Refactor src/synth.c

Changes:

    * Implement xas_synth type to consolidate synthesiser
      implementation and different tone generator types

    * Refactor examples/ code to remove duplicate synthesiser code

3 files changed, 82 insertions, 123 deletions

diff --git a/examples/say.c b/examples/say.c
index 92856f2..fa16242 100644
--- a/examples/say.c
+++ b/examples/say.c
@@ -40,41 +40,15 @@ static void usage(int argc, char **argv, const char *message, ...) {
     exit(EX_USAGE);
 }
 
-static int16_t sine_sample(xas_synth *synth, synth_sine *sine) {
-    static float tau = 2.0f * M_PI;
-
-    int16_t ret;
-
-    if (sine->flags & SYNTH_STATUS_ON) {
-        ret = (int16_t)roundf((INT16_MAX >> 2) * sinf(sine->phase));
-
-        sine->phase += tau / (synth->format.sample_rate / sine->frequency);
-
-        if (sine->phase > tau) {
-            sine->phase -= tau;
-        }
-    } else {
-        ret = 0;
-    }
-
-    return ret;
-}
-
-static void sine_cleanup(xas_synth *synth, synth_sine *sine) {
-    return;
-}
-
 int main(int argc, char **argv) {
-    synth_sine sine_channels[2] = {
-        { SYNTH_STATUS_ON, 0.0f, 220 },
-        { SYNTH_STATUS_ON, 0.0f, 420 },
-    };
-
     xas_mixer *mixer;
 
     xas_bank *bank;
     xas_vox *vox;
 
+    xas_synth *sine_l,
+                *sine_r;
+
     xas_bank_player *player;
 
     xas_audio_stream *voice,
@@ -97,6 +71,18 @@ int main(int argc, char **argv) {
         usage(argc, argv, "No output file provided");
     }
 
+    if ((sine_l = xas_synth_new(format,
+                                  buffer_size,
+                                  XAS_SYNTH_SINE)) == NULL) {
+        goto error_synth_new_l;
+    }
+
+    if ((sine_r = xas_synth_new(format,
+                                  buffer_size,
+                                  XAS_SYNTH_SINE)) == NULL) {
+        goto error_synth_new_r;
+    }
+
     if ((vox = xas_vox_new(format,
                              buffer_size,
                              "/usr/bin/text2wave")) == NULL) {
@@ -125,20 +111,12 @@ int main(int argc, char **argv) {
         goto error_bank_player_stream_new;
     }
 
-    if ((synth_l = xas_synth_new((xas_synth_callback_sample)sine_sample,
-                                   (xas_synth_callback_cleanup)sine_cleanup,
-                                   format,
-                                   buffer_size,
-                                   &sine_channels[0])) == NULL) {
-        goto error_synth_new_l;
+    if ((synth_l = xas_synth_new_stream(sine_l)) == NULL) {
+        goto error_synth_new_stream_l;
     }
 
-    if ((synth_r = xas_synth_new((xas_synth_callback_sample)sine_sample,
-                                   (xas_synth_callback_cleanup)sine_cleanup,
-                                   format,
-                                   buffer_size,
-                                   &sine_channels[1])) == NULL) {
-        goto error_synth_new_r;
+    if ((synth_r = xas_synth_new_stream(sine_r)) == NULL) {
+        goto error_synth_new_stream_r;
     }
 
     if ((mixer = xas_mixer_new(format, buffer_size)) == NULL) {
@@ -157,10 +135,18 @@ int main(int argc, char **argv) {
         goto error_mixer_input_add;
     }
 
+    xas_synth_set_frequency(sine_l, 220);
+    xas_synth_start(sine_l);
+
+    xas_synth_set_frequency(sine_l, 420);
+    xas_synth_start(sine_r);
+
     /*
      * Time to fill the sample bank, meow!
      */
-    xas_vox_say(vox, "I want to eat your soul.  You don't understand.  I really want to eat your soul.\n");
+    xas_vox_say(vox, "I want to eat your soul.");
+    xas_vox_say(vox, "You don't understand.");
+    xas_vox_say(vox, "I really want to eat your soul.");
 
     xas_vox_generate(vox);
 
@@ -192,6 +178,8 @@ int main(int argc, char **argv) {
     xas_mixer_destroy(mixer);
     xas_audio_stream_destroy(synth_r);
     xas_audio_stream_destroy(synth_l);
+    xas_synth_destroy(sine_r);
+    xas_synth_destroy(sine_l);
     xas_audio_stream_destroy(player_stream);
     xas_audio_stream_destroy(voice);
     xas_audio_stream_destroy(output);
@@ -210,10 +198,10 @@ error_mixer_input_add:
 error_mixer_new:
     xas_audio_stream_destroy(synth_r);
 
-error_synth_new_r:
+error_synth_new_stream_r:
     xas_audio_stream_destroy(synth_l);
 
-error_synth_new_l:
+error_synth_new_stream_l:
     xas_audio_stream_destroy(player_stream);
 
 error_bank_player_stream_new:
@@ -232,5 +220,11 @@ error_bank_new:
     xas_vox_destroy(vox);
 
 error_vox_new:
+    xas_synth_destroy(sine_r);
+
+error_synth_new_r:
+    xas_synth_destroy(sine_l);
+
+error_synth_new_l:
     return EX_OSERR;
 }
diff --git a/examples/spatial.c b/examples/spatial.c
index ec606d6..c5c658c 100644
--- a/examples/spatial.c
+++ b/examples/spatial.c
@@ -39,32 +39,11 @@ static void usage(int argc, char **argv, const char *message, ...) {
     exit(EX_USAGE);
 }
 
-static int16_t sine_sample(xas_synth *synth, synth_sine *sine) {
-    int16_t ret;
-    static float tau = 2.0f * M_PI;
-
-    if (sine->flags & SYNTH_STATUS_ON) {
-        ret = (int16_t)roundf((INT16_MAX >> 2) * sinf(sine->phase));
-
-        sine->phase += tau / (synth->format.sample_rate / sine->frequency);
-
-        if (sine->phase > tau) {
-            sine->phase -= tau;
-        }
-    } else {
-        ret = 0;
-    }
-
-    return ret;
-}
-
-static void sine_cleanup(xas_synth *synth, synth_sine *sine) {
-    return;
-}
-
 int main(int argc, char **argv) {
     xas_spatial_scene *scene;
 
+    xas_synth *sine;
+
     xas_audio_stream *synth,
                        *voice,
                        *output,
@@ -72,11 +51,6 @@ int main(int argc, char **argv) {
 
     xas_vox *vox;
 
-    synth_sine sine_channels[2] = {
-        { SYNTH_STATUS_ON, 0.0f, 2600 },
-        { SYNTH_STATUS_ON, 0.0f,  420 },
-    };
-
     xas_audio_format format = {
         .channels    = XAS_AUDIO_STEREO,
         .sample_size = XAS_AUDIO_PCM_16_BIT,
@@ -102,14 +76,16 @@ int main(int argc, char **argv) {
         goto error_riff_new_file;
     }
 
-    if ((synth = xas_synth_new((xas_synth_callback_sample)sine_sample,
-                                 (xas_synth_callback_cleanup)sine_cleanup,
-                                 format,
-                                 buffer_size,
-                                 &sine_channels[0])) == NULL) {
+    if ((sine = xas_synth_new(format,
+                                buffer_size,
+                                XAS_SYNTH_SINE)) == NULL) {
         goto error_synth_new;
     }
 
+    if ((synth = xas_synth_new_stream(sine)) == NULL) {
+        goto error_synth_new_stream;
+    }
+
     if ((vox = xas_vox_new(format,
                              buffer_size,
                              "/usr/bin/text2wave")) == NULL) {
@@ -136,7 +112,7 @@ int main(int argc, char **argv) {
     if (xas_spatial_scene_add_object(scene,
                                        (xas_spatial_coord){ 5.2, 0.0, 0.0 },
                                        synth,
-                                       &sine_channels[0]) == NULL) {
+                                       sine) == NULL) {
         goto error_spatial_scene_add_object;
     }
 
@@ -147,6 +123,9 @@ int main(int argc, char **argv) {
         goto error_spatial_scene_add_object;
     }
 
+    xas_synth_set_frequency(sine, 320);
+    xas_synth_start(sine);
+
     xas_vox_sayf(vox, "I want to eat your soul.\n");
     xas_vox_sayf(vox, "You don't understand.\n");
     xas_vox_sayf(vox, "I really want to eat your soul.\n");
@@ -196,6 +175,9 @@ error_vox_stream_new:
 error_vox_new:
     xas_audio_stream_destroy(synth);
 
+error_synth_new_stream:
+    xas_synth_destroy(sine);
+
 error_synth_new:
     xas_audio_stream_destroy(wave);
 
diff --git a/examples/test.c b/examples/test.c
index 1fbd8c4..272e32d 100644
--- a/examples/test.c
+++ b/examples/test.c
@@ -11,16 +11,6 @@
 #include <xas/mixer.h>
 #include <xas/riff.h>
 
-#define SYNTH_STATUS_CLEAR  0
-#define SYNTH_STATUS_ON    (1 << 0)
-
-typedef struct _synth_sine {
-    int flags;
-    float phase;
-
-    size_t frequency;
-} synth_sine;
-
 static void usage(int argc, char **argv, const char *message, ...) {
     va_list args;
 
@@ -38,29 +28,6 @@ static void usage(int argc, char **argv, const char *message, ...) {
     exit(EX_USAGE);
 }
 
-static int16_t sine_sample(xas_synth *synth, synth_sine *sine) {
-    int16_t ret;
-    static float tau = 2.0f * M_PI;
-
-    if (sine->flags & SYNTH_STATUS_ON) {
-        ret = (int16_t)roundf((INT16_MAX >> 2) * sinf(sine->phase));
-
-        sine->phase += tau / (synth->format.sample_rate / sine->frequency);
-
-        if (sine->phase > tau) {
-            sine->phase -= tau;
-        }
-    } else {
-        ret = 0;
-    }
-
-    return ret;
-}
-
-static void sine_cleanup(xas_synth *synth, synth_sine *sine) {
-    return;
-}
-
 int main(int argc, char **argv) {
     xas_mixer *mixer;
 
@@ -68,10 +35,8 @@ int main(int argc, char **argv) {
                        *synth_r,
                        *wave;
 
-    synth_sine sine_channels[2] = {
-        { SYNTH_STATUS_ON, 0.0f, 220 },
-        { SYNTH_STATUS_ON, 0.0f, 420 },
-    };
+    xas_synth *sine_l,
+                *sine_r;
 
     xas_audio_format format = {
         .channels    = XAS_AUDIO_STEREO,
@@ -93,22 +58,26 @@ int main(int argc, char **argv) {
         goto error_riff_new_file;
     }
 
-    if ((synth_l = xas_synth_new((xas_synth_callback_sample)sine_sample,
-                                   (xas_synth_callback_cleanup)sine_cleanup,
-                                   format,
+    if ((sine_l = xas_synth_new(format,
                                    buffer_size,
-                                   &sine_channels[0])) == NULL) {
+                                   XAS_SYNTH_SINE)) == NULL) {
         goto error_synth_new_l;
     }
 
-    if ((synth_r = xas_synth_new((xas_synth_callback_sample)sine_sample,
-                                   (xas_synth_callback_cleanup)sine_cleanup,
-                                   format,
+    if ((synth_l = xas_synth_new_stream(sine_l)) == NULL) {
+        goto error_synth_new_stream_l;
+    }
+
+    if ((sine_r = xas_synth_new(format,
                                    buffer_size,
-                                   &sine_channels[1])) == NULL) {
+                                   XAS_SYNTH_SINE)) == NULL) {
         goto error_synth_new_r;
     }
 
+    if ((synth_r = xas_synth_new_stream(sine_r)) == NULL) {
+        goto error_synth_new_stream_r;
+    }
+
     if ((mixer = xas_mixer_new(format, buffer_size)) == NULL) {
         goto error_mixer_new;
     }
@@ -121,6 +90,12 @@ int main(int argc, char **argv) {
         goto error_mixer_input_add;
     }
 
+    xas_synth_set_frequency(sine_l, 2600);
+    xas_synth_start(sine_l);
+
+    xas_synth_set_frequency(sine_r, 420);
+    xas_synth_start(sine_r);
+
     for (i=0; i<duration_s; i++) {
         void *buf;
         ssize_t readlen;
@@ -140,7 +115,9 @@ int main(int argc, char **argv) {
 
     xas_mixer_destroy(mixer);
     xas_audio_stream_destroy(synth_r);
+    xas_synth_destroy(sine_r);
     xas_audio_stream_destroy(synth_l);
+    xas_synth_destroy(sine_l);
     xas_audio_stream_destroy(wave);
 
     return EX_OK;
@@ -153,9 +130,15 @@ error_mixer_input_add:
 error_mixer_new:
     xas_audio_stream_destroy(synth_r);
 
+error_synth_new_stream_r:
+    xas_synth_destroy(sine_r);
+
 error_synth_new_r:
     xas_audio_stream_destroy(synth_l);
 
+error_synth_new_stream_l:
+    xas_synth_destroy(sine_l);
+
 error_synth_new_l:
     xas_audio_stream_destroy(wave);