- [NEW] mòdul 'zx_speaker' per a unificar la eixida de só

zx_speaker.cpp

@@ -0,0 +1,60 @@
+#include "zx_speaker.h"
+#include <SDL2/SDL.h>
+#include "z80.h"
+#include <vector>
+
+namespace speaker
+{
+    #define SAMPLING_FREQ 44100
+    #define AUDIO_BUFFER_SIZE 2048
+    SDL_AudioDeviceID sdlAudioDevice;
+    uint8_t sound_buffer[AUDIO_BUFFER_SIZE];
+    uint16_t sound_pos=0;
+    uint16_t t_sound=0;
+    std::vector<uint8_t(*)()> sources;
+
+    float cycles_per_sample;
+
+    void init()
+    {
+        SDL_AudioSpec audioSpec{SAMPLING_FREQ, AUDIO_U8, 1, 0, AUDIO_BUFFER_SIZE>>2, 0, 0, NULL, NULL};
+        sdlAudioDevice = SDL_OpenAudioDevice(NULL, 0, &audioSpec, NULL, 0);
+        cycles_per_sample = z80::getClock() / SAMPLING_FREQ;
+        enable();
+    }
+
+    void enable()
+    {
+        SDL_PauseAudioDevice(sdlAudioDevice, 0);
+    }
+
+    void disable()
+    {
+        SDL_PauseAudioDevice(sdlAudioDevice, 1);
+    }
+
+    void register_source(uint8_t(*callback)())
+    {
+        sources.push_back(callback);
+    }
+
+    void update(const uint8_t dt)
+    {
+        t_sound += dt;
+        if (t_sound>=cycles_per_sample) {
+            t_sound-=cycles_per_sample;
+
+            uint32_t sample = 0;
+            for (auto callback : sources) sample += callback();
+            sample /= sources.size();
+            
+            sound_buffer[(sound_pos++)&(AUDIO_BUFFER_SIZE-1)] = sample;
+        }
+        if (sound_pos>=1000) {
+            SDL_QueueAudio(sdlAudioDevice, sound_buffer, sound_pos);
+            sound_pos = 0;
+            while (SDL_GetQueuedAudioSize(sdlAudioDevice) > 4096 ) {}
+        }
+    }
+
+}