add basics, new signal for changed pendulums, added shaders

CMakeLists.txt

@@ -10,6 +10,6 @@ find_package(Qt6 COMPONENTS OpenGLWidgets REQUIRED)
 find_package(OpenMP REQUIRED)
 
 file(GLOB_RECURSE SOURCE_FILES src/**.cpp)
-add_executable(Pendulum WIN32 ${SOURCE_FILES} icons/icons.qrc)
+add_executable(Pendulum WIN32 ${SOURCE_FILES} icons/icons.qrc shaders/shaders.qrc)
 
 target_link_libraries(Pendulum Qt6::OpenGLWidgets OpenMP::OpenMP_CXX)

shaders/fragment.glsl

@@ -0,0 +1,9 @@
+#version 330 core
+
+out vec4 FragColor;
+
+in vec3 color;
+
+void main() {
+    FragColor = vec4(color, 1);
+}

shaders/shaders.qrc

@@ -0,0 +1,6 @@
+<RCC>
+    <qresource prefix="/shaders/">
+        <file>vertex.glsl</file>
+        <file>fragment.glsl</file>
+    </qresource>
+</RCC>

shaders/vertex.glsl

@@ -0,0 +1,11 @@
+#version 330 core
+
+layout (location = 0) in vec2 vPos;
+layout (location = 1) in vec3 vColor;
+
+out vec3 color;
+
+void main() {
+    gl_Position = vec4(vPos, 0.0, 1.0);
+    color = vColor;
+}

src/GLWidget.cpp

@@ -7,29 +7,93 @@
 #include <QApplication>
 #include <QDialog>
 #include "FPS.h"
+#include <QOpenGLShaderProgram>
 
 GLWidget::GLWidget(Simulation * simulation) : simulation(simulation) {
 	startTimer(1000 / 144);
 	fps = new FPS;
 	fps->setUpdateInterval(500);
+	connect(simulation, &Simulation::pendulaChanged, this, &GLWidget::initGPUMemory);
 }
 
-void GLWidget::paintEvent(QPaintEvent *e) {
-	fps->newFrame();
-	QString fpsString = "FPS: " + QString::fromStdString(std::to_string(fps->current));
+void GLWidget::initializeGL() {
+	initializeOpenGLFunctions();
+	glEnable(GL_PRIMITIVE_RESTART);
+	glEnable(GL_PRIMITIVE_RESTART_FIXED_INDEX);
+	glClearColor(.15, .15, .15, 1);
+	program = new QOpenGLShaderProgram;
+	program->addShaderFromSourceFile(QOpenGLShader::Vertex, ":/shaders/vertex.glsl");
+	program->addShaderFromSourceFile(QOpenGLShader::Fragment, ":/shaders/fragment.glsl");
+	program->link();
+	program->bind();
+
+	glGenVertexArrays(1, &VAO);
+	glBindVertexArray(VAO);
+
+	float vertices[] = {
+			-0.5, -0.5,
+			0.5, -0.5,
+			0.5, 0.5,
+			-0.5, 0.5
+	};
+
+	float colors[] = {
+			1, 0, 0,
+			0, 1, 0,
+			0, 0, 1,
+			1, 1, 0
+	};
+
+	GLushort indices[] = {
+			0, 1, 0xffff, 2, 3
+	};
+
+	glGenBuffers(1, &positionVBO);
+	glBindBuffer(GL_ARRAY_BUFFER, positionVBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_DYNAMIC_DRAW);
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), nullptr);
+	glEnableVertexAttribArray(0);
+
+	GLuint colorVBO;
+	glGenBuffers(1, &colorVBO);
+	glBindBuffer(GL_ARRAY_BUFFER, colorVBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(colors), colors, GL_STATIC_DRAW);
+	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), nullptr);
+	glEnableVertexAttribArray(1);
+
+	GLuint ebo;
+	glGenBuffers(1, &ebo);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
+
+	glBindVertexArray(0);
+}
 
+void GLWidget::paintGL() {
 	auto p = new QPainter(this);
 	p->setRenderHint(QPainter::Antialiasing);
-	p->fillRect(e->rect(), QColor(30, 30, 30));
+	p->beginNativePainting();
+
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glViewport(0, 0, QWidget::width(), QWidget::height());
+
+	program->bind();
+	glBindVertexArray(VAO);
+	glDrawElements(GL_LINE_STRIP, 5, GL_UNSIGNED_SHORT, nullptr);
+	simulation->draw(nullptr, std::min(width(), height()));
+	glBindVertexArray(0);
+
+	p->endNativePainting();
+
 	p->setPen(Qt::white);
 	auto font = p->font();
 	font.setPixelSize(20);
 	p->setFont(font);
-	p->drawText(0, 0, 400, 400, Qt::AlignTop | Qt::AlignLeft, fpsString);
-	p->translate(e->rect().center());
 
-	simulation->draw(p, std::min(width(), height()));
+	fps->newFrame();
+	QString fpsString = "FPS: " + QString::fromStdString(std::to_string(fps->current));
 
+	p->drawText(0, 0, 100, 100, Qt::AlignTop | Qt::AlignLeft, fpsString);
 	p->end();
 }
 
@@ -46,4 +110,12 @@ bool GLWidget::AnyDialogOpen() {
 	return false;
 }
 
+void GLWidget::initGPUMemory(const std::vector<Pendulum *> &addPendula) {
+	glBindBuffer(GL_ARRAY_BUFFER, positionVBO);
+	auto positions = (GLfloat*) glMapBufferRange(GL_ARRAY_BUFFER, 0, 2 * 3 * sizeof(float), GL_MAP_WRITE_BIT);
+
+	glUnmapBuffer(GL_ARRAY_BUFFER);
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+}
+
 

src/GLWidget.h

@@ -1,18 +1,25 @@
 #include <QOpenGLWidget>
-#include <QOpenGLFunctions>
-
-
+#include <QOpenGLExtraFunctions>
 
+class Pendulum;
 class Simulation;
 class FPS;
+class QOpenGLShaderProgram;
 
-class GLWidget : public QOpenGLWidget, protected QOpenGLFunctions {
+class GLWidget : public QOpenGLWidget, protected QOpenGLExtraFunctions {
 public:
 	explicit GLWidget(Simulation *);
 protected:
-	void paintEvent(QPaintEvent* e) override;
 	void timerEvent(QTimerEvent* e) override;
+	void initializeGL() override;
+	void paintGL() override;
+private slots:
+	void initGPUMemory(const std::vector<Pendulum *> &addPendula);
 private:
+	QOpenGLShaderProgram * program;
+	GLuint VAO;
+	GLuint positionVBO;
+	GLsizei indexCount;
 	Simulation * simulation;
 	FPS * fps;
 	static bool AnyDialogOpen();

src/MainWindow.cpp

@@ -30,6 +30,9 @@ MainWindow::MainWindow() {
 	resetLengths();
 
 	buildUI();
+
+	normalizeLengths();
+	add();
 }
 
 void MainWindow::buildUI() {

src/Pendulum.h

@@ -1,3 +1,5 @@
+#pragma once
+
 #include <vector>
 #include <QVector2D>
 #include <QColor>
@@ -13,7 +15,6 @@ public:
 
 	void draw(QPainter*, double) const;
 	void update(double, double);
-
 private:
 	std::vector<Vector> X, V;
 	std::vector<double> M, L;

src/Simulation.cpp

@@ -1,5 +1,4 @@
 #include "Simulation.h"
-#include "Pendulum.h"
 #include <QPainter>
 #include <QTimer>
 #include <QThread>
@@ -19,8 +18,12 @@ void Simulation::draw(QPainter *p, int screenSize) {
 
 	double scale = screenSize * 0.95 / size;
 
+
+
+	/*
 	for (const auto pendulum : pendula)
 		pendulum->draw(p, scale);
+	*/
 
 	pendulaMutex.unlock();
 }
@@ -52,10 +55,18 @@ void Simulation::clearPendula() {
 	pendula.shrink_to_fit();
 
 	pendulaMutex.unlock();
+
+	emit pendulaChanged(pendula);
 }
 
 void Simulation::addPendula(const std::vector<Pendulum *> &add) {
+	pendulaMutex.lock();
+
 	for (auto p : add)
 		pendula.push_back(p);
+
+	pendulaMutex.unlock();
+
+	emit pendulaChanged(pendula);
 }
 

src/Simulation.h

@@ -3,14 +3,15 @@
 #include <QObject>
 #include <chrono>
 #include <mutex>
+#include "Pendulum.h"
 
 using namespace std::chrono;
 
-class Pendulum;
 class QPainter;
 class QTimer;
 
 class Simulation : public QObject {
+	Q_OBJECT
 public:
 	explicit Simulation();
 
@@ -23,6 +24,8 @@ public:
 	bool isPlaying = false;
 
 	void draw(QPainter*, int);
+signals:
+	void pendulaChanged(const std::vector<Pendulum *> &newPendula);
 public slots:
 	void clearPendula();
 	void addPendula(const std::vector<Pendulum *> &add);