CartagenCoordinates

The Cartagen coordinate system describes x and y coordinates for both the entire map (effectively the whole world) and for the viewport - creating confusion for some developers. Here we outline all the notable coordinate systems you can use in JavaScript:

Viewport coordinates

• Map.lon - the longitude of the spot on the planet the Viewport is centered on, i.e. the spot we're looking at, in longitude.
• Map.lat - the latitude of the spot on the planet the Viewport is centered on, i.e. the spot we're looking at.
• Map.x - the y position on the planet of the center of the viewport (what's on the screen). This is basically a direct projection from Map.lon.
• Map.y - the y position on the planet of the center of the viewport (what's on the screen). This is basically a direct projection from Map.lat.
• Map.zoom - ...

Map.x and Map.y may not be 1:1 scale to the pixel dimensions of the browser window. They should be related via the Map.zoom

Mouse coordinates

• Mouse.x - The x position of the mouse pointer with regard to the Viewport in pixels
• Mouse.y - The y position of the mouse pointer with regard to the Viewport in pixels
• Map.pointer_x - The x position of the mouse pointer with regard to the planet - that is, the lat/lon position of the mouse on the planet, projected into x/y.
• Map.pointer_y - The y position of the mouse pointer with regard to the planet - that is, the lat/lon position of the mouse on the planet, projected into x/y.