I've got a problem filling 25 canvas elements automatically in a for loop. They are numbered like so: can01 to can25.
I've tried all I knew to draw different images on the canvas and I have spent a lot of time in searching a few articles which are about this problem but I haven't found any.
This is my working code to fill all canvas elements with the same image:
var imageGrass = new Image();
imageGrass.src = 'recources/imagesBG/grass.jpg';
imageGrass.onload = function() {
for (var i = 1; i < 26; i++)
{
if( i < 10 )
{
var task = "can0" + i + "_ctx.drawImage(imageGrass, 0, 0);";
eval(task);
}
else
{
var task = "can" + i + "_ctx.drawImage(imageGrass, 0, 0);";
eval(task);
}
}
}
But I really don't know how to make the imageGrass.src dynamic. For example, the canvas element no. 5 (can05) in this case shall look like stone texture.
I´m really looking forward to read your ideas. I just don't get it.
Here’s how to impliment Dave’s good idea of using arrays to organize your canvases:
Create an array that will hold references to all your 25 canvases (do the same for 25 contexts)
var canvases=[];
var contexts=[];
Next, fill the array with all your canvases and contexts:
for(var i=0;i<25;i++){
var canvas=document.getElementById("can"+(i<10?"0":""));
var context=canvas.getContext("2d");
canvases[i]=canvas;
contexts[i]=context;
}
If you haven't seen it before: i<10?"0":"" is an inline if/else used here to add a leading zero to your lower-numbered canvases.
Then you can fetch your “can05” canvas like this:
var canvas=canvases[4];
Why 4 and not 5? Arrays are zero based, so canvases[0] holds can01. Therefore array element 4 contains your 5th canvas “can05”.
So you can fetch the drawing context for your “can05” like this:
var context=contexts[4];
As Dave says, “evals are evil” so here’s how to fetch the context for “can05” and draw the stone image on it.
var context=contexts[4];
context.drawImage(stoneImage,0,0);
This stone drawing can be shortened to:
contexts[4].drawImage(stoneImage,0,0);
You can even put this shortened code into a function for easy reuse and modification:
function reImage( canvasIndex, newImage ){
contexts[ canvasIndex ].drawImage( newImage,0,0 );
}
Then you can change the image on any of your canvases by calling the function:
reimage( 4,stoneImage );
That’s it!
The evil-evals have been vanquished (warning: never invite them to your computer again!)
Here is example code and a Fiddle: http://jsfiddle.net/m1erickson/ZuU2e/
This code creates 25 canvases dynamically rather than hard-coding 25 html canvas elements.
<!doctype html>
<html>
<head>
<link rel="stylesheet" type="text/css" media="all" href="css/reset.css" /> <!-- reset css -->
<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<style>
body{ background-color: ivory; padding:0px; margin:0px;border:0px; }
canvas{vertical-align: top; }
</style>
<script>
$(function(){
var canvases=[];
var contexts=[];
var grass=new Image();
grass.onload=function(){
// the grass is loaded
// now make 25 canvases and fill them with grass
// ALSO !!!
// keep track of them in an array
// so we can use them later!
make25CanvasesFilledWithGrass()
// just a test
// fill canvas#3 with gold
draw(3,"gold");
// fill canvas#14 with red
draw(14,"red");
}
//grass.src="https://dl.dropboxusercontent.com/u/139992952/stackoverflow/grass.jpg";
//grass.src="grass.jpg";
function make25CanvasesFilledWithGrass(){
// get the div that we will fill with 25 canvases
var container=document.getElementById("canvasContainer");
for(var i=0;i<25;i++){
// create a new html canvas element
var canvas=document.createElement("canvas");
// assign the new canvas an id, width and height
canvas.id="can"+(i<10?"0":"")+i;
canvas.width=grass.width;
canvas.height=grass.height;
// get the context for this new canvas
var ctx=canvas.getContext("2d");
// draw the grass image in the new canvas
ctx.drawImage(grass,0,0);
// add this new canvas to the web page
container.appendChild(canvas);
// add this new canvas to the canvases array
canvases[i]=canvas;
// add the context for this new canvas to the contexts array
contexts[i]=ctx;
}
}
// test -- just fill the specified canvas with the specified color
function draw(canvasIndex,newColor){
var canvas=canvases[canvasIndex];
var ctx=contexts[canvasIndex];
ctx.beginPath();
ctx.fillStyle=newColor;
ctx.rect(0,0,canvas.width,canvas.height);
ctx.fill();
}
}); // end $(function(){});
</script>
</head>
<body>
<div id="canvasContainer"></div>
</body>
</html>
Related
I have been practicing using sprites for a game I am going to make and have watched and read a few tutorials, I thought I was close to getting my sprite to appear so I could finally start my game but while practicing I cant get it to work, I have dont 2 seperate tutorials where I can get the sprite and the background to appear by themselfs but cannot get them to work together, I have been using EaselJS too. some of the sprite animation code has been copied from tutorials too.
<!DOCTYPE HTML>
<html>
<head>
<meta charset="UTF-8">
<title>sprite prac<title>
<!-- EaselJS library -->
<script src="lib/easel.js"></script>
<script>
// Initialize on start up so game runs smoothly
function init() {
canvas = document.getElementById("canvas");
stage = new Stage(canvas);
bg = new Image();
bg.src = "img/grassbg.jpg";
bg.onload = setBG;
stage.addChild(background);
imgMonsterARun = new Image();
imgMonsterARun.onload = handleImageLoad;
imgMonsterARun.onerror = handleImageError;
imgMonsterARun.src = "img/MonsterARun.png";
stage.update();
}
function handleImageLoad(e) {
startGame();
}
// Simple function for setting up the background
function setBG(event){
var bgrnd = new Bitmap(bg);
stage.addChild(bgrnd);
stage.update();
}
function startGame() {
// create a new stage and point it at our canvas:
stage = new createjs.Stage(canvas);
// grab canvas width and height for later calculations:
screen_width = canvas.width;
screen_height = canvas.height;
// create spritesheet and assign the associated data.
var spriteSheet = new createjs.SpriteSheet({
// image to use
images: [imgMonsterARun],
// width, height & registration point of each sprite
frames: {width: 64, height: 64, regX: 32, regY: 32},
animations: {
walk: [0, 9, "walk"]
}
});
// create a BitmapAnimation instance to display and play back the sprite sheet:
bmpAnimation = new createjs.BitmapAnimation(spriteSheet);
// start playing the first sequence:
bmpAnimation.gotoAndPlay("walk"); //animate
// set up a shadow. Note that shadows are ridiculously expensive. You could display hundreds
// of animated rats if you disabled the shadow.
bmpAnimation.shadow = new createjs.Shadow("#454", 0, 5, 4);
bmpAnimation.name = "monster1";
bmpAnimation.direction = 90;
bmpAnimation.vX = 4;
bmpAnimation.x = 16;
bmpAnimation.y = 32;
// have each monster start at a specific frame
bmpAnimation.currentFrame = 0;
stage.addChild(bmpAnimation);
// we want to do some work before we update the canvas,
// otherwise we could use Ticker.addListener(stage);
createjs.Ticker.addListener(window);
createjs.Ticker.useRAF = true;
createjs.Ticker.setFPS(60);
}
//called if there is an error loading the image (usually due to a 404)
function handleImageError(e) {
console.log("Error Loading Image : " + e.target.src);
}
function tick() {
// Hit testing the screen width, otherwise our sprite would disappear
if (bmpAnimation.x >= screen_width - 16) {
// We've reached the right side of our screen
// We need to walk left now to go back to our initial position
bmpAnimation.direction = -90;
}
if (bmpAnimation.x < 16) {
// We've reached the left side of our screen
// We need to walk right now
bmpAnimation.direction = 90;
}
// Moving the sprite based on the direction & the speed
if (bmpAnimation.direction == 90) {
bmpAnimation.x += bmpAnimation.vX;
}
else {
bmpAnimation.x -= bmpAnimation.vX;
}
// update the stage:
stage.update();
}
</script>
</head>
<body onload="init();">
<canvas id="canvas" width="500" height="500" style="border: thin black solid;" ></canvas>
</body>
</html>
There are a few places where you are using some really old APIs, which may or may not be supported depending on your version of EaselJS. Where did you get the easel.js script you reference?
Assuming you have a version of EaselJS that matches the APIs you are using, there are a few issues:
You add background to the stage. There is no background, so you are probably getting an error when you add it. You already add bgrnd in the setBackground method, which should be fine. If you get an error here, then this could be your main issue.
You don't need to update the stage any time you add something, just when you want the stage to "refresh". In your code, you update after setting the background, and again immediately at the end of your init(). These will fire one after the other.
Are you getting errors in your console? That would be a good place to start debugging. I would also recommend posting code if you can to show an actual demo if you continue to have issues, which will help identify what is happening.
If you have a newer version of EaselJS:
BitmapAnimation is now Sprite, and doesn't support direction. To flip Sprites, use scaleX=-1
Ticker no longer uses addListener. Instead it uses the EventDispatcher. createjs.Ticker.addEventListener("tick", tickFunction);
You can get new versions of the CreateJS libraries at http://code.createjs.com, and you can get updated examples and code on the website and GitHub.
I am looking for a way to wrap a bitmap image around the canvas, for an infinite scrolling effect. I'm looking at EaselJS but clean javascript code will also suffice.
Right now I am displacing an image to the left, and when it reaches a certain mark, it resets itself.
Coming from actionscript, there was an option to "wrap" the pixels of a bitmap around to the other side, thereby never really displacing the image, instead you were wrapping the pixels inside the image. Is this possible in javascript with canvas?
My current code:
this.update = function() {
// super large graphic
_roadContainer.x -= 9;
if(_roadContainer.x < -291) _roadContainer.x = 0;
}
Start with a good landscape image.
Flip the image horizontally using context.scale(-1,1).
Combine the flipped image to the right side of the original image.
Because we have exactly mirrored the images, the far left and right sides of the combined image are exactly the same.
Therefore, as we pan across the combined image and “run out of image”, we can just add another copy of the combined image to the right side and we have infinite + seamless panning.
Here's code and a Fiddle: http://jsfiddle.net/m1erickson/ywDp5/
<!doctype html>
<html>
<head>
<link rel="stylesheet" type="text/css" media="all" href="css/reset.css" /> <!-- reset css -->
<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<style>
body{ background-color: ivory; }
canvas{border:1px solid red;}
</style>
<script>
$(function(){
// thanks Paul Irish for this RAF fallback shim
window.requestAnimFrame = (function(callback) {
return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
})();
var canvas=document.getElementById("canvas");
var ctx=canvas.getContext("2d");
var infiniteImage;
var infiniteImageWidth;
var img=document.createElement("img");
img.onload=function(){
// use a tempCanvas to create a horizontal mirror image
// This makes the panning appear seamless when
// transitioning to a new image on the right
var tempCanvas=document.createElement("canvas");
var tempCtx=tempCanvas.getContext("2d");
tempCanvas.width=img.width*2;
tempCanvas.height=img.height;
tempCtx.drawImage(img,0,0);
tempCtx.save();
tempCtx.translate(tempCanvas.width,0);
tempCtx.scale(-1,1);
tempCtx.drawImage(img,0,0);
tempCtx.restore();
infiniteImageWidth=img.width*2;
infiniteImage=document.createElement("img");
infiniteImage.onload=function(){
pan();
}
infiniteImage.src=tempCanvas.toDataURL();
}
img.crossOrigin="anonymous";
img.src="https://dl.dropboxusercontent.com/u/139992952/stackoverflow/mountain.jpg";
var fps = 60;
var offsetLeft=0;
function pan() {
// increase the left offset
offsetLeft+=1;
if(offsetLeft>infiniteImageWidth){ offsetLeft=0; }
ctx.drawImage(infiniteImage,-offsetLeft,0);
ctx.drawImage(infiniteImage,infiniteImage.width-offsetLeft,0);
setTimeout(function() {
requestAnimFrame(pan);
}, 1000 / fps);
}
}); // end $(function(){});
</script>
</head>
<body>
<canvas id="canvas" width=500 height=143></canvas><br>
</body>
</html>
You can achieve this quite easily with the html5 canvas.
Look at the drawImage specification here :
http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#drawing-images
drawImage comes in 3 flavors, the first being a simple copy of the image, the second allowing to scale the image, and the third is the one you seek, it allows to perform clipping in a single call.
What you have to do :
- have a counter that will move from zero to the width of your image, then loop to zero again.
- each frame, draw the maximum of the image that you can on the canvas.
- If there is still some part of the canvas not drawn, draw again the image starting from zero to fill the canvas.
i made a fiddle, the only part that matters is in the animate function (other things are tools i often use in my fiddles).
(Rq : I assumed in this example that two images would be enough to fill the canvas.)
http://jsfiddle.net/gamealchemist/5VJhp/
var startx = Math.round(startPos);
var clippedWidth = Math.min(landscape.width - startx, canvasWidth);
// fill left part of canvas with (clipped) image.
ctx.drawImage(landscape, startx, 0, clippedWidth, landscape.height,
0, 0, clippedWidth, landscape.height);
if (clippedWidth < canvasWidth) {
// if we do not fill the canvas
var remaining = canvasWidth - clippedWidth;
ctx.drawImage(landscape, 0, 0, remaining, landscape.height,
clippedWidth, 0, remaining, landscape.height);
}
// have the start position move and loop
startPos += dt * rotSpeed;
startPos %= landscape.width;
To answer my own question: I found a way to achieve this effect with EaselJS. The great benefit of this method is that you don't have to check for the position of your bitmap. It will scroll infinitely - without ever resetting the position to 0.
The trick is to fill a shape with a bitmapfill. You can set a bitmapfill to repeat infinitely. Then you use a Matrix2D to decide the offset of the bitmapfill. Since it repeats automatically, this will generate a scrolling effect.
function.createRoad() {
// road has a matrix, shape and image
_m = new createjs.Matrix2D();
// this gets the image from the preloader - but this can be any image
_r = queue.getResult("road");
// this creates a shape that will hold the repeating bitmap
_roadshape = new createjs.Shape();
// put the shape on the canvas
addChild(_roadshape);
}
//
// the draw code gets repeatedly called, for example by requestanimationframe
//
function.drawRoad() {
// var _speed = 4;
_m.translate(-_speed, 0);
_roadshape.graphics.clear().beginBitmapFill(_r, "repeat", _m).rect(0, 0, 900, 400);
}
I have JavaScript code in my site.
The code is using 2 identical photos-same size, same resolution - only different colors.
First photo is black and white photo - this is what the canvas presents.
Second photo is the same only with the original colors.
I have a button that triggers JS code - which generally removes a pixel from the black and white -and paints color pixel on the canvas. At first I used Math.random for the pixel locations.
And than I decided to use it by order. No matter where it starts or begging.. as long it will go
in this order (x,y)..(x+1,y).. until maximum x.. and than (x,y+1).. until maximum x.. and so on until all the black and white photo "transformed" into the colorful photo..
for some reason I just cant make it happen.. i tried a lot of techniques..
here is demo for global understanding:
demo is working sorry - they deactivated my free host :\ hope you still understand..
here is the original code- i just changed the last function : **removeDrawRandomPixel** ..it's just playing the function there and it should be fixed..
///////////////////////global variables///////////////////
var gray_url="bwcat.jpg"; //black and white image URI
var regular_url="cat.jpg"; //regular image URI
var n=100; //number of pixels changed per click
/////////////////////////////////////
document.addEventListener("DOMContentLoaded", function(){
var c=new EditableCanvas(document.getElementById('cnvs'));
grayScaleImage=new Image();
grayScaleImage.src=gray_url;
grayScaleImage.onload=function()
{
c.drawImage(this);
}
regularImage=new Image();
regularImage.src=regular_url;
regularImage.onload=function()
{
var p=getPixelArray(this);
btn.onclick=function(){
for(var i=1;i<=n&&p.length>0;i++){
removeDrawRandomPixel(p,c);
}
}
}
},false);
//create a Pixel object
function ImagePixel(x,y,r,g,b,a)
{
this.x=x;
this.y=y;
this.r=r;
this.g=g;
this.b=b;
this.a=a;
}
//object that allows custom methods
function EditableCanvas(canvas)
{
this.canvas=canvas;
this.context=canvas.getContext('2d');
this.width=canvas.width;
this.height=canvas.height;
this.pixelImage=this.context.createImageData(1,1);
//draw an entire picture and adjust the canvas for it
this.drawImage=function(image)
{
this.width=image.width;
this.height=image.height;
this.canvas.height=image.height;
this.canvas.width=image.width;
this.context.drawImage(image,0,0);
}
//draw a single pixel, ImagePixel pixel
this.drawPixel=function(pixel)
{
this.pixelImage.data[0]=pixel.r;
this.pixelImage.data[1]=pixel.g;
this.pixelImage.data[2]=pixel.b;
this.pixelImage.data[3]=pixel.a;
this.context.putImageData(this.pixelImage,pixel.x,pixel.y);//,pixel.x,pixel.y);
}
}
//the function returns an ordered array of Pixel pixels of the image at `src`.
function getPixelArray(img)
{
var pixelArray=[];
var cnvs=document.createElement('canvas');
cnvs.width=img.width;
cnvs.height=img.width;
var context=cnvs.getContext('2d');
context.drawImage(img,0,0);
var originalData = context.getImageData(0,0,img.width,img.height).data;
for(var i=0,pixelId=0,px;i<originalData.length;i+=4)
{
px=new ImagePixel(pixelId%img.width,Math.floor(pixelId/img.width),originalData[i],originalData[i+1],originalData[i+2],originalData[i+3]);
pixelArray.push(px);
pixelId++;
}
return pixelArray;
}
//the function remove a random pixel from pixelArray and draws it on editableCnvs
function removeDrawRandomPixel(pixelArray,editableCnvs)
{
var place=Math.floor(Math.random()*pixelArray.length);
var px=pixelArray.splice(place,1)[0];
editableCnvs.drawPixel(px);
}
html :
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>canvas rules</title>
<script src="pixel.js"></script>
</head>
<body>
<canvas id="cnvs">
oh goddmamit no support
</canvas>
<button id="btn">click to convert</button>
</body>
</html>
I tried playing the last function.. because i know the answer is in the function,how to choose the pixels..
This is untested however this is what I would change the removeDrawRandomPixel function to. You are grabbing a random point in the array currently and passing it, so it could be starting on the blue component of one pixel and ending on the g component of another pixel.
//the function remove a random pixel from pixelArray and draws it on editableCnvs
function removeDrawRandomPixel(pixelArray,editableCnvs)
{
// width and height need to be the width and height of the canvas.
var width = canvas.width,
height = canvas.height,
x = Math.floor(Math.random()*width),
y = Math.floo(Math.random()*height);
var px = (y * width + x) * 4;
editableCnvs.drawPixel(px);
}
I'm working on a simple diagram editor using KineticJS. I would like to use two separate canvases for the palette area (that contains a number of Kinetic.Groups that represent the different nodes of the network I might create), and the diagramming area where I can add nodes from the palette via drag and drop, and then add connections between the various nodes as specific anchor points. I'm having trouble figuring out the drag and drop process from the palette canvas of (stationary) Kinetic.Groups over to the other canvas containing diagramming area. I'm guessing that I need to fire off of the dragstart event for the palette objects (although I don't want these themselves to be draggable), and then do something like create an opague copy of the palette object that can be dragged around, and finally dropped into the diagramming area (with full opacity).
Can groups be dragged outside of a the staging canvases boundaries? Maybe I need to generate an image when I start to drag from the palette, drag that image over, and then create another group when dropping into the diagramming area.
Does any one know of any examples that might point me in the right direction, or who can offer some insight (even code) into the required process. I've searched the KineticJS examples but can't quite find enough to get me going.
Here’s one way to drag nodes from a source palette into a destination group:
A Fiddle: http://jsfiddle.net/m1erickson/xtVyL/
Network nodes are represented by small icons (which are really small kinetic image objects).
The user can drag any icon from the source palette to any destination group.
The groups are just defined areas on the canvas, but could be Kinetc.Groups for more flexibility.
During the dragend event, a new duplicate copy of the dragged icon is created in the destination group.
After the dragend event is complete, the original palette icon is automatically moved from
The newly created duplicate icon can be dragged around the destination group (but not outside that group).
Here is code and a Fiddle: http://jsfiddle.net/m1erickson/xtVyL/
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Prototype</title>
<script type="text/javascript" src="http://code.jquery.com/jquery.min.js"></script>
<script src="http://d3lp1msu2r81bx.cloudfront.net/kjs/js/lib/kinetic-v4.5.5.min.js"></script>
<style>
#container{
border:solid 1px #ccc;
margin-top: 10px;
width:350px;
height:350px;
}
</style>
<script>
$(function(){
var stage = new Kinetic.Stage({
container: 'container',
width: 350,
height: 350
});
var layer = new Kinetic.Layer();
stage.add(layer);
// image loader
var imageURLs=[];
var imagesOK=0;
var imgs=[];
imageURLs.push("https://dl.dropboxusercontent.com/u/139992952/stackoverflow/tempPC.png");
imageURLs.push("https://dl.dropboxusercontent.com/u/139992952/stackoverflow/tempServer.png");
imageURLs.push("https://dl.dropboxusercontent.com/u/139992952/stackoverflow/tempRouter.png");
loadAllImages();
function loadAllImages(callback){
for (var i = 0; i < imageURLs.length; i++) {
var img = new Image();
imgs.push(img);
img.onload = function(){
imagesOK++;
if (imagesOK==imageURLs.length ) {
start();
}
};
img.src = imageURLs[i];
}
}
// top icon positions
var nextIconX=20;
var nextIconY=20;
// define groups
var groups=[];
groups.push({x:0,y:100,w:175,h:250,fill:"skyblue"});
groups.push({x:175,y:100,w:175,h:250,fill:"cornsilk"});
// add boundary info to each group
// draw colored rect to show group area
for(var i=0;i<groups.length;i++){
var g=groups[i];
g.left=g.x;
g.right=g.x+g.w;
g.top=g.y;
g.bottom=g.y+g.h;
var rect=new Kinetic.Rect({
x:g.x,
y:g.y,
width:g.w,
height:g.h,
fill:g.fill,
stroke:"gray"
});
layer.add(rect);
}
// hittest for each group
function groupHit(x,y){
for(var i=0;i<groups.length;i++){
var g=groups[i];
if(x>g.left && x<g.right && y>g.top && y<g.bottom){return(i);}
}
return(-1);
}
function start(){
makePaletteIcon(imgs[0]);
makePaletteIcon(imgs[1]);
makePaletteIcon(imgs[2]);
layer.draw();
}
function makePaletteIcon(img){
// make an icon that stays in the pallette tray
var fixedIcon=newImage(nextIconX,nextIconY,img,false);
layer.add(fixedIcon);
// make an icon that is dragged from the tray to a group
var dragIcon=makeDraggableIcon(nextIconX,nextIconY,img);
layer.add(dragIcon);
// calc the next icon position
nextIconX+=(img.width+20);
}
function makeDraggableIcon(x,y,img){
var i=newImage(x,y,img,true);
//
i.trayX=x;
i.trayY=y;
//
i.setOpacity(0.50);
i.on("dragend",function(){
var x=this.getX();
var y=this.getY();
// if this pallette icon was not dropped in a group
// put the icon back in the tray and return
var hit=groupHit(x,y);
if(hit==-1){
this.setPosition(this.trayX,this.trayY);
return;
}
// add a copy of this icon to the drop group
var component=newImage(x,y,this.getImage(),true);
// set drag limits
var group=groups[hit];
component.maxDragLeft=group.left;
component.maxDragRight=group.right;
component.maxDragTop=group.top;
component.maxDragBottom=group.bottom;
// limit component dragging to inside the assigned group
component.setDragBoundFunc(function(pos) {
var xx=pos.x;
var yy=pos.y;
var w=this.getWidth();
var h=this.getHeight();
if(pos.x<this.maxDragLeft){xx=this.maxDragLeft;}
if(pos.x+w>this.maxDragRight){xx=this.maxDragRight-w;}
if(pos.y<this.maxDragTop){yy=this.maxDragTop;}
if(pos.y+h>this.maxDragBottom){yy=this.maxDragBottom-h;}
return{ x:xx, y:yy };
});
layer.add(component);
// move the dragIcon back into the pallette tray
this.setPosition(this.trayX,this.trayY);
layer.draw();
});
return(i);
}
// make a new Kinetic.Image
function newImage(x,y,img,isDraggable){
var i=new Kinetic.Image({
image:img,
x: x,
y: y,
width: img.width,
height: img.height,
draggable:isDraggable
});
return(i);
}
}); // end $(function(){});
</script>
</head>
<body>
<p>Drag any icon from top into blue or yellow group</p>
<div id="container"></div>
</body>
</html>
Hey, I'm looking for a way to take a black and white img element, and using JavaScript, specify an RGB value so that the image becomes that color. Any ideas (aside from libraries)?
Also I'm trying to do this with IE only. The reason I'm doing it in IE only is because I'm making a small sidebar gadget.
In Internet Explorer, you could use Visual Filters.
Edit: you want to use the Light filter, here is an exemple
<STYLE>
.aFilter {
filter:light();
}
</STYLE>
<SCRIPT>
window.onload=fnInit;
function fnInit(){
oDiv.filters[0].addAmbient(50,20,180,100);
}
</SCRIPT>
with filter: <img CLASS="aFilter" ID="oDiv" src="http://cache2.artprintimages.com/p/LRG/8/853/2USY000Z/black-and-white-cats.jpg">
without: <img src="http://cache2.artprintimages.com/p/LRG/8/853/2USY000Z/black-and-white-cats.jpg">
Something like this?
Edit: Ah, no canvas. No worries.
<html>
<head>
<script type="text/javascript">
function createCanvas(image){
// create a new canvas element
var myCanvas = document.createElement("canvas");
var myCanvasContext = myCanvas.getContext("2d");
var imgWidth=image.width;
var imgHeight=image.height;
// set the width and height to the same as the image
myCanvas.width= imgWidth;
myCanvas.height = imgHeight;
// draw the image
myCanvasContext.drawImage(image,0,0);
// get all the image data into an array
var imageData = myCanvasContext.getImageData(0,0, imgWidth, imgHeight);
// go through it all...
for (j=0; j<imageData.width; j++)
{
for (i=0; i<imageData.height; i++)
{
// index: red, green, blue, alpha, red, green, blue, alpha..etc.
var index=(i*4)*imageData.width+(j*4);
var red=imageData.data[index];
var alpha=imageData.data[index+3];
// set the red to the same
imageData.data[index]=red;
// set the rest to black
imageData.data[index+1]=0;
imageData.data[index+2]=0;
imageData.data[index+3]=alpha;
delete c;
}
}
// put the image data back into the canvas
myCanvasContext.putImageData(imageData,0,0,0,0, imageData.width, imageData.height);
// append it to the body
document.body.appendChild(myCanvas);
}
function loadImage(){
var img = new Image();
img.onload = function (){
createCanvas(img);
}
img.src = "monkey.jpg";
}
</script>
</head>
<body onload="loadImage()">
</body>
</html>
The only way you'll be able to do this in JavaScript is with the <canvas> tag. Here is an excellent tutorial if you're interested in learning how to use it.
Edit: I'm not an expert on MS proprietary filters, but here are the Microsoft docs for image filters in IE.