OpenGL with QtWidgets：投光物、多光源

╰+哭是因爲堅強的太久メ 2022-08-28 10:54 154阅读 0赞

** （本文是LearnOpenGL的学习笔记， 教程中文翻译地址[https://learnopengl-cn.github.io/][https_learnopengl-cn.github.io]（备用地址[https://learnopengl-cn.readthedocs.io/zh/latest/][https_learnopengl-cn.readthedocs.io_zh_latest]），写于 2021-10-2）**

# **0.前言** #

上一节学习了材质和光照贴图（[https://gongjianbo1992.blog.csdn.net/article/details/120397134][https_gongjianbo1992.blog.csdn.net_article_details_120397134]），教程接下来讲了投光物和多光源。

# 1.知识点 #

投光物就是在基础光照的内容上进行扩展，之前的光照都是拟定一个点，现实世界中，我们有很多种类的光照，每种的表现都不同。将光投射(Cast)到物体的光源叫做投光物(Light Caster)。教程讲了三种投光物：定向光(Directional Light)，点光源(Point Light)，聚光(Spotlight)。

平行光：当一个光源处于很远的地方时，来自光源的每条光线就会近似于互相平行。（相对于之前基础光照的点光源，简化了光照方向的计算，只需要固定值，而不是计算光源指向物体表面顶点的向量）

点光源：前面基础光照用的就是点光源，某个点的光源朝着所有方向散射光线。只是前面课程没有进行衰减模拟计算，距离越远光照强度越弱。

聚光：聚光是位于环境中某个位置的光源，它只朝一个特定方向而不是所有方向照射光线（手电筒/聚光灯的效果）。相当于以一个方向为基准，夹角超过一定就不进行光照计算。

# 2.实现代码 #

（项目git链接：[https://github.com/gongjianbo/OpenGLwithQtWidgets.git][https_github.com_gongjianbo_OpenGLwithQtWidgets.git]）

多光源实现效果：

![watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA6b6a5bu65rOi_size_17_color_FFFFFF_t_70_g_se_x_16][]

#pragma once
    #include <QOpenGLWidget>
    #include <QOpenGLFunctions_3_3_Core>
    #include <QOpenGLShaderProgram>
    #include <QOpenGLVertexArrayObject>
    #include <QOpenGLBuffer>
    #include <QOpenGLTexture>
    #include <QVector3D>
    #include <QMatrix4x4>
    #include <QQuaternion>
    #include <QTimer>
    
    //多光源
    //QOpenGLWidget窗口上下文
    //QOpenGLFunctions访问OpenGL接口，可以不继承作为成员变量使用
    class GLMultipleLights
            : public QOpenGLWidget
            , protected QOpenGLFunctions_3_3_Core
    {
        Q_OBJECT
    public:
        explicit GLMultipleLights(QWidget *parent = nullptr);
        ~GLMultipleLights();
    
    protected:
        //【】继承QOpenGLWidget后重写这三个虚函数
        //设置OpenGL资源和状态。在第一次调用resizeGL或paintGL之前被调用一次
        void initializeGL() override;
        //渲染OpenGL场景，每当需要更新小部件时使用
        void paintGL() override;
        //设置OpenGL视口、投影等，每当尺寸大小改变时调用
        void resizeGL(int width, int height) override;
    
    private:
        void initShader();
        QOpenGLTexture *initTexture(const QString &imgpath);
    
    private:
        //着色器程序
        QOpenGLShaderProgram lightingShader,lampShader;
        //顶点数组对象
        QOpenGLVertexArrayObject lightingVao,lampVao;
        //顶点缓冲
        QOpenGLBuffer vbo;
        //纹理
        QOpenGLTexture *diffuseMap{ nullptr };
        QOpenGLTexture *specularMap{ nullptr };
        //
        QTimer timer;
        int rotate{ 0 };
    };

#include "GLMultipleLights.h"
    #include <cmath>
    #include <QtMath>
    #include <QDebug>
    
    GLMultipleLights::GLMultipleLights(QWidget *parent)
        : QOpenGLWidget(parent)
    {
        connect(&timer,&QTimer::timeout,this,[this](){
            rotate+=1;
            if(isVisible()){
                update();
            }
        });
        timer.setInterval(50);
    }
    
    GLMultipleLights::~GLMultipleLights()
    {
        //initializeGL在显示时才调用，释放未初始化的会异常
        if(!isValid())
            return;
        //QOpenGLWidget
        //三个虚函数不需要makeCurrent，对应的操作已由框架完成
        //但是释放时需要设置当前上下文
        makeCurrent();
        vbo.destroy();
        lightingVao.destroy();
        lampVao.destroy();
        delete diffuseMap;
        delete specularMap;
        doneCurrent();
    }
    
    void GLMultipleLights::initializeGL()
    {
        //为当前上下文初始化OpenGL函数解析
        initializeOpenGLFunctions();
        initShader();
    
        //方块的顶点、法向量、纹理坐标
        float vertices[] = {
            // positions          // normals           // texture coords
            -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,
    
            -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,
    
            -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,
    
            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,
    
            -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,
    
            -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
        };
    
        vbo=QOpenGLBuffer(QOpenGLBuffer::VertexBuffer);
        vbo.create();
    
        //light vao
        lightingVao.create();
        lightingVao.bind();
        vbo.bind();
        vbo.allocate(vertices,sizeof(vertices));
        //setAttributeBuffer(int location, GLenum type, int offset, int tupleSize, int stride = 0)
        lightingShader.setAttributeBuffer(0, GL_FLOAT, sizeof(GLfloat) * 0, 3, sizeof(GLfloat) * 8);
        lightingShader.enableAttributeArray(0);
        lightingShader.setAttributeBuffer(1, GL_FLOAT, sizeof(GLfloat) * 3, 3, sizeof(GLfloat) * 8);
        lightingShader.enableAttributeArray(1);
        lightingShader.setAttributeBuffer(2, GL_FLOAT, sizeof(GLfloat) * 6, 2, sizeof(GLfloat) * 8);
        lightingShader.enableAttributeArray(2);
        vbo.release();
        lightingVao.release();
    
        //lamp vao
        lampVao.create();
        lampVao.bind();
        vbo.bind();
        //setAttributeBuffer(int location, GLenum type, int offset, int tupleSize, int stride = 0)
        lampShader.setAttributeBuffer(0, GL_FLOAT, 0, 3, sizeof(GLfloat) * 8);
        lampShader.enableAttributeArray(0);
        vbo.release();
        lampVao.release();
    
        //纹理
        diffuseMap = initTexture(":/container2.png");
        specularMap = initTexture(":/container2_specular.png");
        //shader configuration
        lightingShader.bind();
        lightingShader.setUniformValue("material.diffuse", 0);
        lightingShader.setUniformValue("material.specular", 1);
        lightingShader.release();
    
        //timer.start();
    }
    
    //绘制多个盒子
    static QVector3D cubePositions[] = {
        QVector3D( 0.0f,  0.0f,  0.0f),
        QVector3D( 0.0f, -4.0f,  0.0f),
        QVector3D( 0.0f,  4.0f,  0.0f),
        QVector3D( 1.0f, -5.0f, 1.0f),
        QVector3D(-1.5f, -2.2f, -2.5f),
        QVector3D(-3.8f, -2.0f, -7.3f),
        QVector3D( 2.4f, -0.4f, -3.5f),
        QVector3D(-1.7f, -3.0f, -6.5f),
        QVector3D( 5.3f, -2.0f, -2.5f),
        QVector3D(-1.3f,  1.0f, -1.5f)
    };
    
    //多个光源
    static QVector3D pointLightPositions[] = {
        QVector3D( 0.0f,  2.0f,  0.0f),
        QVector3D( 2.3f, -3.0f, -1.0f),
        QVector3D(-3.0f,  2.0f, 0.5f),
        QVector3D( 2.0f,  3.0f, 2.0f)
    };
    
    void GLMultipleLights::paintGL()
    {
        glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
        //清除深度缓冲
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
        //Z缓冲(Z-buffer),深度缓冲(Depth Buffer)。
        glEnable(GL_DEPTH_TEST);
    
        //draw lighting
        lightingShader.bind();
        QMatrix4x4 view; //观察矩阵
        view.translate(0.0f, 0.0f, -10.0f);
        view.rotate(45, QVector3D(1.0f, 0.8f, 0.0f));
        lightingShader.setUniformValue("view", view);
        QMatrix4x4 projection; //透视投影
        projection.perspective(45.0f, 1.0f * width() / height(), 0.1f, 100.0f);
        lightingShader.setUniformValue("projection", projection);
        // Directional light
        lightingShader.setUniformValue("dirLight.direction", -0.2f, -1.0f, -0.3f);
        lightingShader.setUniformValue("dirLight.ambient", 0.05f, 0.05f, 0.05f);
        lightingShader.setUniformValue("dirLight.diffuse", 0.2f, 0.2f, 0.2f);
        lightingShader.setUniformValue("dirLight.specular", 0.5f, 0.5f, 0.5f);
        QVector3D ambient_color(0.05f, 0.05f, 0.05f);
        QVector3D diffuse_color(0.0f, 0.0f, 0.4f);
        QVector3D specular_color(0.0f, 0.0f, 1.0f);
        // Point light 1
        lightingShader.setUniformValue("pointLights[0].position", pointLightPositions[0]);
        lightingShader.setUniformValue("pointLights[0].ambient", ambient_color);
        lightingShader.setUniformValue("pointLights[0].diffuse", diffuse_color);
        lightingShader.setUniformValue("pointLights[0].specular", specular_color);
        lightingShader.setUniformValue("pointLights[0].constant", 1.0f);
        lightingShader.setUniformValue("pointLights[0].linear", 0.09f);
        lightingShader.setUniformValue("pointLights[0].quadratic", 0.032f);
        // Point light 2
        lightingShader.setUniformValue("pointLights[1].position", pointLightPositions[1]);
        lightingShader.setUniformValue("pointLights[1].ambient", ambient_color);
        lightingShader.setUniformValue("pointLights[1].diffuse", diffuse_color);
        lightingShader.setUniformValue("pointLights[1].specular", specular_color);
        lightingShader.setUniformValue("pointLights[1].constant", 1.0f);
        lightingShader.setUniformValue("pointLights[1].linear", 0.09f);
        lightingShader.setUniformValue("pointLights[1].quadratic", 0.032f);
        // Point light 3
        lightingShader.setUniformValue("pointLights[2].position", pointLightPositions[2]);
        lightingShader.setUniformValue("pointLights[2].ambient", ambient_color);
        lightingShader.setUniformValue("pointLights[2].diffuse", diffuse_color);
        lightingShader.setUniformValue("pointLights[2].specular", specular_color);
        lightingShader.setUniformValue("pointLights[2].constant", 1.0f);
        lightingShader.setUniformValue("pointLights[2].linear", 0.09f);
        lightingShader.setUniformValue("pointLights[2].quadratic", 0.032f);
        // Point light 4
        lightingShader.setUniformValue("pointLights[3].position", pointLightPositions[3]);
        lightingShader.setUniformValue("pointLights[3].ambient", ambient_color);
        lightingShader.setUniformValue("pointLights[3].diffuse", diffuse_color);
        lightingShader.setUniformValue("pointLights[3].specular", specular_color);
        lightingShader.setUniformValue("pointLights[3].constant", 1.0f);
        lightingShader.setUniformValue("pointLights[3].linear", 0.09f);
        lightingShader.setUniformValue("pointLights[3].quadratic", 0.032f);
        // SpotLight
        QMatrix4x4 model;//模型矩阵
        model.translate(pointLightPositions[0]);
        model.scale(0.2f);
        QVector3D light_pos = model.map(QVector3D(0.0f, 0.0f, 0.0f));
        QVector3D direction_pos = QVector3D(0.0f, -20.0f, 0.0f);
        lightingShader.setUniformValue("spotLight.direction", direction_pos);
        lightingShader.setUniformValue("spotLight.position", light_pos);
        lightingShader.setUniformValue("spotLight.ambient", 0.0f, 0.0f, 0.0f);
        lightingShader.setUniformValue("spotLight.diffuse", 0.3f, 1.0f, 0.3f);
        lightingShader.setUniformValue("spotLight.specular", 0.3f, 1.0f, 0.3f);
        lightingShader.setUniformValue("spotLight.constant", 1.0f);
        lightingShader.setUniformValue("spotLight.linear", 0.09f);
        lightingShader.setUniformValue("spotLight.quadratic", 0.032f);
        lightingShader.setUniformValue("spotLight.cutOff", (float)std::cos(qDegreesToRadians(12.5)));
        lightingShader.setUniformValue("spotLight.outerCutOff", (float)std::cos(qDegreesToRadians(15.0)));
        //材质-material properties
        //shininess影响镜面高光的散射/半径
        lightingShader.setUniformValue("material.shininess", 32.0f);
        lightingVao.bind();
        //绑定2d纹理
        //bind diffuse map
        glActiveTexture(GL_TEXTURE0);
        diffuseMap->bind();
        //bind specular map
        glActiveTexture(GL_TEXTURE1);
        specularMap->bind();
        //glDrawArrays(GL_TRIANGLES, 0, 36);
        //多个盒子便于对比
        for (unsigned int i = 0; i < 10; i++) {
            //模型矩阵
            QMatrix4x4 box_model;
            //平移
            box_model.translate(cubePositions[i]);
            float angle = 20.0f * i;
            //旋转
            box_model.rotate(angle, QVector3D(1.0f, 0.3f, 0.5f));
            //传入着色器并绘制
            lightingShader.setUniformValue("model", box_model);
            glDrawArrays(GL_TRIANGLES, 0, 36);
        }
        lightingVao.release();
        lightingShader.release();
    
        //draw lamp
        lampShader.bind();
        lampShader.setUniformValue("view", view);
        lampShader.setUniformValue("projection", projection);
        lampVao.bind();
        for (unsigned int i = 0; i < 4; i++) {
            //模型矩阵
            QMatrix4x4 lamb_model;
            lamb_model.translate(pointLightPositions[i]);
            lamb_model.scale(0.2f);
            //传入着色器并绘制
            lampShader.setUniformValue("model", lamb_model);
            glDrawArrays(GL_TRIANGLES, 0, 36);
        }
        lampVao.release();
        lampShader.release();
    }
    
    void GLMultipleLights::resizeGL(int width, int height)
    {
        glViewport(0, 0, width, height);
    }
    
    void GLMultipleLights::initShader()
    {
        //lingting shader
        //in输入，out输出,uniform从cpu向gpu发送
        const char *lighting_vertex=R"(#version 330 core
    layout (location = 0) in vec3 aPos;
    layout (location = 1) in vec3 aNormal;
    layout (location = 2) in vec2 aTexCoords;
    
    out vec3 FragPos;
    out vec3 Normal;
    out vec2 TexCoords;
    
    uniform mat4 model;
    uniform mat4 view;
    uniform mat4 projection;
    
    void main()
    {
        FragPos = vec3(model * vec4(aPos, 1.0));
        Normal = mat3(transpose(inverse(model))) * aNormal;
        TexCoords = aTexCoords;
    
        gl_Position = projection * view * vec4(FragPos, 1.0);
    })";
        const char *lighting_fragment=R"(#version 330 core
    struct Material {
        sampler2D diffuse;
        sampler2D specular;
        float shininess;
    };
    
    struct DirLight {
        vec3 direction;
    
        vec3 ambient;
        vec3 diffuse;
        vec3 specular;
    };
    
    struct PointLight {
        vec3 position;
    
        float constant;
        float linear;
        float quadratic;
    
        vec3 ambient;
        vec3 diffuse;
        vec3 specular;
    };
    
    struct SpotLight {
        vec3 position;
        vec3 direction;
        float cutOff;
        float outerCutOff;
    
        float constant;
        float linear;
        float quadratic;
    
        vec3 ambient;
        vec3 diffuse;
        vec3 specular;
    };
    
    #define NR_POINT_LIGHTS 4
    
    in vec3 FragPos;
    in vec3 Normal;
    in vec2 TexCoords;
    
    out vec4 color;
    
    uniform vec3 viewPos;
    uniform DirLight dirLight;
    uniform PointLight pointLights[NR_POINT_LIGHTS];
    uniform SpotLight spotLight;
    uniform Material material;
    
    // Function prototypes
    vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir);
    vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir);
    vec3 CalcSpotLight(SpotLight light, vec3 normal, vec3 fragPos, vec3 viewDir);
    
    void main()
    {
        // Properties
        vec3 norm = normalize(Normal);
        vec3 viewDir = normalize(viewPos - FragPos);
    
        // == ======================================
        // Our lighting is set up in 3 phases: directional, point lights and an optional flashlight
        // For each phase, a calculate function is defined that calculates the corresponding color
        // per lamp. In the main() function we take all the calculated colors and sum them up for
        // this fragment's final color.
        // == ======================================
        // Phase 1: Directional lighting
        vec3 result = CalcDirLight(dirLight, norm, viewDir);
        // Phase 2: Point lights
        for(int i = 0; i < NR_POINT_LIGHTS; i++)
            result += CalcPointLight(pointLights[i], norm, FragPos, viewDir);
        // Phase 3: Spot light
        result += CalcSpotLight(spotLight, norm, FragPos, viewDir);
    
        color = vec4(result, 1.0);
    }
    
    // Calculates the color when using a directional light.
    vec3 CalcDirLight(DirLight light, vec3 normal, vec3 viewDir)
    {
        vec3 lightDir = normalize(-light.direction);
        // Diffuse shading
        float diff = max(dot(normal, lightDir), 0.0);
        // Specular shading
        vec3 reflectDir = reflect(-lightDir, normal);
        float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
        // Combine results
        vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
        vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));
        vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
        return (ambient + diffuse + specular);
    }
    
    // Calculates the color when using a point light.
    vec3 CalcPointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
    {
        vec3 lightDir = normalize(light.position - fragPos);
        // Diffuse shading
        float diff = max(dot(normal, lightDir), 0.0);
        // Specular shading
        vec3 reflectDir = reflect(-lightDir, normal);
        float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
        // Attenuation
        float distance = length(light.position - fragPos);
        float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
        // Combine results
        vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
        vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));
        vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
        ambient *= attenuation;
        diffuse *= attenuation;
        specular *= attenuation;
        return (ambient + diffuse + specular);
    }
    
    // Calculates the color when using a spot light.
    vec3 CalcSpotLight(SpotLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
    {
        vec3 lightDir = normalize(light.position - fragPos);
        // Diffuse shading
        float diff = max(dot(normal, lightDir), 0.0);
        // Specular shading
        vec3 reflectDir = reflect(-lightDir, normal);
        float spec = pow(max(dot(viewDir, reflectDir), 0.0), material.shininess);
        // Attenuation
        float distance = length(light.position - fragPos);
        float attenuation = 1.0f / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
        // Spotlight intensity
        float theta = dot(lightDir, normalize(-light.direction));
        float epsilon = light.cutOff - light.outerCutOff;
        float intensity = clamp((theta - light.outerCutOff) / epsilon, 0.0, 1.0);
        // Combine results
        vec3 ambient = light.ambient * vec3(texture(material.diffuse, TexCoords));
        vec3 diffuse = light.diffuse * diff * vec3(texture(material.diffuse, TexCoords));
        vec3 specular = light.specular * spec * vec3(texture(material.specular, TexCoords));
        ambient *= attenuation * intensity;
        diffuse *= attenuation * intensity;
        specular *= attenuation * intensity;
        return (ambient + diffuse + specular);
    })";
    
        //将source编译为指定类型的着色器，并添加到此着色器程序
        if(!lightingShader.addCacheableShaderFromSourceCode(
                    QOpenGLShader::Vertex,lighting_vertex)){
            qDebug()<<"compiler vertex error"<<lightingShader.log();
        }
        if(!lightingShader.addCacheableShaderFromSourceCode(
                    QOpenGLShader::Fragment,lighting_fragment)){
            qDebug()<<"compiler fragment error"<<lightingShader.log();
        }
        //使用addShader()将添加到该程序的着色器链接在一起。
        if(!lightingShader.link()){
            qDebug()<<"link shaderprogram error"<<lightingShader.log();
        }
    
        //lamp shader
        const char *lamp_vertex=R"(#version 330 core
    layout (location = 0) in vec3 aPos;
    uniform mat4 model;
    uniform mat4 view;
    uniform mat4 projection;
    
    void main()
    {
    gl_Position = projection * view * model * vec4(aPos, 1.0f);
    })";
        const char *lamp_fragment=R"(#version 330 core
    out vec4 FragColor;
    void main()
    {
    FragColor = vec4(1.0);
    })"; // set alle 4 vector values to 1.0
    
        if(!lampShader.addCacheableShaderFromSourceCode(
                    QOpenGLShader::Vertex,lamp_vertex)){
            qDebug()<<"compiler vertex error"<<lampShader.log();
        }
        if(!lampShader.addCacheableShaderFromSourceCode(
                    QOpenGLShader::Fragment,lamp_fragment)){
            qDebug()<<"compiler fragment error"<<lampShader.log();
        }
        if(!lampShader.link()){
            qDebug()<<"link shaderprogram error"<<lampShader.log();
        }
    }
    
    QOpenGLTexture *GLMultipleLights::initTexture(const QString &imgpath)
    {
        QOpenGLTexture *texture = new QOpenGLTexture(QImage(imgpath), QOpenGLTexture::GenerateMipMaps);
        if(!texture->isCreated()){
            qDebug() << "Failed to create texture";
        }
        //set the texture wrapping parameters
        //等于glTexParameteri(GLtexture_2D, GLtexture_WRAP_S, GL_REPEAT);
        texture->setWrapMode(QOpenGLTexture::DirectionS, QOpenGLTexture::Repeat);
        texture->setWrapMode(QOpenGLTexture::DirectionT, QOpenGLTexture::Repeat);//
        //set texture filtering parameters
        //等价于glTexParameteri(GLtexture_2D, GLtexture_MIN_FILTER, GL_LINEAR);
        texture->setMinificationFilter(QOpenGLTexture::Linear);
        texture->setMagnificationFilter(QOpenGLTexture::Linear);
        return texture;
    }

# 3.参考 #

LearnOpenGL：[https://learnopengl-cn.github.io/02%20Lighting/05%20Light%20casters/][https_learnopengl-cn.github.io_02_20Lighting_05_20Light_20casters]

LearnOpenGL：[https://learnopengl-cn.github.io/02%20Lighting/06%20Multiple%20lights/][https_learnopengl-cn.github.io_02_20Lighting_06_20Multiple_20lights]

[https_learnopengl-cn.github.io]: https://learnopengl-cn.github.io/
[https_learnopengl-cn.readthedocs.io_zh_latest]: https://learnopengl-cn.readthedocs.io/zh/latest/
[https_gongjianbo1992.blog.csdn.net_article_details_120397134]: https://gongjianbo1992.blog.csdn.net/article/details/120397134
[https_github.com_gongjianbo_OpenGLwithQtWidgets.git]: https://github.com/gongjianbo/OpenGLwithQtWidgets.git
[watermark_type_ZHJvaWRzYW5zZmFsbGJhY2s_shadow_50_text_Q1NETiBA6b6a5bu65rOi_size_17_color_FFFFFF_t_70_g_se_x_16]: /images/20220828/2851b360dd9f403485d9b2f5414ced97.png
[https_learnopengl-cn.github.io_02_20Lighting_05_20Light_20casters]: https://learnopengl-cn.github.io/02%20Lighting/05%20Light%20casters/
[https_learnopengl-cn.github.io_02_20Lighting_06_20Multiple_20lights]: https://learnopengl-cn.github.io/02%20Lighting/06%20Multiple%20lights/