Teste de colisão em JS

Teste de colisão

function colCheck(shapeA,shapeB){
        var  vX = (shapeA.x + (shapeA.width/2)) - (shapeB.x + (shapeB.width/2)),
             vY = (shapeA.y + (shapeA.height/2)) - (shapeB.y + (shapeB.height/2)),
             hWdiths = (shapeA.width/2) + (shapeB.width/2),
             hHeights =(shapeA.height/2) + (shapeB.height/2),
             colDir = null;

        if(Math.abs(vX) < hWdiths && Math.abs(vY) < hHeights){
            var oX = hWdiths - Math.abs(vX), 
                oY = hHeights - Math.abs(vY);

            if(oX >= oY){
                if(vY > 0){
                    colDir = "t";
                    shapeA.y += oY;
                }else{
                    colDir = "b";
                    shapeA.y -= oY; 
                }
            }else {
                if(vX > 0){
                    colDir = "l";
                    shapeA.x += oX; 
                }else{
                    colDir = "r";
                    shapeA.x -= oX; 
                }   
            }
        }
        return colDir;
    }