DummyLayerOperations Class Reference

Inheritance diagram for DummyLayerOperations:

Collaboration diagram for DummyLayerOperations:

Public Member Functions
int	getBpp () override
void	initializeCairo (cairo_t *) override
void	draw (cairo_t *, const ConstTile::Ptr &, Scroom::Utils::Rectangle< double >, Scroom::Utils::Rectangle< double >, int, Scroom::Utils::Stuff) override
void	drawState (cairo_t *, TileState, Scroom::Utils::Rectangle< double >) override
void	reduce (Tile::Ptr, const ConstTile::Ptr, int, int) override
Public Member Functions inherited from LayerOperations
virtual Scroom::Utils::Stuff	cache (const ConstTile::Ptr &)
virtual Scroom::Utils::Stuff	cacheZoom (const ConstTile::Ptr &, int, Scroom::Utils::Stuff &)

Static Public Member Functions
static Ptr	create ()

Additional Inherited Members
Public Types inherited from LayerOperations
using	Ptr = std::shared_ptr< LayerOperations >

Member Function Documentation

create()

static Ptr DummyLayerOperations::create ( )

inlinestatic

{ return Ptr(new DummyLayerOperations()); }

draw()

void DummyLayerOperations::draw ( cairo_t *  cr, const ConstTile::Ptr &  tile, Scroom::Utils::Rectangle< double >  tileArea, Scroom::Utils::Rectangle< double >  viewArea, int  zoom, Scroom::Utils::Stuff  cache  )

inlineoverridevirtual

Draw the given tileArea into the given viewArea at the requested zoom level

Parameters

cr	The canvas on which to draw
tile	The tile to take data from
tileArea	Area of the tile that needs to be drawn
viewArea	Area of the canvas that the tile needs to be drawn in
zoom	The requested zoom level. One pixel of your presentation should have size 2**zoom when drawn. zoom will be negative for all but the first layer.
cache	Depending on whether the cacheZoom() function finished already, this may either be an empty reference, or a reference to the value returned by cacheZoom()

Implements LayerOperations.

  {
  }

drawState()

void DummyLayerOperations::drawState ( cairo_t *  cr, TileState  s, Scroom::Utils::Rectangle< double >  viewArea  )

inlineoverridevirtual

Draw the given state into the given viewArea

The associated tile is likely not loaded or not initialized or in whatever other TileState that doesn't allow its contents to be drawn.

Something needs to be drawn in the given viewArea anyway. Implementors might want to just draw an empty rectangle, maybe color-coded to reflect the state of the tile.

Implements LayerOperations.

{}

getBpp()

int DummyLayerOperations::getBpp ( )

inlineoverridevirtual

Return the number of bits per pixel that the layer will use.

This number will be used to compute the amount of memory required to store one tile

Implements LayerOperations.

{ return 8; }

initializeCairo()

void DummyLayerOperations::initializeCairo ( cairo_t *  cr )

inlineoverridevirtual

Initialize the canvas for drawing the bitmap

When TiledBitmapInterface::redraw() is called, (a portion of) the Layer needs to be redrawn. TiledBitmap will compute which tiles are involved in the redraw, and call draw() or drawState() for each of them, as appropriate. However, before doing so, it will first call initializeCairo(). You can take this opportunity to set various properties that are needed in all subsequent calls to draw() and drawState(), such as anti-aliasing and line caps.

Implements LayerOperations.

{}

reduce()

void DummyLayerOperations::reduce ( Tile::Ptr  target, const ConstTile::Ptr  source, int  x, int  y  )

inlineoverridevirtual

Reduce the source tile by a factor of 8

The target tile will contain data for 8*8 source tiles. Offsets x and y indicate which of those 64 source tiles is currently being processed

Parameters

target	Tile that will contain the reduced bitmap
source	Tile that is to be reduced
x	x-offset (0..7) of the source tile in the target tile
y	y-offset (0..7) of the source tile in the target tile

Note

The target tile belongs to a different layer, and hence possibly has a different bpp than the current one, depending on the LayerSpec given to createTiledBitmap()

Implements LayerOperations.

{}

---

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

• libs/tiled-bitmap/test/tiledbitmap-tests.cc