source: opengl-game/pong.cpp@ eeece4e

feature/imgui-sdl points-test
Last change on this file since eeece4e was eeece4e, checked in by Dmitry Portnoy <dmp1488@…>, 7 years ago

In the pong game, allow shapes to be composed of multiple triangles and create a stationary red paddle on the left side of the screen.

  • Property mode set to 100644
File size: 6.1 KB
Line 
1#include "logger.h"
2
3#include <GL/glew.h>
4#include <GLFW/glfw3.h>
5
6#include <cstdio>
7#include <iostream>
8#include <fstream>
9#include <cmath>
10
11using namespace std;
12
13GLuint loadShader(GLenum type, string file);
14GLuint createDataBuffer(size_t size, GLfloat* data);
15GLuint createArrayBuffer(GLuint points_vbo, GLuint colors_vbo);
16
17const bool FULLSCREEN = false;
18
19void glfw_error_callback(int error, const char* description) {
20 gl_log_err("GLFW ERROR: code %i msg: %s\n", error, description);
21}
22
23int main(int argc, char* argv[]) {
24 cout << "New OpenGL Game" << endl;
25
26 if (!restart_gl_log()) {}
27 gl_log("starting GLFW\n%s\n", glfwGetVersionString());
28
29 glfwSetErrorCallback(glfw_error_callback);
30 if (!glfwInit()) {
31 fprintf(stderr, "ERROR: could not start GLFW3\n");
32 return 1;
33 }
34
35#ifdef __APPLE__
36 glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
37 glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
38 glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
39 glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
40#endif
41
42 glfwWindowHint(GLFW_SAMPLES, 4);
43
44 GLFWwindow* window = NULL;
45
46 int width = 640;
47 int height = 480;
48
49 if (FULLSCREEN) {
50 GLFWmonitor* mon = glfwGetPrimaryMonitor();
51 const GLFWvidmode* vmode = glfwGetVideoMode(mon);
52
53 cout << "Fullscreen resolution " << vmode->width << "x" << vmode->height << endl;
54 window = glfwCreateWindow(vmode->width, vmode->height, "Extended GL Init", mon, NULL);
55
56 width = vmode->width;
57 height = vmode->height;
58 } else {
59 window = glfwCreateWindow(width, height, "Hello Triangle", NULL, NULL);
60 }
61
62 if (!window) {
63 fprintf(stderr, "ERROR: could not open window with GLFW3\n");
64 glfwTerminate();
65 return 1;
66 }
67 glfwMakeContextCurrent(window);
68 glewExperimental = GL_TRUE;
69 glewInit();
70
71 // glViewport(0, 0, width*2, height*2);
72
73 const GLubyte* renderer = glGetString(GL_RENDERER);
74 const GLubyte* version = glGetString(GL_VERSION);
75 printf("Renderer: %s\n", renderer);
76 printf("OpenGL version supported %s\n", version);
77
78 glEnable(GL_DEPTH_TEST);
79 glDepthFunc(GL_LESS);
80
81 glEnable(GL_CULL_FACE);
82 // glCullFace(GL_BACK);
83 // glFrontFace(GL_CW);
84
85 GLfloat points[] = {
86 0.0f, 0.5f, 0.5f,
87 -0.5f, -0.5f, 0.5f,
88 0.5f, -0.5f, 0.5f,
89 };
90
91 GLfloat colors[] = {
92 1.0, 0.0, 0.0,
93 0.0, 0.0, 1.0,
94 0.0, 1.0, 0.0,
95 };
96
97 GLfloat points_paddle[] = {
98 -1.0f, 1.0f, 0.0f,
99 -1.0f, 0.7f, 0.0f,
100 -0.9f, 0.7f, 0.0f,
101 -1.0f, 1.0f, 0.0f,
102 -0.9f, 0.7f, 0.0f,
103 -0.9f, 1.0f, 0.0f,
104 };
105
106 GLfloat colors_paddle[] = {
107 1.0, 0.0, 0.0,
108 1.0, 0.0, 0.0,
109 1.0, 0.0, 0.0,
110 1.0, 0.0, 0.0,
111 1.0, 0.0, 0.0,
112 1.0, 0.0, 0.0,
113 };
114
115 GLfloat model[] = {
116 1.0f, 0.0f, 0.0f, 0.0f, // column 1
117 0.0f, 1.0f, 0.0f, 0.0f, // column 2
118 0.0f, 0.0f, 1.0f, 0.0f, // column 3
119 0.0f, 0.0f, 0.0f, 1.0f, // column 4
120 };
121
122 GLuint ball_points_vbo = createDataBuffer(sizeof(points), points);
123 GLuint ball_colors_vbo = createDataBuffer(sizeof(colors), colors);
124 GLuint ball_vao = createArrayBuffer(ball_points_vbo, ball_colors_vbo);
125
126 GLuint paddle_points_vbo = createDataBuffer(sizeof(points_paddle), points_paddle);
127 GLuint paddle_colors_vbo = createDataBuffer(sizeof(colors_paddle), colors_paddle);
128 GLuint paddle_vao = createArrayBuffer(paddle_points_vbo, paddle_colors_vbo);
129
130 GLuint vs = loadShader(GL_VERTEX_SHADER, "./test.vert");
131 GLuint fs = loadShader(GL_FRAGMENT_SHADER, "./test.frag");
132
133 GLuint shader_program = glCreateProgram();
134 glAttachShader(shader_program, vs);
135 glAttachShader(shader_program, fs);
136
137 glLinkProgram(shader_program);
138 glUseProgram(shader_program);
139
140 GLint location = glGetUniformLocation(shader_program, "model");
141
142 float speed = 1.0f;
143 float last_position = 0.0f;
144
145 double previous_seconds = glfwGetTime();
146 while (!glfwWindowShouldClose(window)) {
147 double current_seconds = glfwGetTime();
148 double elapsed_seconds = current_seconds - previous_seconds;
149 previous_seconds = current_seconds;
150
151 if (fabs(last_position) > 1.0f) {
152 speed = -speed;
153 }
154
155 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
156
157 model[12] = 0.0f;
158 glUniformMatrix4fv(location, 1, GL_FALSE, model);
159
160 glBindVertexArray(paddle_vao);
161 glEnableVertexAttribArray(0);
162 glEnableVertexAttribArray(1);
163
164 glDrawArrays(GL_TRIANGLES, 0, sizeof(points_paddle)/sizeof(GLfloat)/3);
165
166 model[12] = last_position + speed*elapsed_seconds;
167 last_position = model[12];
168 glUniformMatrix4fv(location, 1, GL_FALSE, model);
169
170 glBindVertexArray(ball_vao);
171 glEnableVertexAttribArray(0);
172 glEnableVertexAttribArray(1);
173
174 glDrawArrays(GL_TRIANGLES, 0, sizeof(points)/sizeof(GLfloat)/3);
175
176 glfwPollEvents();
177 glfwSwapBuffers(window);
178
179 if (GLFW_PRESS == glfwGetKey(window, GLFW_KEY_ESCAPE)) {
180 glfwSetWindowShouldClose(window, 1);
181 }
182 }
183
184 glfwTerminate();
185 return 0;
186}
187
188GLuint loadShader(GLenum type, string file) {
189 cout << "Loading shader from file " << file << endl;
190
191 ifstream shaderFile(file);
192 GLuint shaderId = 0;
193
194 if (shaderFile.is_open()) {
195 string line, shaderString;
196
197 while(getline(shaderFile, line)) {
198 shaderString += line + "\n";
199 }
200 shaderFile.close();
201 const char* shaderCString = shaderString.c_str();
202
203 shaderId = glCreateShader(type);
204 glShaderSource(shaderId, 1, &shaderCString, NULL);
205 glCompileShader(shaderId);
206
207 cout << "Loaded successfully" << endl;
208 } else {
209 cout << "Failed to loade the file" << endl;
210 }
211
212 return shaderId;
213}
214
215GLuint createDataBuffer(size_t size, GLfloat* data) {
216 GLuint vbo = 0;
217 glGenBuffers(1, &vbo);
218 glBindBuffer(GL_ARRAY_BUFFER, vbo);
219 glBufferData(GL_ARRAY_BUFFER, size, data, GL_STATIC_DRAW);
220 return vbo;
221}
222
223GLuint createArrayBuffer(GLuint points_vbo, GLuint colors_vbo) {
224 GLuint vao = 0;
225 glGenVertexArrays(1, &vao);
226 glBindVertexArray(vao);
227 glBindBuffer(GL_ARRAY_BUFFER, points_vbo);
228 glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
229 glBindBuffer(GL_ARRAY_BUFFER, colors_vbo);
230 glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, NULL);
231 return vao;
232}
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