54 lines
2.2 KiB
C
54 lines
2.2 KiB
C
#ifndef WHACK_HARE_AUDIO_H
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#define WHACK_HARE_AUDIO_H
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// audio.h — SID audio service for the Whack Hare! state machine.
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//
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// The audio layer is a thin state-driven service: the game's per-state
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// "enter" actions call audio_state_enter() to set up the SID for that
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// state's cue, and the raster IRQ handler's per-frame tick calls
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// audio_state_step() to advance the cue's schedule.
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//
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// audio_init() must be called once at startup, after memmap_setup()
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// and before rasterirq_setup(). audio_play_fault_stinger() is called
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// from the DRAW state's fault handler (in game.c) to start a short
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// low square-wave stinger on voice 1; the stinger cleans itself up
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// over the next 10 frames via audio_state_step().
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//
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// **No leakage between states.** audio_state_enter() calls
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// audio_stop() internally before setting up the new state, so the
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// previous state's SID writes (e.g. the WAIT voice 0/1 loop) cannot
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// bleed into the next state (e.g. DRAW's voice 2 noise stab).
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//
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// **The audio_state argument.** The STATE_* constants are defined in
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// game.h. We include it here so audio_state_enter() and
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// audio_state_step() can switch on the same values the game uses.
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#include "game.h"
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void audio_init(void);
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// audio_stop() — silence all 3 SID voices and reset their registers.
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// Called internally by audio_state_enter() and also available to the
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// game for explicit silencing (currently unused at the game layer).
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void audio_stop(void);
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// audio_state_enter(state) — silence the SID, then set up the cue
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// for the given state. Resets the per-state schedule. See audio.c
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// for the per-state cue definitions.
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void audio_state_enter(int state);
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// audio_state_step(state) — advance the per-state schedule by one
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// frame. Called from game_step() once per frame. Also ticks down
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// the fault-stinger counter and gates voice 1 off when it expires.
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void audio_state_step(int state);
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// audio_play_fault_stinger() — start a 10-frame low square-wave
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// stinger on voice 1. Called from game_step_draw() when the DRAW
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// fault timeout fires (after audio_state_enter(TITLE) so the stinger
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// isn't immediately silenced by the state transition).
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void audio_play_fault_stinger(void);
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#pragma compile("audio.c")
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#endif
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