Class IWProjection

An interface which has to be implemented by all map projections. A projection is used by the map to convert from pixel space to map coordinates and vice versa.

IWProjection

IWProjection()

Default constructor.

calculateGridOffset

IWPoint calculateGridOffset(map)

Calculates the offset of the point (0, 0) to a position on the tile grid.

Parameters:
IWMap map - a map

Returns:
IWPoint the offset

clone

clone()

Returns a copy of this projection.

generateTileInformation

object generateTileInformation(x, y, gridOffset)

Generates information like the tile screen position, tile index and tile id for a pixel position.

Parameters:
number x - screen position of the tile
number y - screen position of the tile
IWPoint gridOffset - offset of (0, 0) to the tile grid

Returns:
object 

initialize

void initialize(xmlDocument)

Initializes the projection parameters from a XML document.

Parameters:
Document xmlDocument - a XML document storing all parameters used by the current projection

Returns:
void 

meterToPixel

IWPoint meterToPixel(coord)

Returns the offset in pixels of the specified coordinate to the map center.

Parameters:
IWCoordinate coord - a coordinate

Returns:
IWPoint 

needsReload

boolean needsReload(size)

Checks whether the map has to be reloaded completely to display the specified region.

Parameters:
IWSize size - the size of the visible part of the map in pixels

Returns:
boolean 

pixelToMeter

IWCoordinate pixelToMeter(offset)

Returns the coordinate of the current map center plus the specified offset in pixels.

Parameters:
IWPoint offset - an offset

Returns:
IWCoordinate 

toString

String toString()

Returns a text representation of this projection.

Returns:
String