I &pos) const = 0;
/// And this does checks on leaf nodes.
virtual bool castLeafRay(const Point2I pos, const Point3F &start, const Point3F &end, const F32 &startT, const F32 &endT, RayInfo *info) = 0;
/// Helper function to calculate intercepts.
inline const F32 calcIntercept(const F32 vStart, const F32 invDeltaV, const F32 intercept) const
{
return (intercept - vStart) * invDeltaV;
}
public:
/// Size of a quadtree of depth.
static inline const U32 getNodeCount(const U32 depth)
{
return 0x55555555 & ((1 << depth*2) - 1);
}
/// Index of a node at given position in a quadtree.
static inline const U32 getNodeIndex(const U32 level, const Point2I pos)
{
//AssertFatal(level < mTreeDepth, "QuadTreeTracer::getNodeIndex - out of range level!)
AssertFatal(pos.x < BIT(level) && pos.x >= 0 , "QuadTreeTracer::getNodeIndex - out of range x for level!");
AssertFatal(pos.y < BIT(level) && pos.y >= 0 , "QuadTreeTracer::getNodeIndex - out of range y for level!");
const U32 base = getNodeCount(level);
return base + (pos.x << level) + pos.y;
}
/// Cast a ray against a quadtree of hierarchical bounding boxes.
///
/// This method assumes the quadtree extends from (0..1) along the
/// X and Y axes. Z is unscaled. You may need to adjust the points
/// you pass into this method to get the proper results.
bool castRay(const Point3F &start, const Point3F &end, RayInfo *info);
};
#endif