Added synth thread that plays a simple note

1 files changed, 67 insertions, 0 deletions

diff --git a/synth.c b/synth.c
new file mode 100644
index 0000000..d391056
--- /dev/null
+++ b/synth.c
@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <unistd.h>
+
+#include "synth.h"
+#include "minisdl_audio.h"
+
+#define TSF_IMPLEMENTATION
+#include "tsf.h"
+
+static tsf* g_TinySoundFont;
+static SDL_mutex* g_Mutex;
+
+// Render the audio samples in float format.
+static void AudioCallback(void* data, Uint8 *stream, int len) {
+	int SampleCount = (len / (2 * sizeof(float))); // 2 output channels.
+	SDL_LockMutex(g_Mutex); // Get exclusive lock.
+	tsf_render_float(g_TinySoundFont, (float*)stream, SampleCount, 0);
+	SDL_UnlockMutex(g_Mutex);
+}
+
+void *synth(void *arg) {
+	SynthArgs* args = (SynthArgs*)arg;
+
+	SDL_AudioSpec OutputAudioSpec;
+	OutputAudioSpec.freq = 44100;
+	OutputAudioSpec.format = AUDIO_F32;
+	OutputAudioSpec.channels = 2;
+	OutputAudioSpec.samples = 4096;
+	OutputAudioSpec.callback = AudioCallback;
+
+	// Initialize the audio system.
+	if (SDL_AudioInit(TSF_NULL) < 0) {
+		fprintf(stderr, "Could not initialize audio hardware or driver\n");
+		exit(1);
+	}
+
+	// Load the SoundFont from a file.
+	g_TinySoundFont = tsf_load_filename(args->soundfont_file);
+	if (!g_TinySoundFont) {
+		fprintf(stderr, "Could not load SoundFont\n");
+		exit(1);
+	}
+
+	// Set the SoundFont rendering output mode.
+	tsf_set_output(g_TinySoundFont, TSF_STEREO_INTERLEAVED, OutputAudioSpec.freq, 0);
+
+	// Create the mutex.
+	g_Mutex = SDL_CreateMutex();
+
+	// Request the desired audio output format.
+	if (SDL_OpenAudio(&OutputAudioSpec, TSF_NULL) < 0) {
+		fprintf(stderr, "Could not open the audio hardware or the desired audio output format\n");
+		exit(1);
+	}
+
+	SDL_PauseAudio(0);
+
+	while (1) {
+		sleep(1);
+
+		SDL_LockMutex(g_Mutex);
+		tsf_note_off(g_TinySoundFont, 1, 50);
+		tsf_note_on(g_TinySoundFont, 1, 50, 1.0f);
+		SDL_UnlockMutex(g_Mutex);
+	}
+}
+