I have downloaded a ready-made HTML5 tile-swapping puzzle, but I am not getting how to change the canvas position.
If we change the canvas position by giving a margin to the body, the puzzle doesn't work. I'd like to align the puzzle to the middle of the page.
Here is a JSFiddle with the code for the puzzle:
https://jsfiddle.net/kilobyte/0ej6cv6w/
Here is an excerpt of the code you should examine, where I'm changing the margin:
function Add(){
alert("Congratulation...! You have Won...!!");
var btn=document.createElement("input");
btn.type="button";
btn.id="mybutton";
btn.value="Submit";
btn.style.width="100px";
btn.style.height="50px";
btn.style.background="green";
btn.style.margin="100px";
document.body.appendChild(btn);
var buttonid =document.getElementById("mybutton");
buttonid.addEventListener('click', ButtonClick,false);
}
function gameOver(){
document.onmousedown = null;
document.onmousemove = null;
document.onmouseup = null;
Add();
//initPuzzle();
}
Edit: Ok, seems like Firefox works, but chrome has a different behaviour. Im not going to rewrite the game, but i can give you a pointer on what to do. You need to edit the function called onPuzzleClick(), its located on on line 103 in the code. Thats where the click position is set (_mouse.x and _mouse.y). You need to find out whats different in chrome and set the correct position there, id advise looking at the left-margin and top-margin or some absolute position or similar
The code that you quote in your question doesn't actually change the margin of the canvas. It assigns a margin to a button at the end of the game. But never mind that. In my demonstration below, I've removed the unnecessary button and I set the canvas margin with CSS.
We can fix the problem of the shifted canvas with the help of a function that calculates the offset of an HTML element with respect to an HTML element that encloses it:
function getOffset(element, ancestor) {
var left = 0,
top = 0;
while (element != ancestor) {
left += element.offsetLeft;
top += element.offsetTop;
element = element.parentNode;
}
return { left: left, top: top };
}
We also need a function that computes the mouse position with respect to the upper left corner of the page:
function getMousePosition (event) {
event = event || window.event;
if (event.pageX) {
return { x: event.pageX, y: event.pageY };
}
return {
x: event.clientX + document.body.scrollLeft +
document.documentElement.scrollLeft,
y: event.clientY + document.body.scrollTop +
document.documentElement.scrollTop
};
}
In setCanvas(), we calculate and save the offset of the canvas relative to the page:
_canvas.offset = getOffset(_canvas, document.body);
Subsequently, when we need the mouse coordinates in onPuzzleClick() and updatePuzzle(), we take the canvas offset into account:
var position = getMousePosition(e);
_mouse.x = position.x - _canvas.offset.left;
_mouse.y = position.y - _canvas.offset.top;
Now the puzzle works correctly regardless of where the canvas is positioned:
const PUZZLE_DIFFICULTY = 4;
const PUZZLE_HOVER_TINT = '#009900';
var _canvas;
var _stage;
var _img;
var _pieces;
var _puzzleWidth;
var _puzzleHeight;
var _pieceWidth;
var _pieceHeight;
var _currentPiece;
var _currentDropPiece;
var _mouse;
function getOffset(element, ancestor) {
var left = 0,
top = 0;
while (element != ancestor) {
left += element.offsetLeft;
top += element.offsetTop;
element = element.parentNode;
}
return { left: left, top: top };
}
function getMousePosition (event) {
event = event || window.event;
if (event.pageX) {
return { x: event.pageX, y: event.pageY };
}
return {
x: event.clientX + document.body.scrollLeft +
document.documentElement.scrollLeft,
y: event.clientY + document.body.scrollTop +
document.documentElement.scrollTop
};
}
function init(){
_img = new Image();
_img.addEventListener('load',onImage,false);
_img.src = "http://www.justvape247.com/ekmps/shops/justvape247/images/red-apple-natural-f.w-16946-p.jpg";
}
function onImage(e){
_pieceWidth = Math.floor(_img.width / PUZZLE_DIFFICULTY)
_pieceHeight = Math.floor(_img.height / PUZZLE_DIFFICULTY)
_puzzleWidth = _pieceWidth * PUZZLE_DIFFICULTY;
_puzzleHeight = _pieceHeight * PUZZLE_DIFFICULTY;
setCanvas();
initPuzzle();
}
function setCanvas(){
_canvas = document.getElementById('gameCanvas');
_stage = _canvas.getContext('2d');
_canvas.width = _puzzleWidth;
_canvas.height = _puzzleHeight;
_canvas.style.border = "1px solid black";
_canvas.offset = getOffset(_canvas, document.body);
}
function initPuzzle(){
_pieces = [];
_mouse = {x:0,y:0};
_currentPiece = null;
_currentDropPiece = null;
_stage.drawImage(_img, 0, 0, _puzzleWidth, _puzzleHeight, 0, 0, _puzzleWidth, _puzzleHeight);
createTitle("Click to Start Puzzle");
buildPieces();
}
function createTitle(msg){
_stage.fillStyle = "#000000";
_stage.globalAlpha = .4;
_stage.fillRect(100,_puzzleHeight - 40,_puzzleWidth - 200,40);
_stage.fillStyle = "#FFFFFF";//text color
_stage.globalAlpha = 1;
_stage.textAlign = "center";
_stage.textBaseline = "middle";
_stage.font = "20px Arial";
_stage.fillText(msg,_puzzleWidth / 2,_puzzleHeight - 20);
}
function buildPieces(){
var i;
var piece;
var xPos = 0;
var yPos = 0;
for(i = 0;i < PUZZLE_DIFFICULTY * PUZZLE_DIFFICULTY;i++){
piece = {};
piece.sx = xPos;
piece.sy = yPos;
_pieces.push(piece);
xPos += _pieceWidth;
if(xPos >= _puzzleWidth){
xPos = 0;
yPos += _pieceHeight;
}
}
document.onmousedown = shufflePuzzle;
}
function shufflePuzzle(){
_pieces = shuffleArray(_pieces);
_stage.clearRect(0,0,_puzzleWidth,_puzzleHeight);
var i;
var piece;
var xPos = 0;
var yPos = 0;
for(i = 0;i < _pieces.length;i++){
piece = _pieces[i];
piece.xPos = xPos;
piece.yPos = yPos;
_stage.drawImage(_img, piece.sx, piece.sy, _pieceWidth, _pieceHeight, xPos, yPos, _pieceWidth, _pieceHeight);
_stage.strokeRect(xPos, yPos, _pieceWidth,_pieceHeight);
xPos += _pieceWidth;
if(xPos >= _puzzleWidth){
xPos = 0;
yPos += _pieceHeight;
}
}
document.onmousedown = onPuzzleClick;
}
function shuffleArray(o){
for(var j, x, i = o.length; i; j = parseInt(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);
return o;
}
function onPuzzleClick(e){
var position = getMousePosition(e);
_mouse.x = position.x - _canvas.offset.left;
_mouse.y = position.y - _canvas.offset.top;
_currentPiece = checkPieceClicked();
if(_currentPiece != null){
_stage.clearRect(_currentPiece.xPos,_currentPiece.yPos,_pieceWidth,_pieceHeight);
_stage.save();
_stage.globalAlpha = .9;
_stage.drawImage(_img, _currentPiece.sx, _currentPiece.sy, _pieceWidth, _pieceHeight, _mouse.x - (_pieceWidth / 2), _mouse.y - (_pieceHeight / 2), _pieceWidth, _pieceHeight);
_stage.restore();
document.onmousemove = updatePuzzle;
document.onmouseup = pieceDropped;
}
}
function checkPieceClicked(){
var i;
var piece;
for(i = 0;i < _pieces.length;i++){
piece = _pieces[i];
if(_mouse.x < piece.xPos || _mouse.x > (piece.xPos + _pieceWidth) || _mouse.y < piece.yPos || _mouse.y > (piece.yPos + _pieceHeight)){
//PIECE NOT HIT
}
else{
return piece;
}
}
return null;
}
function updatePuzzle(e){
var position = getMousePosition(e);
_mouse.x = position.x - _canvas.offset.left;
_mouse.y = position.y - _canvas.offset.top;
_currentDropPiece = null;
_stage.clearRect(0,0,_puzzleWidth,_puzzleHeight);
var i;
var piece;
for(i = 0;i < _pieces.length;i++){
piece = _pieces[i];
if(piece == _currentPiece){
continue;
}
_stage.drawImage(_img, piece.sx, piece.sy, _pieceWidth, _pieceHeight, piece.xPos, piece.yPos, _pieceWidth, _pieceHeight);
_stage.strokeRect(piece.xPos, piece.yPos, _pieceWidth,_pieceHeight);
if(_currentDropPiece == null){
if(_mouse.x < piece.xPos || _mouse.x > (piece.xPos + _pieceWidth) || _mouse.y < piece.yPos || _mouse.y > (piece.yPos + _pieceHeight)){
//NOT OVER
}
else{
_currentDropPiece = piece;
_stage.save();
_stage.globalAlpha = .4;
_stage.fillStyle = PUZZLE_HOVER_TINT;
_stage.fillRect(_currentDropPiece.xPos,_currentDropPiece.yPos,_pieceWidth, _pieceHeight);
_stage.restore();
}
}
}
_stage.save();
_stage.globalAlpha = .6;
_stage.drawImage(_img, _currentPiece.sx, _currentPiece.sy, _pieceWidth, _pieceHeight, _mouse.x - (_pieceWidth / 2), _mouse.y - (_pieceHeight / 2), _pieceWidth, _pieceHeight);
_stage.restore();
_stage.strokeRect( _mouse.x - (_pieceWidth / 2), _mouse.y - (_pieceHeight / 2), _pieceWidth,_pieceHeight);
}
function pieceDropped(e){
document.onmousemove = null;
document.onmouseup = null;
if(_currentDropPiece != null){
var tmp = {xPos:_currentPiece.xPos,yPos:_currentPiece.yPos};
_currentPiece.xPos = _currentDropPiece.xPos;
_currentPiece.yPos = _currentDropPiece.yPos;
_currentDropPiece.xPos = tmp.xPos;
_currentDropPiece.yPos = tmp.yPos;
}
resetPuzzleAndCheckWin();
}
function resetPuzzleAndCheckWin(){
_stage.clearRect(0,0,_puzzleWidth,_puzzleHeight);
var gameWin = true;
var i;
var piece;
for(i = 0;i < _pieces.length;i++){
piece = _pieces[i];
_stage.drawImage(_img, piece.sx, piece.sy, _pieceWidth, _pieceHeight, piece.xPos, piece.yPos, _pieceWidth, _pieceHeight);
_stage.strokeRect(piece.xPos, piece.yPos, _pieceWidth,_pieceHeight);
if(piece.xPos != piece.sx || piece.yPos != piece.sy){
gameWin = false;
}
}
if(gameWin){
setTimeout(gameOver,500);
}
}
function gameOver(){
document.onmousedown = null;
document.onmousemove = null;
document.onmouseup = null;
alert("Congratulations...! You have Won...!!");
}
window.onload = init;
#gameCanvas {
margin: 20px 50px;
}
<canvas id="gameCanvas"></canvas>
Related
I wish to create a simple webgame that involves a tiled board. I have a collection of svg's for the background of each square (i.e one for grass, one for stone, one for dirt etc). I also have svg's for items that will be displayed on the layer above the background (such as trees, wood, sword).
I have an in memory database of what the background for each square is and if and which item it contains.
I wish to be able to:
* Zoom in or out
* Scroll left or right
* Scolll up or down
* Have items displayed above the background for that square
Only needs to work in recent versions of modern browsers
What is the best approach for this:
1. Have a canvas object. Get the current zoom, top most XY, canvas width and canvas height. Loop though the squares in the in memory database and print the corresponding SVG's in the correct locations. Each time it is scrolled or zoomed reprint the entire board.
2. Have a div. Get the current zoom, top most XY, canvas width and canvas height. Loop though the squares in the in memory database and create SVG's in the correct locations.
Each time the board scrolls add new SVGs as they become visible, delete SVGs as they move of the board. Translate all the existing SVGs by the appropriate amount.
Each time the board zooms enlarge or shrink all the existing SVGs based on the new zoom level.
3. Some third approach that I am unaware of.
The example below uses two modules svg to load images (Any image format will work) & board which handles panning, zooming & rendering. It also provides an onClick event which will give you an object that describes the tile that has been clicked on.
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<style>
body {
background-color: black;
}
canvas {
display: block;
margin: 30px auto 0px auto;
border: solid 1px white;
border-radius: 10px;
}
</style>
</head>
<body>
<canvas id="canvas"></canvas>
<script type="application/javascript">
var svg = function() {
"use strict";
var svgImages = [];
var areImagesLoaded = true;
var isPageLoaded = false;
addEventListener("load",function() { isPageLoaded = true; isFinished(); });
var exports = {
onload: function() {},
request: null,
get: null
};
function isFinished() {
if (isPageLoaded && areImagesLoaded) {
exports.onload();
}
}
function onSvgError() {
this.isDone = true;
console.warn("SVG " + this.src + " failed to load.");
}
function onSvgLoaded() {
this.isDone = true;
for (var id in svgImages) {
if (!svgImages[id].isDone) {
return;
}
}
areImagesLoaded = true;
isFinished();
}
function request(id,path) {
if (svgImages[id]) {
return;
}
areImagesLoaded = false;
var img = document.createElement("img");
img.onerror = onSvgError;
img.onload = onSvgLoaded;
img.isDone = false;
img.id = id;
img.src = path;
svgImages[id] = img;
}
function get(id) {
return svgImages[id];
}
exports.request = request;
exports.get = get;
return exports;
}();
var board = function() {
"use strict";
var canvasWidth = 0;
var canvasHeight = 0;
var canvas = null;
var ctx = null;
var frameRequested = false;
var tileWidth = 0;
var tileHeight = 0;
var tileTypes = [];
var boardWidth = 0;
var boardHeight = 0;
var board = [];
var hasInitialized = false;
var camera = {
x: 0.0,
y: 0.0,
zoom: 1.0
};
function mapToBoard(x,y) {
var invZoom = 1.0 / camera.zoom;
return [
(x - (canvasWidth >> 1)) * invZoom - camera.x,
(y - (canvasHeight >> 1)) * invZoom - camera.y
];
}
var isMouseDragging = false;
var mouseStartX = 0;
var mouseStartY = 0;
var mouseLastX = 0;
var mouseLastY = 0;
var tileEvent = {
background: "",
foreground: "",
x: 0,
y: 0
};
function onTileSelected(e) {
}
function onMouseDown(e) {
isMouseDragging = true;
var bounds = canvas.getBoundingClientRect();
mouseStartX = mouseLastX = e.clientX - bounds.left;
mouseStartY = mouseLastY = e.clientY - bounds.top;
}
function onMouseUp(e) {
isMouseDragging = false;
var bounds = canvas.getBoundingClientRect()
var x = e.clientX - bounds.left - mouseStartX;
var y = e.clientY - bounds.top - mouseStartY;
var l = Math.sqrt(x * x + y * y);
if (l < 2.0) {
[x,y] = mapToBoard(e.clientX - bounds.left,e.clientY - bounds.top);
if (x > 0 && y > 0 && x < boardWidth * tileWidth && y < boardHeight * tileHeight) {
x = (x / tileWidth) | 0;
y = (y / tileHeight) | 0;
var tile = board[x + y * boardWidth];
tileEvent.background = tile.background;
tileEvent.foreground = tile.foreground;
tileEvent.x = x;
tileEvent.y = y;
} else {
tileEvent.background = "";
tileEvent.foreground = "";
tileEvent.x = -1;
tileEvent.y = -1;
}
onTileSelected(tileEvent);
}
}
function onMouseMove(e) {
if (hasInitialized && isMouseDragging) {
var bounds = canvas.getBoundingClientRect();
var x = e.clientX - bounds.left;
var y = e.clientY - bounds.top;
camera.x += (x - mouseLastX) / camera.zoom;
camera.y += (y - mouseLastY) / camera.zoom;
mouseLastX = x;
mouseLastY = y;
requestDraw();
}
}
function onWheel(e) {
if (Math.sign(e.deltaY) === -1) {
camera.zoom *= 1.1;
} else {
camera.zoom *= 0.9;
}
requestDraw();
}
function draw() {
ctx.fillStyle = "gray";
ctx.fillRect(-canvasWidth >> 1,-canvasHeight >> 1,canvasWidth,canvasHeight);
var _tileWidth = tileWidth * camera.zoom;
var _tileHeight = tileHeight * camera.zoom;
var _ox = camera.x * camera.zoom;
var _oy = camera.y * camera.zoom;
var _x = _ox;
var _y = _oy;
for (var x = 0; x <boardWidth; ++x) {
for (var y = 0; y < boardHeight; ++y) {
var index = x + y * boardWidth;
var tile = board[index];
var background = tileTypes[tile.background];
var foreground = tileTypes[tile.foreground];
if (background) {
ctx.drawImage(
background,
_x,
_y,
_tileWidth,
_tileHeight
);
}
if (foreground) {
ctx.drawImage(
foreground,
_x,
_y,
_tileWidth,
_tileHeight
);
}
_y += _tileHeight;
}
_y = _oy;
_x += _tileWidth;
}
frameRequested = false;
}
function requestDraw() {
if (!frameRequested) {
frameRequested = true;
requestAnimationFrame(draw);
}
}
return {
BACKGROUND: 0,
FOREGROUND: 1,
set canvas(canvasID) {
if (!hasInitialized) {
canvas = document.getElementById(canvasID);
canvas.onmousedown = onMouseDown;
canvas.onmouseup = onMouseUp;
canvas.onmousemove = onMouseMove;
canvas.onwheel = onWheel;
ctx = canvas.getContext("2d");
}
},
set canvasWidth(w) {
if (!hasInitialized && canvas) {
canvasWidth = canvas.width = w;
}
},
set canvasHeight(h) {
if (!hasInitialized && canvas) {
canvasHeight = canvas.height = h;
}
},
set tileWidth(w) {
if (!hasInitialized) {
tileWidth = w;
}
},
set tileHeight(h) {
if (!hasInitialized) {
tileHeight = h;
}
},
set width(w) {
if (!hasInitialized) {
boardWidth = w;
}
},
set height(h) {
if (!hasInitialized) {
boardHeight = h;
}
},
set onTileSelected(callback) {
onTileSelected = callback;
},
get width() {
return boardWidth;
},
get height() {
return boardHeight;
},
get onTileSelected() {
return onTileSelected;
},
defineTileTypes: function(types) {
if (types.length % 2 !== 0) {
return;
}
for (var i = 0; i < types.length; i += 2) {
var id = types[i];
var img = types[i + 1];
tileTypes[id] = img;
}
},
init: function() {
camera.x = -(boardWidth >> 1) * tileWidth;
camera.y = -(boardHeight >> 1) * tileHeight;
ctx.translate(canvasWidth >> 1,canvasHeight >> 1);
board.length = boardWidth * boardHeight;
for (var i = 0; i < board.length; ++i) {
board[i] = {
background: "",
foreground: ""
};
}
hasInitialized = true;
requestAnimationFrame(draw);
},
set: function(type,id,x,y) {
if (hasInitialized
&& tileTypes[id]
&& x > -1
&& x < boardWidth
&& y > -1
&& y < boardHeight) {
var index = x + y * boardWidth;
if (type === this.BACKGROUND) {
board[index].background = id;
} else {
board[index].foreground = id;
}
requestDraw();
}
}
};
}();
void function() {
"use strict";
svg.request("grass","https://i.stack.imgur.com/CkvU7.png");
svg.request("water","https://i.stack.imgur.com/an6a5.png");
svg.onload = function() {
board.canvas = "canvas";
board.canvasWidth = 180;
board.canvasHeight = 160;
board.tileWidth = 25;
board.tileHeight = 25;
board.width = 20;
board.height = 20;
board.defineTileTypes([
"GRASS",svg.get("grass"),
"WATER",svg.get("water")
]);
board.init();
for (var x = 0; x < board.width; ++x) {
for (var y = 0; y < board.height; ++y) {
board.set(board.BACKGROUND,"WATER",x,y);
if (Math.random() > 0.2) {
board.set(board.BACKGROUND,"GRASS",x,y);
} else {
board.set(board.BACKGROUND,"WATER",x,y);
}
}
}
}
board.onTileSelected = function(e) {
if (e.background === "GRASS") {
board.set(board.BACKGROUND,"WATER",e.x,e.y);
} else {
board.set(board.BACKGROUND,"GRASS",e.x,e.y);
}
}
}();
</script>
</body>
</html>
I am developing a animation in javascript where a car moves towards a person and picks but currently instead of a path I am just driving diagonally to the person with below code.
Car.prototype.main = function() {
var angle = angleBetweenTwoPoints(this.target.position, this.position);
var cos = Math.cos(degreeToRadian(angle)) * -1;
var sin = Math.sin(degreeToRadian(angle));
var _this = _super.call(this) || this;
this.angle = angle;
this.position.x += cos * this.speed;
this.position.y -= sin * this.speed;
if (distance(this.position, this.target.position) < 10 && this.image == GameImage.getImage("hero") ) {
this.target.position.x = Math.random() * mainCanvas.width;
this.target.position.y = Math.random() * mainCanvas.height;
this.hitCount++;
console.log(hitCount);
ctx.fillText("points : " + hitCount, 32, 32);
this.changeImage = true;
_this.speed = 3;
this.changeImageTime = Date.now() + 600; //0.5 sec from now.
this.image = (this.image == GameImage.getImage("hero"))? GameImage.getImage("hero_other") : GameImage.getImage("hero");
}
if(this.changeImage){
if(Date.now() > this.changeImageTime){
this.changeImage = false;
_this.speed = 9;
this.image = (this.image == GameImage.getImage("hero_other"))? GameImage.getImage("hero") : GameImage.getImage("hero_other");
}
}
};
return Car;
}(Actor));
But instaed of this I want to follow a path.I also created some grids when u click the image it logs the console which grid it is.But I am unable move the car in a path.For complete understanding the animation is in
animation.
Any help is appreciated
Waypoints as a queue.
For waypoints path following you use a type of array called a queue. As the name suggests the queue holds items that need to be used, specifically they need to be used in the order in which they arrive. The first object on the queue is the first object out (unless you push in line)
In javascript a queue is easy to implement using an array.
const path = {
points : [],
currentPos : null,
dist : 0,
totalDistMoved : 0,
atEnd : false,
addPoint(x,y) {
if(this.currentPos === null){
this.currentPos = { x :0,y : 0};
this.dist = 0;
this.totalDistMoved = 0;
}
this.points.push({x,y}) ;
},
moveAlong(dist){
if(dist > 0){
if(this.points.length > 1){
var x = this.points[1].x - this.points[0].x;
var y = this.points[1].y - this.points[0].y;
var len = Math.sqrt(x*x+y*y) ;
if(len - this.dist < dist){
this.points.shift();
dist -= (len - this.dist);
this.totalDistMoved += (len - this.dist);
this.dist = 0;
this.moveAlong(dist);
return;
}
const frac = this.dist + dist / len;
this.currentPos.x = this.points[0].x + x * frac;
this.currentPos.y = this.points[0].y + y * frac;
this.dist += dist;
this.totalDistMoved += dist;
}else{
this.currentPos.x = this.points[0].x;
this.currentPos.y = this.points[0].y;
this.dist = 0;
this.atEnd = true;
}
}
}
}
To use
Add some way points.
path.addPoint(1,1);
path.addPoint(100,20);
path.addPoint(110,120);
path.addPoint(210,120);
path.addPoint(250,420);
Then for each step of the animations get a distance along
path.moveAlong(10); // move ten pixels
and use the current position
ctx.drawImage(car,path.currentPos.x,path.currentPos.y);
You know you have reached the end of the path when.
if(path.atEnd) {
// you have arrived
}
And at any time you know how far you have moved with
path.totalDistMoved
This is meant for animations that only play forward. It will ignore negative distances as way points are dumped when you have passed them
You will need to make some modifications if you wish to reuse the path object, or if the waypoints are being added as you go
A simple example.
Thing moves along at constant speed. Click on page to add more waypoints.
const ctx = canvas.getContext("2d");
requestAnimationFrame(mainLoop);
function mainLoop(time){
gTime = !gTime ? time : gTime;
fTime = time - gTime;
gTime = time;
if(canvas.width !== innerWidth || canvas.height !== innerHeight){
canvas.width = innerWidth;
canvas.height = innerHeight;
}else{
ctx.setTransform(1,0,0,1,0,0);
ctx.clearRect(0,0,canvas.width,canvas.height);
}
if(mouse.button){
if(!point){
point = {x:0,y:0};
path.addPoint(point);
}
point.x = mouse.x;
point.y = mouse.y;
}else{
if(point){ point = null }
}
ctx.beginPath();
var i = 0;
while(i < path.points.length){ ctx.lineTo(path.points[i].x,path.points[i++].y)}
ctx.strokeStyle = "blue";
ctx.lineWidth = 2;
ctx.stroke();
var i = 0;
while(i < path.points.length){ ctx.strokeRect(path.points[i].x-4,path.points[i++].y-4,8,8)}
path.moveAlong(4 * fTime / 100);
var x = path.currentPos.x - thingPos.x;
var y = path.currentPos.y - thingPos.y;
thingPos.x = path.currentPos.x;
thingPos.y = path.currentPos.y;
drawThing(thingPos.x,thingPos.y,Math.atan2(y,x));
requestAnimationFrame(mainLoop);
}
var point;
const thingPos = {x:0,y:0};
const path = {
points : [],
currentPos : null,
distAlong : 0,
totalDistMoved : 0,
atEnd : false,
addPoint(x,y) {
if(y === undefined){
this.points.push(x); // add point as object
return;
}
if(this.currentPos === null){
this.currentPos = { x :0,y : 0};
this.distAlong = 0;
this.totalDistMoved = 0;
}
this.points.push({x,y}) ;
},
moveAlong(dist){
if(dist > 0){
if(this.points.length > 1){
var x = this.points[1].x - this.points[0].x;
var y = this.points[1].y - this.points[0].y;
var len = Math.sqrt(x*x+y*y) ;
if(len - this.distAlong < dist){
this.points.shift();
dist -= (len - this.distAlong);
this.totalDistMoved += (len - this.distAlong);
this.distAlong = 0;
this.moveAlong(dist);
return;
}
const frac = (this.distAlong + dist) / len;
this.currentPos.x = this.points[0].x + x * frac;
this.currentPos.y = this.points[0].y + y * frac;
this.distAlong += dist;
this.totalDistMoved += dist;
}else{
this.currentPos.x = this.points[0].x;
this.currentPos.y = this.points[0].y;
this.distAlong = 0;
this.atEnd = true;
}
}
}
}
path.addPoint(20,20);
path.addPoint(120,20);
path.addPoint(220,120);
path.addPoint(320,120);
path.addPoint(420,20);
function mouseEvents(e) {
const m = mouse;
m.x = e.pageX;
m.y = e.pageY;
m.button = e.type === "mousemove" ? m.button : e.type === "mousedown";
}
function drawThing(x,y,dir) {
ctx.setTransform(1,0,0,1,x,y);
ctx.rotate(dir);
ctx.fillStyle = "red";
ctx.strokeStyle = "black";
ctx.lineWidth = 2;
ctx.beginPath();
var i = 0;
while(i < thing.length){ ctx.lineTo(thing[i++],thing[i++]) };
ctx.closePath();
ctx.fill();
ctx.stroke();
}
const thing = [-20,-10,20,-10,22,-7,22,7,20,10,-20,10];
var gTime; // global and frame time
var fTime;
const mouse = { x:0,y:0,button:false};
["mousemove","mousedown","mouseup"].forEach(t=>document.addEventListener(t,mouseEvents));
canvas {
position: absolute;
top : 0px;
left : 0px;
}
<canvas id="canvas"></canvas>
click drag to add waypoints.
I want to click on one of the floating particles, upon clicking it, I want the particle colour to change from light grey to blue and then fade. Particle quantity is set as 100, as particles are clicked on to fade away particle quantity decreases. I'm unfamiliar with js, just started learning about canvas and particle systems yesterday, this is code from a pen that I've changed a bit and would like to add more changes to by adding the fade onclick event. I know that the particles within canvas are under one variable that defines them altogether, I don't know how to isolate one particle in the canvas to work with as I would need to know it's exact x,y coordinates.
Would I then have to find the coordinates for all 100 particles and add elements to each individual particle- and how do I do this?
$(document).ready(function() {
var PARTICLE_QUANT = 100;
var FPS = 60;
var BOUNCE = -1;
var PARTICLE_COLOR = '#ced4d4';
var ARC_RADIUS = 12;
var Particles = function($element) {
if ($element.length === 0) {
return;
}
this.$element = $element;
this.lastTimeStamp = null;
this.particles = [];
this.init();
};
var proto = Particles.prototype;
proto.init = function() {
this.createChildren()
.layout()
.enable();
};
proto.createChildren = function() {
this.canvas = this.$element[0];
this.context = this.canvas.getContext('2d');
this.canvasWidth = this.canvas.width;
this.canvasHeight = this.canvas.height;
this.lastTimeStamp = new Date().getTime();
return this;
};
proto.layout = function() {
window.requestAnimFrame = (function() {
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame;
})();
return this;
};
proto.removeChildren = function() {
this.context = null;
this.canvasWidth = null;
this.canvasHeight = null;
this.lastTimeStamp = null;
return this;
};
proto.enable = function() {
this.createParticleData();
this.renderLoop();
};
proto.createParticleData = function() {
var i = 0;
var l = PARTICLE_QUANT;
for (; i < l; i++) {
this.particles[i] = {};
this.setParticleData(this.particles[i]);
}
};
proto.setParticleData = function(particle) {
particle.x = Math.random() * this.canvasWidth;
particle.y = Math.random() * this.canvasHeight;
particle.vx = (Math.random()) - 0.5;
particle.vy = (Math.random()) - 0.5;
};
proto.update = function() {
var i = 0;
var l = PARTICLE_QUANT;
for (; i < l; i++) {
var particle = this.particles[i];
particle.x += particle.vx;
particle.y += particle.vy;
if (particle.x > this.canvasWidth) {
particle.x = this.canvasWidth;
particle.vx *= BOUNCE;
} else if (particle.x < 0) {
particle.x = 0;
particle.vx *= BOUNCE;
}
if (particle.y > this.canvasHeight) {
particle.y = this.canvasHeight;
particle.vy *= BOUNCE;
} else if (particle.y < 0) {
particle.y = 0;
particle.vy *= BOUNCE;
}
}
};
proto.draw = function() {
var i = 0;
if (!this.context) {
return;
}
this.context.clearRect(0, 0, this.canvasWidth, this.canvasHeight);
this.context.fillStyle = PARTICLE_COLOR;
for (; i < PARTICLE_QUANT; i++) {
var particle = this.particles[i];
this.context.save();
this.context.beginPath();
this.context.arc(particle.x, particle.y, ARC_RADIUS, 0, Math.PI * 2);
this.context.fill();
this.context.restore();
}
};
proto.renderLoop = function() {
requestAnimationFrame(this.renderLoop.bind(this));
this.update();
this.draw();
};
var particles = new Particles($('#js-particles'));
//Everything above works, it is what comes next (below), is this the right approach?
var elem = document.getElementById('js-particles'),
elemLeft = elem.offsetLeft,
elemTop = elem.offsetTop,
context = elem.getContext('2d'),
elements = [];
// Add event listener for `click` events.
elem.addEventListener('click', function(event) {
var x = event.pageX - elemLeft,
y = event.pageY - elemTop;
// Collision detection between clicked offset and element.
elements.forEach(function(element) {
if (y > element.top && y < element.top + element.height && x > element.left && x < element.left + element.width)
});
}, false);
// Add element.
elements.push({
colour: '#05EFFF',
width: 150,
height: 100,
top: 20,
left: 15
});
// Render elements.
elements.forEach(function(element) {
context.fillStyle = element.colour;
context.fillRect(element.left, element.top, element.width, element.height);
});
<canvas id="js-particles" class="particles" width="960" height="960">
<p>text appears if browser doesn 't support canvas</p>
</canvas>
I have a sorting game with 10 elements to drag and drop in the correct order.
When i begin to drag an object i want it to appear in front of all the other objects. Since createjs does not have a zindex property I was told to readd the item to the stage with stage.adchild(sequenceNumbers);
How do I properly add this to the mousedown or pressmove function?
for (var a = 0; a < gameData.Terms.length; a++) {
rect = new createjs.Shape();
rect.graphics.beginFill("blue").drawRoundRect(0, 0, 350, 30, 8);
rect.name = a;
var name = new createjs.Text(gameData.Terms[a].Definition, "14pt arial bold", "white");
name.id = gameData.Terms[a].Name;
name.textAlign = "left";
name.y = rect.y + 2;
name.x = rect.x + 4;
var sequenceNumbers = new createjs.Container();
sequenceNumbers.landingSpot = landingSpots[a];
landingSpots[a].sequenceNumber = sequenceNumbers;
sequenceNumbers.addChild(rect, name);
stage.addChild(sequenceNumbers);
sequenceNumbers.x = 300;
sequenceNumbers.y = xOffset;
xOffset += 40;
var startPositionX;
var startPostitionY;
sequenceNumbers.on('mousedown', function (e) {
stage.adchild(sequenceNumbers);
var posX = e.stageX;
var posY = e.stageY;
startPositionX = e.stageX;
startPositionY = e.stageY;
this.offset = { x: this.x - posX, y: this.y - posY };
});
sequenceNumbers.on("pressmove", function (evt) {
evt.currentTarget.x = evt.stageX;
evt.currentTarget.y = evt.stageY;
var posX = evt.stageX;
var posY = evt.stageY;
this.x = posX + this.offset.x;
this.y = posY + this.offset.y;
stage.update();
});
sequenceNumbers.on("pressup", function (evt) {
var stuffUnderMouse = landingSpotContainer.getObjectsUnderPoint(evt.rawX, evt.rawY, 0);
var oldSpot = evt.currentTarget.landingSpot;
var spotToMoveTo = null;
for (var i = 0; i < stuffUnderMouse.length; ++i) {
if (typeof stuffUnderMouse[i].landingSpot !== 'undefined' && stuffUnderMouse[i].landingSpot != oldSpot) {
spotToMoveTo = stuffUnderMouse[i].landingSpot;
break;
}
}
}
Just add the child again to its parent container:
evt.currentTarget.parent.addChild(evt.currentTarget);
should do the trick inside the mouse event function.
Notice the function is called addChild and not adchild.
I am trying to make this game, you should not collide the falling object. I have the objects falling and I have my black square, but it flashes when I run it and Im not sure how to make the code stop when the two objects collide together.
here is the code that I have so far!
<html>
<body>
<canvas id="canvasRegn" width="600" height="450"style="margin:100px;"></canvas>
<script>
var ctx;
var imgBg;
var imgDrops;
var noOfDrops = 50;
var fallingDrops = [];
function drawBackground(){
ctx.drawImage(imgBg, 0, 0); //Background
}
function draw() {
drawBackground();
for (var i=0; i< noOfDrops; i++)
{
ctx.drawImage (fallingDrops[i].image, fallingDrops[i].x, fallingDrops[i].y); //The rain drop
fallingDrops[i].y += fallingDrops[i].speed; //Set the falling speed
if (fallingDrops[i].y > 480) { //Repeat the raindrop when it falls out of view
fallingDrops[i].y = -25 //Account for the image size
fallingDrops[i].x = Math.random() * 800; //Make it appear randomly along the width
}
}
}
function setup() {
var canvas = document.getElementById('canvasRegn');
if (canvas.getContext) {
ctx = canvas.getContext('2d');
imgBg = new Image();
imgBg.src = "http://www.hamdancommunications.com/HComm/img/wite%20square.png";
setInterval(draw, 36);
for (var i = 0; i < noOfDrops; i++) {
var fallingDr = new Object();
fallingDr["image"] = new Image();
fallingDr.image.src = 'http://s18.postimg.org/o6jpmdf9x/Line1.jpg';
fallingDr["x"] = Math.random() * 800;
fallingDr["y"] = Math.random() * 5;
fallingDr["speed"] = 3 + Math.random() * 5;
fallingDrops.push(fallingDr);
anotherGame();
}
}
}
setup();
function anotherGame(){
var canvas = document.getElementById("canvasRegn");
var ctx = canvas.getContext('2d');
canvas.addEventListener("mousedown", clicked);
canvas.addEventListener("mousemove", moved);
canvas.addEventListener("mouseup", released);
var isclicked = 0;
var square = new Object();
square.color = "black";
square.x = 100;
square.y = 100;
square.w = 50;
square.h = 50;
var offX = 0;
var offY = 0;
function draw(){
ctx.clearRect(0,0,canvas.width,canvas.height);
ctx.fillStyle = square.color;
ctx.fillRect(square.x,square.y,square.w,square.h);
}
function game(){
}
function clicked(e){
var x = e.offsetX;
var y = e.offsetY;
if(x >= square.x && x <= square.x + square.w &&
y >= square.y && y <= square.y + square.h){
isclicked = 1;
offX = x - square.x;
offY = y - square.y;
}
}
function moved(e){
if(isclicked == 1){
var x = e.offsetX;
var y = e.offsetY;
square.x = x - offX;
square.y = y - offY;
}
}
function released(e){
var x = e.offsetX;
var y = e.offsetY;
isclicked = 0;
}
var drawtimer = setInterval(draw, 1000/30);
var gametimer = setInterval(game, 1000/10);
}
</script>
</body>
</html>