Visual Studio 2019 和 qt 5.15.1 下 opengl 的运用 - Getting-started - 02 - Hello-Triangle
学习learnopengl文章对应地址:https://learnopengl-cn.github.io/01%20Getting%20started/04%20Hello%20Triangle/
Visual Studio c++ 文件和 qt 项目链接（在一个包内）：https://download.csdn.net/download/zzjzmdx/16605193
展示图：
此部分代码分为两部分，如果看矩形就把三角形标注内的全部注释，矩形标注内的全部打开
Visual Studio 2019
代码如下:
三角形：
#include
#include
#include
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow* window);
//点数组 每三个值 确定一个点
float vertices[] = {
-0.5f, -0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
0.0f, 0.5f, 0.0f
};
const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
" gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"}\0";
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
" FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
"}\n\0";
int main()
{
//init
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
GLFWwindow* window = glfwCreateWindow(800, 600, "DrawTriangle01", NULL, NULL);
if (window == NULL)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
//将该窗口作为当前线程的主上下文
glfwMakeContextCurrent(window);
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
//init
//vertex shader 顶点着色器
unsigned int vertexShader;
vertexShader = glCreateShader(GL_VERTEX_SHADER);//创建顶点着色器
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);//将着色器中的源代码设置为string指定的字符串数组中的源代码
glCompileShader(vertexShader);//编译着色器
//测试编译是否成功
int success;
char infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
std::cout << "vertex shader 顶点着色器::编译失败\n" << infoLog << std::endl;
}
//测试编译是否成功
//vertex shader 顶点着色器
//fragment shader 片段着色器
unsigned int fragmentShader;
fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);//创建片段着色器
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);//将着色器中的源代码设置为string指定的字符串数组中的源代码
glCompileShader(fragmentShader);//编译着色器
//测试编译是否成功
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//测试编译是否成功
//fragment shader 片段着色器
//链接着色器到program对象
unsigned int shaderProgram;
shaderProgram = glCreateProgram();//创建一个program对象
glAttachShader(shaderProgram, vertexShader);//将顶点着色器对象附加到program对象
glAttachShader(shaderProgram, fragmentShader);//将着片段色器对象附加到program对象
glLinkProgram(shaderProgram);//连接一个program对象
//测试链接是否成功
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
}
//测试链接是否成功
//链接着色器到program对象
//删除片段着色器
glDeleteShader(vertexShader);
//删除顶点着色器
glDeleteShader(fragmentShader);
//创建VAO VAO: 顶点数组对象：Vertex Array Object,
unsigned int VAO;
glGenVertexArrays(1, &VAO); // 用来生成缓冲区对象
glBindVertexArray(VAO);//绑定VAO
//创建VBO, VBO:顶点缓冲对象：Vertex Buffer Object
unsigned int VBO;
glGenBuffers(1, &VBO);//用来生成缓冲区对象
//把新创建的缓冲绑定到GL_ARRAY_BUFFER目标上
glBindBuffer(GL_ARRAY_BUFFER, VBO);
//复制顶点数组到缓冲中供OpenGL使用
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
//告诉OpenGL该如何解析顶点数据
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
//允许顶点着色器读取GPU（服务器端）数据
glEnableVertexAttribArray(0);
//解绑VAO
glBindVertexArray(0);
//解绑VBO
glBindBuffer(GL_ARRAY_BUFFER, 0);
while (!glfwWindowShouldClose(window))
{
processInput(window);
//glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(shaderProgram);//使用程序对象作为当前渲染状态的一部分
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 3);
glfwSwapBuffers(window);
glfwPollEvents();
}
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
glDeleteProgram(shaderProgram);
glfwTerminate();
return 0;
}
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
glViewport(0, 0, width, height);
}
void processInput(GLFWwindow* window)
{
if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
glfwSetWindowShouldClose(window, true);
}
矩形：
#include
#include
#include
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow* window);
float vertices[] = {
0.5f, 0.5f, 0.0f, // top right
0.5f, -0.5f, 0.0f, // bottom right
-0.5f, -0.5f, 0.0f, // bottom left
-0.5f, 0.5f, 0.0f // top left
};
unsigned int indices[] = { // note that we start from 0!
0, 1, 3, // first Triangle
1, 2, 3 // second Triangle
};
const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
" gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"}\0";
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
" FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
"}\n\0";
int main()
{
//init
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
GLFWwindow* window = glfwCreateWindow(800, 600, "DrawRectangle02-VAOandVBO", NULL, NULL);
if (window == NULL)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
//init
//vertex shader 顶点着色器
unsigned int vertexShader;
vertexShader = glCreateShader(GL_VERTEX_SHADER);//创建顶点着色器
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);//将着色器中的源代码设置为string指定的字符串数组中的源代码
glCompileShader(vertexShader);//编译着色器
//测试编译是否成功
int success;
char infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
std::cout << "vertex shader 顶点着色器::编译失败\n" << infoLog << std::endl;
}
//测试编译是否成功
//vertex shader 顶点着色器
//fragment shader 片段着色器
unsigned int fragmentShader;
fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);//创建片段着色器
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);//将着色器中的源代码设置为string指定的字符串数组中的源代码
glCompileShader(fragmentShader);//编译着色器
//测试编译是否成功
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
}
//测试编译是否成功
//fragment shader 片段着色器
//链接着色器到program对象
unsigned int shaderProgram;
shaderProgram = glCreateProgram();//创建一个program对象
glAttachShader(shaderProgram, vertexShader);//将顶点着色器对象附加到program对象
glAttachShader(shaderProgram, fragmentShader);//将着片段色器对象附加到program对象
glLinkProgram(shaderProgram);//连接一个program对象
//测试链接是否成功
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
}
//测试链接是否成功
//链接着色器到program对象
//删除片段着色器
glDeleteShader(vertexShader);
//删除顶点着色器
glDeleteShader(fragmentShader);
//创建VAO VAO: 顶点数组对象：Vertex Array Object,
unsigned int VAO;
glGenVertexArrays(1, &VAO); // 用来生成缓冲区对象
glBindVertexArray(VAO);//绑定VAO
//创建EBO
unsigned int VBO;
glGenBuffers(1, &VBO);// 用来生成缓冲区对象
//把新创建的缓冲绑定到GL_ARRAY_BUFFER目标上
glBindBuffer(GL_ARRAY_BUFFER, VBO);
//复制顶点数组到缓冲中供OpenGL使用
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
//创建EBO
unsigned int EBO;
glGenBuffers(1, &EBO);// 用来生成缓冲区对象
//把新创建的缓冲绑定到GL_ELEMENT_ARRAY_BUFFER目标上
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
//把我们的顶点数组复制到一个顶点缓冲中，供OpenGL使用
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
//告诉OpenGL该如何解析顶点数据
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
//解绑VAO
glBindVertexArray(0);
//解绑VBO
glBindBuffer(GL_ARRAY_BUFFER, 0);
//解绑EBO
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
while (!glfwWindowShouldClose(window))
{
processInput(window);
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
glUseProgram(shaderProgram);//使用程序对象作为当前渲染状态的一部分
glBindVertexArray(VAO);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
glfwSwapBuffers(window);
glfwPollEvents();
}
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &EBO);
glDeleteProgram(shaderProgram);
glfwTerminate();
return 0;
}
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
glViewport(0, 0, width, height);
}
void processInput(GLFWwindow* window)
{
if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
glfwSetWindowShouldClose(window, true);
}
qt 5.15.1
代码如下:
main.cpp
#include "HelloTriangle.h"
#include
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QSurfaceFormat format;
format.setDepthBufferSize(24);
format.setVersion(3, 3);
QSurfaceFormat::setDefaultFormat(format);
app.setApplicationName("Hello-Triangle");
HelloTriangle hellotriangle;
hellotriangle.resize(800, 600);
hellotriangle.show();
return app.exec();
}
HelloTriangle.h
#ifndef HELLOTRIANGLE_H
#define HELLOTRIANGLE_H
#include
#include
#include
#include
#include
class HelloTriangle : public QOpenGLWidget, protected QOpenGLFunctions
{
Q_OBJECT
public:
HelloTriangle(QWidget *parent = nullptr);
~HelloTriangle();
protected:
void paintGL() override;
void initializeGL() override;
void resizeGL(int w,int h) override;
private:
QOpenGLShaderProgram *m_program;
QOpenGLVertexArrayObject *m_vao;
QOpenGLBuffer *m_vbo;
QOpenGLBuffer *m_ebo;
};
#endif // HELLOTRIANGLE_H
HelloTriangle.cpp
#include "HelloTriangle.h"
const char* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"void main()\n"
"{\n"
" gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);\n"
"}\0";
const char* fragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"void main()\n"
"{\n"
" FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
"}\n\0";
float vertices[] = {
-0.5f, -0.5f, 0.0f,
0.5f, -0.5f, 0.0f,
0.0f, 0.5f, 0.0f
};
float vertices_triangle[] = {
0.5f, 0.5f, 0.0f, // top right
0.5f, -0.5f, 0.0f, // bottom right
-0.5f, -0.5f, 0.0f, // bottom left
-0.5f, 0.5f, 0.0f // top left
};
unsigned int indices[] = { // note that we start from 0!
0, 1, 3, // first Triangle
1, 2, 3 // second Triangle
};
HelloTriangle::HelloTriangle(QWidget *parent)
: QOpenGLWidget(parent)
{
}
HelloTriangle::~HelloTriangle()
{
qDebug()<<"~HelloTriangle";
m_vao->release();
m_vbo->release();
m_program->release(); //解绑
}
void HelloTriangle::initializeGL()
{
initializeOpenGLFunctions();
glEnable(GL_DEPTH_TEST);
//QOpenGLShaderProgram
m_program = new QOpenGLShaderProgram(this);
//vertex shader 顶点着色器
m_program->addShaderFromSourceCode(QOpenGLShader::Vertex, vertexShaderSource);
//fragment shader 片段着色器
m_program->addShaderFromSourceCode(QOpenGLShader::Fragment, fragmentShaderSource);
m_program->link();
m_program->bind();//激活Program对象
m_vao = new QOpenGLVertexArrayObject();
m_vao->create();
m_vao->bind();
//画三角形
m_vbo = new QOpenGLBuffer(QOpenGLBuffer::Type::VertexBuffer);
m_vbo->create();
m_vbo->bind();
m_vbo->allocate(vertices, sizeof(vertices));
m_vbo->setUsagePattern(QOpenGLBuffer::StreamDraw);
//以下是两种实现方式
//方式1
//void setAttributeBuffer (int location, GLenum type, int offset, int tupleSize, int stride = 0);
m_program->setAttributeBuffer(0, GL_FLOAT, 0, 3, 0); //设置顶点属性
m_program->enableAttributeArray(0); //使能顶点属性
//方式1
//方式2
// //void setAttributeBuffer (const char *name, GLenum type, int offset, int tupleSize, int stride = 0);
// GLint aPos = m_program->attributeLocation("aPos"); //获取aPos位置
// if(aPos==-1)
// {
// return;
// }
// m_program->setAttributeBuffer(aPos, GL_FLOAT, 0, 3, 0); //设置顶点属性
// m_program->enableAttributeArray(aPos); //使能顶点属性
//方式2
//画三角形
//画矩形
// m_vbo = new QOpenGLBuffer(QOpenGLBuffer::Type::VertexBuffer);
// m_vbo->create();
// m_vbo->bind();
// m_vbo->allocate(vertices_triangle, sizeof(vertices_triangle));
// m_vbo->setUsagePattern(QOpenGLBuffer::StreamDraw);
// m_ebo = new QOpenGLBuffer(QOpenGLBuffer::Type::IndexBuffer);
// m_ebo->create();
// m_ebo->bind();
// m_ebo->allocate(indices,sizeof(indices));
// m_ebo->setUsagePattern(QOpenGLBuffer::StaticDraw);
//方式1
// //void setAttributeBuffer (int location, GLenum type, int offset, int tupleSize, int stride = 0);
// m_program->setAttributeBuffer(0, GL_FLOAT, 0, 3, 0); //设置顶点属性
// m_program->enableAttributeArray(0); //使能顶点属性
//方式1
//方式2
// GLint aPos = m_program->attributeLocation("aPos"); //获取aPos位置
// if(aPos==-1)
// {
// return;
// }
// m_program->setAttributeBuffer(aPos, GL_FLOAT, 0, 3, 0); //设置顶点属性
// m_program->enableAttributeArray(aPos); //使能顶点属性
//方式2
// m_ebo->release();
//画矩形
m_vao->release();
m_vbo->release();
}
void HelloTriangle::paintGL()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
// 渲染Shader
m_program->bind(); //绑定激活Program对象
m_vao->bind(); //绑定激活vao
//画三角形
glDrawArrays(GL_TRIANGLES, 0, 3); //绘制3个定点,样式为三角形
//画三角形
//画矩形
// glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
//画矩形
m_vao->release(); //解绑
}
void HelloTriangle::resizeGL(int w, int h)
{
}