Marble::StackedTile Class Reference

#include <StackedTile.h>

Inheritance diagram for Marble::StackedTile:

Public Member Functions
	StackedTile (TileId const &id, QImage const &resultImage, QVector< QSharedPointer< TextureTile > > const &tiles)
int	byteCount () const
int	depth () const
uint	pixel (int x, int y) const
uint	pixelF (qreal x, qreal y) const
uint	pixelF (qreal x, qreal y, const QRgb &pixel) const
QImage const *	resultImage () const
void	setUsed (bool used)
QVector< QSharedPointer< TextureTile > >	tiles () const
bool	used () const
Public Member Functions inherited from Marble::Tile
	Tile (TileId const &tileId)
TileId const &	id () const

Detailed Description

A single tile that consists of a stack of Tile layers.

The StackedTile is a tile container that covers a certain area and is used for a particular zoom level. It consists of a stack of several individual thematic Tiles that cover the very same area and are used for the very same zoom level: This stack of Tiles is built up from the ground: The first Tile at the bottom usually represents the ground surface. Optionally there might be a range of other Tiles stacked on top which cover e.g. relief, streets and clouds.

For rendering the whole stack of tiles gets merged and blended into a single QImage. This merging/blending operation is usually only performed once the stack of tiles changes visually. As a result access to the visual composition of all TextureTile layers is very fast since it is reduced to a single QImage that also consumes very little memory.

The whole mechanism is comparable to layers in applications like Gimp or Photoshop (TM) which can be blended on top of each other via so called filters and can be merged into a single layer if required.

Restrictions: The Tiles that are part of the stack need to be of the same size and need to cover the same area at the same zoom level using the very same projection.

Definition at line 50 of file StackedTile.h.

Constructor & Destructor Documentation

StackedTile()

StackedTile::StackedTile ( TileId const & id, QImage const & resultImage, QVector< QSharedPointer< TextureTile > > const & tiles )

explicit

Definition at line 69 of file StackedTile.cpp.

~StackedTile()

StackedTile::~StackedTile ( )

override

Definition at line 87 of file StackedTile.cpp.

Member Function Documentation

byteCount()

int StackedTile::byteCount

(

)

const

Definition at line 315 of file StackedTile.cpp.

depth()

int StackedTile::depth

(

)

const

Definition at line 310 of file StackedTile.cpp.

pixel()

uint StackedTile::pixel	(	int	x,
		int	y ) const

Returns the color value of the result tile at the given integer position.

Returns

The uint that describes the color value of the given pixel

Note: for gray scale images the color value of a single pixel is described via a uchar (1 byte) while for RGB(A) images uint (4 bytes) are used.

Definition at line 93 of file StackedTile.cpp.

pixelF() [1/2]

uint StackedTile::pixelF	(	qreal	x,
		qreal	y ) const

Returns the color value of the result tile at a given floating point position.

Returns

The uint that describes the color value of the given pixel

Subpixel calculation is done via bilinear interpolation.

Note: for gray scale images the color value of a single pixel is described via a uchar (1 byte) while for RGB(A) images uint (4 bytes) are used.

Definition at line 300 of file StackedTile.cpp.

pixelF() [2/2]

uint StackedTile::pixelF	(	qreal	x,
		qreal	y,
		const QRgb &	pixel ) const

Definition at line 114 of file StackedTile.cpp.

resultImage()

QImage const * StackedTile::resultImage

(

)

const

Returns the QImage that describes the merged stack of Tiles.

Returns

A non-zero pointer to the resulting QImage

Definition at line 325 of file StackedTile.cpp.

setUsed()

void StackedTile::setUsed

(

bool

used

)

Definition at line 290 of file StackedTile.cpp.

tiles()

QVector< QSharedPointer< TextureTile > > StackedTile::tiles

(

)

const

Returns the stack of Tiles.

Returns

A container of Tile objects.

Definition at line 320 of file StackedTile.cpp.

used()

bool StackedTile::used

(

)

const

Definition at line 295 of file StackedTile.cpp.

---

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

• StackedTile.h
• StackedTile.cpp