dtTerrain::SoarXDrawable Class Reference

This class encapsulates the SoarX rendering algorithm itself. More...

#include <soarxdrawable.h>

List of all members.

Public Member Functions
	SoarXDrawable (int baseBits, float horizontalResolution)
	Sets up some default rendering parameters used during the rendering and progressive refinement.
	SoarXDrawable (const SoarXDrawable &rhs, const osg::CopyOp &copyOp=osg::CopyOp::SHALLOW_COPY)
	Makes a copy of the right hand side drawable.
virtual osg::Object *	cloneType () const
	Calls the default constructor on this class and returns a new instance.
virtual osg::Object *	clone (const osg::CopyOp &copyop) const
	Makes a new instance of this class by calling its copy constructor.
virtual void	drawImplementation (osg::RenderInfo &renderInfo) const
	Draws the current view of the terrain dataset.
virtual bool	supports (osg::PrimitiveFunctor &) const
virtual osg::BoundingBox	computeBound () const
	Computes the dimensions of the currently loaded terrain.
bool	Build (const PagedTerrainTile &tile)
	Builds the internal data structures for use in rendering and managing terrain data for a tile.
void	Clear ()
	Clears any memory used by the internal rendering structures.
float	GetHeight (float x, float y)
	Gets the elevation at the current (x,y) coordinates.
void	SetEyePoint (const osg::Vec3 &pos)
	Sets the eye point of the camera.
float	SetDetailMultiplier (float value)
	Calculates and caches values used to determine error approximation in the rendering/refinement process.
float	GetDetailMultiplier () const
	Gets the current detail multiplier.
float	SetThreshold (float value)
	Sets the threshold value used during error projection and refinement in the rendering process.
float	GetThreshold () const
	Gets the current error threshold.
float	GetBaseVerticalResolution () const
	Gets the base vertical resolution.
float	GetBaseHorizontalResolution () const
	Gets the base horizontal resolution.
float	GetDetailHorizontalResolution () const
	Gets the detail map's horizontal resolution.
void	SetDetailNoise (int detailBits, float detailVerticalResolution, float *detailData)
	Sets the noise data used to procedurally generate additional detail vertices when rendering the terrain.
float	GetDetailVerticalResolution () const
	Gets the detail map's vertical resolution.
int	GetDetailSize () const
	Gets the size of the detail map.
bool	RestoreDataFromCache (const PagedTerrainTile &tile)
void	WriteDataToCache (const PagedTerrainTile &tile)
Protected Member Functions
virtual	~SoarXDrawable ()
	Simply destroys the terrain drawable.
RawData *	GetRawData (Index index)
	Gets the raw data at the given index.
void	CalculateVertexErrors ()
	Precalculates vertex bounding spheres based on an object space error metric.
void	CalculateVertexErrorsHelper (Index i, Index j)
	Recursive method used by the above method to build the error values.
float	CalculateError (Index i, Index j)
	Calculates the object space error value of a vertex using the two indices provided.
Vertex	GetVertex (Index index)
	Gets a vertex based on the provided index.
void	CalculateRadii (float f)
void	RepairBoundingSphereHierarchy ()
	Ensures that the bounding spheres for each vertex satisfy the requirement that a vertex's bounding sphere contains all of its descendant vertices' bounding spheres.
void	CheckChildren1 (Index index, unsigned int shift)
void	CheckChildren2 (Index index, unsigned int shift)
void	Repair (Index i, Index c)
void	Render (osg::State &state)
	Refines and renders the terrain.
void	Append (Vertex &v)
	Adds a vertex and associated index to the vertex and index array.
void	Refine (Vertex &v1, Vertex &v2, bool in, bool out, unsigned int planes)
	Starts the procedural view-dependent refinement process.
void	RightRefine (Vertex v1, Vertex &v2, bool out, unsigned int planes)
	Recursivly refines the right of the two child triangles of the root refinement procedure.
void	LeftRefine (Vertex &v1, Vertex &v2, bool in, unsigned int planes)
	Recursivly refines the left of the two child triangles of the root refinement procedure.
void	TurnCorner ()
	Inserts a degenerate triangle in the terrain vertex stream in order to generate a maximum length triangle strip during the refinement process.
bool	Active (Vertex &v, unsigned int &planes)
	Decides is a vertex to be in the resulting rendered terrain mesh.
void	GetVertex (Vertex &v)
	Retrieves a vertex from the procedural terrain mesh.
Friends
struct	SoarXCullCallback
Classes
struct	Index
	This structure represents a location on the terrain's 2D grid. More...
struct	RawData
	This structure is the raw data on disk. More...
struct	Vertex
	This is the structure for a single processed vertex in the terrain. More...

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Detailed Description

This class encapsulates the SoarX rendering algorithm itself.

See also:

SoarXTerrainRenderer

---

Constructor & Destructor Documentation

dtTerrain::SoarXDrawable::SoarXDrawable	(	int	baseBits,
		float	horizontalResolution
	)

Sets up some default rendering parameters used during the rendering and progressive refinement.

Parameters:

	baseBits	The size of the terrain chunk. (size=(2^baseBits))
	horizontalResolution	The distance between each height value.

dtTerrain::SoarXDrawable::SoarXDrawable	(	const SoarXDrawable &	rhs,
		const osg::CopyOp &	copyOp = osg::CopyOp::SHALLOW_COPY
	)

Makes a copy of the right hand side drawable.

Parameters:

	rhs	The SoarXDrawable to copy.
	copyOp	Specifies whether a deep copy or a shallow copy should occur.

dtTerrain::SoarXDrawable::~SoarXDrawable

(

)

[protected, virtual]

Simply destroys the terrain drawable.

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Member Function Documentation

osg::Object * dtTerrain::SoarXDrawable::cloneType

(

)

const [virtual]

Calls the default constructor on this class and returns a new instance.

osg::Object * dtTerrain::SoarXDrawable::clone

(

const osg::CopyOp &

copyop

)

const [virtual]

Makes a new instance of this class by calling its copy constructor.

void dtTerrain::SoarXDrawable::drawImplementation

(

osg::RenderInfo &

renderInfo

)

const [virtual]

Draws the current view of the terrain dataset.

Parameters:

state

The current OpenGL state.

virtual bool dtTerrain::SoarXDrawable::supports

(

osg::PrimitiveFunctor &

)

const [inline, virtual]

osg::BoundingBox dtTerrain::SoarXDrawable::computeBound

(

)

const [virtual]

Computes the dimensions of the currently loaded terrain.

bool dtTerrain::SoarXDrawable::Build

(

const PagedTerrainTile &

tile

)

Builds the internal data structures for use in rendering and managing terrain data for a tile.

Parameters:

The

source terrain tile.

Returns:

True if the data was paged from the tile's cache, false otherwise.

Note:

This method will load pre-computed data from the tile's cache if present. If the cache is not present, the data will be precomputed and then cached if the tile has its caching enabled.

void dtTerrain::SoarXDrawable::Clear

(

)

Clears any memory used by the internal rendering structures.

float dtTerrain::SoarXDrawable::GetHeight	(	float	x,
		float	y
	)

Gets the elevation at the current (x,y) coordinates.

void dtTerrain::SoarXDrawable::SetEyePoint

(

const osg::Vec3 &

pos

)

[inline]

Sets the eye point of the camera.

This is used during the refinement process to calculate vertex projection errors.

Parameters:

pos

The camera position.

float dtTerrain::SoarXDrawable::SetDetailMultiplier

(

float

value

)

[inline]

Calculates and caches values used to determine error approximation in the rendering/refinement process.

Parameters:

value

Returns:

The clamped multiplier value.

Note:

The value given is clamped within the range 1-20.

float dtTerrain::SoarXDrawable::GetDetailMultiplier

(

)

const [inline]

Gets the current detail multiplier.

Returns:

The detail multiplier.

float dtTerrain::SoarXDrawable::SetThreshold

(

float

value

)

[inline]

Sets the threshold value used during error projection and refinement in the rendering process.

Parameters:

value

The new threshold value.

Returns:

The clamped value.

Note:

The value given is clamped within the range 1-10

float dtTerrain::SoarXDrawable::GetThreshold

(

)

const [inline]

Gets the current error threshold.

Returns:

The current value.

float dtTerrain::SoarXDrawable::GetBaseVerticalResolution

(

)

const [inline]

Gets the base vertical resolution.

This number determines the overall scaling for height values in the terrain.

Returns:

The current vertical resolution.

float dtTerrain::SoarXDrawable::GetBaseHorizontalResolution

(

)

const [inline]

Gets the base horizontal resolution.

This number determines the overall scaling for the terrain's X and Y dimensions.

Returns:

The current horizonal resolution.

float dtTerrain::SoarXDrawable::GetDetailHorizontalResolution

(

)

const [inline]

Gets the detail map's horizontal resolution.

void dtTerrain::SoarXDrawable::SetDetailNoise	(	int	detailBits,
		float	detailVerticalResolution,
		float *	detailData
	)

Sets the noise data used to procedurally generate additional detail vertices when rendering the terrain.

Parameters:

	detailBits	The size of the detail data. The amount of data should be (2^detailBits * 2^detailBits).
	detailVerticalResolution	A scale value used when calculating the final detail vertex position.
	detailData	The detail noise values.

float dtTerrain::SoarXDrawable::GetDetailVerticalResolution

(

)

const [inline]

Gets the detail map's vertical resolution.

int dtTerrain::SoarXDrawable::GetDetailSize

(

)

const [inline]

Gets the size of the detail map.

bool dtTerrain::SoarXDrawable::RestoreDataFromCache

(

const PagedTerrainTile &

tile

)

void dtTerrain::SoarXDrawable::WriteDataToCache

(

const PagedTerrainTile &

tile

)

RawData* dtTerrain::SoarXDrawable::GetRawData

(

Index

index

)

[inline, protected]

Gets the raw data at the given index.

void dtTerrain::SoarXDrawable::CalculateVertexErrors

(

)

[protected]

Precalculates vertex bounding spheres based on an object space error metric.

void dtTerrain::SoarXDrawable::CalculateVertexErrorsHelper	(	Index	i,
		Index	j
	)			[protected]

Recursive method used by the above method to build the error values.

float dtTerrain::SoarXDrawable::CalculateError	(	Index	i,
		Index	j
	)			[protected]

Calculates the object space error value of a vertex using the two indices provided.

SoarXDrawable::Vertex dtTerrain::SoarXDrawable::GetVertex

(

Index

index

)

[protected]

Gets a vertex based on the provided index.

void dtTerrain::SoarXDrawable::CalculateRadii

(

float

f

)

[protected]

void dtTerrain::SoarXDrawable::RepairBoundingSphereHierarchy

(

)

[protected]

Ensures that the bounding spheres for each vertex satisfy the requirement that a vertex's bounding sphere contains all of its descendant vertices' bounding spheres.

This ensures a proper sphere tree for all the vertices.

void dtTerrain::SoarXDrawable::CheckChildren1	(	Index	index,
		unsigned int	shift
	)			[protected]

void dtTerrain::SoarXDrawable::CheckChildren2	(	Index	index,
		unsigned int	shift
	)			[protected]

void dtTerrain::SoarXDrawable::Repair	(	Index	i,
		Index	c
	)			[protected]

void dtTerrain::SoarXDrawable::Render

(

osg::State &

state

)

[protected]

Refines and renders the terrain.

(111111) bitmask instructing the start of the refinement process to check all 6 planes.

void dtTerrain::SoarXDrawable::Append

(

Vertex &

v

)

[protected]

Adds a vertex and associated index to the vertex and index array.

void dtTerrain::SoarXDrawable::Refine	(	Vertex &	v1,
		Vertex &	v2,
		bool	in,
		bool	out,
		unsigned int	planes
	)			[protected]

Starts the procedural view-dependent refinement process.

The SoarX refinement proceess is based on the longest edge bisection of isosceles right triangles. It subdivides each triangle about its hypotenuse, creating two smaller triangles.

void dtTerrain::SoarXDrawable::RightRefine	(	Vertex	v1,
		Vertex &	v2,
		bool	out,
		unsigned int	planes
	)			[protected]

Recursivly refines the right of the two child triangles of the root refinement procedure.

void dtTerrain::SoarXDrawable::LeftRefine	(	Vertex &	v1,
		Vertex &	v2,
		bool	in,
		unsigned int	planes
	)			[protected]

Recursivly refines the left of the two child triangles of the root refinement procedure.

void dtTerrain::SoarXDrawable::TurnCorner

(

)

[protected]

Inserts a degenerate triangle in the terrain vertex stream in order to generate a maximum length triangle strip during the refinement process.

bool dtTerrain::SoarXDrawable::Active	(	Vertex &	v,
		unsigned int &	planes
	)			[protected]

Decides is a vertex to be in the resulting rendered terrain mesh.

This is performed by calculating its position and its 2D/3D projected error. Hierarchial view-frustum culling is also performed here.

Parameters:

	v	The vertex to check.
	planes	A bitmask designating which planes to cull to.
	level	Current level of recursion.

void dtTerrain::SoarXDrawable::GetVertex

(

Vertex &

v

)

[protected]

Retrieves a vertex from the procedural terrain mesh.

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Friends And Related Function Documentation

friend struct SoarXCullCallback [friend]

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