main.cpp (11230B)
1 // Dear ImGui: standalone example application for SDL2 + OpenGL 2 // (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.) 3 // (GL3W is a helper library to access OpenGL functions since there is no standard header to access modern OpenGL functions easily. Alternatives are GLEW, Glad, etc.) 4 // If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp. 5 // Read online: https://github.com/ocornut/imgui/tree/master/docs 6 7 #include "imgui.h" 8 #include "imgui_impl_sdl.h" 9 #include "imgui_impl_opengl3.h" 10 #include <stdio.h> 11 #include <SDL.h> 12 13 #if defined(IMGUI_IMPL_OPENGL_ES2) 14 #include <GLES2/gl2.h> 15 // About Desktop OpenGL function loaders: 16 // Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers. 17 // Helper libraries are often used for this purpose! Here we are supporting a few common ones (gl3w, glew, glad). 18 // You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own. 19 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GL3W) 20 #include <GL/gl3w.h> // Initialize with gl3wInit() 21 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW) 22 #include <GL/glew.h> // Initialize with glewInit() 23 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD) 24 #include <glad/glad.h> // Initialize with gladLoadGL() 25 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2) 26 #include <glad/gl.h> // Initialize with gladLoadGL(...) or gladLoaderLoadGL() 27 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2) 28 #define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors. 29 #include <glbinding/Binding.h> // Initialize with glbinding::Binding::initialize() 30 #include <glbinding/gl/gl.h> 31 using namespace gl; 32 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3) 33 #define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors. 34 #include <glbinding/glbinding.h>// Initialize with glbinding::initialize() 35 #include <glbinding/gl/gl.h> 36 using namespace gl; 37 #else 38 #include IMGUI_IMPL_OPENGL_LOADER_CUSTOM 39 #endif 40 41 // Main code 42 int main(int, char**) 43 { 44 // Setup SDL 45 // (Some versions of SDL before <2.0.10 appears to have performance/stalling issues on a minority of Windows systems, 46 // depending on whether SDL_INIT_GAMECONTROLLER is enabled or disabled.. updating to latest version of SDL is recommended!) 47 if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0) 48 { 49 printf("Error: %s\n", SDL_GetError()); 50 return -1; 51 } 52 53 // Decide GL+GLSL versions 54 #if defined(IMGUI_IMPL_OPENGL_ES2) 55 // GL ES 2.0 + GLSL 100 56 const char* glsl_version = "#version 100"; 57 SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0); 58 SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES); 59 SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2); 60 SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0); 61 #elif defined(__APPLE__) 62 // GL 3.2 Core + GLSL 150 63 const char* glsl_version = "#version 150"; 64 SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_FORWARD_COMPATIBLE_FLAG); // Always required on Mac 65 SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE); 66 SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3); 67 SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2); 68 #else 69 // GL 3.0 + GLSL 130 70 const char* glsl_version = "#version 130"; 71 SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, 0); 72 SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE); 73 SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3); 74 SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0); 75 #endif 76 77 // Create window with graphics context 78 SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1); 79 SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24); 80 SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8); 81 SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI); 82 SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+OpenGL3 example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags); 83 SDL_GLContext gl_context = SDL_GL_CreateContext(window); 84 SDL_GL_MakeCurrent(window, gl_context); 85 SDL_GL_SetSwapInterval(1); // Enable vsync 86 87 // Initialize OpenGL loader 88 #if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W) 89 bool err = gl3wInit() != 0; 90 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW) 91 bool err = glewInit() != GLEW_OK; 92 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD) 93 bool err = gladLoadGL() == 0; 94 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2) 95 bool err = gladLoadGL((GLADloadfunc)SDL_GL_GetProcAddress) == 0; // glad2 recommend using the windowing library loader instead of the (optionally) bundled one. 96 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2) 97 bool err = false; 98 glbinding::Binding::initialize(); 99 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3) 100 bool err = false; 101 glbinding::initialize([](const char* name) { return (glbinding::ProcAddress)SDL_GL_GetProcAddress(name); }); 102 #else 103 bool err = false; // If you use IMGUI_IMPL_OPENGL_LOADER_CUSTOM, your loader is likely to requires some form of initialization. 104 #endif 105 if (err) 106 { 107 fprintf(stderr, "Failed to initialize OpenGL loader!\n"); 108 return 1; 109 } 110 111 // Setup Dear ImGui context 112 IMGUI_CHECKVERSION(); 113 ImGui::CreateContext(); 114 ImGuiIO& io = ImGui::GetIO(); (void)io; 115 //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls 116 //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad; // Enable Gamepad Controls 117 118 // Setup Dear ImGui style 119 ImGui::StyleColorsDark(); 120 //ImGui::StyleColorsClassic(); 121 122 // Setup Platform/Renderer backends 123 ImGui_ImplSDL2_InitForOpenGL(window, gl_context); 124 ImGui_ImplOpenGL3_Init(glsl_version); 125 126 // Load Fonts 127 // - 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. 128 // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple. 129 // - 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). 130 // - 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. 131 // - Read 'docs/FONTS.md' for more instructions and details. 132 // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ ! 133 //io.Fonts->AddFontDefault(); 134 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f); 135 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f); 136 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f); 137 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f); 138 //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese()); 139 //IM_ASSERT(font != NULL); 140 141 // Our state 142 bool show_demo_window = true; 143 bool show_another_window = false; 144 ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f); 145 146 // Main loop 147 bool done = false; 148 while (!done) 149 { 150 // Poll and handle events (inputs, window resize, etc.) 151 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs. 152 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application. 153 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application. 154 // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags. 155 SDL_Event event; 156 while (SDL_PollEvent(&event)) 157 { 158 ImGui_ImplSDL2_ProcessEvent(&event); 159 if (event.type == SDL_QUIT) 160 done = true; 161 if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window)) 162 done = true; 163 } 164 165 // Start the Dear ImGui frame 166 ImGui_ImplOpenGL3_NewFrame(); 167 ImGui_ImplSDL2_NewFrame(window); 168 ImGui::NewFrame(); 169 170 // 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!). 171 if (show_demo_window) 172 ImGui::ShowDemoWindow(&show_demo_window); 173 174 // 2. Show a simple window that we create ourselves. We use a Begin/End pair to created a named window. 175 { 176 static float f = 0.0f; 177 static int counter = 0; 178 179 ImGui::Begin("Hello, world!"); // Create a window called "Hello, world!" and append into it. 180 181 ImGui::Text("This is some useful text."); // Display some text (you can use a format strings too) 182 ImGui::Checkbox("Demo Window", &show_demo_window); // Edit bools storing our window open/close state 183 ImGui::Checkbox("Another Window", &show_another_window); 184 185 ImGui::SliderFloat("float", &f, 0.0f, 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f 186 ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color 187 188 if (ImGui::Button("Button")) // Buttons return true when clicked (most widgets return true when edited/activated) 189 counter++; 190 ImGui::SameLine(); 191 ImGui::Text("counter = %d", counter); 192 193 ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate); 194 ImGui::End(); 195 } 196 197 // 3. Show another simple window. 198 if (show_another_window) 199 { 200 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) 201 ImGui::Text("Hello from another window!"); 202 if (ImGui::Button("Close Me")) 203 show_another_window = false; 204 ImGui::End(); 205 } 206 207 // Rendering 208 ImGui::Render(); 209 glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y); 210 glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w); 211 glClear(GL_COLOR_BUFFER_BIT); 212 ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData()); 213 SDL_GL_SwapWindow(window); 214 } 215 216 // Cleanup 217 ImGui_ImplOpenGL3_Shutdown(); 218 ImGui_ImplSDL2_Shutdown(); 219 ImGui::DestroyContext(); 220 221 SDL_GL_DeleteContext(gl_context); 222 SDL_DestroyWindow(window); 223 SDL_Quit(); 224 225 return 0; 226 }