its kinda working i guess

src/Application.cpp

@@ -32,8 +32,7 @@ void Application::Quit()
 
 	if (window != nullptr)
 	{
-		delete file;
-		delete topology;
+		delete spectrogram;
 
 		manager.Clear();
 
@@ -148,44 +147,15 @@ void Application::Init(int width, int height, const std::string& title)
 	data.camera = &camera;
 	data.aspectRatio = (float)width / (float)height;
 
-	topology = new ScrollingPlot(
-		manager, 
-		glm::vec2(15.0f, 15.0f), 
-		glm::uvec2(500, 500),
-		glm::vec2(-1.0f, 1.0f),
-		0.001f,
-		// [](float t, float y)
-		// {
-		// 	return cos(t) + 0.5f * cos(2.0f * t) + 0.1f * sin(1.3f * t) + 0.3f * cos(3.5f * t) + 2.0f * (y * y) - 2.0f;
-		// }
-		[](float t, float y)
-		{
-			// Weierstraß
-			float z = 0.0f;
-			for(unsigned k = 1; k < 100; k++)
-			{
-				unsigned int twoK = std::pow(2, k);
-				z += twoK * sin(twoK * t) * cos(twoK * y) / std::pow(3, k);
-			}
-
-			return z;
-		}
+	spectrogram = new Spectrogram(
+		manager,
+		glm::vec2(5.0f, 5.0f),
+		glm::uvec2(200, 2000),
+		AudioFile("res/payday.wav")
 	);
 
 	colormap = 3;
-	topology->SetColormap(colormaps[colormap]);
-
-	file = new AudioFile("res/payday.wav");
-	SDL_AudioSpec specs = file->GetAudioSpec();
-	std::cout << "Channels: " << (int)specs.channels << std::endl;
-	std::cout << "Format: " << std::bitset<16>{specs.format} << std::endl;
-	std::cout << "Samples: " << specs.samples << std::endl;
-	std::cout << "Frequency: " << specs.freq << std::endl;
-	file->Normalize();
-
-	std::cout << "First 50 samples: " << std::endl;
-	for(auto it = file->begin(); it != file->begin() + 50; it++)
-		std::cout << *it << std::endl;
+	spectrogram->SetColormap(colormaps[colormap]);
 
 	// glEnable(GL_CULL_FACE);
 	glEnable(GL_MULTISAMPLE);
@@ -205,10 +175,10 @@ void Application::Launch()
 	
 		camera.SetPosition(pitch, yaw, distance);
 
-		topology->SetHeightMapping(enableHeightMap);
-		topology->SetColorMapping(enableColorMap);
+		spectrogram->SetHeightMapping(enableHeightMap);
+		spectrogram->SetColorMapping(enableColorMap);
 		if(enableScroll)
-			topology->StepForward(3);
+			spectrogram->Update();
 
 		if(orthogonal)
 			camera.SetOrthogonal(-width / 2.0f * data.aspectRatio, width / 2.0f * data.aspectRatio, -width / 2.0, width / 2.0f, -1.0f, 100.0f);
@@ -218,7 +188,7 @@ void Application::Launch()
 		glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
 		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
-		camera.Draw(*topology);
+		camera.Draw(*spectrogram);
 
 		ImGui_ImplOpenGL3_NewFrame();
 		ImGui_ImplGlfw_NewFrame();
@@ -256,7 +226,7 @@ void Application::Launch()
 			ImGui::Checkbox("Scrolling", &enableScroll);
 
 			ImGui::ListBox("Colormap", &colormap, colormapNames.data(), colormapNames.size());
-			topology->SetColormap(colormaps[colormap]);
+			spectrogram->SetColormap(colormaps[colormap]);
 		}
 
 		ImGui::End();

src/Application.hpp

@@ -4,8 +4,7 @@
 #include <chrono>
 #include "Util.hpp"
 #include "OrbitingCamera.hpp"
-#include "ScrollingPlot.hpp"
-#include "AudioFile.hpp"
+#include "Spectrogram.hpp"
 
 struct GLFWwindow;
 
@@ -59,6 +58,5 @@ private:
 	bool enableScroll = false;
 	int colormap = 0;
 
-	ScrollingPlot* topology;
-	AudioFile* file;
+	Spectrogram* spectrogram;
 };

src/CMakeLists.txt

@@ -6,6 +6,7 @@ add_executable(visualizer
 	"Colormaps.cpp"
 	"ScrollingPlot.cpp"
 	"AudioFile.cpp"
+	"Spectrogram.cpp"
 )
 
 target_sources(visualizer PUBLIC 

src/Spectrogram.cpp

@@ -0,0 +1,114 @@
+#include "Spectrogram.hpp"
+
+#include <complex>
+
+#define POW_OF_TWO(x) ((x) && !((x) & ((x) - 1)))
+
+std::vector<std::complex<float>> radix2dit(
+    const std::vector<float> samples, 
+    size_t offset,
+    size_t N, 
+    size_t s
+);
+
+Spectrogram::Spectrogram(
+    lol::ObjectManager& manager, 
+    const glm::vec2& size, 
+    const glm::uvec2& subdivision,
+    const AudioFile& audio
+) :
+    Topology(manager, size, subdivision), audio(audio)
+{
+    this->audio.Normalize();
+
+    range = glm::vec2(0.0f, 0.0005f);
+    MakeTexture();
+} 
+
+void Spectrogram::Update()
+{
+    // Load samples
+    unsigned int sampleNumber = audio.GetAudioSpec().freq / 60;
+    std::vector<float> samples(audio.begin() + currentStrip * sampleNumber, audio.begin() + (currentStrip + 1) * sampleNumber);
+    size_t N = samples.size();
+
+    // Zeropad the signal
+    while(!POW_OF_TWO(N))
+    {
+        samples.push_back(0.0f);
+        N++;
+    }
+
+    N = samples.size() << 3;
+    samples.insert(samples.end(), N - samples.size(), 0.0f);
+
+    // Perform Fourier transformation on the next samples
+    std::vector<std::complex<float>> spectrum = radix2dit(samples, 0, N, 1);
+    float freqRes = (float)audio.GetAudioSpec().freq / (float)N;
+	float nyquistLimit = (float)audio.GetAudioSpec().freq / 2.0f;
+
+	std::vector<std::pair<float, float>> output;
+	float freq = 50.0f;
+	float maxFreq = nyquistLimit;
+
+	for (int k = freq / freqRes; freq < nyquistLimit && freq < maxFreq; k++)    // ??? wtf is going on here?
+	{
+		output.push_back(std::make_pair(freq, 2.0f * std::abs(spectrum[k]) / (float)N));
+
+		freq += freqRes;
+	}
+
+    float* pixels = GetTopology();
+    glm::uvec2 dims = image.GetDimensions();
+
+    glm::vec2 arrayDomain(0.0f, N);
+    glm::vec2 imageDomain(0.0f, dims.y);
+
+    unsigned int imageStrip = currentStrip % dims.x;
+    for(unsigned int y = 0; y < dims.y; y++)
+    {
+        std::complex<float> sample = output[Map(imageDomain, arrayDomain, y)].second;
+        float magnitude = std::abs(sample);
+
+        pixels[y * dims.x + imageStrip] = magnitude;
+    }
+
+    MakeTexture();
+
+    currentStrip++;
+    offset += 1.0f / (float)dims.x;
+}
+
+std::vector<std::complex<float>> radix2dit(
+    const std::vector<float> samples, 
+    size_t offset,
+    size_t N, 
+    size_t s
+)
+{
+    std::vector<std::complex<float>> output(N);
+
+    if(N == 1)
+    {
+        output[0] = samples[offset];
+    }
+    else
+    {
+        size_t halfN = N >> 1;
+        std::vector<std::complex<float>> first = radix2dit(samples, offset, halfN, 2 * s);
+        std::vector<std::complex<float>> second = radix2dit(samples, offset + s, halfN, 2 * s);
+
+        float coeff = -M_PI / (float)halfN;
+
+		for (int k = 0; k < halfN; k++)
+		{
+			std::complex<float> p = first[k];
+			std::complex<float> q = std::exp(coeff * (float)k) * second[k];
+
+			output[k] = p + q;
+			output[halfN + k] = p - q;
+		}
+    }
+
+    return output;
+}

src/Spectrogram.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "Topology.hpp"
+#include "AudioFile.hpp"
+
+class Spectrogram : public Topology
+{
+public:
+    Spectrogram(
+        lol::ObjectManager& manager, 
+        const glm::vec2& size, 
+        const glm::uvec2& subdivision,
+        const AudioFile& audio
+    );
+
+    void Update();
+
+private:
+    AudioFile audio;
+    unsigned int currentStrip = 0;
+};

src/Topology.hpp

@@ -16,7 +16,7 @@ public:
 
 	void PreRender(const lol::CameraBase& camera) override;
 
-	inline void SetHeightMapping(bool enable) { heightFactor = enable ? 2.0f : 0.0f; }
+	inline void SetHeightMapping(bool enable) { heightFactor = enable ? 200.0f : 0.0f; }
 	inline void SetColorMapping(bool enable) { renderColor = enable; }
 	inline virtual void Scroll(bool enable) { scroll = enable; }
 
@@ -41,7 +41,7 @@ protected:
 	float offset = 0.0f;
 	
 private:
-	float heightFactor = 2.0f;
+	float heightFactor = 200.0f;
 	bool renderColor = true;
 	bool scroll = false;
 };