QT OpenGL makes objects move under care to form animation

Look at the effect ：

Refer to the previous article ：Qt OPenGL Diffuse reflection of light
Add a timer ：

#pragma once

#include <QOpenGLWindow>
#include <QOpenGLExtraFunctions>
#include <QDebug>
#include <QOpenGLTexture>
#include <QElapsedTimer>
#include <QOpenGLShader>
#include <QOpenGLShaderProgram>

class DiffuseLightWnd : public QOpenGLWindow {
    
	Q_OBJECT

public:
	DiffuseLightWnd();
	~DiffuseLightWnd();

protected:
	void initializeGL()override;
	void paintGL()override;

	void keyPressEvent(QKeyEvent *event);
	void mouseMoveEvent(QMouseEvent *event);
	void wheelEvent(QWheelEvent *event);
	void mousePressEvent(QMouseEvent *event);
	void mouseReleaseEvent(QMouseEvent *event);
	void resizeGL(int w, int h) Q_DECL_OVERRIDE;
private:
	void drawObj();
private slots:
	void slotTimeout();
private:
	GLuint _VBO, _VAO;
	class QOpenGLFunctions_3_3_Core* _openGLCore;
	QOpenGLShaderProgram _shaderProgram;// Shader program , All shaders in the system 

	QMatrix4x4 model, view, projection;

	class DiffuseLightCamera* _diffuseLightCamera = nullptr;

	bool _lBtnDown = false;
	QPoint _lBtnDownPos;
	class QTimer* _timer;
	float _rotateModel = 45.0;
};

#include "DiffuseLightWnd.h"
#include <QKeyEvent>
#include <QMouseEvent>
#include <QWheelEvent>
#include <QTimer>
#include <QOpenGLFunctions_3_3_Core>
#include "DiffuseLightCamera.h"

DiffuseLightWnd::DiffuseLightWnd() {
    
	_diffuseLightCamera = new DiffuseLightCamera(QVector3D(0.0, 0.0, -4.0), 0.0, 90.0, QVector3D(0.0, 1.0, 0.0));
	_timer = new QTimer;
	connect(_timer, SIGNAL(timeout()), this, SLOT(slotTimeout()));
	_timer->start(50);
}

DiffuseLightWnd::~DiffuseLightWnd() {
    
}

void DiffuseLightWnd::initializeGL() {
    
	_openGLCore = QOpenGLContext::currentContext()->versionFunctions<QOpenGLFunctions_3_3_Core>();
	// Open depth test 
	_openGLCore->glEnable(GL_DEPTH_TEST);
	_openGLCore->glDepthFunc(GL_LESS);

	//  Vertex data （ Texture coordinates are not used ）
	float vertices[] = {
    
		// positions // normal vector // texture 
		-0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
		 0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  0.0f,
		 0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
		 0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  1.0f,  1.0f,
		-0.5f,  0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  1.0f,
		-0.5f, -0.5f, -0.5f,  0.0f,  0.0f, -1.0f,  0.0f,  0.0f,
		// 2
		-0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
		 0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  0.0f,
		 0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
		 0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  1.0f,  1.0f,
		-0.5f,  0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  1.0f,
		-0.5f, -0.5f,  0.5f,  0.0f,  0.0f,  1.0f,  0.0f,  0.0f,
		// 3
		-0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
		-0.5f,  0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
		-0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
		-0.5f, -0.5f, -0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
		-0.5f, -0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
		-0.5f,  0.5f,  0.5f, -1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
		// 4
		 0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
		 0.5f,  0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  1.0f,
		 0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
		 0.5f, -0.5f, -0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  1.0f,
		 0.5f, -0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  0.0f,  0.0f,
		 0.5f,  0.5f,  0.5f,  1.0f,  0.0f,  0.0f,  1.0f,  0.0f,
		// 5
		-0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
		 0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  1.0f,
		 0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
		 0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  1.0f,  0.0f,
		-0.5f, -0.5f,  0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  0.0f,
		-0.5f, -0.5f, -0.5f,  0.0f, -1.0f,  0.0f,  0.0f,  1.0f,
		// 6
		-0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
		 0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  1.0f,
		 0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
		 0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  1.0f,  0.0f,
		-0.5f,  0.5f,  0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  0.0f,
		-0.5f,  0.5f, -0.5f,  0.0f,  1.0f,  0.0f,  0.0f,  1.0f,
	};

	// 1. Create objects 
	_openGLCore->glGenVertexArrays(1, &_VAO);
	_openGLCore->glGenBuffers(1, &_VBO);
	// 2. Bound object 
	_openGLCore->glBindVertexArray(_VAO);
	_openGLCore->glBindBuffer(GL_ARRAY_BUFFER, _VBO);
	// 3. Data storage 
	_openGLCore->glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

	// 4. Parsing data 
	_openGLCore->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
	_openGLCore->glEnableVertexAttribArray(0);

	// 5. Vertex normal vector 
	_openGLCore->glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
	_openGLCore->glEnableVertexAttribArray(1);

	// 6. Unbundling 
	_openGLCore->glBindBuffer(GL_ARRAY_BUFFER, 0);
	_openGLCore->glBindVertexArray(0);

	// 7. Shader program 
	_shaderProgram.addShaderFromSourceFile(QOpenGLShader::Vertex, "E:/Projects/QtGuiTest/OPenGLApp/DiffuseLight/DiffuseLight.vert");
	_shaderProgram.addShaderFromSourceFile(QOpenGLShader::Fragment, "E:/Projects/QtGuiTest/OPenGLApp/DiffuseLight/DiffuseLight.frag");
	_shaderProgram.link();
}

void DiffuseLightWnd::paintGL() {
    
	_openGLCore->glClearColor(0.4f, 0.4f, 0.4f, 1.0f);
	_openGLCore->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	_openGLCore->glBindVertexArray(_VAO);

	drawObj();


	update();
}

void DiffuseLightWnd::keyPressEvent(QKeyEvent *event) {
    
	_diffuseLightCamera->keyPress(event->key());

}

void DiffuseLightWnd::mouseMoveEvent(QMouseEvent *event) {
    
	if (_lBtnDown) {
    
		float xpos = static_cast<float>(event->pos().x());
		float ypos = static_cast<float>(event->pos().y());

		float xoffset = _lBtnDownPos.x() - xpos;
		float yoffset = _lBtnDownPos.y() - ypos;

		_lBtnDownPos = event->pos();

		_diffuseLightCamera->mouseMove(xoffset, yoffset);
	}
}

void DiffuseLightWnd::wheelEvent(QWheelEvent *event) {
    
	_diffuseLightCamera->wheel(event->delta());
	update();
}

void DiffuseLightWnd::mousePressEvent(QMouseEvent *event) {
    
	if (event->button() == Qt::LeftButton) {
    
		_lBtnDown = true;
		_lBtnDownPos = event->pos();
	}
}

void DiffuseLightWnd::mouseReleaseEvent(QMouseEvent *event) {
    
	if (event->button() == Qt::LeftButton) {
    
		_lBtnDown = false;
	}
}

void DiffuseLightWnd::resizeGL(int w, int h) {
    
	glViewport(0, 0, w, h);

}

void DiffuseLightWnd::drawObj() {
    
	_shaderProgram.bind();

	QMatrix4x4 model;
	model.rotate(_rotateModel, QVector3D(1.0, 1.0, 1.0));
	model.scale(0.5);
	QMatrix4x4 view = _diffuseLightCamera->getViewMatrix();
	QMatrix4x4 projection;
	projection.perspective(_diffuseLightCamera->getZoom(), width() / height(), 0.1, 100);

	_shaderProgram.setUniformValue("model", model);
	_shaderProgram.setUniformValue("view", view);
	_shaderProgram.setUniformValue("projection", projection);

	_shaderProgram.setUniformValue("objectColor", 1.0f, 0.5f, 0.31f);
	_shaderProgram.setUniformValue("lightColor", 1.0f, 1.0f, 1.0f);

	_shaderProgram.setUniformValue("lightPos", 0.0f, 0.0f, -4.0f);


	_openGLCore->glDrawArrays(GL_TRIANGLES, 0, 36);
}

void DiffuseLightWnd::slotTimeout() {
    
	_rotateModel++;
}

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