/**

* @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 SnapFloor = require('../../math/snap/SnapFloor');

var SnapCeil = require('../../math/snap/SnapCeil');

/**

* Returns the tiles in the given layer that are within the camera's viewport. This is used

* internally.

*

* @function Phaser.Tilemaps.Components.CullTiles

* @private

* @since 3.0.0

*

* @param {Phaser.Tilemaps.LayerData} layer - The Tilemap Layer to act upon.

* @param {Phaser.Cameras.Scene2D.Camera} [camera] - The Camera to run the cull check against.

* @param {array} [outputArray] - [description]

*

* @return {Phaser.Tilemaps.Tile[]} An array of Tile objects.

*/

var CullTiles = function (layer, camera, outputArray)

{

if (outputArray === undefined) { outputArray = []; }

outputArray.length = 0;

var tilemap = layer.tilemapLayer.tilemap;

var tilemapLayer = layer.tilemapLayer;

var mapData = layer.data;

var mapWidth = layer.width;

var mapHeight = layer.height;

// We need to use the tile sizes defined for the map as a whole, not the layer,

// in order to calculate the bounds correctly. As different sized tiles may be

// placed on the grid and we cannot trust layer.baseTileWidth to give us the true size.

var tileW = Math.floor(tilemap.tileWidth * tilemapLayer.scaleX);

var tileH = Math.floor(tilemap.tileHeight * tilemapLayer.scaleY);

var drawLeft = 0;

var drawRight = mapWidth;

var drawTop = 0;

var drawBottom = mapHeight;

if (!tilemapLayer.skipCull && tilemapLayer.scrollFactorX === 1 && tilemapLayer.scrollFactorY === 1)

{

// Camera world view bounds, snapped for scaled tile size

// Cull Padding values are given in tiles, not pixels

var boundsLeft = SnapFloor(camera.worldView.x - tilemapLayer.x, tileW, 0, true) - tilemapLayer.cullPaddingX;

var boundsRight = SnapCeil(camera.worldView.right - tilemapLayer.x, tileW, 0, true) + tilemapLayer.cullPaddingX;

var boundsTop = SnapFloor(camera.worldView.y - tilemapLayer.y, tileH, 0, true) - tilemapLayer.cullPaddingY;

var boundsBottom = SnapCeil(camera.worldView.bottom - tilemapLayer.y, tileH, 0, true) + tilemapLayer.cullPaddingY;

drawLeft = Math.max(0, boundsLeft);

drawRight = Math.min(mapWidth, boundsRight);

drawTop = Math.max(0, boundsTop);

drawBottom = Math.min(mapHeight, boundsBottom);

}

for (var y = drawTop; y < drawBottom; y++)

{

for (var x = drawLeft; x < drawRight; x++)

{

var tile = mapData[y][x];

if (!tile || tile.index === -1 || !tile.visible || tile.alpha === 0)

{

continue;

}

outputArray.push(tile);

}

}

tilemapLayer.tilesDrawn = outputArray.length;

tilemapLayer.tilesTotal = mapWidth * mapHeight;

return outputArray;

};

module.exports = CullTiles;