Initial commit: CRT photobooth

screensaver.py

@@ -0,0 +1,106 @@
+"""Fish tank screensaver.
+
+Burn-in safe for the CRT: the background is pure black and every drawn
+element is always in motion. Fish images are loaded from the fish folder
+and are assumed to face right; a fish swimming left gets flipped
+horizontally. Bubbles rise from each fish's mouth.
+"""
+
+import math
+import random
+
+import pygame
+
+FISH_MIN_H, FISH_MAX_H = 60, 140
+FISH_MIN_SPEED, FISH_MAX_SPEED = 40, 130  # px/sec
+BUBBLE_COLOR = (150, 200, 255)
+
+
+class Bubble:
+    def __init__(self, x, y):
+        self.x = x
+        self.y = y
+        self.radius = random.uniform(2, 6)
+        self.speed = random.uniform(30, 70)
+        self.wobble_phase = random.uniform(0, math.tau)
+        self.wobble_amp = random.uniform(2, 8)
+
+    def update(self, dt):
+        self.y -= self.speed * dt
+        self.wobble_phase += dt * 3
+
+    def draw(self, screen):
+        x = self.x + math.sin(self.wobble_phase) * self.wobble_amp
+        pygame.draw.circle(screen, BUBBLE_COLOR, (int(x), int(self.y)),
+                           int(self.radius), width=1)
+
+
+class Fish:
+    def __init__(self, image, screen_size):
+        self.screen_w, self.screen_h = screen_size
+        height = random.randint(FISH_MIN_H, FISH_MAX_H)
+        width = int(image.get_width() * height / image.get_height())
+        self.image_right = pygame.transform.smoothscale(image, (width, height))
+        self.image_left = pygame.transform.flip(self.image_right, True, False)
+        self.w, self.h = width, height
+        self.speed = random.uniform(FISH_MIN_SPEED, FISH_MAX_SPEED)
+        self.direction = random.choice([-1, 1])
+        self.x = random.uniform(0, self.screen_w - width)
+        self.base_y = random.uniform(0, self.screen_h - height)
+        self.bob_phase = random.uniform(0, math.tau)
+        self.bob_amp = random.uniform(5, 20)
+        self.bubble_timer = random.uniform(1, 4)
+
+    @property
+    def y(self):
+        return self.base_y + math.sin(self.bob_phase) * self.bob_amp
+
+    def mouth_pos(self):
+        mouth_x = self.x + self.w if self.direction > 0 else self.x
+        return mouth_x, self.y + self.h * 0.45
+
+    def update(self, dt, bubbles):
+        self.x += self.speed * self.direction * dt
+        self.bob_phase += dt * random.uniform(0.8, 1.2)
+
+        # Wrap around: swim fully off one edge, re-enter from the other
+        # at a fresh depth so fish never sit still or trace fixed lines.
+        if self.direction > 0 and self.x > self.screen_w:
+            self.x = -self.w
+            self.base_y = random.uniform(0, self.screen_h - self.h)
+        elif self.direction < 0 and self.x < -self.w:
+            self.x = self.screen_w
+            self.base_y = random.uniform(0, self.screen_h - self.h)
+
+        self.bubble_timer -= dt
+        if self.bubble_timer <= 0:
+            self.bubble_timer = random.uniform(1.5, 5)
+            mx, my = self.mouth_pos()
+            for _ in range(random.randint(1, 3)):
+                bubbles.append(Bubble(mx + random.uniform(-4, 4),
+                                      my + random.uniform(-4, 4)))
+
+    def draw(self, screen):
+        image = self.image_right if self.direction > 0 else self.image_left
+        screen.blit(image, (int(self.x), int(self.y)))
+
+
+class FishTank:
+    def __init__(self, screen_size, fish_images, num_fish):
+        self.fish = [Fish(random.choice(fish_images), screen_size)
+                     for _ in range(num_fish)]
+        self.bubbles = []
+
+    def update(self, dt):
+        for fish in self.fish:
+            fish.update(dt, self.bubbles)
+        for bubble in self.bubbles:
+            bubble.update(dt)
+        self.bubbles = [b for b in self.bubbles if b.y > -10]
+
+    def draw(self, screen):
+        screen.fill((0, 0, 0))
+        for bubble in self.bubbles:
+            bubble.draw(screen)
+        for fish in self.fish:
+            fish.draw(screen)