phaser/src/tilemaps/components/WorldToTileY.js

36 lines
1.2 KiB
JavaScript
Raw Normal View History

2017-11-27 13:33:30 +00:00
/**
* Converts from world Y coordinates (pixels) to tile Y coordinates (tile units), factoring in the
* layer's position, scale and scroll.
*
* @param {number} worldY - [description]
* @param {boolean} [snapToFloor=true] - Whether or not to round the tile coordinate down to the
* nearest integer.
* @param {Camera} [camera=main camera] - [description]
* @param {LayerData} layer - [description]
* @returns {number} The Y location in tile units.
*/
var WorldToTileY = function (worldY, snapToFloor, camera, layer)
{
if (snapToFloor === undefined) { snapToFloor = true; }
var tileHeight = layer.baseTileHeight;
var tilemapLayer = layer.tilemapLayer;
if (tilemapLayer)
{
if (camera === undefined) { camera = tilemapLayer.scene.cameras.main; }
// Find the world position relative to the static or dynamic layer's top left origin,
// factoring in the camera's vertical scroll
worldY = worldY - (tilemapLayer.y + camera.scrollY * (1 - tilemapLayer.scrollFactorY));
tileHeight *= tilemapLayer.scaleY;
}
return snapToFloor
? Math.floor(worldY / tileHeight)
: worldY / tileHeight;
};
module.exports = WorldToTileY;