phaser/v3/src/gameobjects/tilemap/components/WorldToTileX.js
2017-11-27 07:33:30 -06:00

35 lines
1.2 KiB
JavaScript

/**
* Converts from world X coordinates (pixels) to tile X coordinates (tile units), factoring in the
* layer's position, scale and scroll.
*
* @param {number} worldX - [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 X location in tile units.
*/
var WorldToTileX = function (worldX, snapToFloor, camera, layer)
{
if (snapToFloor === undefined) { snapToFloor = true; }
var tileWidth = layer.tileWidth;
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 horizontal scroll
worldX = worldX + (camera.scrollX * tilemapLayer.scrollFactorX) - tilemapLayer.x;
tileWidth *= tilemapLayer.scaleX;
}
return snapToFloor
? Math.floor(worldX / tileWidth)
: worldX / tileWidth;
};
module.exports = WorldToTileX;