phaser/src/physics/arcade/tilemap/SeparateTile.js

A fast, free and fun HTML5 Game Framework for Desktop and Mobile web browsers.

/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2018 Photon Storm Ltd.
 * @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
 */

var TileCheckX = require('./TileCheckX');
var TileCheckY = require('./TileCheckY');
var TileIntersectsBody = require('./TileIntersectsBody');

/**
 * The core separation function to separate a physics body and a tile.
 *
 * @function Phaser.Physics.Arcade.Tilemap.SeparateTile
 * @since 3.0.0
 *
 * @param {number} i - [description]
 * @param {Phaser.Physics.Arcade.Body} body - The Body object to separate.
 * @param {Phaser.Tilemaps.Tile} tile - The tile to collide against.
 * @param {Phaser.Geom.Rectangle} tileWorldRect - [description]
 * @param {(Phaser.Tilemaps.DynamicTilemapLayer|Phaser.Tilemaps.StaticTilemapLayer)} tilemapLayer - The tilemapLayer to collide against.
 * @param {number} tileBias - [description]
 *
 * @return {boolean} Returns true if the body was separated, otherwise false.
 */
var SeparateTile = function (i, body, tile, tileWorldRect, tilemapLayer, tileBias)
{
    var tileLeft = tileWorldRect.left;
    var tileTop = tileWorldRect.top;
    var tileRight = tileWorldRect.right;
    var tileBottom = tileWorldRect.bottom;
    var faceHorizontal = tile.faceLeft || tile.faceRight;
    var faceVertical = tile.faceTop || tile.faceBottom;

    //  We don't need to go any further if this tile doesn't actually have any colliding faces. This
    //  could happen if the tile was meant to be collided with re: a callback, but otherwise isn't
    //  needed for separation.
    if (!faceHorizontal && !faceVertical)
    {
        return false;
    }

    var ox = 0;
    var oy = 0;
    var minX = 0;
    var minY = 1;

    if (body.deltaAbsX() > body.deltaAbsY())
    {
        //  Moving faster horizontally, check X axis first
        minX = -1;
    }
    else if (body.deltaAbsX() < body.deltaAbsY())
    {
        //  Moving faster vertically, check Y axis first
        minY = -1;
    }

    if (body.deltaX() !== 0 && body.deltaY() !== 0 && faceHorizontal && faceVertical)
    {
        //  We only need do this if both axes have colliding faces AND we're moving in both
        //  directions
        minX = Math.min(Math.abs(body.position.x - tileRight), Math.abs(body.right - tileLeft));
        minY = Math.min(Math.abs(body.position.y - tileBottom), Math.abs(body.bottom - tileTop));
    }

    if (minX < minY)
    {
        if (faceHorizontal)
        {
            ox = TileCheckX(body, tile, tileLeft, tileRight, tileBias);

            //  That's horizontal done, check if we still intersects? If not then we can return now
            if (ox !== 0 && !TileIntersectsBody(tileWorldRect, body))
            {
                return true;
            }
        }

        if (faceVertical)
        {
            oy = TileCheckY(body, tile, tileTop, tileBottom, tileBias);
        }
    }
    else
    {
        if (faceVertical)
        {
            oy = TileCheckY(body, tile, tileTop, tileBottom, tileBias);

            //  That's vertical done, check if we still intersects? If not then we can return now
            if (oy !== 0 && !TileIntersectsBody(tileWorldRect, body))
            {
                return true;
            }
        }

        if (faceHorizontal)
        {
            ox = TileCheckX(body, tile, tileLeft, tileRight, tileBias);
        }
    }

    return (ox !== 0 || oy !== 0);
};

module.exports = SeparateTile;