/**
* LittleJS Tile Layer System
* - Caches arrays of tiles to off screen canvas for fast rendering
* - Unlimited numbers of layers, allocates canvases as needed
* - Tile layers can be drawn to using their context with canvas2d
* - Tile layers can also have collision with EngineObjects
* @namespace TileCollision
*/
'use strict';
///////////////////////////////////////////////////////////////////////////////
// Tile Layer System
/** Keep track of all tile layers with collision
* @type {Array<TileCollisionLayer>}
* @memberof TileCollision */
const tileCollisionLayers = [];
/** Get tile collision data for a given cell in the grid
* @param {Vector2} pos
* @return {number}
* @memberof TileCollision */
function tileCollisionGetData(pos)
{
// check all tile collision layers
for (const layer of tileCollisionLayers)
if (pos.arrayCheck(layer.size))
return layer.getCollisionData(pos);
return 0;
}
/** Check if a tile layer collides with another object
* @param {Vector2} pos
* @param {Vector2} [size=(0,0)]
* @param {EngineObject} [object] - An object or undefined for generic test
* @param {boolean} [solidOnly] - Only check solid layers if true
* @return {TileCollisionLayer}
* @memberof TileCollision */
function tileCollisionTest(pos, size=vec2(), object, solidOnly=true)
{
for (const layer of tileCollisionLayers)
{
if (!solidOnly || layer.isSolid)
if (layer.collisionTest(pos, size, object))
return layer;
}
}
/** Return the center of first tile hit, undefined if nothing was hit.
* This does not return the exact intersection, but the center of the tile hit.
* @param {Vector2} posStart
* @param {Vector2} posEnd
* @param {EngineObject} [object] - An object or undefined for generic test
* @param {boolean} [solidOnly=true] - Only check solid layers if true
* @return {Vector2}
* @memberof TileCollision */
function tileCollisionRaycast(posStart, posEnd, object, solidOnly=true)
{
for (const layer of tileCollisionLayers)
{
if (!solidOnly || layer.isSolid)
{
const hitPos = layer.collisionRaycast(posStart, posEnd, object)
if (hitPos)
return hitPos;
}
}
}
///////////////////////////////////////////////////////////////////////////////
/**
* Load tile layers from exported data
* @param {Object} tileMapData - Level data from exported data
* @param {TileInfo} [tileInfo] - Default tile info (used for size and texture)
* @param {number} [renderOrder] - Render order of the top layer
* @param {number} [collisionLayer] - Layer to use for collision if any
* @param {boolean} [draw] - Should the layer be drawn automatically
* @return {Array<TileCollisionLayer>}
* @memberof TileCollision */
function tileCollisionLoad(tileMapData, tileInfo=tile(), renderOrder=0, collisionLayer, draw=true)
{
if (!tileMapData)
{
// default level data if loading failed
const s = 50;
tileMapData = {};
tileMapData.height = tileMapData.width = s;
tileMapData.layers = [{}];
tileMapData.layers[0].data = new Array(s*s).fill(0);
}
// validate the tile map data
ASSERT(tileMapData.width && tileMapData.height);
ASSERT(tileMapData.layers && tileMapData.layers.length);
// create tile layers and fill with data
const tileLayers = [];
const levelSize = vec2(tileMapData.width, tileMapData.height);
const layerCount = tileMapData.layers.length;
for (let layerIndex=layerCount; layerIndex--;)
{
const dataLayer = tileMapData.layers[layerIndex];
ASSERT(dataLayer.data && dataLayer.data.length);
ASSERT(levelSize.area() === dataLayer.data.length);
const layerRenderOrder = renderOrder - (layerCount - 1 - layerIndex);
const tileLayer = new TileCollisionLayer(vec2(), levelSize, tileInfo, layerRenderOrder);
tileLayers[layerIndex] = tileLayer;
for (let x=levelSize.x; x--;)
for (let y=levelSize.y; y--;)
{
const pos = vec2(x, levelSize.y-1-y);
const data = dataLayer.data[x + y*levelSize.x];
if (data)
{
const layerData = new TileLayerData(data-1);
tileLayer.setData(pos, layerData);
// set collision for top layer
if (layerIndex === collisionLayer)
tileLayer.setCollisionData(pos, 1);
}
}
if (draw)
tileLayer.redraw();
}
return tileLayers;
}
///////////////////////////////////////////////////////////////////////////////
/**
* Tile layer data object stores info about how to draw a tile
* @example
* // create tile layer data with tile index 0 and random orientation and color
* const tileIndex = 0;
* const direction = randInt(4)
* const mirror = randInt(2);
* const color = randColor();
* const data = new TileLayerData(tileIndex, direction, mirror, color);
*/
class TileLayerData
{
/** Create a tile layer data object, one for each tile in a TileLayer
* @param {number} [tile] - The tile to use, untextured if undefined
* @param {number} [direction] - Integer direction of tile, in 90 degree increments
* @param {boolean} [mirror] - If the tile should be mirrored along the x axis
* @param {Color} [color] - Color of the tile */
constructor(tile, direction=0, mirror=false, color=new Color)
{
/** @property {number} - The tile to use, untextured if undefined */
this.tile = tile;
/** @property {number} - Integer direction of tile, in 90 degree increments */
this.direction = direction;
/** @property {boolean} - If the tile should be mirrored along the x axis */
this.mirror = mirror;
/** @property {Color} - Color of the tile */
this.color = color.copy();
}
/** Set this tile to clear, it will not be rendered */
clear() { this.tile = this.direction = 0; this.mirror = false; this.color = new Color; }
}
///////////////////////////////////////////////////////////////////////////////
/**
* Canvas Layer - cached off screen rendering system
* - Contains an offscreen canvas that can be rendered to
* - WebGL rendering is optional, call useWebGL to enable
* @extends EngineObject
* @example
* const canvasLayer = new CanvasLayer(vec2(), vec2(200,100));
*/
class CanvasLayer extends EngineObject
{
/** Create a canvas layer object
* @param {Vector2} [position] - World space position of the layer
* @param {Vector2} [size] - World space size of the layer
* @param {number} [angle] - Angle the layer is rotated by
* @param {number} [renderOrder] - Objects sorted by renderOrder
* @param {Vector2} [canvasSize] - Default size of canvas, can be changed later
*/
constructor(position, size, angle=0, renderOrder=0, canvasSize=vec2(512))
{
super(position, size, undefined, angle, WHITE, renderOrder);
/** @property {HTMLCanvasElement} - The canvas used by this layer */
this.canvas = headlessMode ? undefined : new OffscreenCanvas(canvasSize.x, canvasSize.y);
/** @property {OffscreenCanvasRenderingContext2D} - The 2D canvas context used by this layer */
this.context = headlessMode ? undefined : this.canvas.getContext('2d');
/** @property {WebGLTexture} - Texture if using WebGL for this layer, call useWebGL to enable */
this.glTexture = undefined;
this.gravityScale = 0; // disable gravity by default for canvas layers
}
/** Destroy this canvas layer */
destroy()
{
if (this.destroyed)
return;
// free up the WebGL texture
if (this.glTexture)
glDeleteTexture(this.glTexture);
super.destroy();
}
// Render the layer, called automatically by the engine
render()
{
this.draw(this.pos, this.size, this.angle, this.color, this.mirror, this.additiveColor);
}
/** Draw this canvas layer centered in world space, with color applied if using WebGL
* @param {Vector2} pos - Center in world space
* @param {Vector2} [size] - Size in world space
* @param {Color} [color] - Color to modulate with
* @param {number} [angle] - Angle to rotate by
* @param {boolean} [mirror] - If true image is flipped along the Y axis
* @param {Color} [additiveColor] - Additive color to be applied if any
* @param {boolean} [screenSpace] - If true the pos and size are in screen space
* @param {CanvasRenderingContext2D|OffscreenCanvasRenderingContext2D} [context] - Canvas 2D context to draw to
* @memberof Draw */
draw(pos, size, angle=0, color=WHITE, mirror=false, additiveColor, screenSpace=false, context)
{
// draw the canvas layer as a single tile that uses the whole texture
const useWebGL = glEnable && this.glTexture !== undefined;
const tileInfo = new TileInfo().setFullImage(this.canvas, this.glTexture);
drawTile(pos, size, tileInfo, color, angle, mirror, additiveColor, useWebGL, screenSpace, context);
}
/** Draw onto the layer canvas in world space (bypass WebGL)
* @param {Vector2} pos
* @param {Vector2} size
* @param {number} angle
* @param {boolean} mirror
* @param {Function} drawFunction */
drawCanvas2D(pos, size, angle, mirror, drawFunction)
{
const context = this.context;
context.save();
pos = pos.subtract(this.pos).multiply(this.tileInfo.size);
size = size.multiply(this.tileInfo.size);
context.translate(pos.x, this.canvas.height - pos.y);
context.rotate(angle);
context.scale(mirror ? -size.x : size.x, size.y);
drawFunction(context);
context.restore();
}
/** Draw a tile onto the layer canvas in world space
* @param {Vector2} pos
* @param {Vector2} [size=(1,1)]
* @param {TileInfo} [tileInfo]
* @param {Color} [color=(1,1,1,1)]
* @param {number} [angle=0]
* @param {boolean} [mirror=false] */
drawTile(pos, size=vec2(1), tileInfo, color=new Color, angle, mirror)
{
this.drawCanvas2D(pos, size, angle, mirror, (context)=>
{
const textureInfo = tileInfo && tileInfo.textureInfo;
if (textureInfo)
{
context.globalAlpha = color.a; // only alpha is supported
context.drawImage(textureInfo.image,
tileInfo.pos.x, tileInfo.pos.y,
tileInfo.size.x, tileInfo.size.y, -.5, -.5, 1, 1);
context.globalAlpha = 1;
}
else
{
// untextured
context.fillStyle = color;
context.fillRect(-.5, -.5, 1, 1);
}
});
}
/** Draw a rectangle onto the layer canvas in world space
* @param {Vector2} pos
* @param {Vector2} [size=(1,1)]
* @param {Color} [color=(1,1,1,1)]
* @param {number} [angle=0] */
drawRect(pos, size, color, angle)
{ this.drawTile(pos, size, undefined, color, angle); }
/** Create or update the WebGL texture for this layer
* @param {boolean} [enable] - enable WebGL rendering and update the texture */
useWebGL(enable=true)
{
if (glEnable && enable)
{
if (this.glTexture)
glSetTextureData(this.glTexture, this.canvas);
else
this.glTexture = glCreateTexture(this.canvas);
}
else
this.glTexture = undefined;
}
}
///////////////////////////////////////////////////////////////////////////////
/**
* Tile Layer - cached rendering system for tile layers
* - Each Tile layer is rendered to an off screen canvas
* - To allow dynamic modifications, layers are rendered using canvas 2d
* - Some devices like mobile phones are limited to 4k texture resolution
* - For with 16x16 tiles this limits layers to 256x256 on mobile devices
* @extends CanvasLayer
* @example
* const tileLayer = new TileLayer(vec2(), vec2(200,100));
*/
class TileLayer extends CanvasLayer
{
/** Create a tile layer object
* @param {Vector2} position - World space position
* @param {Vector2} size - World space size
* @param {TileInfo} [tileInfo] - Default tile info for layer (used for size and texture)
* @param {Vector2} [scale=(1,1)] - How much to scale this layer when rendered
* @param {number} [renderOrder] - Objects are sorted by renderOrder
* @param {boolean} [useWebGL=glEnable] - Use accelerated WebGL rendering
*/
constructor(position, size, tileInfo=tile(), scale=vec2(1), renderOrder=0, useWebGL=glEnable)
{
super(position, size, 0, renderOrder, size);
this.tileInfo = tileInfo;
const canvasSize = size.multiply(tileInfo.size);
/** @property {HTMLCanvasElement} - The canvas used by this tile layer */
this.canvas = new OffscreenCanvas(canvasSize.x, canvasSize.y);
/** @property {OffscreenCanvasRenderingContext2D} - The 2D canvas context used by this tile layer */
this.context = this.canvas.getContext('2d');
/** @property {WebGLTexture} - Texture if using WebGL for this layer */
this.glTexture = useWebGL ? glCreateTexture(this.canvas) : undefined;
// set no friction by default, applied friction is max of both objects
this.friction = 0;
// set no restitution by default, applied restitution is max of both objects
this.restitution = 0;
// init tile data
this.data = [];
for (let j = this.size.area(); j--;)
this.data.push(new TileLayerData);
if (headlessMode)
{
// disable rendering
this.redraw = () => {};
this.render = () => {};
this.redrawStart = () => {};
this.redrawEnd = () => {};
this.drawTileData = () => {};
this.drawCanvas2D = () => {};
this.useWebGL = () => {};
}
}
/** Set data at a given position in the array
* @param {Vector2} layerPos - Local position in array
* @param {TileLayerData} data - Data to set
* @param {boolean} [redraw] - Force the tile to redraw if true */
setData(layerPos, data, redraw=false)
{
if (layerPos.arrayCheck(this.size))
{
this.data[(layerPos.y|0)*this.size.x+layerPos.x|0] = data;
redraw && this.drawTileData(layerPos);
}
}
/** Get data at a given position in the array
* @param {Vector2} layerPos - Local position in array
* @return {TileLayerData} */
getData(layerPos)
{ return layerPos.arrayCheck(this.size) && this.data[(layerPos.y|0)*this.size.x+layerPos.x|0]; }
// Render the tile layer, called automatically by the engine
render()
{
ASSERT(drawContext !== this.context, 'must call redrawEnd() after drawing tiles!');
// draw the tile layer as a single tile
const tileInfo = new TileInfo().setFullImage(this.canvas, this.glTexture);
const pos = this.pos.add(this.size.scale(.5));
const useWebGL = glEnable && this.glTexture !== undefined;
drawTile(pos, this.size, tileInfo, WHITE, 0, false, CLEAR_BLACK, useWebGL);
}
/** Draw all the tile data to an offscreen canvas
* - This may be slow in some browsers but only needs to be done once */
redraw()
{
this.redrawStart(true);
for (let x = this.size.x; x--;)
for (let y = this.size.y; y--;)
this.drawTileData(vec2(x,y), false);
this.redrawEnd();
if (this.glTexture)
this.useWebGL(); // update WebGL texture
}
/** Call to start the redraw process
* - This can be used to manually update small parts of the level
* @param {boolean} [clear] - Should it clear the canvas before drawing */
redrawStart(clear=false)
{
// save current render settings
/** @type {[HTMLCanvasElement|OffscreenCanvas, CanvasRenderingContext2D|OffscreenCanvasRenderingContext2D, Vector2, Vector2, number]} */
this.savedRenderSettings = [drawCanvas, drawContext, mainCanvasSize, cameraPos, cameraScale];
// set the draw canvas and context to this layer
// use camera settings to match this layer's canvas
drawCanvas = this.canvas;
drawContext = this.context;
cameraPos = this.size.scale(.5);
cameraScale = this.tileInfo.size.x;
mainCanvasSize = this.size.multiply(this.tileInfo.size);
if (clear)
{
// clear and set size
drawCanvas.width = mainCanvasSize.x;
drawCanvas.height = mainCanvasSize.y;
}
// disable smoothing for pixel art
this.context.imageSmoothingEnabled = !tilesPixelated;
// setup gl rendering if enabled
glPreRender();
}
/** Call to end the redraw process */
redrawEnd()
{
ASSERT(drawContext === this.context, 'must call redrawStart() before drawing tiles');
glCopyToContext(drawContext);
//debugSaveCanvas(this.canvas);
// set stuff back to normal
[drawCanvas, drawContext, mainCanvasSize, cameraPos, cameraScale] = this.savedRenderSettings;
}
/** Draw the tile at a given position in the tile grid
* This can be used to clear out tiles when they are destroyed
* Tiles can also be redrawn if inside a redrawStart/End block
* @param {Vector2} layerPos
* @param {boolean} [clear] - should the old tile be cleared out
*/
drawTileData(layerPos, clear=true)
{
// clear out where the tile was, for full opaque tiles this can be skipped
const s = this.tileInfo.size;
if (clear)
{
const pos = layerPos.multiply(s);
this.context.clearRect(pos.x, this.canvas.height-pos.y, s.x, -s.y);
}
// draw the tile if it has layer data
const d = this.getData(layerPos);
if (d.tile !== undefined)
{
ASSERT(drawContext === this.context, 'must call redrawStart() before drawing tiles');
const pos = layerPos.add(vec2(.5));
const tileInfo = tile(d.tile, s, this.tileInfo.textureIndex, this.tileInfo.padding);
drawTile(pos, vec2(1), tileInfo, d.color, d.direction*PI/2, d.mirror);
}
}
}
///////////////////////////////////////////////////////////////////////////////
/**
* Tile Collision Layer - a tile layer with collision
* - adds collision data and functions to TileLayer
* - there can be multiple tile collision layers
* - tile collision layers should not overlap each other
* @extends TileLayer
*/
class TileCollisionLayer extends TileLayer
{
/** Create a tile layer object
* @param {Vector2} position - World space position
* @param {Vector2} size - World space size
* @param {TileInfo} [tileInfo] - Tile info for layer
* @param {number} [renderOrder] - Objects are sorted by renderOrder
* @param {boolean} [useWebGL=glEnable] - Use accelerated WebGL rendering
*/
constructor(position, size, tileInfo=tile(), renderOrder=0, useWebGL=glEnable)
{
const scale = vec2(1); // collision layers are not scaled
super(position, size.floor(), tileInfo, scale, renderOrder, useWebGL);
/** @property {Array<number>} - The tile collision grid */
this.collisionData = [];
this.initCollision(this.size);
// keep track of all collision layers
tileCollisionLayers.push(this);
// tile collision layers are solid by default
this.isSolid = true;
}
/** Destroy this tile layer */
destroy()
{
if (this.destroyed)
return;
// remove from collision layers array and destroy
const index = tileCollisionLayers.indexOf(this);
ASSERT(index >= 0, 'tile collision layer not found in array');
tileCollisionLayers.splice(index, 1);
super.destroy();
}
/** Clear and initialize tile collision to new size
* @param {Vector2} size - width and height of tile collision 2d grid */
initCollision(size)
{
this.size = size.floor();
this.collisionData = [];
this.collisionData.length = size.area();
this.collisionData.fill(0);
}
/** Set tile collision data for a given cell in the grid
* @param {Vector2} gridPos
* @param {number} [data] */
setCollisionData(gridPos, data=1)
{
const i = (gridPos.y|0)*this.size.x + gridPos.x|0;
gridPos.arrayCheck(this.size) && (this.collisionData[i] = data);
}
/** Get tile collision data for a given cell in the grid
* @param {Vector2} gridPos
* @return {number} */
getCollisionData(gridPos)
{
const i = (gridPos.y|0)*this.size.x + gridPos.x|0;
return gridPos.arrayCheck(this.size) ? this.collisionData[i] : 0;
}
/** Check if collision with another object should occur
* @param {Vector2} pos
* @param {Vector2} [size=(0,0)]
* @param {EngineObject} [object]
* @return {boolean} */
collisionTest(pos, size=new Vector2, object)
{
// transform to local layer space
const posX = pos.x - this.pos.x;
const posY = pos.y - this.pos.y;
// check any tiles in the area for collision
const minX = max(posX - size.x/2|0, 0);
const minY = max(posY - size.y/2|0, 0);
const maxX = min(posX + size.x/2, this.size.x);
const maxY = min(posY + size.y/2, this.size.y);
const hitPos = new Vector2;
for (let y = minY; y < maxY; ++y)
for (let x = minX; x < maxX; ++x)
{
// check if the object should collide with this tile
const tileData = this.collisionData[y*this.size.x+x];
if (tileData)
if (!object || object.collideWithTile(tileData, hitPos.set(x, y)))
return true;
}
return false;
}
/** Return the center of first tile hit, undefined if nothing was hit.
* This does not return the exact intersection, but the center of the tile hit.
* @param {Vector2} posStart
* @param {Vector2} posEnd
* @param {EngineObject} [object]
* @return {Vector2} */
collisionRaycast(posStart, posEnd, object)
{
// transform to local layer space
const posStartX = posStart.x - this.pos.x;
const posStartY = posStart.y - this.pos.y;
const posEndX = posEnd.x - this.pos.x;
const posEndY = posEnd.y - this.pos.y;
// test if a ray collides with tiles from start to end
const deltaX = posEndX - posStartX;
const deltaY = posEndY - posStartY;
const totalLength = (deltaX**2 + deltaY**2)**.5;
const unitX = abs(totalLength/deltaX);
const unitY = abs(totalLength/deltaY);
// setup iteration variables
const pos = posStart.floor(), signDeltaX = sign(deltaX), signDeltaY = sign(deltaY);
let xi = unitX * (deltaX < 0 ? posStart.x - pos.x : pos.x - posStart.x + 1) || 0;
let yi = unitY * (deltaY < 0 ? posStart.y - pos.y : pos.y - posStart.y + 1) || 0;
// use line drawing algorithm to test for collisions
while (true)
{
// check for tile collision
const tileData = this.getCollisionData(pos);
if (tileData && (!object || object.collideWithTile(tileData, pos)))
{
pos.x += .5; pos.y += .5;
debugRaycast && debugLine(posStart, posEnd, '#f00', .02);
debugRaycast && debugPoint(pos, '#ff0');
return pos;
}
// check if past the end
if (xi >= totalLength && yi >= totalLength)
break;
// get coordinates of next tile to check
if (xi > yi)
pos.y += signDeltaY, yi += unitY;
else
pos.x += signDeltaX, xi += unitX;
}
debugRaycast && debugLine(posStart, posEnd, '#00f', .02);
}
}