（本文是LearnOpenGL的学习笔记， 教程中文翻译地址https://learnopengl-cn.github.io/（备用地址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），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）
多光源实现效果：
#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/
LearnOpenGL：https://learnopengl-cn.github.io/02%20Lighting/06%20Multiple%20lights/