draw_ring (GML)

///draw_ring ( x, y, radius, thickness (inner), quality (optional, default 32))
var xx=argument0,yy=argument1,rad=argument2,thick=argument3,qual=32;
if argument4>0{qual = argument4;}

draw_primitive_begin(pr_trianglestrip);
var i;
for(i=0;i<=qual;i+=1)
{
    draw_vertex(xx+lengthdir_x(rad,i*360/qual),yy+lengthdir_y(rad,i*360/qual));
    draw_vertex(xx+lengthdir_x(rad-thick,(i+.5)*360/qual),yy+lengthdir_y(rad-thick,(i+.5)*360/qual));
}
draw_primitive_end();