Torque Game Engine Documentation
TGE Version 1.5.2

QuadTreeTracer Class Reference

#include <quadTreeTracer.h>

Detailed Description

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!

Public Member Functions

bool castRay (const Point3F &start, const Point3F &end, RayInfo *info)

Cast a ray against a quadtree of hierarchical bounding boxes.

Static Public Member Functions

static const U32 getNodeCount (const U32 depth)

Size of a quadtree of depth.

static const U32 getNodeIndex (const U32 level, const Point2I pos)

Index of a node at given position in a quadtree.

Protected Member Functions

QuadTreeTracer (U32 treeDepth)

virtual const F32 getSquareMin (const U32 &level, const Point2I &pos) const =0

Children better implement these! They return min/max height bounds of the specified square.

virtual const F32 getSquareMax (const U32 &level, const Point2I &pos) const =0

virtual bool castLeafRay (const Point2I pos, const Point3F &start, const Point3F &end, const F32 &startT, const F32 &endT, RayInfo *info)=0

And this does checks on leaf nodes.

const F32 calcIntercept (const F32 vStart, const F32 invDeltaV, const F32 intercept) const

Helper function to calculate intercepts.

Protected Attributes

U32 mTreeDepth

Data Structures

struct RayStackNode

struct StackNode

Constructor & Destructor Documentation

QuadTreeTracer::QuadTreeTracer ( U32 treeDepth ) [inline, protected]

Member Function Documentation

virtual const F32 QuadTreeTracer::getSquareMin	(	const U32 &	level,
		const Point2I &	pos
	)			const `[protected, pure virtual]`

Children better implement these! They return min/max height bounds of the specified square.

virtual const F32 QuadTreeTracer::getSquareMax	(	const U32 &	level,
		const Point2I &	pos
	)			const `[protected, pure virtual]`

virtual bool QuadTreeTracer::castLeafRay	(	const Point2I	pos,
		const Point3F &	start,
		const Point3F &	end,
		const F32 &	startT,
		const F32 &	endT,
		RayInfo *	info
	)			`[protected, pure virtual]`

And this does checks on leaf nodes.

const F32 QuadTreeTracer::calcIntercept	(	const F32	vStart,
		const F32	invDeltaV,
		const F32	intercept
	)			const `[inline, protected]`

Helper function to calculate intercepts.

static const U32 QuadTreeTracer::getNodeCount ( const U32 depth ) [inline, static]

Size of a quadtree of depth.

static const U32 QuadTreeTracer::getNodeIndex	(	const U32	level,
		const Point2I	pos
	)			`[inline, static]`

Index of a node at given position in a quadtree.

bool QuadTreeTracer::castRay	(	const Point3F &	start,
		const Point3F &	end,
		RayInfo *	info
	)

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.

Field Documentation

U32 QuadTreeTracer::mTreeDepth [protected]