commit 11802fc935cf703d0a832543c1380db6c268c42d
parent 1947439a87a381aceb38ef93aa8845edf84171cd
Author: Andrew Laack <andrew@laack.co>
Date: Sun, 30 Aug 2026 13:53:54 -0500
boids
Diffstat:
| A | movement/boids.py | | | 140 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | movement/seek.py | | | 73 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
2 files changed, 213 insertions(+), 0 deletions(-)
diff --git a/movement/boids.py b/movement/boids.py
@@ -0,0 +1,140 @@
+import pygame
+import random
+import time
+
+red = (255, 0, 0)
+white = (255,255,255)
+
+
+NUM_BOIDS = 300
+
+class Boid:
+
+ pos_x = 0
+ pos_y = 0
+ vel_x = 100
+ vel_y = 100
+ delta_y = 0
+ delta_x = 0
+ max_velocity = 100
+ ACC = 1
+
+ NEARBY_DISTANCE = 40
+ SEPERATION_DISTANCE = 10
+
+ def __init__(self):
+ self.pos_x = random.randint(0,500)
+ self.pos_y = random.randint(0,500)
+ self.last_time = time.time()
+ self.vel_x = random.randint(-100,100)
+ self.vel_y = random.randint(-100,100)
+
+ def draw(self,display):
+ pygame.draw.circle(display, white, (self.pos_x, self.pos_y), 2)
+
+ def distance(self,otr):
+ return ((self.pos_x - otr.pos_x) ** 2 + (self.pos_y - otr.pos_y) ** 2) ** .5
+
+ def move(self):
+ self.pos_x = self.pos_x + self.delta_x
+ self.pos_y = self.pos_y + self.delta_y
+
+ def compute_move(self, flock):
+
+ if self.pos_x > 500 and self.vel_x > 0:
+ self.vel_x *= -1
+
+ if self.pos_x < 0 and self.vel_x < 0:
+ self.vel_x *= -1
+
+ if self.pos_y > 500 and self.vel_y > 0:
+ self.vel_y *= -1
+
+ if self.pos_y < 0 and self.vel_y < 0:
+ self.vel_y *= -1
+
+ nearby_headings = []
+ nearby_positions = []
+ too_close = []
+
+ for i in range(0,len(flock)):
+ if flock[i] == self:
+ continue
+ dist = self.distance(flock[i])
+
+ if dist < self.SEPERATION_DISTANCE:
+ too_close.append([flock[i].pos_x, flock[i].pos_y])
+ if dist < self.NEARBY_DISTANCE:
+ nearby_headings.append([flock[i].vel_x, flock[i].vel_y])
+ nearby_positions.append([flock[i].pos_x, flock[i].pos_y])
+
+ if nearby_positions:
+ center_x = sum(p[0] for p in nearby_positions) / len(nearby_positions)
+ center_y = sum(p[1] for p in nearby_positions) / len(nearby_positions)
+ self.vel_x += (center_x - self.pos_x) * .08
+ self.vel_y += (center_y - self.pos_y) * .08
+
+ if nearby_headings:
+ avg_x = sum(p[0] for p in nearby_headings) / len(nearby_headings)
+ avg_y = sum(p[1] for p in nearby_headings) / len(nearby_headings)
+ self.vel_x += (avg_x - self.vel_x) * .02
+ self.vel_y += (avg_y - self.vel_y) * .02
+
+ sep_x = 0
+ sep_y = 0
+
+ for pos in too_close:
+ sep_x += self.pos_x - pos[0]
+ sep_y += self.pos_y - pos[1]
+
+ self.vel_x += sep_x * .04
+ self.vel_y += sep_y * .04
+
+ vel_current = ((self.vel_x ** 2) + (self.vel_y ** 2)) ** .5
+
+ if vel_current > self.max_velocity:
+ # make unit vector
+ self.vel_x /= vel_current
+ self.vel_y /= vel_current
+
+ # make max speed
+ self.vel_x *= self.max_velocity
+ self.vel_y *= self.max_velocity
+
+ current_time = time.time()
+
+ self.vel_x += self.vel_x * (self.ACC * (current_time - self.last_time))
+ self.vel_y += self.vel_y * (self.ACC * (current_time - self.last_time))
+
+ self.delta_x = self.vel_x * (current_time - self.last_time)
+ self.delta_y = self.vel_y * (current_time - self.last_time)
+ self.last_time = current_time
+
+
+
+
+
+
+
+pygame.init()
+
+display = pygame.display.set_mode((500,500))
+
+flock = []
+
+for i in range(NUM_BOIDS):
+ flock.append(Boid())
+
+while True:
+
+ display.fill(red)
+
+
+ for boid in flock:
+ boid.compute_move(flock)
+
+ for boid in flock:
+ boid.move()
+ boid.draw(display)
+
+ pygame.display.update()
diff --git a/movement/seek.py b/movement/seek.py
@@ -0,0 +1,73 @@
+import pygame
+import time
+
+
+player_pos = (100, 100)
+agent_pos = (200, 200)
+agent_speed = 100
+player_speed = 200
+
+pygame.init()
+
+screen_width = 800
+screen_height = 600
+screen = pygame.display.set_mode((screen_width, screen_height))
+
+black = (0, 0, 0)
+white = (255, 255, 255)
+
+running = True
+last_time = time.time()
+
+
+def draw_players():
+ pygame.draw.circle(screen, white, player_pos, 10)
+ pygame.draw.circle(screen, white, agent_pos, 10)
+
+def vector_length(p1):
+ return (p1[0]**2 + p1[1]**2)**0.5
+
+left = False
+
+while running:
+ for event in pygame.event.get():
+ if event.type == pygame.QUIT:
+ running = False
+
+ current_time = time.time()
+ time_delta = current_time - last_time
+ last_time = current_time
+
+ position_delta = player_pos[0] - agent_pos[0], player_pos[1] - agent_pos[1]
+
+ agent_pos = (
+ agent_pos[0] + ((position_delta[0] / vector_length(position_delta)) * time_delta * agent_speed),
+ agent_pos[1] + ((position_delta[1] / vector_length(position_delta)) * time_delta * agent_speed),
+ )
+
+
+ player_delta = (0,0)
+
+
+ if player_pos[0] > screen_width and not left:
+ left = True
+
+ if player_pos[0] < 0 and left:
+ left = False
+
+ if left:
+ player_delta = (-player_speed,0)
+ else:
+ player_delta = (player_speed,0)
+
+
+ player_pos = (
+ player_pos[0] + player_delta[0] * time_delta,
+ player_pos[1] + player_delta[1] * time_delta
+ )
+
+ screen.fill(black)
+ draw_players()
+ pygame.display.update()
+
+pygame.quit()
