1 // Dear ImGui: standalone example application for GLFW + OpenGL 3, using programmable pipeline
2 // (GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
3 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
4 // Read online: https://github.com/ocornut/imgui/tree/master/docs
5
6 #include "imgui.h"
7 #include "imgui_impl_glfw.h"
8 #include "imgui_impl_opengl3.h"
9 #include <stdio.h>
10
11 #if defined(IMGUI_IMPL_OPENGL_ES2)
12 #include <GLES2/gl2.h>
13 // About Desktop OpenGL function loaders:
14 // Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.
15 // Helper libraries are often used for this purpose! Here we are supporting a few common ones (gl3w, glew, glad).
16 // You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.
17 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
18 #include <GL/gl3w.h> // Initialize with gl3wInit()
19 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
20 #include <GL/glew.h> // Initialize with glewInit()
21 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
22 #include <glad/glad.h> // Initialize with gladLoadGL()
23 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
24 #include <glad/gl.h> // Initialize with gladLoadGL(...) or gladLoaderLoadGL()
25 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
26 #define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
27 #include <glbinding/Binding.h> // Initialize with glbinding::Binding::initialize()
28 #include <glbinding/gl/gl.h>
29 using namespace gl;
30 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
31 #define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
32 #include <glbinding/glbinding.h>// Initialize with glbinding::initialize()
33 #include <glbinding/gl/gl.h>
34 using namespace gl;
35 #else
36 #include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
37 #endif
38
39 // Include glfw3.h after our OpenGL definitions
40 #include <GLFW/glfw3.h>
41
42 // [Win32] Our example includes a copy of glfw3.lib pre-compiled with VS2010 to maximize ease of testing and compatibility with old VS compilers.
43 // To link with VS2010-era libraries, VS2015+ requires linking with legacy_stdio_definitions.lib, which we do using this pragma.
44 // Your own project should not be affected, as you are likely to link with a newer binary of GLFW that is adequate for your version of Visual Studio.
45 #if defined(_MSC_VER) && (_MSC_VER >= 1900) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS)
46 #pragma comment(lib, "legacy_stdio_definitions")
47 #endif
48
glfw_error_callback(int error,const char * description)49 static void glfw_error_callback(int error, const char* description)
50 {
51 fprintf(stderr, "Glfw Error %d: %s\n", error, description);
52 }
53
main(int,char **)54 int main(int, char**)
55 {
56 // Setup window
57 glfwSetErrorCallback(glfw_error_callback);
58 if (!glfwInit())
59 return 1;
60
61 // Decide GL+GLSL versions
62 #if defined(IMGUI_IMPL_OPENGL_ES2)
63 // GL ES 2.0 + GLSL 100
64 const char* glsl_version = "#version 100";
65 glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
66 glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
67 glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);
68 #elif defined(__APPLE__)
69 // GL 3.2 + GLSL 150
70 const char* glsl_version = "#version 150";
71 glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
72 glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
73 glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // 3.2+ only
74 glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // Required on Mac
75 #else
76 // GL 3.0 + GLSL 130
77 const char* glsl_version = "#version 130";
78 glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
79 glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
80 //glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // 3.2+ only
81 //glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // 3.0+ only
82 #endif
83
84 // Create window with graphics context
85 GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+OpenGL3 example", NULL, NULL);
86 if (window == NULL)
87 return 1;
88 glfwMakeContextCurrent(window);
89 glfwSwapInterval(1); // Enable vsync
90
91 // Initialize OpenGL loader
92 #if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
93 bool err = gl3wInit() != 0;
94 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
95 bool err = glewInit() != GLEW_OK;
96 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
97 bool err = gladLoadGL() == 0;
98 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
99 bool err = gladLoadGL(glfwGetProcAddress) == 0; // glad2 recommend using the windowing library loader instead of the (optionally) bundled one.
100 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
101 bool err = false;
102 glbinding::Binding::initialize();
103 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
104 bool err = false;
105 glbinding::initialize([](const char* name) { return (glbinding::ProcAddress)glfwGetProcAddress(name); });
106 #else
107 bool err = false; // If you use IMGUI_IMPL_OPENGL_LOADER_CUSTOM, your loader is likely to requires some form of initialization.
108 #endif
109 if (err)
110 {
111 fprintf(stderr, "Failed to initialize OpenGL loader!\n");
112 return 1;
113 }
114
115 // Setup Dear ImGui context
116 IMGUI_CHECKVERSION();
117 ImGui::CreateContext();
118 ImGuiIO& io = ImGui::GetIO(); (void)io;
119 io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls
120 //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad; // Enable Gamepad Controls
121 io.ConfigFlags |= ImGuiConfigFlags_DockingEnable; // Enable Docking
122 io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable; // Enable Multi-Viewport / Platform Windows
123 //io.ConfigViewportsNoAutoMerge = true;
124 //io.ConfigViewportsNoTaskBarIcon = true;
125
126 // Setup Dear ImGui style
127 ImGui::StyleColorsDark();
128 //ImGui::StyleColorsClassic();
129
130 // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
131 ImGuiStyle& style = ImGui::GetStyle();
132 if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
133 {
134 style.WindowRounding = 0.0f;
135 style.Colors[ImGuiCol_WindowBg].w = 1.0f;
136 }
137
138 // Setup Platform/Renderer backends
139 ImGui_ImplGlfw_InitForOpenGL(window, true);
140 ImGui_ImplOpenGL3_Init(glsl_version);
141
142 // Load Fonts
143 // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
144 // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
145 // - If the file cannot be loaded, the function will return NULL. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
146 // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
147 // - Read 'docs/FONTS.md' for more instructions and details.
148 // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
149 //io.Fonts->AddFontDefault();
150 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
151 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
152 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
153 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f);
154 //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
155 //IM_ASSERT(font != NULL);
156
157 // Our state
158 bool show_demo_window = true;
159 bool show_another_window = false;
160 ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
161
162 // Main loop
163 while (!glfwWindowShouldClose(window))
164 {
165 // Poll and handle events (inputs, window resize, etc.)
166 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
167 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
168 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
169 // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
170 glfwPollEvents();
171
172 // Start the Dear ImGui frame
173 ImGui_ImplOpenGL3_NewFrame();
174 ImGui_ImplGlfw_NewFrame();
175 ImGui::NewFrame();
176
177 // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
178 if (show_demo_window)
179 ImGui::ShowDemoWindow(&show_demo_window);
180
181 // 2. Show a simple window that we create ourselves. We use a Begin/End pair to created a named window.
182 {
183 static float f = 0.0f;
184 static int counter = 0;
185
186 ImGui::Begin("Hello, world!"); // Create a window called "Hello, world!" and append into it.
187
188 ImGui::Text("This is some useful text."); // Display some text (you can use a format strings too)
189 ImGui::Checkbox("Demo Window", &show_demo_window); // Edit bools storing our window open/close state
190 ImGui::Checkbox("Another Window", &show_another_window);
191
192 ImGui::SliderFloat("float", &f, 0.0f, 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f
193 ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
194
195 if (ImGui::Button("Button")) // Buttons return true when clicked (most widgets return true when edited/activated)
196 counter++;
197 ImGui::SameLine();
198 ImGui::Text("counter = %d", counter);
199
200 ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
201 ImGui::End();
202 }
203
204 // 3. Show another simple window.
205 if (show_another_window)
206 {
207 ImGui::Begin("Another Window", &show_another_window); // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
208 ImGui::Text("Hello from another window!");
209 if (ImGui::Button("Close Me"))
210 show_another_window = false;
211 ImGui::End();
212 }
213
214 // Rendering
215 ImGui::Render();
216 int display_w, display_h;
217 glfwGetFramebufferSize(window, &display_w, &display_h);
218 glViewport(0, 0, display_w, display_h);
219 glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);
220 glClear(GL_COLOR_BUFFER_BIT);
221 ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
222
223 // Update and Render additional Platform Windows
224 // (Platform functions may change the current OpenGL context, so we save/restore it to make it easier to paste this code elsewhere.
225 // For this specific demo app we could also call glfwMakeContextCurrent(window) directly)
226 if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
227 {
228 GLFWwindow* backup_current_context = glfwGetCurrentContext();
229 ImGui::UpdatePlatformWindows();
230 ImGui::RenderPlatformWindowsDefault();
231 glfwMakeContextCurrent(backup_current_context);
232 }
233
234 glfwSwapBuffers(window);
235 }
236
237 // Cleanup
238 ImGui_ImplOpenGL3_Shutdown();
239 ImGui_ImplGlfw_Shutdown();
240 ImGui::DestroyContext();
241
242 glfwDestroyWindow(window);
243 glfwTerminate();
244
245 return 0;
246 }
247