Qt OpenGL一个旋转的立方体

先看效果：

顶点着色器：

#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec2 aTextureCoord;
out vec3 outColor;
out vec2 textureCoord;

//矩阵必须初始化，初始化单位矩阵，否则GLSL语言中默认矩阵是0矩阵
uniform mat4 trans = mat4(1.0);

uniform mat4 model = mat4(1.0);
uniform mat4 view = mat4(1.0);
uniform mat4 projection = mat4(1.0);

void main(){
	gl_Position = projection * view * model * vec4(aPos, 1.0);
	textureCoord = aTextureCoord;
}

片段着色器

#version 330 core
out vec4 fragColor;
in vec3 outColor;//从顶点着色器中传过来的颜色
in vec2 textureCoord;
uniform sampler2D textureImg;
void main(){
	fragColor = texture(textureImg, textureCoord);
}

#pragma once

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

class RotateCubeWnd : public QOpenGLWindow{
	Q_OBJECT

public:
	RotateCubeWnd();
	~RotateCubeWnd();

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

private slots:
	void slotTimeOut();
private:
	GLuint _VBO, _VAO;
	class QOpenGLFunctions_3_3_Core* _openGLCore;
	QOpenGLShaderProgram _shaderProgram;//着色器程序，所里系统所有的着色器

	class QOpenGLTexture *_texture1;

	QMatrix4x4 view, model, projection;
	class QTimer* _timer = nullptr;
	double _angle = 30.0;
};

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

RotateCubeWnd::RotateCubeWnd(){
	_timer = new QTimer;
	_timer->start(20);
	connect(_timer, SIGNAL(timeout()), this, SLOT(slotTimeOut()));
}

RotateCubeWnd::~RotateCubeWnd(){
}

void RotateCubeWnd::initializeGL() {
	_openGLCore = QOpenGLContext::currentContext()->versionFunctions<QOpenGLFunctions_3_3_Core>();
	
	//开启深度测试
	_openGLCore->glEnable(GL_DEPTH_TEST);
	_openGLCore->glDepthFunc(GL_LESS);

	GLfloat vertexData[] = {
		//  X     Y     Z    U     V
		// 下
	   -1.0f,-1.0f,-1.0f,   0.0f, 0.0f,
		1.0f,-1.0f,-1.0f,   1.0f, 0.0f,
	   -1.0f,-1.0f, 1.0f,   0.0f, 1.0f,
		1.0f,-1.0f,-1.0f,   1.0f, 0.0f,
		1.0f,-1.0f, 1.0f,   1.0f, 1.0f,
	   -1.0f,-1.0f, 1.0f,   0.0f, 1.0f,
		// 上
	   -1.0f, 1.0f,-1.0f,   0.0f, 0.0f,
	   -1.0f, 1.0f, 1.0f,   0.0f, 1.0f,
		1.0f, 1.0f,-1.0f,   1.0f, 0.0f,
		1.0f, 1.0f,-1.0f,   1.0f, 0.0f,
	   -1.0f, 1.0f, 1.0f,   0.0f, 1.0f,
		1.0f, 1.0f, 1.0f,   1.0f, 1.0f,
		// 前
	   -1.0f,-1.0f, 1.0f,   1.0f, 0.0f,
		1.0f,-1.0f, 1.0f,   0.0f, 0.0f,
	   -1.0f, 1.0f, 1.0f,   1.0f, 1.0f,
		1.0f,-1.0f, 1.0f,   0.0f, 0.0f,
		1.0f, 1.0f, 1.0f,   0.0f, 1.0f,
	   -1.0f, 1.0f, 1.0f,   1.0f, 1.0f,
		// 后
	   -1.0f,-1.0f,-1.0f,   0.0f, 0.0f,
	   -1.0f, 1.0f,-1.0f,   0.0f, 1.0f,
		1.0f,-1.0f,-1.0f,   1.0f, 0.0f,
		1.0f,-1.0f,-1.0f,   1.0f, 0.0f,
	   -1.0f, 1.0f,-1.0f,   0.0f, 1.0f,
		1.0f, 1.0f,-1.0f,   1.0f, 1.0f,
		// 左
	   -1.0f,-1.0f, 1.0f,   0.0f, 1.0f,
	   -1.0f, 1.0f,-1.0f,   1.0f, 0.0f,
	   -1.0f,-1.0f,-1.0f,   0.0f, 0.0f,
	   -1.0f,-1.0f, 1.0f,   0.0f, 1.0f,
	   -1.0f, 1.0f, 1.0f,   1.0f, 1.0f,
	   -1.0f, 1.0f,-1.0f,   1.0f, 0.0f,
		// 右
		1.0f,-1.0f, 1.0f,   1.0f, 1.0f,
		1.0f,-1.0f,-1.0f,   1.0f, 0.0f,
		1.0f, 1.0f,-1.0f,   0.0f, 0.0f,
		1.0f,-1.0f, 1.0f,   1.0f, 1.0f,
		1.0f, 1.0f,-1.0f,   0.0f, 0.0f,
		1.0f, 1.0f, 1.0f,   0.0f, 1.0f
	};

	_openGLCore->glGenVertexArrays(1, &_VAO);
	_openGLCore->glGenBuffers(1, &_VBO);

	_openGLCore->glBindVertexArray(_VAO);

	_openGLCore->glBindBuffer(GL_ARRAY_BUFFER, _VBO);
	_openGLCore->glBufferData(GL_ARRAY_BUFFER, sizeof(vertexData), vertexData, GL_STATIC_DRAW);

	// 位置属性
	_openGLCore->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
	_openGLCore->glEnableVertexAttribArray(0);
	// 坐标属性
	_openGLCore->glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
	_openGLCore->glEnableVertexAttribArray(1);

	//垂直镜像mirrored
	_texture1 = new QOpenGLTexture(QImage("E:/Projects/QtGuiTest/OPenGLApp/RotateCube/a.jpg").mirrored());
	if (!_texture1->isCreated()) {
		qDebug() << "Failed to load texture";
	}
	_texture1->setWrapMode(QOpenGLTexture::DirectionS, QOpenGLTexture::Repeat);
	_texture1->setWrapMode(QOpenGLTexture::DirectionT, QOpenGLTexture::Repeat);
	_texture1->setMinificationFilter(QOpenGLTexture::Linear);
	_texture1->setMagnificationFilter(QOpenGLTexture::Linear);
	

	_shaderProgram.addShaderFromSourceFile(QOpenGLShader::Vertex, "E:/Projects/QtGuiTest/OPenGLApp/RotateCube/RotateCube.vert");
	_shaderProgram.addShaderFromSourceFile(QOpenGLShader::Fragment, "E:/Projects/QtGuiTest/OPenGLApp/RotateCube/RotateCube.frag");
	_shaderProgram.link();

	_shaderProgram.bind();
	_shaderProgram.setUniformValue("textureImg", 0);

	view.lookAt(QVector3D(3.0, 3.0,-3.0), QVector3D(0.0, 0.0, 0.0), QVector3D(0.0, 1.0, 0.0));
	projection.perspective(45.0, width() / height(), 0.1, 100);
	model.scale(0.5);
}

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

	_openGLCore->glActiveTexture(GL_TEXTURE0);
	_texture1->bind();

	_shaderProgram.bind();

	//每次旋转都是在当前位置的基础上旋转，第一次旋转30度，以后每次旋转1度
	model.rotate(_angle, QVector3D(1.0, 0.0, 0.0));

	_shaderProgram.setUniformValue("model", model);
	_shaderProgram.setUniformValue("view", view);
	_shaderProgram.setUniformValue("projection", projection);
	/*
	立方体6个面，每个面有2个三角形，每个三角形有3个顶点，所以需要绘制的顶点数是：6 × 2 × 3 = 36
	*/
	_openGLCore->glDrawArrays(GL_TRIANGLES, 0, 36);
}

void RotateCubeWnd::slotTimeOut() {
	_angle = 1.0;
	update();
}

使用的图片

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