html5-canvas Collisions and Intersections Is an X,Y point inside a wedge?
Example
Tests if the [x,y] point is inside a wedge.
// wedge objects: {cx:,cy:,radius:,startAngle:,endAngle:}
// var wedge={
// cx:150, cy:150, // centerpoint
// radius:100,
// startAngle:0, endAngle:Math.PI
// }
// Return true if the x,y point is inside the closed wedge
function isPointInWedge(x,y,wedge){
var PI2=Math.PI*2;
var dx=x-wedge.cx;
var dy=y-wedge.cy;
var rr=wedge.radius*wedge.radius;
if(dx*dx+dy*dy>rr){return(false);}
var angle=(Math.atan2(dy,dx)+PI2)%PI2;
return(angle>=wedge.startAngle && angle<=wedge.endAngle);
}
