Ubuntu20.04搭建OpenGL环境(glfw+glad)
Linux环境搭建
本文在VMware安装Ubuntu20.04桌面版的环境下搭建OpenGL，按照本文搭建完成后可以执行LearnOpenGL网站上的demo。
关于VMware可自行到VMware Workstation Pro | CN下载
关于Ubuntu20.04桌面版可自行到官网或Index of /ubuntu-releases/20.04.6/ | 清华大学开源软件镜像站 | Tsinghua Open Source Mirror下载
这里窗口系统是X11，如果最新版Ubuntu窗口系统应该是Wayland那配置方法可能有所差异，没有实测过。
啰嗦几句基操~
关于虚拟机和物理机的通信：
可以采用scp命令或建立共享文件夹的方式。
关于建立共享文件夹的几个步骤：
- 在编辑虚拟机设置里选择一个共享文件夹
- 在开启虚拟机的瞬间，不断点击选项栏的
虚拟机，直到刷出安装VMware Tools是可以点击的状态，然后点击安装。 - 进入虚拟机后
/mnt/hgfs在这个目录下会发现和物理机的共享文件夹
正文开始
安装g++
sudo apt install g++
安装mesa工具
sudo apt install mesa-utils
查看opengl的版本
glxinfo -B | grep 'OpenGL version string'
得到 `OpenGL version string: 4.1 (Compatibility Profile) Mesa 21.2.6` 字样，我们记住自己的版本号，我的是4.1
安装xorg依赖(GLFW的依赖)
sudo apt install xorg-dev
下载glfw源码进行编译
git clone https://github.com/glfw/glfw
cd glfw
cmake -S . -B build
cd build
make
sudo make install
安装GLAD
登录到GLAD官网，点这里。只需要把API中gl的版本设置成我们刚才查看的版本即可(作者是4.1)。最后点击GENERATE。
这时浏览器会跳至文件页，我们把glad.zip文件保存到本地并解压。
解压之后得到一个include目录，和一个src目录
我们首先把include这个目录里的内容移动到标准头目录下，sudo mv include/* /usr/local/include。
src目录下有个glad.c文件我们需要把他放到项目文件中，一会再弄！
创建项目
mkdir opengl_code
cd opengl_code
- 把
glad.c文件copy过来 - 创建一个
build目录mkdir build - 创建
CMakeLists.txt文件，并添加以下内容
cmake_minimum_required(VERSION 2.8)
set(CMAKE_C_STANDARD 11)
set(CMAKE_CXX_STANDARD 14)
project(test)
find_package(glfw3 REQUIRED)
find_package( OpenGL REQUIRED )
include_directories( ${OPENGL_INCLUDE_DIRS} )
file(GLOB project_file glad.c main.cpp)
add_executable(${PROJECT_NAME} ${project_file})
target_link_libraries(${PROJECT_NAME} ${OPENGL_LIBRARIES} glfw)
- 创建
main.cpp文件，并添加以下内容
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <iostream>
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow *window);
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;
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()
{
// glfw: initialize and configure
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
#ifdef __APPLE__
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
#endif
// glfw window creation
GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
if (window == NULL)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
// glad: load all OpenGL function pointers
if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{
std::cout << "Failed to initialize GLAD" << std::endl;
return -1;
}
// build and compile our shader program
// ------------------------------------
// vertex shader
int vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
// check for shader compile errors
int success;
char infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
}
// fragment shader
int fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glCompileShader(fragmentShader);
// check for shader compile errors
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success)
{
glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
}
// link shaders
int shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
// check for linking errors
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
std::cout << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
}
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
float vertices[] = {
-0.5f, -0.5f, 0.0f, // left
0.5f, -0.5f, 0.0f, // right
0.0f, 0.5f, 0.0f // top
};
unsigned int VBO, VAO;
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
glEnableVertexAttribArray(0);
glBindVertexArray(0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
// render loop
// -----------
while (!glfwWindowShouldClose(window))
{
// input
// -----
processInput(window);
// render
// ------
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// draw our first triangle
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 3);
glfwSwapBuffers(window);
glfwPollEvents();
}
// optional: de-allocate all resources
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
glDeleteProgram(shaderProgram);
glfwTerminate();
return 0;
}
void processInput(GLFWwindow *window)
{
if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
glfwSetWindowShouldClose(window, true);
}
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
glViewport(0, 0, width, height);
}
- 创建
run.sh文件，并添加以下内容
cd build
cmake ..
make
./test
cd ..
完成
现在运行bash run.sh 即可执行OpneGL程序，效果如下：
PS
如果想通过gdb调试的话，那需要手动进行编译。
-
sudo apt-get install libglfw3-dev libgl1-mesa-dev -
g++ -O0 -g glad.c main.cpp -lglfw3 -ldl -lGL -lpthread
这样就可以gdb a.out了
