convert classes to stucts

Author: tomdaley92

shared/Audio.cc

@@ -1,58 +1,61 @@
 #include "Audio.h"
 #include <stdio.h>
 
-Audio::Audio() {
-    wave_position = 0;
-    wave_increment = ((double) TONE * (2.0 * M_PI)) / (double) FREQUENCY;
+/* Global audio instance */
+struct audio audio;
+
+void audio_create(void) {
+    audio.wave_position = 0;
+    audio.wave_increment = ((double) TONE * (2.0 * M_PI)) / (double) FREQUENCY;
 }
 
-Audio::~Audio() {
+void audio_destroy(void) {
     /* pause & close the audio */
-    SDL_PauseAudioDevice(device, 1);
-    if (device) SDL_CloseAudioDevice(device);
-    free(audio_buffer);
+    SDL_PauseAudioDevice(audio.device, 1);
+    if (audio.device) SDL_CloseAudioDevice(audio.device);
+    free(audio.audio_buffer);
 }
 
-int Audio::Initialize() {
-    audiospec.freq = FREQUENCY;
-    audiospec.format = AUDIO_U8; /* unsigned 8-bit data stream */
-    audiospec.channels = 1; /* mono */
-    audiospec.samples = 2048; /* must be a power of 2 */
-    audiospec.callback = NULL;
-    audiospec.userdata = NULL;
+int audio_initialize(void) {
+    audio.audiospec.freq = FREQUENCY;
+    audio.audiospec.format = AUDIO_U8; /* unsigned 8-bit data stream */
+    audio.audiospec.channels = 1; /* mono */
+    audio.audiospec.samples = 2048; /* must be a power of 2 */
+    audio.audiospec.callback = NULL;
+    audio.audiospec.userdata = NULL;
 
     /* open default audio device (allow audio changes) */
-    device = SDL_OpenAudioDevice(NULL, 0, &audiospec, NULL, SDL_AUDIO_ALLOW_ANY_CHANGE);
+    audio.device = SDL_OpenAudioDevice(NULL, 0, &audio.audiospec, NULL, SDL_AUDIO_ALLOW_ANY_CHANGE);
 
-    if (!device) {
+    if (!audio.device) {
         fprintf(stderr, "Error: %s\n", SDL_GetError());
         return 1;
     }
 
     /* ~.5 seconds worth of audio (probably overkill) */
-    audio_buffer = (unsigned char *)malloc(SAMPLES_PER_FRAME * 30);
-    if (!audio_buffer) {
+    audio.audio_buffer = (unsigned char *)malloc(SAMPLES_PER_FRAME * 30);
+    if (!audio.audio_buffer) {
         fprintf(stderr, "Unable to allocate memory for audio buffer.\n");
         return 1;
     }
 
     /* start playing audio */
-    SDL_PauseAudioDevice(device, 0);
+    SDL_PauseAudioDevice(audio.device, 0);
 
     return 0;
 }
 
-void Audio::SineWave(int length) {
+static void audio_sine_wave(int length) {
     for (int i = 0; i < length; i++) {
         /* sine wave varies from 120 - 134 */
-        audio_buffer[i] = (unsigned char) ((AMPLITUDE * sin(wave_position)) + BIAS);
-        wave_position += wave_increment;
+        audio.audio_buffer[i] = (unsigned char) ((AMPLITUDE * sin(audio.wave_position)) + BIAS);
+        audio.wave_position += audio.wave_increment;
     }
 }
 
-void Audio::Beep(int length) {
-    if (SDL_GetQueuedAudioSize(device) < (SAMPLES_PER_FRAME * 2)) {
-        SineWave(length);
-        SDL_QueueAudio(device, audio_buffer, length);
+void audio_beep(int length) {
+    if (SDL_GetQueuedAudioSize(audio.device) < (SAMPLES_PER_FRAME * 2)) {
+        audio_sine_wave(length);
+        SDL_QueueAudio(audio.device, audio.audio_buffer, length);
     }
 }

shared/Audio.h

@@ -9,23 +9,22 @@
 #define BIAS 127
 #define SAMPLES_PER_FRAME ((FREQUENCY / 60) * 3)
 
-class Audio {
-    private:
-        SDL_AudioSpec audiospec;
-        SDL_AudioDeviceID device;
-        unsigned char *audio_buffer;
+struct audio {
+    SDL_AudioSpec audiospec;
+    SDL_AudioDeviceID device;
+    unsigned char *audio_buffer;
 
-        double wave_position;
-        double wave_increment;
-
-        void SineWave(int length);
+    double wave_position;
+    double wave_increment;
+};
 
-    public:
+/* Global audio instance */
+extern struct audio audio;
 
-        Audio();
-        ~Audio();
-        int Initialize();
-        void Beep(int length);
-};
+/* Audio functions */
+void audio_create(void);
+void audio_destroy(void);
+int audio_initialize(void);
+void audio_beep(int length);
 
 #endif