def force_as_dxdy(pixel_a: Pixel_xy, pixel_b: Pixel_xy,
screen_distance_unit, repulsive):
"""
Compute the force between pixel_a pixel and pixel_b and return it as a velocity: direction * force.
"""
direction: Velocity = normalize_dxdy((
pixel_a - pixel_b) if repulsive else (pixel_b - pixel_a))
d = pixel_a.distance_to(pixel_b, wrap=False)
if repulsive:
dist = max(
1,
pixel_a.distance_to(pixel_b, wrap=False) /
screen_distance_unit)
rep_coefficient = SimEngine.gui_get('rep_coef')
rep_exponent = SimEngine.gui_get('rep_exponent')
force = direction * (10**rep_coefficient) / 10 * dist**rep_exponent
return force
else: # attraction
dist = max(1, max(d, screen_distance_unit) / screen_distance_unit)
att_exponent = SimEngine.gui_get('att_exponent')
force = direction * dist**att_exponent
# If the link is too short, push away instead of attracting.
if d < screen_distance_unit:
force = force * (-1)
att_coefficient = SimEngine.gui_get('att_coef')
return 10**(att_coefficient - 1) * force
def force_as_dxdy(pixel_a: Pixel_xy, pixel_b: Pixel_xy,
screen_distance_unit, repulsive):
"""
Compute the force between pixel_a pixel and pixel_b and return it as a velocity: direction * force.
"""
direction: Velocity = normalize_dxdy((
pixel_a - pixel_b) if repulsive else (pixel_b - pixel_a))
d = max(1, pixel_a.distance_to(pixel_b)) #, wrap=False))
if repulsive:
dist = max(1,
pixel_a.distance_to(pixel_b) /
screen_distance_unit) #, wrap=False)
rep_coefficient = gui_get(REP_COEFF)
rep_exponent = gui_get(REP_EXPONENT)
force = direction * (
(10**rep_coefficient) / 10) * dist**rep_exponent
return force
else: # attraction
dist = max(1, max(d, screen_distance_unit) / screen_distance_unit)
att_exponent = gui_get(ATT_EXPONENT)
force = direction * dist**att_exponent
# If the link is too short, push away instead of attracting.
if d < screen_distance_unit:
force = force * (-1)
att_coefficient = gui_get(ATT_COEFF)
final_force = force * 10**(att_coefficient - 1)
return final_force