First PPM experiment

sound_server.cpp

@@ -0,0 +1,37 @@
+#include "sound_server.h"
+
+#include <SDL/SDL.h>
+
+#include <iostream>
+
+void audio_callback(void* param, uint8_t* stream, int len) {
+  sound_producer_1bit* producer = reinterpret_cast<sound_producer_1bit*>(param);
+  for (int i = 0; i < len; i++) {
+    *stream++ = producer->tick() ? 255 : 0;
+  }
+}
+
+sound_server_1bit::sound_server_1bit(uint16_t samplerate,
+                                     sound_producer_1bit& producer) {
+  if (SDL_Init(SDL_INIT_AUDIO) < 0) {
+    std::cerr << "Init failed" << std::endl;
+    exit(1);
+  }
+
+  SDL_AudioSpec as;
+  as.freq = samplerate;
+  as.format = AUDIO_U8;
+  as.samples = 256;
+  as.callback = audio_callback;
+  as.userdata = reinterpret_cast<void*>(&producer);
+  as.channels = 1;
+
+  if (SDL_OpenAudio(&as, NULL) < 0) {
+    std::cerr << "Unable to open audio" << std::endl;
+    exit(1);
+  }
+
+  SDL_PauseAudio(0);
+}
+
+sound_server_1bit::~sound_server_1bit() { SDL_Quit(); }