Add audio, overhaul makefiles

Adds simple audio support to Simple
Overhaul makefiles; remove common boilerplate; make them more uniform

5 files changed, 209 insertions, 0 deletions

diff --git a/chapter31/src/main/c/simple_audio.c b/chapter31/src/main/c/simple_audio.c
new file mode 100644
index 00000000..b8ed62de
--- /dev/null
+++ b/chapter31/src/main/c/simple_audio.c
@@ -0,0 +1,40 @@
+#include "simple_audio.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dlfcn.h>
+
+static const struct simple_audio_api *api;
+static void *library;
+
+int32_t simple_audio_open(void) {
+    const char *path = getenv("SIMPLE_MINIAUDIO");
+    if (path && strcmp(path,"off")==0) return -1;
+    if (!api) {
+        if (!path || !*path) return -1; // Optional: games may run silently.
+        library = dlopen(path,RTLD_NOW | RTLD_LOCAL);
+        if (!library) {
+            fprintf(stderr,"Simple audio: cannot load backend '%s': %s\n",path,dlerror());
+            return -1;
+        }
+        const struct simple_audio_api *(*get_api)(void) =
+            (const struct simple_audio_api *(*)(void))dlsym(library,"simple_miniaudio_api");
+        const struct simple_audio_api *candidate = get_api ? get_api() : NULL;
+        if (!candidate || candidate->version!=SIMPLE_AUDIO_VERSION || !candidate->open ||
+            !candidate->load || !candidate->play || !candidate->stop ||
+            !candidate->playing || !candidate->close) {
+            fprintf(stderr,"Simple audio: incompatible backend; rebuild with make audio.\n");
+            dlclose(library);
+            library=NULL;
+            return -1;
+        }
+        api=candidate;
+        atexit(api->close);
+    }
+    return api->open();
+}
+int32_t simple_audio_load(const int16_t *samples, uint32_t count) { return api ? api->load(samples,count) : -1; }
+int32_t simple_audio_play(int32_t sound) { return api ? api->play(sound) : -1; }
+int32_t simple_audio_stop(void) { return api ? api->stop() : 0; }
+int32_t simple_audio_playing(void) { return api ? api->playing() : 0; }
+int32_t simple_audio_close(void) { if (api) api->close(); return 0; }
diff --git a/chapter31/src/main/c/simple_audio.h b/chapter31/src/main/c/simple_audio.h
new file mode 100644
index 00000000..77cce530
--- /dev/null
+++ b/chapter31/src/main/c/simple_audio.h
@@ -0,0 +1,16 @@
+#ifndef SIMPLE_AUDIO_H
+#define SIMPLE_AUDIO_H
+#include <stdint.h>
+
+// Main-thread API. Samples are copied; no Simple heap pointer is retained.
+struct simple_audio_api {
+    int32_t version;
+    int32_t (*open)(void);
+    int32_t (*load)(const int16_t *, uint32_t);
+    int32_t (*play)(int32_t);
+    int32_t (*stop)(void);
+    int32_t (*playing)(void);
+    void (*close)(void);
+};
+#define SIMPLE_AUDIO_VERSION 1
+#endif
diff --git a/chapter31/src/main/c/simple_miniaudio.c b/chapter31/src/main/c/simple_miniaudio.c
new file mode 100644
index 00000000..03dbadd7
--- /dev/null
+++ b/chapter31/src/main/c/simple_miniaudio.c
@@ -0,0 +1,123 @@
+#include "simple_audio.h"
+#define MA_NO_DECODING
+#define MA_NO_ENCODING
+#define MA_NO_RESOURCE_MANAGER
+#define MA_NO_NODE_GRAPH
+#define MA_NO_ENGINE
+#define MINIAUDIO_IMPLEMENTATION
+#include <miniaudio.h>
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#define RATE 48000
+#define SLOTS 32
+static ma_device device;
+static ma_mutex mutex;
+static int opened, active;
+static uint32_t cursor;
+static struct { int16_t *pcm; uint32_t count; } sounds[SLOTS];
+
+// Only native-owned immutable PCM is read on the audio thread. The lock covers
+// a bounded copy, never allocation, synthesis, device calls, or Simple code.
+static void output(ma_device *unused, void *out, const void *in, ma_uint32 frames) {
+    (void)unused; (void)in;
+    memset(out,0,frames*sizeof(int16_t));
+    ma_mutex_lock(&mutex);
+    if (active) {
+        uint32_t count=sounds[active].count-cursor;
+        if (count>frames) count=frames;
+        memcpy(out,sounds[active].pcm+cursor,count*sizeof(int16_t));
+        cursor+=count;
+        if (cursor==sounds[active].count) active=0;
+    }
+    ma_mutex_unlock(&mutex);
+}
+static int32_t load(const int16_t *pcm, uint32_t count) {
+    if (!opened || !pcm || !count || count>RATE*10) return -1;
+    int slot;
+    for (slot=4; slot<SLOTS && sounds[slot].pcm; ++slot) {}
+    if (slot==SLOTS) return -1;
+    int16_t *copy=malloc(count*sizeof(*copy));
+    if (!copy) return -1;
+    memcpy(copy,pcm,count*sizeof(*copy));
+    ma_mutex_lock(&mutex);
+    sounds[slot].pcm=copy; sounds[slot].count=count;
+    ma_mutex_unlock(&mutex);
+    return slot;
+}
+static int32_t play(int32_t sound) {
+    if (!opened || sound<=0 || sound>=SLOTS || !sounds[sound].pcm) return -1;
+    ma_mutex_lock(&mutex);
+    active=sound; cursor=0;
+    ma_mutex_unlock(&mutex);
+    return 0;
+}
+static int32_t stop(void) {
+    if (opened) { ma_mutex_lock(&mutex); active=0; ma_mutex_unlock(&mutex); }
+    return 0;
+}
+static int32_t playing(void) {
+    if (!opened) return 0;
+    ma_mutex_lock(&mutex);
+    int result=active!=0;
+    ma_mutex_unlock(&mutex);
+    return result;
+}
+static void close_audio(void) {
+    if (!opened) return;
+    ma_device_uninit(&device); // Joins callback before freeing buffers/mutex.
+    ma_mutex_uninit(&mutex);
+    for (int i=1;i<SLOTS;++i) {
+        free(sounds[i].pcm); sounds[i].pcm=NULL; sounds[i].count=0;
+    }
+    opened=0; active=0; cursor=0;
+}
+static int tone(int slot, int descending) {
+    uint32_t note=slot==1 ? RATE*7/100 : RATE*16/100;
+    int notes=slot==1 ? 1 : 3;
+    sounds[slot].count=note*notes;
+    sounds[slot].pcm=calloc(note*notes,sizeof(int16_t));
+    if (!sounds[slot].pcm) return -1;
+    const double pitches[3]={523.251,659.255,783.991};
+    for (int n=0;n<notes;++n) {
+        double hz=slot==1 ? 440.0 : pitches[descending ? 2-n : n];
+        for (uint32_t i=0;i<note;++i) {
+            double t=(double)i/note;
+            double envelope=sin(3.141592653589793*t);
+            sounds[slot].pcm[n*note+i]=(int16_t)(3200*envelope*envelope*sin(6.283185307179586*hz*i/RATE));
+        }
+    }
+    return 0;
+}
+static int32_t open_audio(void) {
+    if (opened) return 0;
+    if (ma_mutex_init(&mutex)!=MA_SUCCESS) return -1;
+    ma_device_config config=ma_device_config_init(ma_device_type_playback);
+    config.playback.format=ma_format_s16;
+    config.playback.channels=1;
+    config.sampleRate=RATE;
+    config.dataCallback=output;
+#ifdef SIMPLE_AUDIO_TEST_NULL
+    ma_backend backend=ma_backend_null;
+    ma_result result=ma_device_init_ex(&backend,1,NULL,&config,&device);
+#else
+    ma_result result=ma_device_init(NULL,&config,&device);
+#endif
+    if (result!=MA_SUCCESS) {
+        ma_mutex_uninit(&mutex);
+        fprintf(stderr,"Simple audio: no playback device (%d); continuing silently.\n",result);
+        return -1;
+    }
+    opened=1;
+    if (tone(1,0) || tone(2,0) || tone(3,1) || ma_device_start(&device)!=MA_SUCCESS) {
+        close_audio(); return -1;
+    }
+    return 0;
+}
+static const struct simple_audio_api api={SIMPLE_AUDIO_VERSION,open_audio,load,play,stop,playing,close_audio};
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+const struct simple_audio_api *simple_miniaudio_api(void) { return &api; }
diff --git a/chapter31/src/main/smp/sys.smp b/chapter31/src/main/smp/sys.smp
index 3ef19099..40a4b955 100644
--- a/chapter31/src/main/smp/sys.smp
+++ b/chapter31/src/main/smp/sys.smp
@@ -2,6 +2,7 @@
 // top-level default standard library import
 
 val adt = adt;                  // Abstract Data Types
+val audio = audio;              // Optional background sound (miniaudio)
 val ary = ary;                  // Array utilities
 val aryi64 = aryi64;            // Variable sized array of i64
 val aryu8 = aryu8;              // Variable sized array of u8
diff --git a/chapter31/src/main/smp/sys/audio.smp b/chapter31/src/main/smp/sys/audio.smp
new file mode 100644
index 00000000..89e6dfa9
--- /dev/null
+++ b/chapter31/src/main/smp/sys/audio.smp
@@ -0,0 +1,29 @@
+// Optional background audio. All API calls belong on the game/main thread.
+int OK = 0;
+int ERROR = -1;
+int BOOP = 1;
+int WIN = 2;
+int LOSE = 3;
+int RATE = 48000;
+{ i32 } simple_audio_open = "C";
+{ i64 u32 -> i32 } simple_audio_load = "C";
+{ i32 -> i32 } simple_audio_play = "C";
+{ i32 } simple_audio_stop = "C";
+{ i32 } simple_audio_playing = "C";
+{ i32 } simple_audio_close = "C";
+// Missing/disabled backend returns ERROR quietly; the game may remain silent.
+val open = { -> simple_audio_open(); };
+// Mono signed 16-bit PCM at RATE, up to ten seconds. Copies into native memory.
+// Load at startup: up to 28 custom handles, valid until close, then reload.
+val load = { i16[~] samples ->
+    i64 ptr = samples;
+    simple_audio_load(ptr,samples#);
+};
+// Starts/restarts immediately, replacing the previous sound; never waits for it.
+val play = { int sound -> simple_audio_play(sound); };
+val boop = { -> simple_audio_play(BOOP); };
+val win = { -> simple_audio_play(WIN); };
+val lose = { -> simple_audio_play(LOSE); };
+val stop = { -> simple_audio_stop(); };
+val playing = { -> simple_audio_playing(); };
+val close = { -> simple_audio_close(); };