绘制4条线段
1 #define GLEW_STATIC
2 #include <GL/glew.h>
3 #include <GLFW/glfw3.h>
4
5 #include "Shader.h"
6 #include <fstream>
7 #include <iostream>
8 using namespace std;
9
10 void framebuffer_size_callback(GLFWwindow* window, int width, int height);
11 void processInput(GLFWwindow *window);
12
13
14 // settings
15 const unsigned int SCR_WIDTH = 800;
16 const unsigned int SCR_HEIGHT = 600;
17
18
19 // timing
20 float deltaTime = 0.0f;
21 float lastFrame = 0.0f;
22
23 int main()
24 {
25 // glfw: initialize and configure
26 // ------------------------------
27 glfwInit();
28 glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
29 glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
30 glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
31
32 #ifdef __APPLE__
33 glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // uncomment this statement to fix compilation on OS X
34 #endif
35
36 // glfw window creation
37 // --------------------
38 GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
39 if (window == NULL)
40 {
41 std::cout << "Failed to create GLFW window" << std::endl;
42 glfwTerminate();
43 return -1;
44 }
45 glfwMakeContextCurrent(window);
46 glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
47
48
49 glewExperimental = GL_TRUE;
50 if (glewInit() != GLEW_OK)
51 {
52 cout << "Failed to initialize GLEW!" << endl;
53 return -1;
54 }
55 // configure global opengl state
56 // -----------------------------
57
58 Shader shader("E:\C++\High_level_GLSL\2.1ver1.txt", "E:\C++\High_level_GLSL\2.1frag1.txt",
59 "E:\C++\High_level_GLSL\2.1geo1.txt");
60
61 float points[] = {
62 -0.5f, 0.5f,
63 0.5f, 0.5f,
64 0.5f, -0.5f,
65 -0.5f, -0.5f
66 };
67
68 /*float points[] = {
69 -0.5f, 0.5f, 1.0f, 0.0f, 0.0f,
70 0.5f, 0.5f, 0.0f, 1.0f, 0.0f,
71 0.5f, -0.5f, 0.0f, 0.0f, 1.0f,
72 -0.5f, -0.5f, 1.0f, 1.0f, 0.0f
73 };*/
74
75 unsigned int VAO, VBO;
76 glGenVertexArrays(1, &VAO);
77 glGenBuffers(1, &VBO);
78 glBindVertexArray(VAO);
79 glBindBuffer(GL_ARRAY_BUFFER, VBO);
80 glBufferData(GL_ARRAY_BUFFER, sizeof(points), &points, GL_STATIC_DRAW);
81 glEnableVertexAttribArray(0);
82 glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), (void*)0);
83 //glEnableVertexAttribArray(1);
84 //glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(2 * sizeof(float)));
85 glBindVertexArray(0);
86
87 while (!glfwWindowShouldClose(window))
88 {
89 processInput(window);
90
91 glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
92 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
93
94 shader.use();
95 glBindVertexArray(VAO);
96 glDrawArrays(GL_POINTS, 0, 4);
97
98 glfwSwapBuffers(window);
99 glfwPollEvents();
100 }
101
102 glDeleteVertexArrays(1, &VAO);
103 glDeleteBuffers(1, &VBO);
104
105 }
106
107 void processInput(GLFWwindow *window)
108 {
109 if (glfwGetKey(window, GLFW_KEY_ENTER) == GLFW_PRESS)
110 glfwSetWindowShouldClose(window, true);
111 }
112
113 // glfw: whenever the window size changed (by OS or user resize) this callback function executes
114 // ---------------------------------------------------------------------------------------------
115 void framebuffer_size_callback(GLFWwindow* window, int width, int height)
116 {
117 // make sure the viewport matches the new window dimensions; note that width and
118 // height will be significantly larger than specified on retina displays.
119 glViewport(0, 0, width, height);
120 }
121
122
E:\C++\High_level_GLSL\2.1ver1.txt
1 #version 330 core
2 layout (location = 0) in vec2 aPos;
3
4 void main()
5 {
6 gl_Position = vec4(aPos, 0.0f, 1.0f);
7 }
E:\C++\High_level_GLSL\2.1frag1.txt
1 #version 330 core
2 out vec4 FragColor;
3 void main()
4 {
5 FragColor = vec4(0.0f, 1.0f, 0.0f, 1.0f);
6 }
E:\C++\High_level_GLSL\2.1geo1.txt
1 #version 330 core
2 layout (points) in;
3 layout (line_strip, max_vertices = 2) out;
4
5 void main()
6 {
7 gl_Position = gl_in[0].gl_Position + vec4(-0.1f, 0.0f, 0.0f, 0.0f);
8 EmitVertex();
9 gl_Position = gl_in[0].gl_Position + vec4(0.1f, 0.0f, 0.0f, 0.0f);
10 EmitVertex();
11
12 EndPrimitive();
13 }
Shader.h头文件，只需将链接里的#include <glad/glad.h>换成
#define GLEW_STATIC
#include <GL/glew.h>
就行