point_dist=point_distance(mouse_x,mouse_y,mouse_prevx,mouse_prevy)
if (point_dist>=20) {
if (mouse_x<x) {
view_angle[0]-=point_dist;
}
if (mouse_x>x) {
view_angle[0]+=point_dist;
}
mouse_prevx=mouse_x;
mouse_prevy=mouse_y;
}