Ogre::TerrainLayerBlendMap Class Reference

Class exposing an interface to a blend map for a given layer. More...

#include <OgreTerrainLayerBlendMap.h>

Inheritance diagram for Ogre::TerrainLayerBlendMap:

Public Member Functions
	TerrainLayerBlendMap (Terrain *parent, uint8 layerIndex, HardwarePixelBuffer *buf)
	Constructor.
virtual	~TerrainLayerBlendMap ()
void	blit (const PixelBox &src)
	Blits a set of values into the entire map.
void	blit (const PixelBox &src, const Box &dstBox)
	Blits a set of values into a region on the blend map.
void	convertImageToTerrainSpace (size_t x, size_t y, Real *outX, Real *outY)
	Convert image space (0, imageSize) to terrain space values (0,1).
void	convertImageToUVSpace (size_t x, size_t y, Real *outX, Real *outY)
	Convert image space (0, imageSize) to local space values (0,1).
void	convertTerrainToImageSpace (Real x, Real y, size_t *outX, size_t *outY)
	Convert terrain space values (0,1) to image space (0, imageSize).
void	convertUVToImageSpace (Real x, Real y, size_t *outX, size_t *outY)
	Convert local space values (0,1) to image space (0, imageSize).
void	convertUVToWorldSpace (Real x, Real y, Vector3 *outWorldPos)
	Helper method - convert a point in local space to worldspace based on the terrain settings.
void	convertWorldToUVSpace (const Vector3 &worldPos, Real *outX, Real *outY)
	Helper method - convert a point in world space to UV space based on the terrain settings.
void	dirty ()
	Indicate that all of the blend data is dirty and needs updating.
void	dirtyRect (const Rect &rect)
	Indicate that a portion of the blend data is dirty and needs updating.
float *	getBlendPointer ()
	Get a pointer to the whole blend data.
float	getBlendValue (uint32 x, uint32 y)
	Get a single value of blend information, in image space.
uint8	getLayerIndex () const
	Get the index of the layer this is targeting.
Terrain *	getParent () const
	Get the parent terrain.
void	loadImage (const Image &img)
	Load an image into this blend layer.
void	loadImage (const String &filename, const String &groupName)
	Load an image into this blend layer.
void	loadImage (DataStreamPtr &stream, const String &ext=BLANKSTRING)
	Load an image into this blend layer.
void	setBlendValue (uint32 x, uint32 y, float val)
	Set a single value of blend information (0 = transparent, 255 = solid)
void	update ()
	Publish any changes you made to the blend data back to the blend map.

Detailed Description

Class exposing an interface to a blend map for a given layer.

Each layer after the first layer in a terrain has a blend map which expresses how it is alpha blended with the layers beneath. Internally, this blend map is packed into one channel of an RGBA texture in order to use the smallest number of samplers, but this class allows a caller to manipulate the data more easily without worrying about this packing. Also, the values you use to interact with the blend map are floating point, which gives you full precision for updating, but in fact the values are packed into 8-bit integers in the actual blend map.

You shouldn't construct this class directly, use Terrain::getLayerBlendMap().

Constructor & Destructor Documentation

TerrainLayerBlendMap()

Ogre::TerrainLayerBlendMap::TerrainLayerBlendMap	(	Terrain *	parent,
		uint8	layerIndex,
		HardwarePixelBuffer *	buf
	)

Constructor.

Parameters

parent	The parent terrain
layerIndex	The layer index (should be 1 or higher)
buf	The buffer holding the data

~TerrainLayerBlendMap()

virtual Ogre::TerrainLayerBlendMap::~TerrainLayerBlendMap ( )

virtual

Member Function Documentation

getParent()

Terrain * Ogre::TerrainLayerBlendMap::getParent ( ) const

inline

Get the parent terrain.

getLayerIndex()

uint8 Ogre::TerrainLayerBlendMap::getLayerIndex ( ) const

inline

Get the index of the layer this is targeting.

convertWorldToUVSpace()

void Ogre::TerrainLayerBlendMap::convertWorldToUVSpace	(	const Vector3 &	worldPos,
		Real *	outX,
		Real *	outY
	)

Helper method - convert a point in world space to UV space based on the terrain settings.

Parameters

worldPos	World position
outX,outY	Pointers to variables which will be filled in with the local UV space value. Note they are deliberately signed Real values, because the point you supply may be outside of image space and may be between texels. The values will range from 0 to 1, top/bottom, left/right.

convertUVToWorldSpace()

void Ogre::TerrainLayerBlendMap::convertUVToWorldSpace	(	Real	x,
		Real	y,
		Vector3 *	outWorldPos
	)

Helper method - convert a point in local space to worldspace based on the terrain settings.

Parameters

x,y	Local position, ranging from 0 to 1, top/bottom, left/right.
outWorldPos	Pointer will be filled in with the world space value

convertUVToImageSpace()

void Ogre::TerrainLayerBlendMap::convertUVToImageSpace	(	Real	x,
		Real	y,
		size_t *	outX,
		size_t *	outY
	)

Convert local space values (0,1) to image space (0, imageSize).

convertImageToUVSpace()

void Ogre::TerrainLayerBlendMap::convertImageToUVSpace	(	size_t	x,
		size_t	y,
		Real *	outX,
		Real *	outY
	)

Convert image space (0, imageSize) to local space values (0,1).

convertImageToTerrainSpace()

void Ogre::TerrainLayerBlendMap::convertImageToTerrainSpace	(	size_t	x,
		size_t	y,
		Real *	outX,
		Real *	outY
	)

Convert image space (0, imageSize) to terrain space values (0,1).

convertTerrainToImageSpace()

void Ogre::TerrainLayerBlendMap::convertTerrainToImageSpace	(	Real	x,
		Real	y,
		size_t *	outX,
		size_t *	outY
	)

Convert terrain space values (0,1) to image space (0, imageSize).

getBlendValue()

float Ogre::TerrainLayerBlendMap::getBlendValue	(	uint32	x,
		uint32	y
	)

Get a single value of blend information, in image space.

Parameters

x,y	Coordinates of the point of data to get, in image space (top down)

Returns

The blend data

setBlendValue()

void Ogre::TerrainLayerBlendMap::setBlendValue	(	uint32	x,
		uint32	y,
		float	val
	)

Set a single value of blend information (0 = transparent, 255 = solid)

Parameters

x,y	Coordinates of the point of data to get, in image space (top down)
val	The blend value to set (0..1)

getBlendPointer()

float * Ogre::TerrainLayerBlendMap::getBlendPointer

(

)

Get a pointer to the whole blend data.

This method allows you to get a raw pointer to all the blend data, to update it as you like. However, you must then call dirtyRect manually if you want those changes to be recognised.

dirty()

void Ogre::TerrainLayerBlendMap::dirty

(

)

Indicate that all of the blend data is dirty and needs updating.

dirtyRect()

void Ogre::TerrainLayerBlendMap::dirtyRect

(

const Rect &

rect

)

Indicate that a portion of the blend data is dirty and needs updating.

Parameters

rect	Rectangle in image space

blit() [1/2]

void Ogre::TerrainLayerBlendMap::blit	(	const PixelBox &	src,
		const Box &	dstBox
	)

Blits a set of values into a region on the blend map.

Parameters

src	PixelBox containing the source pixels and format
dstBox	Box describing the destination region in this map

Remarks

The source and destination regions dimensions don't have to match, in which case scaling is done.

Note

You can call this method in a background thread if you want. You still need to call update() to commit the changes to the GPU.

blit() [2/2]

void Ogre::TerrainLayerBlendMap::blit

(

const PixelBox &

src

)

Blits a set of values into the entire map.

The source data is scaled if needed.

Parameters

src	PixelBox containing the source pixels and format

Note

You can call this method in a background thread if you want. You still need to call update() to commit the changes to the GPU.

loadImage() [1/3]

void Ogre::TerrainLayerBlendMap::loadImage

(

const Image &

img

)

Load an image into this blend layer.

loadImage() [2/3]

void Ogre::TerrainLayerBlendMap::loadImage	(	DataStreamPtr &	stream,
		const String &	ext = BLANKSTRING
	)

Load an image into this blend layer.

Parameters

stream	Stream containing the image data
ext	Extension identifying the image type, if the stream data doesn't identify

loadImage() [3/3]

void Ogre::TerrainLayerBlendMap::loadImage	(	const String &	filename,
		const String &	groupName
	)

Load an image into this blend layer.

update()

void Ogre::TerrainLayerBlendMap::update

(

)

Publish any changes you made to the blend data back to the blend map.

Note

Can only be called in the main render thread.

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The documentation for this class was generated from the following file:

• OgreTerrainLayerBlendMap.h