Initial commit

1 files changed, 115 insertions, 0 deletions

diff --git a/main.cpp b/main.cpp
new file mode 100644
index 0000000..de39d1c
--- /dev/null
+++ b/main.cpp
@@ -0,0 +1,115 @@
+#include <SDL2/SDL.h>
+#define _USE_MATH_DEFINES
+#include <cmath>
+#include <iostream>
+
+const float AMPLITUDE = 0.2f;
+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 currentStep;
+};
+
+void AudioCallback(void *userData, Uint8 *rawBuffer, int bytes)
+{
+	float *buffer = (float*)rawBuffer;
+	int length = bytes / sizeof(float);
+	CallbackInfo *info = (CallbackInfo*)userData;
+
+	for (int i = 0; i < length; i++, info->sampleCount++) {
+		float freq = sequence[info->currentStep];
+		float time = (float)info->sampleCount / (float)SAMPLE_RATE;
+		buffer[i] = (sinf(2.0f * M_PI * freq * time)) * AMPLITUDE;
+	}
+}
+
+void DrawInterface(SDL_Renderer* renderer, int currentStep)
+{
+	SDL_Rect rect = { 
+		(640 - 8 * (32 + 8)) / 2, 
+		(320 - 32) / 2, 
+		32, 
+		32 
+	};
+
+	for (int i = 0; i < 8; i++) {
+		SDL_SetRenderDrawColor(renderer, 128, i * (255 / 8), 255, 255);
+
+		if (i == currentStep) {
+			SDL_RenderFillRect(renderer, &rect);
+		} else {
+			SDL_RenderDrawRect(renderer, &rect);
+		}
+
+		rect.x += rect.w + 8;
+	}
+}
+
+int main(int argc, char** argv)
+{
+	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0) {
+		std::cerr << "Failed to initalize SDL! " << SDL_GetError() << std::endl;
+		return 1;
+	}
+
+	SDL_Window* window = SDL_CreateWindow("fmseq", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 320, SDL_WINDOW_SHOWN);
+	SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
+	SDL_Event event;
+
+	CallbackInfo info;
+	info.sampleCount = 0;
+	info.currentStep = 0;
+
+	SDL_AudioSpec desiredSpec;
+	desiredSpec.freq = SAMPLE_RATE;
+	desiredSpec.format = AUDIO_F32SYS;
+	desiredSpec.channels = 1;
+	desiredSpec.samples = 2048;
+	desiredSpec.callback = AudioCallback;
+	desiredSpec.userdata = &info;
+
+	SDL_AudioSpec obtainedSpec;
+	if (SDL_OpenAudio(&desiredSpec, &obtainedSpec) < 0) {
+		std::cerr << "Failed to initalize audio! " << SDL_GetError() << std::endl;
+		return 1;
+	}
+
+	if (desiredSpec.format != obtainedSpec.format) {
+		std::cerr << "Different format: " << obtainedSpec.format << std::endl;
+	}
+
+	SDL_PauseAudio(0);
+
+	bool running = true;
+	while (running) {
+		while (SDL_PollEvent(&event)) {
+			switch (event.type) {
+			case SDL_QUIT:
+				running = false;
+				break;
+			}
+		}
+		
+		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_PauseAudio(1);
+	SDL_CloseAudio();
+
+	SDL_DestroyWindow(window);
+	SDL_Quit();
+
+	return 0;
+}
\ No newline at end of file