getIntersection broken on Safari iOS10 iPad (not tested with concrete)

[denweng]

Just want to inform you.
We had a problem with kineticjs which might be in concrete too.

best regards Tobias & Dennis from SinusQuadrat

getImageData gives back wrong colors in Safari iOS10 iPad. (Tested on an early iPad Air)
Colors values higher than 240 differ 1 from the originaly set value. This breaks the function of hitCanvas and colorIndex / coloKey and getIntersection.

Our solution in kineticjs is to use ios save colors for identifiers:

getRandomColor: function(iosSave) {
    var randColor;
    if(iosSave){
        randColor = (Math.random() * 0xadcea0 << 0).toString(15);
    }else{
        randColor = (Math.random() * 0xFFFFFF << 0).toString(16);
    }
    while (randColor.length < 6) {
        randColor = ZERO + randColor;
    }
    return HASH + randColor;
}

to test independet (canvas in html needed, loggs differing values):

dndcanvas = document.getElementById("dndcanvas");
var ctx = dndcanvas.getContext('2d');
ctx.clearRect(0, 0, dndcanvas.width, dndcanvas.height);

for (var i = 0; i <= 255; i++) {
    ctx.fillStyle = 'rgb(230,230,' + i + ')';
    ctx.fillRect(i, canvasObj.y-35, 1, 1);
    var p = ctx.getImageData(i, canvasObj.y-35, 1, 1).data;
    if (i != p[2]) {
        console.log(p[2]);
    }
}

[GuichiZhao]

I think the same error occurs in chrome, getImageData cannot get rgba correctly