if (!variable_local_exists('mouse_prevx')) { mouse_prevx=mouse_x; mouse_prevy=mouse_y;  }
if (mouse_x<x) {
view_angle[0]-=floor(point_distance(mouse_x,mouse_y,mouse_prevx,mouse_prevy))
mouse_prevx=mouse_x;
mouse_prevy=mouse_y;
}
if (mouse_x>x) {
view_angle[0]+=floor(point_distance(mouse_x,mouse_y,mouse_prevx,mouse_prevy))
mouse_prevx=mouse_x;
mouse_prevy=mouse_y;
}