How to drop items on canvas from viewer perspective?
Question
Where can I find an example of dropping items on a canvas? The idea is that from viewer perspective stains/drops fall on the canvas. How can I achieve this? Any help please.
Where to start? the only thing I found what came near the idea was: http://threedubmedia.com/code/event/drop and then the live option.
1 answers
solution1
0 2013-03-12 22:20:18
Here is an example of how to add a couple of coffee stains to the canvas:
This is code for the coffee stain and a Fiddle: http://jsfiddle.net/m1erickson/jkK7L/
<!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(){
// get hold of the canvas
var canvas=document.getElementById("canvas");
// get hold of the canvas's context, which we use to draw with
var context=canvas.getContext("2d");
// ask for a new image
var img=new Image();
// wait for the image to load
img.onload=function(){
// draw the coffee stains on the canvas using the context
context.drawImage(img,0,0,img.width,img.height,50,50,100,100);
}
// tell the new image we asked for above where to find the image file
// note: strangely, this must come after img.onload
img.src="http://dl.dropbox.com/u/139992952/coffee-stain.png";
}); // end $(function(){});
</script>
</head>
<body>
<canvas id="canvas" width=300 height=300></canvas>
</body>
</html>
Here is a neat simulation of water rippling on the canvas:
Click on the canvas to see the ripple effect: http://www.script-tutorials.com/demos/97/index.html
And here is an example of a splat animation
Here is code and a Fiddle: http://jsfiddle.net/m1erickson/r8Grf/
<!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(){
var canvas=document.getElementById("canvas");
var ctx=canvas.getContext("2d");
window.requestAnimFrame = (function(callback) {
return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
function(callback) {
window.setTimeout(callback, 1000 / 60);
};
})();
$("go").html("Loading...");
var count=80;
var win=new Image();
var splash;
win.onload=function(){
splash=new Image();
splash.onload=function(){
ctx.drawImage(win,0,0);
}
splash.src="http://dl.dropbox.com/u/139992952/splash2.svg";
}
win.src="http://dl.dropbox.com/u/139992952/window.png";
$("#go").click(function(){ alert("go"); count=80; animate(); });
function animate() {
// drawings
if(--count>1){
ctx.clearRect(0, 0, canvas.width, canvas.height);
ctx.save();
ctx.drawImage(win,0,0);
ctx.globalCompositeOperation = 'destination-over';
ctx.drawImage(splash,0,0,splash.width,splash.height,25,25,splash.width/count,splash.height/count);
ctx.restore();
}
// request new frame
requestAnimFrame(function() {
animate();
});
}
}); // end $(function(){});
</script>
</head>
<body>
<br/><button id="go">Splash!</button><br/><br/>
<canvas id="canvas" width=326 height=237></canvas>
</body>
</html>
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.