From b1894ad4d4a29baabef88fcf93b793c943936c00 Mon Sep 17 00:00:00 2001
From: Benjamin Kraft <benjamin.kraft@online.de>
Date: Sat, 5 Feb 2022 21:41:59 +0100
Subject: [PATCH] added hue animation

---
 Fragment.glsl        |  8 +++++---
 headers/Mandelbrot.h |  5 +++++
 src/MainWindow.cpp   | 10 ++++++++++
 src/Mandelbrot.cpp   | 12 ++++++++++++
 src/OutputWidget.cpp | 12 ++++++++++--
 5 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/Fragment.glsl b/Fragment.glsl
index e23c85a..8c157e1 100644
--- a/Fragment.glsl
+++ b/Fragment.glsl
@@ -2,6 +2,7 @@
 out vec4 pixColor;
 
 uniform int iterationCount;
+uniform float hueAdd;
 
 in vec2 complexPos;
 
@@ -27,7 +28,7 @@ vec3 hsvToRgb(in float h, in float s, in float v){
 }
 
 vec3 getColor(in float modifier){
-    float hue = modifier * 360;
+    float hue = mod(modifier * 360 + hueAdd, 360);
     float sat = 1;
     float value = modifier == 0 ? 0 : 1;
 
@@ -45,7 +46,7 @@ vec2 m(in vec2 c){
 float mandelbrot(in vec2 c){
     vec2 z = vec2(0, 0);
     float steps = 0;
-    int escapeSquared = pow(1 << 8, 2);
+    float escapeSquared = pow(1 << 8, 2);
     while (steps < iterationCount && pow(z.x, 2) + pow(z.y, 2) < escapeSquared){
         z = m(z);
         ++steps;
@@ -55,7 +56,8 @@ float mandelbrot(in vec2 c){
     float log_zn = log(z.x * z.x + z.y * z.y) / 2;
     float nu = log(log_zn / log(2)) / log(2);
     steps += 1 - nu;
-    return steps / iterationCount;
+    float t = steps / iterationCount;
+    return sqrt(t);
 }
 
 void main(){
diff --git a/headers/Mandelbrot.h b/headers/Mandelbrot.h
index ea2519f..672b22c 100644
--- a/headers/Mandelbrot.h
+++ b/headers/Mandelbrot.h
@@ -9,6 +9,8 @@ class Mandelbrot : public QObject, protected QOpenGLExtraFunctions {
 public:
 	void init(GLuint);
 	void draw();
+	void updateAnimation();
+	void toggleAnimation();
 	void setIterations(int);
 	void translateRelative(QVector2D);
 	void zoomRelative(int, QVector2D);
@@ -16,10 +18,13 @@ public:
 	bool initShader();
 private:
 	int iterations = 0;
+	float hueAdd = 0.0;
 	QVector2D origin {-2, -1};
 	QVector2D size {2, 2};
 	float zoomModifier = 1.05;
 
+	bool animating = true;
+
 	GLuint vao;
 
 	QOpenGLShaderProgram shader;
diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
index 79da82f..88b0ad4 100644
--- a/src/MainWindow.cpp
+++ b/src/MainWindow.cpp
@@ -46,12 +46,22 @@ void MainWindow::buildUI() {
 				});
 			});
 
+	auto animButton = new QPushButton("Toggle animation");
+	connect(
+			animButton,
+			&QPushButton::clicked,
+			this,
+			[this](){
+				this->outputWidget.getMandelbrot().toggleAnimation();
+			});
+
 	auto controls = new QGridLayout;
 	controls->addWidget(iterationsCaption, 1, 1);
 	controls->addWidget(iterationsLabel, 1, 2);
 	controls->addWidget(iterationsSlider, 1, 3);
 	controls->addWidget(saveInfo, 2, 1, 1, 2);
 	controls->addWidget(saveButton, 2, 3, 1, 1);
+	controls->addWidget(animButton, 3, 1, 1, 3);
 
 	auto lyt = new QVBoxLayout(this);
 	lyt->addWidget(&outputWidget);
diff --git a/src/Mandelbrot.cpp b/src/Mandelbrot.cpp
index 994b51c..87cbec7 100644
--- a/src/Mandelbrot.cpp
+++ b/src/Mandelbrot.cpp
@@ -17,6 +17,17 @@ void Mandelbrot::draw() {
 	glBindVertexArray(0);
 }
 
+void Mandelbrot::updateAnimation() {
+	if (!animating)
+		return;
+	hueAdd += 1;
+	hueAdd -= hueAdd >= 360 ? 360 : 0;
+}
+
+void Mandelbrot::toggleAnimation() {
+	animating = !animating;
+}
+
 bool Mandelbrot::initShader() {
 	if (!shader.addShaderFromSourceFile(QOpenGLShader::Vertex, "Vertex.glsl")) return false;
 	if (!shader.addShaderFromSourceFile(QOpenGLShader::Fragment, "Fragment.glsl")) return false;
@@ -29,6 +40,7 @@ void Mandelbrot::setShaderValues() {
 	shader.setUniformValue("origin", origin);
 	shader.setUniformValue("size", size);
 	shader.setUniformValue("iterationCount", iterations);
+	shader.setUniformValue("hueAdd", hueAdd);
 }
 
 void Mandelbrot::zoomRelative(int direction, QVector2D posRelative) {
diff --git a/src/OutputWidget.cpp b/src/OutputWidget.cpp
index 6ae4a42..136a894 100644
--- a/src/OutputWidget.cpp
+++ b/src/OutputWidget.cpp
@@ -5,7 +5,9 @@
 #include <QOpenGLFramebufferObject>
 #include <QFileDialog>
 #include <utility>
+#include <QTimer>
 #include "../headers/OutputWidget.h"
+#include <QTimer>
 
 using std::cout, std::endl;
 
@@ -19,6 +21,14 @@ void OutputWidget::initializeGL() {
 	cout << "OpenGL version: " << format.majorVersion() << "." << format.minorVersion() << endl;
 
 	glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
+
+	auto timer = new QTimer(this);
+	timer->setInterval(17);
+	timer->start();
+	connect(timer, &QTimer::timeout, this, [this](){
+		this->getMandelbrot().updateAnimation();
+		update();
+	});
 }
 
 void OutputWidget::paintGL() {
@@ -86,7 +96,6 @@ void OutputWidget::wheelEvent(QWheelEvent *e) {
 	QVector2D relativePos = divide(pos, size());
 	relativePos.setY(1 - relativePos.y());
 	getMandelbrot().zoomRelative(direction, relativePos);
-	update();
 }
 
 void OutputWidget::mouseMoveEvent(QMouseEvent *e) {
@@ -96,7 +105,6 @@ void OutputWidget::mouseMoveEvent(QMouseEvent *e) {
 	QVector2D relativeDiff = divide(diff, size());
 	relativeDiff.setY(-relativeDiff.y());
 	getMandelbrot().translateRelative(relativeDiff);
-	update();
 }
 
 void OutputWidget::mousePressEvent(QMouseEvent *e) {