littlejsengine
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LittleJS - Tiny and Fast HTML5 Game Engine
656 lines (591 loc) • 26 kB
JavaScript
/**
* 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 TileLayers
*/
'use strict';
///////////////////////////////////////////////////////////////////////////////
// Tile Layer System
/** Keep track of all tile layers with collision
* @type {Array<TileCollisionLayer>}
* @memberof TileLayers */
const tileCollisionLayers = [];
/** Get tile collision data for a given cell in the grid
* @param {Vector2} pos
* @return {number}
* @memberof TileLayers */
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 TileLayers */
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 exact position of the boundary of first tile hit, undefined if nothing was hit.
* The point will be inside the colliding tile if it hits (may have a tiny shift)
* @param {Vector2} posStart
* @param {Vector2} posEnd
* @param {EngineObject} [object] - An object or undefined for generic test
* @param {Vector2} [normal] - Optional normal of the surface hit
* @param {boolean} [solidOnly=true] - Only check solid layers if true
* @return {Vector2|undefined} - position of the center of the tile hit or undefined if no hit
* @memberof TileLayers */
function tileCollisionRaycast(posStart, posEnd, object, normal, solidOnly=true)
{
for (const layer of tileCollisionLayers)
{
if (!solidOnly || layer.isSolid)
{
const hitPos = layer.collisionRaycast(posStart, posEnd, object, normal)
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 TileLayers */
function tileLayersLoad(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;
// apply layer color
const layerColor = dataLayer.tintcolor ?
new Color().setHex(dataLayer.tintcolor) :
dataLayer.color || WHITE;
ASSERT(isColor(layerColor), 'layer color is not a color');
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, 0, false, layerColor);
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
* @memberof TileLayers
* @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
* @memberof TileLayers
* @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))
{
ASSERT(isVector2(canvasSize), 'canvasSize must be a Vector2');
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 = this.canvas?.getContext('2d');
/** @property {TextureInfo} - Texture info to use for this object rendering */
const useWebGL = false; // do not use webgl by default
this.textureInfo = new TextureInfo(this.canvas, useWebGL);
/** @property {boolean} - True if WebGL texture needs to be refreshed */
this.refreshWebGL = false;
// disable physics by default
this.mass = this.gravityScale = this.friction = this.restitution = 0;
}
/** Destroy this canvas layer */
destroy()
{
if (this.destroyed) return;
this.textureInfo.destroyWebGLTexture();
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)
{
const useWebGL = glEnable && this.textureInfo.hasWebGL();
if (useWebGL && this.refreshWebGL)
{
// update the WebGL texture
this.textureInfo.createWebGLTexture();
this.refreshWebGL = false;
}
// draw the canvas layer as a single tile that uses the whole texture
const tileInfo = new TileInfo().setFullImage(this.textureInfo);
drawTile(pos, size, tileInfo, color, angle, mirror, additiveColor, useWebGL, screenSpace, context);
}
/**
* @callback Canvas2DDrawCallback - Function that draws to a canvas 2D context
* @param {CanvasRenderingContext2D|OffscreenCanvasRenderingContext2D} context
* @memberof TileLayers
*/
/** Draw onto the layer canvas in world space (bypass WebGL)
* @param {Vector2} pos
* @param {Vector2} size
* @param {number} angle
* @param {boolean} mirror
* @param {Canvas2DDrawCallback} drawFunction */
drawCanvas2D(pos, size, angle, mirror, drawFunction)
{
if (!this.context) return;
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.toString();
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
* @param {boolean} [immediate] - shoulkd the texture be updated immediately
*/
useWebGL(enable=true, immediate=false)
{
if (!immediate && enable && this.textureInfo.hasWebGL())
{
// refresh the texture when needed
this.refreshWebGL = true;
return;
}
if (enable)
this.textureInfo.createWebGLTexture();
else
this.textureInfo.destroyWebGLTexture();
}
}
///////////////////////////////////////////////////////////////////////////////
/**
* 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
* - Tile layers are centered on their corner, so normal levels are at (0,0)
* @extends CanvasLayer
* @memberof TileLayers
* @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 {number} [renderOrder] - Objects are sorted by renderOrder
*/
constructor(position, size, tileInfo=tile(), renderOrder=0)
{
const canvasSize = tileInfo ? size.multiply(tileInfo.size) : size;
super(position, size, 0, renderOrder, canvasSize);
// set tile info
this.tileInfo = tileInfo;
// 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)
{
ASSERT(isVector2(layerPos), 'layerPos must be a Vector2');
ASSERT(data instanceof TileLayerData, 'data must be a TileLayerData');
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)
{
ASSERT(isVector2(layerPos), 'layerPos must be a Vector2');
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!');
if (this.refreshWebGL)
{
// update the WebGL texture
this.textureInfo.createWebGLTexture();
this.refreshWebGL = false;
}
// draw the tile layer as a single tile
const tileInfo = new TileInfo().setFullImage(this.textureInfo);
const size = this.drawSize || this.size;
const pos = this.pos.add(size.scale(.5));
const useWebGL = glEnable && this.textureInfo.hasWebGL();
drawTile(pos, 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();
this.useWebGL();
}
/** 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)
{
if (!this.context) return;
// 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);
const tileSize = this.tileInfo ? this.tileInfo.size : vec2(1);
cameraScale = tileSize.x;
mainCanvasSize = this.size.multiply(tileSize);
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()
{
if (!this.context) return;
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)
{
if (!this.context) return;
// 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
* @memberof TileLayers
*/
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
*/
constructor(position, size, tileInfo=tile(), renderOrder=0)
{
super(position, size.floor(), tileInfo, renderOrder);
/** @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');
index >= 0 && 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)
{
ASSERT(isVector2(size), 'size must be a Vector2');
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)
{
ASSERT(isVector2(gridPos), 'gridPos must be a Vector2');
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)
{
ASSERT(isVector2(gridPos), 'gridPos must be a Vector2');
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)
{
ASSERT(isVector2(pos) && isVector2(size), 'pos and size must be Vector2s');
ASSERT(!object || object instanceof EngineObject, 'object must be an EngineObject');
// 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 + this.pos.x, y + this.pos.y)))
return true;
}
return false;
}
/** Return the exact position of the boundary of first tile hit, undefined if nothing was hit.
* The point will be inside the colliding tile if it hits (may have a tiny shift)
* @param {Vector2} posStart
* @param {Vector2} posEnd
* @param {EngineObject} [object] - An object or undefined for generic test
* @param {Vector2} [normal] - Optional normal of the surface hit
* @return {Vector2|undefined} */
collisionRaycast(posStart, posEnd, object, normal)
{
ASSERT(isVector2(posStart) && isVector2(posEnd), 'positions must be Vector2s');
ASSERT(!object || object instanceof EngineObject, 'object must be an EngineObject');
const localPos = new Vector2;
const collisionTest = (pos)=>
{
// check for tile collision
localPos.set(pos.x - this.pos.x, pos.y - this.pos.y);
const tileData = this.getCollisionData(localPos);
return tileData && (!object || object.collideWithTile(tileData, pos));
}
debugRaycast && debugLine(posStart, posEnd, '#00f', .02);
const hitPos = lineTest(posStart, posEnd, collisionTest, normal);
if (hitPos)
{
const tilePos = hitPos.floor().add(vec2(.5));
debugRaycast && debugRect(tilePos, vec2(1), '#f008');
debugRaycast && debugLine(posStart, hitPos, '#f00', .02);
debugRaycast && debugPoint(hitPos, '#0f0');
debugRaycast && normal &&
debugLine(hitPos, hitPos.add(normal), '#ff0', .02);
return hitPos;
}
}
}