arrows_renderer = arrow_x = arrow_y = arrow_a = label_x = label_y = arrow_y =None
"""
FOV_ARROWS = { \
    "100um[0.0]": [10.0],   \
    "50um[0.0]": [20.0],   \
    "new_entry": [0.0]
}
"""
run("imaging/FOV_table")

FOV_ARROWS_SIZE=80
FOV_XRAY_ARROW_SIZE=120
FOV_LABEL_POS=FOV_ARROWS_SIZE+15
FOV_XRAY_LABEL_POS=FOV_XRAY_ARROW_SIZE+15
#FOV_ARROWS_ORIGIN=Point(image.getData().width/4, image.getData().height*3/4)
#FOV_ARROWS_ORIGIN=Point(image.getData().width*3/4, image.getData().height/4)
FOV_ARROWS_ORIGIN=Point(image.getData().width-(FOV_LABEL_POS+5), FOV_LABEL_POS+5)
FOV_FUTURE=None
FOV_FUTURE=None
FOV_LABEL_FONT=java.awt.Font("Verdana", java.awt.Font.PLAIN, 12)
FOV_OFFSET=0.0
FOV_COLOR_X = Color.GREEN
FOV_COLOR_Y = Color(173,216,230) # Light Blue
FOV_COLOR_A = Color.YELLOW


AZIMUTH_ROT=0.0
def get_azimuth():
    return AZIMUTH_ROT

def set_fov_offset(value):    
    global FOV_OFFSET
    FOV_OFFSET = value
    update_arrows()

def set_azimuth_rot(value):    
    global AZIMUTH_ROT
    AZIMUTH_ROT = value
    update_arrows()

    
def  update_arrows():
    global arrows_renderer, arrow_x, arrow_y, arrow_a, label_x, label_y, label_a
    if arrows_renderer is not None:
        args = FOV_ARROWS.get(fov.take(), None) 
        if args is not None:
            azimuth=get_azimuth()
            angle=args[0] + FOV_OFFSET
            angle=angle+180
            x,y = FOV_ARROWS_ORIGIN.x, FOV_ARROWS_ORIGIN.y   
            a=math.radians(angle)
            xa,ya=int(x+FOV_XRAY_ARROW_SIZE*math.cos(a)),  int(y-FOV_XRAY_ARROW_SIZE*math.sin(a))
            arrow_a.update(FOV_ARROWS_ORIGIN, Point(xa,ya))
            xa,ya=int(x+FOV_XRAY_LABEL_POS*math.cos(a)),  int(y-FOV_XRAY_LABEL_POS*math.sin(a))
            label_a.update(Point(xa,ya))               
            angle=angle-azimuth         
            a=math.radians(angle)
            xa,ya=int(x+FOV_ARROWS_SIZE*math.cos(a)),  int(y-FOV_ARROWS_SIZE*math.sin(a))
            arrow_x.update(FOV_ARROWS_ORIGIN, Point(xa,ya))
            xa,ya=int(x+FOV_LABEL_POS*math.cos(a)),  int(y-FOV_LABEL_POS*math.sin(a))
            label_x.update(Point(xa,ya))   
            angle=angle-90
            a=math.radians(angle)
            xa,ya=int(x+FOV_ARROWS_SIZE*math.cos(a)),  int(y-FOV_ARROWS_SIZE*math.sin(a))
            arrow_y.update(FOV_ARROWS_ORIGIN, Point(xa,ya))   
            xa,ya=int(x+FOV_LABEL_POS*math.cos(a)),  int(y-FOV_LABEL_POS*math.sin(a))              
            label_y.update(Point(xa,ya))               
        else:
            log("Cannot draw reference arrows - Invalid microscope preset label: " + fov, False)
            arrow_x.update(FOV_ARROWS_ORIGIN, FOV_ARROWS_ORIGIN)
            arrow_y.update(FOV_ARROWS_ORIGIN, FOV_ARROWS_ORIGIN)   
            arrow_a.update(FOV_ARROWS_ORIGIN, FOV_ARROWS_ORIGIN)   
            label_a.update(label_a.UNDEFINED_POINT)  
            label_x.update(label_x.UNDEFINED_POINT)         
            label_y.update(label_y.UNDEFINED_POINT)         
        arrows_renderer.refresh()
            
def  task_update_arrows():  
    global arrows_renderer
    while arrows_renderer is not None:
        try:
            if arrows_renderer.isShowing():
                update_arrows()
                time.sleep(5.0)
            time.sleep(1.0)
        except:         
            pass
            

def start_arrows(renderer=None):
    global arrows_renderer, arrow_x, arrow_y, arrow_a, label_x, label_y, label_a, FOV_FUTURE
    if arrows_renderer is None:
        arrows_renderer = renderer if renderer else show_panel(image)
        arrow_x = Overlays.Arrow(Pen(FOV_COLOR_X))
        arrow_y = Overlays.Arrow(Pen(FOV_COLOR_Y))
        arrow_a = Overlays.Arrow(Pen(FOV_COLOR_A))
        label_x = Overlays.Text(arrow_x.pen, "X",FOV_LABEL_FONT)
        label_y = Overlays.Text(arrow_y.pen, "Y",FOV_LABEL_FONT)
        label_a = Overlays.Text(arrow_a.pen, "X-rays",FOV_LABEL_FONT)
        arrows_renderer.addOverlays([arrow_a, label_a, arrow_x,arrow_y,label_x, label_y])
        #update_arrows()
        FOV_FUTURE = fork(task_update_arrows,)[0]
    

def stop_arrows(renderer=None):
    global arrows_renderer, arrow_x, arrow_y, label_x, label_y, label_a, FOV_FUTURE
    if arrows_renderer is not None:
        arrows_renderer.removeOverlays([arrow_a, label_a, arrow_x,arrow_y, label_x, label_y])
    arrows_renderer=None
    if FOV_FUTURE is not None:
        FOV_FUTURE.cancel(True)
        try:
            join(FOV_FUTURE)
        except:
            pass