Inheritance diagram for vtHeightFieldGrid3d:

Public Member Functions
void	Initialize (const LinearUnits units, const DRECT &earthextents, float fMinHeight, float fMaxHeight, int cols, int rows)

virtual void	SetEarthExtents (const DRECT &ext)

bool	CastRayToSurface (const FPoint3 &point, const FPoint3 &dir, FPoint3 &result) const

bool	LineOfSight (const FPoint3 &point1, const FPoint3 &point2) const

const DPoint2 &	GetSpacing () const

const FPoint2 &	GetWorldSpacing () const

void	GetDimensions (int &nColumns, int &nRows) const

const IPoint2 &	GetDimensions () const

int	NumColumns () const

int	NumRows () const

void	EarthToGrid (const DPoint2 &epos, IPoint2 &ipos)

void	WorldToGrid (const FPoint3 &pos, IPoint2 &ipos)

float	GetInterpolatedElevation (double findex_x, double findex_y, bool bTrue=false) const

int	FindNumUnknown ()

virtual float	GetElevation (int iX, int iZ, bool bTrue=false) const =0

virtual void	GetWorldLocation (int i, int j, FPoint3 &loc, bool bTrue=false) const =0

bool	ColorDibFromElevation (vtBitmapBase pBM, ColorMap cmap, int iGranularity, const RGBAi &nodata, bool progress_callback(int)=NULL) const

bool	ColorDibFromTable (vtBitmapBase pBM, const ColorMap color_map, const RGBAi &nodata, bool progress_callback(int)=NULL) const

void	ShadeDibFromElevation (vtBitmapBase *pBM, const FPoint3 &light_dir, float fLightFactor, float fAmbient=0.1f, float fGamma=1.0f, bool bTrue=false, bool progress_callback(int)=NULL) const

void	ShadeQuick (vtBitmapBase *pBM, float light_factor, bool bTrue=false, bool progress_callback(int)=NULL)

void	ShadowCastDib (vtBitmapBase *pBM, const FPoint3 &ight_dir, float fLightFactor, float fAmbient, bool progress_callback(int)=NULL) const

Public Member Functions inherited from vtHeightField3d
void	Initialize (const LinearUnits units, const DRECT &earthextents, float fMinHeight, float fMaxHeight)

virtual bool	FindAltitudeAtPoint (const FPoint3 &p3, float &fAltitude, bool bTrue=false, int iCultureFlags=0, FPoint3 *vNormal=NULL) const =0

int	PointIsAboveTerrain (const FPoint3 &p) const

bool	ConvertEarthToSurfacePoint (const DPoint2 &epos, FPoint3 &p3, int iCultureFlags=0, bool bTrue=false) const

bool	ContainsWorldPoint (float x, float z) const

void	GetCenter (FPoint3 &center) const

void	SetCulture (CultureExtension *ext)

float	LineOnSurface (const DLine2 &line, float fSpacing, float fOffset, bool bInterp, bool bCurve, bool bTrue, FLine3 &output)

Public Member Functions inherited from vtHeightField
void	Initialize (const DRECT &extents, float fMinHeight, float fMaxHeight)

virtual bool	FindAltitudeOnEarth (const DPoint2 &p, float &fAltitude, bool bTrue=false) const =0

bool	ContainsEarthPoint (const DPoint2 &p, bool bInclusive=false) const

DRECT &	GetEarthExtents ()

const DRECT &	GetEarthExtents () const

void	GetHeightExtents (float &fMinHeight, float &fMaxHeight) const

Protected Attributes
IPoint2	m_iSize

FPoint2	m_fStep

DPoint2	m_dStep

Protected Attributes inherited from vtHeightField3d
float	m_fDiagonalLength

CultureExtension *	m_pCulture

Protected Attributes inherited from vtHeightField
float	m_fMinHeight

float	m_fMaxHeight

DRECT	m_EarthExtents

Additional Inherited Members
Public Attributes inherited from vtHeightField3d
FRECT	m_WorldExtents

LocalCS	m_LocalCS

Protected Member Functions inherited from vtHeightField3d
void	UpdateWorldExtents ()

Detailed Description

This class extends vtHeightField3d with the knowledge of operating on a regular grid of elevation values.

Member Function Documentation

bool vtHeightFieldGrid3d::CastRayToSurface	(	const FPoint3 &	point,
		const FPoint3 &	dir,
		FPoint3 &	result
	)		const

virtual

Tests a ray against a heightfield grid.

Note: This algorithm is not guaranteed to give absolutely correct results, but it is reasonably fast and efficient. It checks a series of points along the ray against the terrain. When a pair of points (segment) is found to straddle the terrain, it refines the segment in a binary fashion.

Since the length of the test is proportional to a single grid element, there is a small chance that it will give results that are off by a small distance (less than 1 grid element)

Returns: true if hit terrain. The resulting point of intersection is placed in the 'result' argument.

Implements vtHeightField3d.

bool vtHeightFieldGrid3d::ColorDibFromElevation	(	vtBitmapBase *	pBM,
		ColorMap *	cmap,
		int	iGranularity,
		const RGBAi &	nodata,
		bool	progress_callbackint = `NULL`
	)		const

Use the height data in the grid to fill a bitmap with colors.

Parameters

pBM	The bitmap to be colored.
cmap	The mapping of elevation values to colors.
iGranularity	The smoothness of the mapping, expressed as the size of the internal mapping table. 2000 is a generally good value.
nodata	The color to use for NODATA areas, where there are no elevation values.
progress_callback	If supplied, this function will be called back with a value of 0 to 100 as the operation progresses.

Returns: true if any invalid elevation values were encountered.

bool vtHeightFieldGrid3d::ColorDibFromTable	(	vtBitmapBase *	pBM,
		const ColorMap *	color_map,
		const RGBAi &	nodata,
		bool	progress_callbackint = `NULL`
	)		const

Use the height data in the grid and a colormap fill a bitmap with colors. Any undefined heixels in the source will be fill with red (255,0,0).

Parameters

pBM	The bitmap to be colored.
color_map	A ColorMap which has already had GenerateColorTable() called.
nodata	The color to use for NODATA areas, where there are no elevation values.
progress_callback	If supplied, this function will be called back with a value of 0 to 100 as the operation progresses.

Returns: true if any invalid elevation values were encountered.

void vtHeightFieldGrid3d::EarthToGrid	(	const DPoint2 &	epos,
		IPoint2 &	ipos
	)

Convert a point from earth coordinates to the integer coordinates of the grid.

int vtHeightFieldGrid3d::FindNumUnknown ( )

Count the number of unknown (invalid) heixels in this grid.

void vtHeightFieldGrid3d::GetDimensions	(	int &	nColumns,
		int &	nRows
	)		const

Get the grid size of the grid. The values are placed into the arguments by reference.

Parameters

nColumns	The number of columns (east-west)
nRows	THe number of rows (north-south)

float vtHeightFieldGrid3d::GetInterpolatedElevation	(	double	findex_x,
		double	findex_y,
		bool	bTrue = `false`
	)		const

Get the interpolated height of the grid at a specific grid coordinate, where the coordinates can be non-integer; the result is interpolated between the source heixels when possible (i.e. not at the edge)

Parameters

findex_x	Floating point index, from 0 to width in heixels.
findex_y	Floating point index, from 0 to height in heixels.
bTrue	Use the true elevation, ignoring any scaling/exaggeration.

const DPoint2& vtHeightFieldGrid3d::GetSpacing ( ) const

inline

Get the grid spacing, the width of each column and row.

bool vtHeightFieldGrid3d::LineOfSight	(	const FPoint3 &	point1,
		const FPoint3 &	point2
	)		const

Returns: true if a line of sight exists between point1 and point2.

void vtHeightFieldGrid3d::SetEarthExtents ( const DRECT & ext )

virtual

Set the geographic extents of the grid.

Reimplemented from vtHeightField3d.

void vtHeightFieldGrid3d::ShadeDibFromElevation	(	vtBitmapBase *	pBM,
		const FPoint3 &	light_dir,
		float	fLightFactor,
		float	fAmbient = `0.1f`,
		float	fGamma = `1.0f`,
		bool	bTrue = `false`,
		bool	progress_callbackint = `NULL`
	)		const

Perform simple shading of a bitmap, based on this grid's elevation values. Lighting is computing using the dot product of the surface normal with the light direction. This is often called "dot-product lighting".

Parameters

pBM	The bitmap to shade.
light_dir	Direction vector of the light.
fLightFactor	Value from 0 (no shading) to 1 (full shading)
fAmbient	Ambient light values from 0 to 1, a typical value is 0.1.
fGamma	Gamma values from 0 to 1, values less than 1 boost the brightness curve.
bTrue	If true, use the real elevation values, ignoring vertical exaggeration.
progress_callback	If supplied, will be called with values from 0 to 100.

void vtHeightFieldGrid3d::ShadeQuick	(	vtBitmapBase *	pBM,
		float	fLightFactor,
		bool	bTrue = `false`,
		bool	progress_callbackint = `NULL`
	)

Quickly produce a shading-like effect by scanning over the bitmap once, using the east-west slope to produce lightening/darkening. The bitmap must be the same size as the elevation grid, or a power of 2 smaller.

void vtHeightFieldGrid3d::ShadowCastDib	(	vtBitmapBase *	pBM,
		const FPoint3 &	light_dir,
		float	fLightFactor,
		float	fAmbient,
		bool	progress_callbackint = `NULL`
	)		const

ShadowCastDib - method to create shadows over the terrain based on the angle of the sun.

Parameters

pBM	An interface to the bitmap to be shaded.
light_dir	The direction of the light, in world coordinates, coming down toward the terrain. For example, (-1,-1,0) is pointing down where the sun would be at 9AM on the equator. Despite this example, light_dir should be normalized to unit length.
fLightFactor	Amount of shading, from 0 to 1. A value of 0 means no lighting, 1 means full lighting.
fAmbient	Amount of ambient light, from 0 to 1. A typical value is 0.1.
progress_callback	Optional callback for progress notification.

void vtHeightFieldGrid3d::WorldToGrid	(	const FPoint3 &	pos,
		IPoint2 &	ipos
	)

Convert a point from world coordinates to the integer coordinates of the grid.

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Function Documentation