I want to create canvas-based site menu using this plugin, to create 'multiply' effect. However this, and also globalCompositeOperation, are working on ctx objects in the same canvas. (in context-blender it uses an off-screen canvas and uses its draw info, globalcompoperation blends the same ctx). I want to create mouse events (hover and click) for each ctx object, so each ctx will lead to a different url.
Here is my test:
function draw(){
var ctx = document.getElementById('canvasOff1').getContext('2d');
var ctx2 = document.getElementById('canvasReal').getContext('2d');
var ctx3 = document.getElementById('canvasOff3').getContext('2d');
// draw circles - each circle should link to different url and has its own focus
ctx.fillStyle = "#c7302a";
ctx.beginPath();
ctx.arc(50,75,35,0,Math.PI*2,true);
ctx.fill();
ctx2.fillStyle = "#395797";
ctx2.beginPath();
ctx2.arc(100,75,35,0,Math.PI*2,true);
ctx2.fill();
ctx3.fillStyle = "#454";
ctx3.beginPath();
ctx3.arc(150,75,35,0,Math.PI*2,true);
ctx3.fill();
var over = canvasOff1.getContext('2d');
var under = canvasReal.getContext('2d');
over.blendOnto(under,'multiply');
var over2 = canvasOff3.getContext('2d');
var under2 = canvasReal.getContext('2d');
over2.blendOnto(under2,'multiply',{destX:0,destY:0});
}
Would be nice to know though how Can I implement jQuery here. Thanks.
You can't add event listeners to a context, only to the canvas:
document.getElementById('canvasOff1').addEventLsitener(
'click',
function(){ goToUrl('http://www.test1.com'); }
);
document.getElementById('canvasReal').addEventLsitener(
'click',
function(){ goToUrl('http://www.test2.com'); }
);
document.getElementById('canvasOff3').addEventLsitener(
'click',
function(){ goToUrl('http://www.test3.com'); }
);
function goToUrl(url){
window.location = url;
}
Or, with jQuery:
$('#canvasOff1').on(
'click',
function(){ goToUrl('http://www.test1.com'); }
);
$('#canvasReal').on(
'click',
function(){ goToUrl('http://www.test2.com'); }
);
$('#canvasOff3').on(
'click',
function(){ goToUrl('http://www.test3.com'); }
);
function goToUrl(url){
window.location = url;
}
(I prefer using a separate function for window.location = X
, but of course, you couls also use it in the onclick
function, like this:
function(){ window.location = 'http://www.test1.com'; }