OpenGL 学习，入门程序

环境

运行环境Mac，Xcode，OpenGL4.1，glew，glfw，glm，soil2
参考书籍：《计算机图形学编程c++版》
以下程序在我的本地都跑出结果了

展示出一个红色的窗口

#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>
 
using namespace std;
void init(GLFWwindow* window){
}
 
void display(GLFWwindow* window,double currentTime){
    glClearColor(1.0, 0.0, 0.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT);
}
 
int main(void){
    if(!glfwInit()){exit(EXIT_FAILURE);}
    GLFWwindow* window = glfwCreateWindow(600,600,"Chapter2 - program1",NULL,NULL);
    glfwMakeContextCurrent(window);
    if(glewInit() != GLEW_OK){exit(EXIT_FAILURE);}
    glfwSwapInterval(1);
 
    init(window);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    while (!glfwWindowShouldClose(window)) {
        display(window, glfwGetTime());
        glfwSwapBuffers(window);
        glfwPollEvents();
    }
    glfwDestroyWindow(window);
    glfwTerminate();
    exit(EXIT_SUCCESS);
}
 

窗口中间显示一个蓝色的点

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdocumentation"
 
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>
 
#define numVAOs 1
GLuint renderingProgram;
GLuint vao[numVAOs];
 
GLuint createShaderProgram(){
    const char *vshaderSource =
    "#version 430 \n"
    "void main(void) \n"
    "{ gl_Position = vec4(0.0,0.0,0.0,1.0); }";
    
    const char *fshaderSource =
    "#version 430 \n"
    "out vec4 color; \n"
    "void main(void) \n"
    "{color = vec4(0.0,0.0,1.0,1.0); }";
    GLuint vShader = glCreateShader(GL_VERTEX_SHADER);
    GLuint fShader = glCreateShader(GL_FRAGMENT_SHADER);
    
    glShaderSource(vShader,1,&vshaderSource,NULL);
    glShaderSource(fShader,1,&fshaderSource,NULL);
    glCompileShader(vShader );
    glCompileShader(fShader);
    
    GLuint vfProgram = glCreateProgram();
    glAttachShader(vfProgram,vShader);
    glAttachShader(vfProgram,fShader);
    glLinkProgram(vfProgram);
    
    return vfProgram;
}
 
void init(GLFWwindow* window){
    renderingProgram = createShaderProgram();
    glGenVertexArrays(numVAOs,vao);
    glBindVertexArray(vao[0]);
}
 
void display(GLFWwindow* window,double currentTime){
    glUseProgram(renderingProgram);
    glDrawArrays(GL_POINTS,0,1);
}
 
int main(void){
    if(!glfwInit()){exit(EXIT_FAILURE);}
    GLFWwindow* window = glfwCreateWindow(600,600,"Chapter2 - program1",NULL,NULL);
    glfwMakeContextCurrent(window);
    glewExperimental = GL_TRUE;
    if(glewInit() != GLEW_OK){exit(EXIT_FAILURE);}
    glfwSwapInterval(1);
 
    init(window);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);
    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
    while (!glfwWindowShouldClose(window)) {
        display(window, glfwGetTime());
        glfwSwapBuffers(window);
        glfwPollEvents();
    }
    glfwDestroyWindow(window);
    glfwTerminate();
    exit(EXIT_SUCCESS);
}
 

绘制点、线、面

#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdocumentation"
 
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>
 
void drawPoint()
{
    /* Draw a point */
    // 设置清除背景时用的颜色 RGBA 值
    glClearColor (0.0, 0.0, 0.0, 0.0);
    // 使用指定的颜色对颜色缓冲区进行填充
    glClear(GL_COLOR_BUFFER_BIT);
    // 指定光栅化点的直径
    glPointSize(2.0f);
    // 分隔基元或一组类似基元的顶点，包括GL_LINES、GL_TRIANGLES、GL QUADS、GL QUAD STRIP
    glBegin(GL_POINTS);
    // 设置当前颜色
    glColor3f(1.0, 0.0, 0.0); // Red
    // 指定顶点
    glVertex2f(0.0f,0.0f);
    glVertex2f(0.5f,0.8f);
    // 分隔基元或一组类似基元的顶点
    glEnd();
}
void drawLint()
{
    // 设置清除背景时用的颜色
    glClearColor (0.0, 0.0, 0.0, 0.0);
    // 使用指定的颜色对颜色缓冲区进行填充
    glClear (GL_COLOR_BUFFER_BIT);
    //设置线段宽度
    glLineWidth(2);
    glBegin(GL_LINES);
    glColor3f(1.0,0.0,0.0);
    // 定点坐标范围2D点只需要xy，3D要xyz
    glVertex2f(-1.0,1.0);
    glVertex2f(0.0,-0.5);
    glEnd();
}
// 画三角形
void drawTriangle()
{
    glClearColor (0.0, 0.0, 0.0, 0.0);
    glClear (GL_COLOR_BUFFER_BIT);
    glBegin(GL_TRIANGLES);
 
    glColor3f(1.0, 0.0, 0.0);    // Red
    glVertex3f(0.0, 1.0, 0.0);
 
    glColor3f(0.0, 1.0, 0.0);    // Green
    glVertex3f(-1.0, -1.0, 0.0);
 
    glColor3f(0.0, 0.0, 1.0);    // Blue
    glVertex3f(1.0, -1.0, 0.0);
    glEnd();
}
int main(void)
{
    GLFWwindow* window;
 
    /* Initialize the library */
    if (!glfwInit())
        return -1;
 
    /* Create a windowed mode window and its OpenGL context */
    // 创建窗口
    window = glfwCreateWindow(480, 320, "Hello World", NULL, NULL);
    if (!window)
    {
        // 关闭glfw库本身
        glfwTerminate();
        return -1;
    }
 
    /* Make the window's context current */
    // 设置参数window中的窗口所关联的OpenGL环境为当前环境。这个环境在当前线程中会一直保持为当前环境，直到另一个环境被设置为当前环境，或者窗口被删除为止
    glfwMakeContextCurrent(window);
 
    /* Loop until the user closes the window */
    // 如果用户准备关闭参数window所指定的窗口，那么此接口将会返回GL_TRUE，否则将会返回GL_FALSE
    while (!glfwWindowShouldClose(window))
    {
 
        /*your draw*/
//         drawPoint();
//         drawLint();
        drawTriangle();
 
        /* Swap front and back buffers */
        glfwSwapBuffers(window);
 
        /* Poll for and process events */
        // 处理事件
        glfwPollEvents();
    }
    
    // 关闭glfw库本身
    glfwTerminate();
    return 0;
}