feat(render): hud overlay and audio backend

game/render/audioBackend.py

@@ -0,0 +1,71 @@
+import array
+import math
+
+import pygame
+
+toneTable = {
+    "jump": (660, 90),
+    "doubleJump": (820, 90),
+    "dash": (300, 80),
+    "stomp": (200, 120),
+    "pickup": (900, 70),
+    "hurt": (160, 160),
+    "die": (110, 300),
+    "shoot": (420, 70),
+    "checkpoint": (1040, 120),
+    "levelComplete": (760, 260),
+    "spark": (520, 40),
+}
+
+
+def synthTone(frequency, milliseconds, volume=0.25):
+    mixerInfo = pygame.mixer.get_init()
+    if mixerInfo is None:
+        return None
+    sampleRate, _, channels = mixerInfo
+    frames = int(sampleRate * milliseconds / 1000.0)
+    amplitude = int(32767 * volume)
+    samples = array.array("h")
+    for index in range(frames):
+        envelope = 1.0 - index / frames
+        value = int(amplitude * envelope * (1.0 if math.sin(2.0 * math.pi * frequency * index / sampleRate) >= 0 else -1.0))
+        for _ in range(max(1, channels)):
+            samples.append(value)
+    return pygame.mixer.Sound(buffer=samples.tobytes())
+
+
+class PygameAudio:
+    def __init__(self):
+        self.enabled = False
+        self.sounds = {}
+        try:
+            if pygame.mixer.get_init() is None:
+                pygame.mixer.init()
+            for name, (frequency, duration) in toneTable.items():
+                sound = synthTone(frequency, duration)
+                if sound is not None:
+                    self.sounds[name] = sound
+            self.enabled = bool(self.sounds)
+        except pygame.error:
+            self.enabled = False
+
+    def sink(self, event):
+        if not self.enabled:
+            return
+        sound = self.sounds.get(event.name)
+        if sound is not None:
+            sound.play()
+
+
+class NullAudio:
+    enabled = False
+
+    def sink(self, event):
+        pass
+
+
+def buildAudioSink():
+    backend = PygameAudio()
+    if backend.enabled:
+        return backend.sink
+    return NullAudio().sink