OpenGL 学习系列-Hello Word
2020-04-14 本文已影响0人
棍子哥丸子妹
我的电脑是windows，在电脑上学习Opengl，推荐开发工具 Clion
推荐一个很好的opengl学习网站 https://learnopengl-cn.readthedocs.io/zh/latest/01%20Getting%20started/03%20Hello%20Window/
话不多说，先创建一个Hello word 工程
1.先下载几个库
需要的三方库.png
- freeglut 这个库最初由MarkKilgard编写，从OpenGL Redbook（红宝书）第二版起就用来作为示例程序的支持环境 GLUT因为其简单、可用性广、可移植性强，被广泛应用于各种OpenGL实际应用中
https://www.transmissionzero.co.uk/software/freeglut-devel/- glad 也是用来访问OpenGL规范接口的第三方库
https://glad.dav1d.de/- glfw 是一个专门针对OpenGL的C语言库，它提供了一些渲染物体所需的最低限度的接口。它允许用户创建OpenGL上下文，定义窗口参数以及处理用户输入
http://www.glfw.org/download.html- glew (OpenGL Extension Wrangler Library) 也是opengl额外的库，这个库封装了opengl复杂的操作，简化的我们opengl的API调用
http://glew.sourceforge.net/
2.Clion 创建工程
工程.png
- 本工程采用glad glew glfw 三个库
- 分别创建inclue lib src三个目录
- inclue主要是头文件，lib主要是需要链接的库
- src下面就一个glad源文件
3.CMakeLists.txt
cmake_minimum_required(VERSION 3.15)
project(OpenglTest2)
# 指定支持的c++版本
set(CMAKE_CXX_STANDARD 14)
# 指定编译后的输出目录
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY bin)
# 指定include 和 链接lib
include_directories(include)
link_directories(lib)
add_executable(OpenglTest2 main.cpp src/glad.c)
# 把glfw 和 glew链接进来
target_link_libraries(OpenglTest2 libglfw3.a glew32s.lib)
4.测试文件
#include <iostream>
#include "glad/glad.h"
#include "GLFW/glfw3.h"
void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void processInput(GLFWwindow *window);
// settings
const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;
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); // uncomment this statement to fix compilation on OS X
#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;
}
// render loop
// -----------
while (!glfwWindowShouldClose(window))
{
// input
// -----
processInput(window);
// render
// ------
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// glfw: swap buffers and poll IO events (keys pressed/released, mouse moved etc.)
// -------------------------------------------------------------------------------
glfwSwapBuffers(window);
glfwPollEvents();
}
// glfw: terminate, clearing all previously allocated GLFW resources.
// ------------------------------------------------------------------
glfwTerminate();
return 0;
}
// process all input: query GLFW whether relevant keys are pressed/released this frame and react accordingly
// ---------------------------------------------------------------------------------------------------------
void processInput(GLFWwindow *window)
{
if(glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
glfwSetWindowShouldClose(window, true);
}
// glfw: whenever the window size changed (by OS or user resize) this callback function executes
// ---------------------------------------------------------------------------------------------
void framebuffer_size_callback(GLFWwindow* window, int width, int height)
{
// make sure the viewport matches the new window dimensions; note that width and
// height will be significantly larger than specified on retina displays.
glViewport(0, 0, width, height);
}
5.运行结果如下
程序.png
1.有用VS开发的配置工程会更简单一些,不过安装VS要电脑要牛逼点
2.Clion 开发工具学习OpenGL足够了
