diff options
| -rw-r--r-- | main.cpp | 19 |
1 files changed, 13 insertions, 6 deletions
@@ -9,7 +9,8 @@ const int SAMPLE_RATE = 44100; const float sequence[8] = { 130.81f, 220.f, 130.81f, 440.f, 330.f, 440.f, 130.81f, 261.63f }; struct CallbackInfo { - int sampleCount; + int samplesDone; + int samplesPerStep; int currentStep; }; @@ -19,9 +20,15 @@ void AudioCallback(void *userData, Uint8 *rawBuffer, int bytes) int length = bytes / sizeof(float); CallbackInfo *info = (CallbackInfo*)userData; - for (int i = 0; i < length; i++, info->sampleCount++) { + for (int i = 0; i < length; i++, info->samplesDone++) { float freq = sequence[info->currentStep]; - float time = (float)info->sampleCount / (float)SAMPLE_RATE; + float time = (float)info->samplesDone / (float)SAMPLE_RATE; + + if (info->samplesDone >= info->samplesPerStep) { + info->samplesDone = 0; + info->currentStep = (info->currentStep + 1) % 8; + } + buffer[i] = (sinf(2.0f * M_PI * freq * time)) * AMPLITUDE; } } @@ -60,7 +67,8 @@ int main(int argc, char** argv) SDL_Event event; CallbackInfo info; - info.sampleCount = 0; + info.samplesDone = 0; + info.samplesPerStep = SAMPLE_RATE * 0.2f; info.currentStep = 0; SDL_AudioSpec desiredSpec; @@ -96,13 +104,12 @@ int main(int argc, char** argv) SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255); SDL_RenderClear(renderer); - info.currentStep = (info.currentStep + 1) % 8; DrawInterface(renderer, info.currentStep); SDL_RenderPresent(renderer); SDL_UpdateWindowSurface(window); - SDL_Delay(200); + SDL_Delay(10); } SDL_PauseAudio(1); |