vec2.toString(this.p3)+', '+
vec2.toString(this.p4)+')';}};function sign(p1,p2,p3){return(p1[0]-p3[0])*(p2[1]-p3[1])-
(p2[0]-p3[0])*(p1[1]-p3[1]);}
function pointInTriangle2(pt,p1,p2,p3){const b1=sign(pt,p1,p2)<0.0;const b2=sign(pt,p2,p3)<0.0;const b3=sign(pt,p3,p1)<0.0;return((b1===b2)&&(b2===b3));}
function pointInImplicitQuad(point,p1,p2,p3,p4){return pointInTriangle2(point,p1,p2,p3)||pointInTriangle2(point,p1,p3,p4);}