From b221c56a6bb90de4631f4b2eb999db8dad05a006 Mon Sep 17 00:00:00 2001
From: rodri <rgl@antares-labs.eu>
Date: Sun, 1 Oct 2023 00:06:50 +0000
Subject: add a mixer and some background sfx.

also postponed the connection establishment
until the subsystem initialization is
complete. there's no point in taking a seat
you're going to leave milliseconds after
a local resource failure.
---
 mixer.h | 123 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 mixer.h

(limited to 'mixer.h')

diff --git a/mixer.h b/mixer.h
new file mode 100644
index 0000000..81e22ee
--- /dev/null
+++ b/mixer.h
@@ -0,0 +1,123 @@
+/*
+ * standalone sound mixer based on rxi's cmixer.
+ */
+enum {
+	FIXED_BITS	= 12,
+	FIXED_UNIT	= 1<<FIXED_BITS,
+	FIXED_MASK	= FIXED_UNIT-1,
+
+	MIXBUFSIZE	= 512,
+	MIXBUFMASK	= MIXBUFSIZE-1,
+
+	AUDIO_STATE_STOPPED = 0,
+	AUDIO_STATE_PLAYING,
+	AUDIO_STATE_PAUSED,
+
+	AUDIO_EVENT_DESTROY = 0,
+	AUDIO_EVENT_SAMPLES,
+	AUDIO_EVENT_REWIND
+};
+
+typedef struct Wav Wav;
+typedef struct WavStream WavStream;
+typedef struct Pcm Pcm;
+typedef struct AudioEvent AudioEvent;
+typedef struct AudioSourceInfo AudioSourceInfo;
+typedef struct AudioSource AudioSource;
+typedef struct Mixer Mixer;
+
+struct Wav
+{
+	void *data;
+	int bitdepth;
+	int samplerate;
+	int channels;
+	int length;
+};
+
+struct WavStream
+{
+	Wav wav;
+	void *data;
+	int idx;
+};
+
+struct Pcm
+{
+	void *data;
+	int len;
+	int off;
+	int depth;
+	int chans;
+	int rate;
+};
+
+struct AudioEvent
+{
+	int type;
+	void *udata;
+	char *msg;
+	s16int *buffer;
+	int length;
+};
+
+struct AudioSourceInfo
+{
+	void *udata;
+	int samplerate;
+	int length;
+
+	void (*handler)(AudioEvent *e);	/* Event handler */
+};
+
+struct AudioSource
+{
+	AudioSource *next;		/* Next source in list */
+	s16int buffer[MIXBUFSIZE];	/* Internal buffer with raw stereo PCM */
+	void *udata;			/* Stream's udata (from AudioSourceInfo) */
+	int samplerate;			/* Stream's native samplerate */
+	int length;			/* Stream's length in samples */
+	int end;			/* End index for the current play-through */
+	int state;			/* Current state (playing|paused|stopped) */
+	s64int position;		/* Current playhead position (fixed point) */
+	int lgain, rgain;		/* Left and right gain (fixed point) */
+	int rate;			/* Playback rate (fixed point) */
+	int nextfill;			/* Next frame idx where the buffer needs to be filled */
+	int loop;			/* Whether the source will loop when `end` is reached */
+	int rewind;			/* Whether the source will rewind before playing */
+	int active;			/* Whether the source is part of `sources` list */
+	double gain;			/* Gain set by `audio_set_gain()` */
+	double pan;			/* Pan set by `audio_set_pan()` */
+
+	void (*handler)(AudioEvent *e);	/* Event handler */
+};
+
+struct Mixer
+{
+	char *lasterror;		/* Last error message */
+	AudioSource *sources;		/* Linked list of active (playing) sources */
+	s32int buffer[MIXBUFSIZE];	/* Internal master buffer */
+	int samplerate;			/* Master samplerate */
+	int gain;			/* Master gain (fixed point) */
+};
+
+
+void audio_init(int);
+void audio_set_master_gain(double);
+void audio_process(s16int*, int);
+
+AudioSource *audio_new_source(AudioSourceInfo*);
+AudioSource *audio_new_source_from_file(char*);
+AudioSource *audio_new_source_from_mp3file(char*);
+AudioSource *audio_new_source_from_mem(void*, int);
+void audio_destroy_source(AudioSource*);
+double audio_get_length(AudioSource*);
+double audio_get_position(AudioSource*);
+int audio_get_state(AudioSource*);
+void audio_set_gain(AudioSource*, double);
+void audio_set_pan(AudioSource*, double);
+void audio_set_pitch(AudioSource*, double);
+void audio_set_loop(AudioSource*, int);
+void audio_play(AudioSource*);
+void audio_pause(AudioSource*);
+void audio_stop(AudioSource*);
-- 
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