QT+OpenGL一之绘制立方体（三角形图元）

.h

#pragma once
#include 
#include 

class MyOpenglWegdit : public QOpenGLWidget, protected QOpenGLFunctions_4_3_Core
{
    Q_OBJECT

public:
    float cameraX, cameraY, cameraZ;
    float cubeLocX, cubeLocY, cubeLocZ;
    QOpenGLShaderProgram shaderProgram;
    QOpenGLBuffer vao;
    GLuint mvLoc, projLoc;
    float aspect;
    QMatrix4x4 pMat, vMat, mMat, mvMat;
    void setupVertices();
    MyOpenglWegdit(QWidget*parent);
    ~MyOpenglWegdit();
protected:
    void initializeGL();
    void resizeGL();
    void paintGL();
};

.cpp

#include "stdafx.h"
#include "MyOpenglWegdit.h"
MyOpenglWegdit::MyOpenglWegdit(QWidget*parent)
    : QOpenGLWidget(parent)
{

}

MyOpenglWegdit::~MyOpenglWegdit()
{
 
}
void MyOpenglWegdit::initializeGL()
{
    initializeOpenGLFunctions();
    glEnable(GL_DEPTH_TEST);
    glClearDepth(1.0);//设置深度缓存
    glDepthFunc(GL_LEQUAL);
    glShadeModel(GL_SMOOTH);//设置阴影平滑模式
    glClearColor(0.98, 0.625, 0.12, 0.5);//改变窗口的背景颜色
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);//进行透视校正
    if (!shaderProgram.addShaderFromSourceFile(QOpenGLShader::Vertex, ":/QtGuiApplication1/Resources/config/shader.vs")) {     //添加并编译顶点着色器
        qDebug() << "编译ERROR:" << shaderProgram.log();    //如果编译出错,打印报错信息
    }
    if (!shaderProgram.addShaderFromSourceFile(QOpenGLShader::Fragment, ":/QtGuiApplication1/Resources/config/shader.fs")) {   //添加并编译片段着色器
        qDebug() << "编译ERROR:" << shaderProgram.log();    //如果编译出错,打印报错信息
    }
    if (!shaderProgram.link()) {                      //链接着色器
        qDebug() << "链接ERROR:" << shaderProgram.log();    //如果链接出错,打印报错信息
    }
    shaderProgram.bind();
    cameraX = 0.0f; cameraY = 0.0f; cameraZ = 8.0f;
    cubeLocX = 0.0f; cubeLocY = -2.0f; cubeLocZ = -0.0f;
    setupVertices();
    mvLoc = shaderProgram.uniformLocation("mv_matrix");
    projLoc = shaderProgram.uniformLocation("proj_matrix");//获取程序的统一变量mv，投影矩阵
    //构建透视矩阵
    aspect = (float)width() / (float)height();
    pMat.perspective(70.0472f, aspect, 0.1f, 1000.f);
    //构建视图矩阵
    vMat.translate(-cameraX, -cameraY, -cameraZ);
    mMat.translate(cubeLocX, cubeLocY, cubeLocZ);
    mvMat = vMat * mMat;
    //将mv矩阵发送给对应的统一变量
    shaderProgram.setUniformValue(mvLoc, mvMat);
    shaderProgram.setUniformValue(projLoc, pMat);
}

void MyOpenglWegdit::resizeGL()
{
    glViewport(0, 0, width(), height());
}

void MyOpenglWegdit::paintGL()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    GLuint vPosition = shaderProgram.attributeLocation("vPosition");
    shaderProgram.setAttributeBuffer(vPosition, GL_FLOAT,0,3,0);
    glEnableVertexAttribArray(vPosition);
    //调整OpenGL设置，绘制模型
    glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);//线框模式
    glDrawArrays(GL_TRIANGLES,0,36);
    MyOpenglWegdit::update();
}
void MyOpenglWegdit::setupVertices() {
    float vertexPositions[108] = {
        -1.0f,1.0f,-1.0f,-1.0f,-1.0f,-1.0f,1.0f,-1.0f,-1.0f,
        1.0f,-1.0f,-1.0f,1.0f,1.0f,-1.0f,-1.0f,1.0f,-1.0f,
       1.0f,-1.0f,-1.0f,1.0f,-1.0f,1.0f,1.0f,1.0f,-1.0f,
        1.0f,-1.0f,1.0f,1.0f, 1.0f, 1.0f,1.0f,1.0f,-1.0f,
         1.0f,-1.0f,1.0f,-1.0f,-1.0f,1.0f,1.0f,1.0f,1.0f,
         -1.0f,-1.0f,1.0f,-1.0f,1.0f,1.0f,1.0f,1.0f,1.0f,
        -1.0f,-1.0f,1.0f,-1.0f,-1.0f,-1.0f,-1.0f,1.0f,1.0f,
        -1.0f,-1.0f,-1.0f,-1.0f,1.0f,-1.0f,-1.0f,1.0f,1.0f,
        -1.0f,-1.0f,1.0f,1.0f,-1.0f,1.0f,1.0f,-1.0f,-1.0f,
        1.0f,-1.0f,-1.0f,-1.0f,-1.0f,-1.0f,-1.0f,-1.0f,1.0f,
        -1.0f,1.0f,-1.0f,1.0f,1.0f,-1.0f,1.0f,1.0f,1.0f,
        1.0f,1.0f,1.0f,-1.0f,1.0f,1.0f,-1.0f,1.0f,-1.0f
    };
    vao.create();
    vao.bind();
    vao.setUsagePattern(QOpenGLBuffer::StaticDraw);
    vao.allocate(vertexPositions, sizeof(vertexPositions));
}

shader.vs

#version 430 
in vec3 vPosition;
uniform mat4 mv_matrix;
uniform mat4 proj_matrix;

void main(void)
{gl_Position=proj_matrix*mv_matrix*vec4(vPosition,1.0);
}

shader.fs

#version 430 
out vec4 color;

uniform mat4 mv_matrix;
uniform mat4 proj_matrix;

void main(void) 
{
color = vec4(1.0, 1.0, 1.0, 1.0);
}

image.png

着色器修改
.vs

#version 430 
uniform mat4 mv_matrix;
uniform mat4 proj_matrix;
out vec4 varringColor;
in vec3 vPosition;
void main(void)
{
gl_Position=proj_matrix*mv_matrix*vec4(vPosition,1.0);
varringColor=vec4(vPosition,1.0)*0.5+vec4(0.5,0.5,0.5,0.5);
}

.fs

#version 430 
in vec4 varringColor;
out vec4 color;
uniform mat4 mv_matrix;
uniform mat4 proj_matrix;

void main(void) 
{
color = varringColor;
}

image.png

目录

VSC++2019+QT+OpenGL
QT+OpenGL一之绘制立方体（三角形图元）
QT+OpenGL二之纹理贴图
QT+OpenGL三之矩阵简解
QT+OpenGL四之相机的移动和旋转
QT+OpenGL五之绘制不同的模型（vao,vbo机制）
QT+OpenGL六之天空盒
QT+OpenGL七之使用EBO
QT+OPenGL八之模型准备
QT+OPenGL九之模型解码
QT+OPenGL十之光照模型
QT+OPenGL十一之漫反射和镜面反射贴图
QT+OPenGL十二之定向光
QT+OPenGL十三之真正的点光源和聚光灯
QT+OPenGL十四之多光源混合的问题
QT+OPenGL十五之深度缓冲区
QT+OPenGL十六之模板缓冲区
QT+OPenGL十七帧缓冲区（离屏渲染）
QT+OPenGL十八抗锯齿
QT+OPenGL十九镜面反射效率调整
QT+OPenGL二十Gamma校正