(Vries的原教程地址如下,
https://learnopengl-cn.github.io/01%20Getting%20started/08%20Coordinate%20Systems/关于函数的具体解析及OpenGL中的坐标系统的具体解释请看这个教程,本篇旨在对Vires基于visual studio的编程思想做Qt平台的移植)
本篇目的是学习OpenGL里的坐标系统,model矩阵,view矩阵,projection矩阵,如何将处于3D坐标系的点,投影到2D的电脑窗口。由2D编程进入3D编程的世界。
(一)初探3D
将平面2D纹理,绕x轴旋转-55度,如下图所示。这里注意,OpenGL的坐标系是右手坐标系,即右为x轴正方向,上为y轴正方向,由屏幕指向你的方向为z轴正方向。旋转时,以逆时针为绕一轴旋转的正方向,顺时针为负方向。
以下为项目源代码,
项目组织管理如下:
相比之前的教程,修改shader.h, widget.cpp与vertexshadersource.vert文件,修改部分见注释。
shader.h,
#ifndef SHADER_H
#define SHADER_H
#include <QDebug>
#include <QOpenGLShader>
#include <QOpenGLShaderProgram>
#include <QString>
class Shader {
public:
Shader(const QString& vertexSourcePath, const QString& fragmentSourcePath);
~Shader();
QOpenGLShaderProgram *shaderProgram;
void use(){
shaderProgram->bind();
}
//还是把设置着色器uniform变量操作写成Shader里的inline成员函数管理,真的方便很多。
void setMat4(const QString& name, const QMatrix4x4& value){
GLuint loc = shaderProgram->uniformLocation(name);
shaderProgram->setUniformValue(loc, value);
}
void setInt(const QString& name, const GLint& value){
GLuint loc = shaderProgram->uniformLocation(name);
shaderProgram->setUniformValue(loc, value);
}
};
#endif // SHADER_H
vertexshadersource.vert
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aColor;
layout (location = 2) in vec2 aTexCoord;
out vec3 ourColor;
out vec2 TexCoord;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main(){
gl_Position = projection * view * model * vec4(aPos, 1.0f);
ourColor = aColor;
TexCoord = aTexCoord;
}
widget.cpp
这里我没将对着色器变量model,view,projection的赋值写进paintGL()函数。在我的思维里,一直认为
initializeGL()函数是初始化函数,在OpenGL开始时仅运行一次,
resizeGL()函数是在窗口大小改变时运行,
paintGL()函数类似于Vires教程里在while()循环里的函数,是不断刷新运行的。(虽然Qt里paintGL()函数只运行一次,想不断刷新,需要使用update()函数)。
所以,我将目前进赋值一次,且不再改编的model等矩阵变量的赋值过程,写进了initializeGL()里。
#include "widget.h"
GLuint VBO, VAO, EBO;
Triangle::Triangle(){
this->setWindowTitle("Coordinate System");
}
Triangle::~Triangle(){
delete ourShader;
core->glDeleteVertexArrays(1, &VAO);
core->glDeleteBuffers(1, &VBO);
core->glDeleteBuffers(1, &EBO);
texture1->destroy();
texture2->destroy();
}
void Triangle::initializeGL(){
//着色器部分
core = QOpenGLContext::currentContext()->versionFunctions<QOpenGLFunctions_3_3_Core>();
ourShader = new Shader(":/shaders/vertexshadersource.vert", ":/shaders/fragmentshadersource.frag");
//VAO,VBO数据部分
GLfloat vertices[] = {
0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, // top right
0.5f, -0.5f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, // bottom right
-0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, // bottom left
-0.5f, 0.5f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f // top left
};
GLuint indices[] = {
0, 1, 3, // first triangle
1, 2, 3 // second triangle
};
core->glGenVertexArrays(1, &VAO);//两个参数,第一个为需要创建的缓存数量。第二个为用于存储单一ID或多个ID的GLuint变量或数组的地址
core->glGenBuffers(1, &VBO);
core->glGenBuffers(1, &EBO);
core->glBindVertexArray(VAO);
core->glBindBuffer(GL_ARRAY_BUFFER, VBO);
core->glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
core->glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
core->glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
core->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
core->glEnableVertexAttribArray(0);
// color attribute
core->glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
core->glEnableVertexAttribArray(1);
// texture coord attribute
core->glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
core->glEnableVertexAttribArray(2);
//纹理
//第一张箱子
texture1 = new QOpenGLTexture(QImage(":/textures/res/textures/container.jpg").mirrored(), QOpenGLTexture::GenerateMipMaps); //直接生成绑定一个2d纹理, 并生成多级纹理MipMaps
if(!texture1->isCreated()){
qDebug() << "Failed to load texture" << endl;
}
texture1->setWrapMode(QOpenGLTexture::DirectionS, QOpenGLTexture::Repeat);// 等于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
texture1->setWrapMode(QOpenGLTexture::DirectionT, QOpenGLTexture::Repeat);// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
texture1->setMinificationFilter(QOpenGLTexture::Linear); //等价于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
texture1->setMagnificationFilter(QOpenGLTexture::Linear); // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
//第二张笑脸
texture2 = new QOpenGLTexture(QImage(":/textures/res/textures/smile.png").mirrored(), QOpenGLTexture::GenerateMipMaps); //直接生成绑定一个2d纹理, 并生成多级纹理MipMaps
if(!texture2->isCreated()){
qDebug() << "Failed to load texture" << endl;
}
texture2->setWrapMode(QOpenGLTexture::DirectionS, QOpenGLTexture::Repeat);// 等于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
texture2->setWrapMode(QOpenGLTexture::DirectionT, QOpenGLTexture::Repeat);// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
texture2->setMinificationFilter(QOpenGLTexture::Linear); //等价于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
texture2->setMagnificationFilter(QOpenGLTexture::Linear); // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
//设置纹理单元编号
ourShader->use();
ourShader->shaderProgram->setUniformValue(ourShader->shaderProgram->uniformLocation("texture1"), 0);//等价于ourShader.setInt("texture1", 0) setInt函数,是Vries自写的函数,实际应用还是要先获取“texture1”的location,然后设值
ourShader->shaderProgram->setUniformValue(ourShader->shaderProgram->uniformLocation("texture2"), 1);
core->glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
//开启计时器,返回毫秒
//time.start();
QMatrix4x4 model, projection, view;
model.rotate(-55.0f, QVector3D(1.0f, 0.0f, 0.0f));
view.translate(QVector3D(0.0f, 0.0f, -3.0f));
projection.perspective(45.0f, (GLfloat)width()/(GLfloat)height(), 0.1f, 100.0f);
ourShader->use();
ourShader->setMat4("model", model);
ourShader->setMat4("view", view);
ourShader->setMat4("projection", projection);
}
void Triangle::resizeGL(int w, int h){
core->glViewport(0, 0, w, h);
}
void Triangle::paintGL(){
core->glClear(GL_COLOR_BUFFER_BIT);
core->glActiveTexture(GL_TEXTURE0);
texture1->bind();
core->glActiveTexture(GL_TEXTURE1);
texture2->bind();
ourShader->use();
core->glBindVertexArray(VAO);
core->glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
update();
}
以下是没有改动过的函数:
fragmentshadersource.frag
#version 330 core
out vec4 FragColor;
in vec3 ourColor;
in vec2 TexCoord;
uniform sampler2D texture1;
uniform sampler2D texture2;
void main()
{
FragColor = mix(texture2D(texture1, TexCoord), texture2D(texture2, TexCoord), 0.2f);
}
shader.cpp
#include "shader.h"
Shader::Shader(const QString& vertexPath, const QString& fragmentPath){
QOpenGLShader vertexShader(QOpenGLShader::Vertex);
bool success = vertexShader.compileSourceFile(vertexPath);
if(!success){
qDebug() << "ERROR::SHADER::VERTEX::COMPILATION_FAILED" << endl;
qDebug() << vertexShader.log() << endl;
}
QOpenGLShader fragmentShader(QOpenGLShader::Fragment);
success =fragmentShader.compileSourceFile(fragmentPath);
if(!success){
qDebug() << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED" << endl;
qDebug() << fragmentShader.log() << endl;
}
shaderProgram = new QOpenGLShaderProgram();
shaderProgram->addShader(&vertexShader);
shaderProgram->addShader(&fragmentShader);
success = shaderProgram->link();
if(!success){
qDebug() << "ERROR::SHADER::PROGRAM::LINKING_FAILED" << endl;
qDebug() << shaderProgram->log() << endl;
}
}
Shader::~Shader(){
delete shaderProgram;
}
widget.h
#ifndef WIDGET_H
#define WIDGET_H
#include <QOpenGLWidget>
#include <QDebug>
#include <QOpenGLFunctions_3_3_Core>
#include "shader.h"
#include <QOpenGLTexture>
#include <QTime> //增添头文件
class Triangle : public QOpenGLWidget
{
public:
Triangle();
GLuint a;
~Triangle();
protected:
virtual void initializeGL();
virtual void resizeGL(int w, int h);
virtual void paintGL();
private:
Shader *ourShader;
QOpenGLTexture *texture1;
QOpenGLTexture *texture2;
QOpenGLFunctions_3_3_Core *core;
QTime time; //增添QTime对象,替代glfwGetTime()函数
};
#endif // WIDGET_H
main.cpp
#include "widget.h"
#include <QApplication>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Triangle t;
t.show();
return a.exec();
}
(二)3D立方体
得到一个旋转的立方体,如下图所示,emmmm,因为gif动图截取工具帧数的限制,看起来不是很流畅,但程序运行起来不是这样,很流畅的。
修改widget.cpp,vertexshadersource.vert与fragmentshadersource.cpp文件。
widget.cpp
#include "widget.h"
GLuint VBO, VAO;
Triangle::Triangle(){
this->setWindowTitle("Coordinate System");
}
Triangle::~Triangle(){
delete ourShader;
core->glDeleteVertexArrays(1, &VAO);
core->glDeleteBuffers(1, &VBO);
texture1->destroy();
texture2->destroy();
}
void Triangle::initializeGL(){
//着色器部分
core = QOpenGLContext::currentContext()->versionFunctions<QOpenGLFunctions_3_3_Core>();
ourShader = new Shader(":/shaders/vertexshadersource.vert", ":/shaders/fragmentshadersource.frag");
//VAO,VBO数据部分
float vertices[] = {
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
0.5f, -0.5f, -0.5f, 1.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
-0.5f, 0.5f, 0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, -0.5f, 1.0f, 1.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f
};
core->glGenVertexArrays(1, &VAO);//两个参数,第一个为需要创建的缓存数量。第二个为用于存储单一ID或多个ID的GLuint变量或数组的地址
core->glGenBuffers(1, &VBO);
core->glBindVertexArray(VAO);
core->glBindBuffer(GL_ARRAY_BUFFER, VBO);
core->glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
core->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
core->glEnableVertexAttribArray(0);
// texture coord attribute
core->glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
core->glEnableVertexAttribArray(1);
//纹理
//第一张箱子
texture1 = new QOpenGLTexture(QImage(":/textures/res/textures/container.jpg").mirrored(), QOpenGLTexture::GenerateMipMaps); //直接生成绑定一个2d纹理, 并生成多级纹理MipMaps
if(!texture1->isCreated()){
qDebug() << "Failed to load texture" << endl;
}
texture1->setWrapMode(QOpenGLTexture::DirectionS, QOpenGLTexture::Repeat);// 等于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
texture1->setWrapMode(QOpenGLTexture::DirectionT, QOpenGLTexture::Repeat);// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
texture1->setMinificationFilter(QOpenGLTexture::Linear); //等价于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
texture1->setMagnificationFilter(QOpenGLTexture::Linear); // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
//第二张笑脸
texture2 = new QOpenGLTexture(QImage(":/textures/res/textures/smile.png").mirrored(), QOpenGLTexture::GenerateMipMaps); //直接生成绑定一个2d纹理, 并生成多级纹理MipMaps
if(!texture2->isCreated()){
qDebug() << "Failed to load texture" << endl;
}
texture2->setWrapMode(QOpenGLTexture::DirectionS, QOpenGLTexture::Repeat);// 等于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
texture2->setWrapMode(QOpenGLTexture::DirectionT, QOpenGLTexture::Repeat);// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
texture2->setMinificationFilter(QOpenGLTexture::Linear); //等价于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
texture2->setMagnificationFilter(QOpenGLTexture::Linear); // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
//设置纹理单元编号
ourShader->use();
ourShader->setInt("texture1", 0);
ourShader->setInt("texture2", 1);
//开启计时器,返回毫秒
time.start();
//给着色器变量赋值
QMatrix4x4 projection, view;
view.translate(QVector3D(0.0f, 0.0f, -3.0f));
projection.perspective(45.0f, (GLfloat)width()/(GLfloat)height(), 0.1f, 100.0f);
ourShader->use();
ourShader->setMat4("view", view);
ourShader->setMat4("projection", projection);
//开启状态
core->glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
core->glEnable(GL_DEPTH_TEST);
}
void Triangle::resizeGL(int w, int h){
core->glViewport(0, 0, w, h);
}
void Triangle::paintGL(){
core->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
core->glActiveTexture(GL_TEXTURE0);
texture1->bind();
core->glActiveTexture(GL_TEXTURE1);
texture2->bind();
QMatrix4x4 model;
model.rotate((float)time.elapsed()/10, QVector3D(0.5f, 1.0f, 0.0f));
ourShader->use();
ourShader->setMat4("model", model);
core->glBindVertexArray(VAO);
core->glDrawArrays(GL_TRIANGLES, 0, 36);
update();
}
vertexshadersource.vert
#version 330 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec2 aTexCoord;
out vec2 TexCoord;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main(){
gl_Position = projection * view * model * vec4(aPos, 1.0f);
TexCoord = aTexCoord;
}
fragmentshadersource.cpp
#version 330 core
out vec4 FragColor;
in vec2 TexCoord;
uniform sampler2D texture1;
uniform sampler2D texture2;
void main()
{
FragColor = mix(texture2D(texture1, TexCoord), texture2D(texture2, TexCoord), 0.2f);
}
学到现在这一步,照着Vries的教程,按Qt风格修改真的不是很大的问题。
(三)更多的立方体
让我们渲染更多的立方体。如下图所示,emmm,gif动图还不是很流程,与程序无关,
简单修改widget.cpp,对Vires大神的变量值稍加改动,详见注释。
widget.cpp
#include "widget.h"
GLuint VBO, VAO;
Triangle::Triangle(){
this->setWindowTitle("Coordinate System");
}
Triangle::~Triangle(){
delete ourShader;
core->glDeleteVertexArrays(1, &VAO);
core->glDeleteBuffers(1, &VBO);
texture1->destroy();
texture2->destroy();
}
void Triangle::initializeGL(){
//着色器部分
core = QOpenGLContext::currentContext()->versionFunctions<QOpenGLFunctions_3_3_Core>();
ourShader = new Shader(":/shaders/vertexshadersource.vert", ":/shaders/fragmentshadersource.frag");
//VAO,VBO数据部分
float vertices[] = {
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
0.5f, -0.5f, -0.5f, 1.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 0.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
0.5f, 0.5f, 0.5f, 1.0f, 1.0f,
-0.5f, 0.5f, 0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
0.5f, -0.5f, -0.5f, 1.0f, 1.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
0.5f, -0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, -0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, -0.5f, -0.5f, 0.0f, 1.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f,
0.5f, 0.5f, -0.5f, 1.0f, 1.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f, 0.0f,
-0.5f, 0.5f, 0.5f, 0.0f, 0.0f,
-0.5f, 0.5f, -0.5f, 0.0f, 1.0f
};
core->glGenVertexArrays(1, &VAO);//两个参数,第一个为需要创建的缓存数量。第二个为用于存储单一ID或多个ID的GLuint变量或数组的地址
core->glGenBuffers(1, &VBO);
core->glBindVertexArray(VAO);
core->glBindBuffer(GL_ARRAY_BUFFER, VBO);
core->glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
core->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
core->glEnableVertexAttribArray(0);
// texture coord attribute
core->glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
core->glEnableVertexAttribArray(1);
//纹理
//第一张箱子
texture1 = new QOpenGLTexture(QImage(":/textures/res/textures/container.jpg").mirrored(), QOpenGLTexture::GenerateMipMaps); //直接生成绑定一个2d纹理, 并生成多级纹理MipMaps
if(!texture1->isCreated()){
qDebug() << "Failed to load texture" << endl;
}
texture1->setWrapMode(QOpenGLTexture::DirectionS, QOpenGLTexture::Repeat);// 等于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
texture1->setWrapMode(QOpenGLTexture::DirectionT, QOpenGLTexture::Repeat);// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
texture1->setMinificationFilter(QOpenGLTexture::Linear); //等价于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
texture1->setMagnificationFilter(QOpenGLTexture::Linear); // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
//第二张笑脸
texture2 = new QOpenGLTexture(QImage(":/textures/res/textures/smile.png").mirrored(), QOpenGLTexture::GenerateMipMaps); //直接生成绑定一个2d纹理, 并生成多级纹理MipMaps
if(!texture2->isCreated()){
qDebug() << "Failed to load texture" << endl;
}
texture2->setWrapMode(QOpenGLTexture::DirectionS, QOpenGLTexture::Repeat);// 等于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
texture2->setWrapMode(QOpenGLTexture::DirectionT, QOpenGLTexture::Repeat);// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
texture2->setMinificationFilter(QOpenGLTexture::Linear); //等价于glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
texture2->setMagnificationFilter(QOpenGLTexture::Linear); // glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
//设置纹理单元编号
ourShader->use();
ourShader->setInt("texture1", 0);
ourShader->setInt("texture2", 1);
//开启计时器,返回毫秒
time.start();
//给着色器变量赋值
QMatrix4x4 projection, view;
view.translate(QVector3D(0.0f, 0.0f, -3.0f));
projection.perspective(45.0f, (GLfloat)width()/(GLfloat)height(), 0.1f, 100.0f);
ourShader->use();
ourShader->setMat4("view", view);
ourShader->setMat4("projection", projection);
//开启状态
core->glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
core->glEnable(GL_DEPTH_TEST);
}
void Triangle::resizeGL(int w, int h){
core->glViewport(0, 0, w, h);
}
QVector3D cubePositions[] = {
QVector3D( 0.0f, 0.0f, -1.0f), //小小改动一下将z轴的0.0f变为-1.0f
QVector3D( 2.0f, 5.0f, -15.0f),
QVector3D(-1.5f, -2.2f, -2.5f),
QVector3D(-3.8f, -2.0f, -12.3f),
QVector3D( 2.4f, -0.4f, -3.5f),
QVector3D(-1.7f, 3.0f, -7.5f),
QVector3D( 1.3f, -2.0f, -2.5f),
QVector3D( 1.5f, 2.0f, -2.5f),
QVector3D( 1.5f, 0.2f, -1.5f),
QVector3D(-1.3f, 1.0f, -1.5f)
};
void Triangle::paintGL(){
core->glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
core->glActiveTexture(GL_TEXTURE0);
texture1->bind();
core->glActiveTexture(GL_TEXTURE1);
texture2->bind();
for(GLuint i = 0; i != 10; ++i){
QMatrix4x4 model;
model.translate(cubePositions[i]);
model.rotate((float)time.elapsed()/10, cubePositions[i]);//这里角度的设置仍然为时间,如果按照Vires大神写的i*20, 箱子不会旋转
ourShader->use();
ourShader->setMat4("model", model);
core->glBindVertexArray(VAO);
core->glDrawArrays(GL_TRIANGLES, 0, 36);
}
update();
}