Working

app/app.pro

@@ -3,12 +3,11 @@
 ###################################################
 
 TEMPLATE = app
-TARGET   = NewAwesomeApplication
+TARGET   = RandomnessVisualizer
 
-#QT = core gui widgets network
+QT = core gui widgets
 #win*:QT += winextras
-CONFIG -= qt
-CONFIG += console
+#CONFIG += console
 
 CONFIG += strict_c++ c++2a
 

app/src/main.cpp

@@ -1,6 +1,129 @@
+#include "hash/wheathash.hpp"
 
+#include <QApplication>
+#include <QElapsedTimer>
+#include <QImage>
+#include <QMainWindow>
+#include <QPainter>
+#include <QtMath>
+
+#include <functional>
+#include <memory>
+#include <string.h>
+
+struct VisualizationWidget final : public QWidget
+{
+	using QWidget::QWidget;
+
+	void setRngFunction(std::function<uint32_t (uint32_t)> nextRandomNumber) {
+		_nextRandomNumber = std::move(nextRandomNumber);
+		update();
+	}
+
+protected:
+	void paintEvent(QPaintEvent*) override
+	{
+		QElapsedTimer timer;
+		timer.start();
+
+		QPainter p{this};
+		if (!_nextRandomNumber)
+			return;
+
+		const int w = qFloor(width() * devicePixelRatioF());
+		const int h = qFloor(height() * devicePixelRatioF());
+		std::unique_ptr<uint32_t[]> field(new uint32_t[w * h]);
+		uint32_t* fieldPtr = field.get();
+		::memset(fieldPtr, 0, w * h * sizeof(fieldPtr[0]));
+
+		int x = 0, y = 0;
+		for (size_t i = 0; i < w * h * 40; ++i)
+		{
+			const uint32_t direction = _nextRandomNumber(4);
+			switch (direction)
+			{
+			case 0:
+				++x;
+				if (x >= w)
+					x -= w;
+				break;
+			case 1:
+				--x;
+				if (x < 0)
+					x += w;
+				break;
+			case 2:
+				++y;
+				if (y >= h)
+					y -= h;
+				break;
+			case 3:
+				--y;
+				if (y < 0)
+					y += h;
+				break;
+			}
+
+			++fieldPtr[y * w + x];
+		}
+
+		// Post-process the values into image
+		for (size_t i = 0; i < w * h; ++i)
+		{
+			QColor color;
+			color.setHsl(270 + std::min(fieldPtr[i], 255u) * 360 / 256, 255, 200);
+			fieldPtr[i] = color.rgb();
+		}
+
+		QImage canvas((const uchar*)fieldPtr, w, h, QImage::Format_RGB32);
+		p.drawImage(0, 0, canvas);
+
+		parentWidget()->setWindowTitle(QString::number(timer.elapsed()));
+	}
+
+private:
+	std::function<uint32_t (uint32_t)> _nextRandomNumber;
+};
+
+static inline uint32_t fnv1a(uint32_t max)
+{
+	static uint64_t seed = 1000;
+	const auto* byte = reinterpret_cast<const uint8_t*>(&seed);
+
+	static constexpr uint32_t Prime = 0x01000193; //   16777619
+	for (size_t i = 0; i < sizeof(seed); ++i)
+	{
+		seed *= Prime;
+		seed ^= byte[i];
+	}
+
+	return seed % max;
+}
+
+static inline uint32_t wheathash(uint32_t max)
+{
+	static uint64_t seed = 1000;
+
+	seed = wheathash64v(seed);
+	return seed % max;
+}
 
 int main(int argc, char* argv[])
 {
-	return 0;
+	QApplication app(argc, argv);
+
+	QMainWindow w;
+	auto visualizer = new VisualizationWidget{&w};
+	//visualizer->setRngFunction([](uint32_t maxValue) {
+	//	return (uint32_t)rand() % maxValue;
+	//});
+
+	visualizer->setRngFunction(&wheathash);
+	//visualizer->setRngFunction(&fnv1a);
+
+	w.resize(1024, 768);
+	w.setCentralWidget(visualizer);
+	w.show();
+
+	return app.exec();
 }