1 // dear imgui: standalone example application for GLFW + OpenGL2, using legacy fixed pipeline
2 // If you are new to dear imgui, see examples/README.txt and documentation at the top of imgui.cpp.
3 // (GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
4
5 // **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)**
6 // **Prefer using the code in the example_glfw_opengl2/ folder**
7 // See imgui_impl_glfw.cpp for details.
8
9 #include "imgui.h"
10 #include "imgui_impl_glfw.h"
11 #include "imgui_impl_opengl2.h"
12 #include <stdio.h>
13 #include <GLFW/glfw3.h>
14
15 // [Win32] Our example includes a copy of glfw3.lib pre-compiled with VS2010 to maximize ease of testing and compatibility with old VS compilers.
16 // To link with VS2010-era libraries, VS2015+ requires linking with legacy_stdio_definitions.lib, which we do using this pragma.
17 // 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.
18 #if defined(_MSC_VER) && (_MSC_VER >= 1900) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS)
19 #pragma comment(lib, "legacy_stdio_definitions")
20 #endif
21
glfw_error_callback(int error,const char * description)22 static void glfw_error_callback(int error, const char* description)
23 {
24 fprintf(stderr, "Glfw Error %d: %s\n", error, description);
25 }
26
main(int,char **)27 int main(int, char**)
28 {
29 // Setup window
30 glfwSetErrorCallback(glfw_error_callback);
31 if (!glfwInit())
32 return 1;
33 GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+OpenGL2 example", NULL, NULL);
34 if (window == NULL)
35 return 1;
36 glfwMakeContextCurrent(window);
37 glfwSwapInterval(1); // Enable vsync
38
39 // Setup Dear ImGui context
40 IMGUI_CHECKVERSION();
41 ImGui::CreateContext();
42 ImGuiIO& io = ImGui::GetIO(); (void)io;
43 //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls
44 //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad; // Enable Gamepad Controls
45
46 // Setup Dear ImGui style
47 ImGui::StyleColorsDark();
48 //ImGui::StyleColorsClassic();
49
50 // Setup Platform/Renderer bindings
51 ImGui_ImplGlfw_InitForOpenGL(window, true);
52 ImGui_ImplOpenGL2_Init();
53
54 // Load Fonts
55 // - 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.
56 // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
57 // - 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).
58 // - 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.
59 // - Read 'misc/fonts/README.txt' for more instructions and details.
60 // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
61 //io.Fonts->AddFontDefault();
62 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
63 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
64 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
65 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f);
66 //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
67 //IM_ASSERT(font != NULL);
68
69 bool show_demo_window = true;
70 bool show_another_window = false;
71 ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
72
73 // Main loop
74 while (!glfwWindowShouldClose(window))
75 {
76 // Poll and handle events (inputs, window resize, etc.)
77 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
78 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
79 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
80 // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
81 glfwPollEvents();
82
83 // Start the Dear ImGui frame
84 ImGui_ImplOpenGL2_NewFrame();
85 ImGui_ImplGlfw_NewFrame();
86 ImGui::NewFrame();
87
88 // 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!).
89 if (show_demo_window)
90 ImGui::ShowDemoWindow(&show_demo_window);
91
92 // 2. Show a simple window that we create ourselves. We use a Begin/End pair to created a named window.
93 {
94 static float f = 0.0f;
95 static int counter = 0;
96
97 ImGui::Begin("Hello, world!"); // Create a window called "Hello, world!" and append into it.
98
99 ImGui::Text("This is some useful text."); // Display some text (you can use a format strings too)
100 ImGui::Checkbox("Demo Window", &show_demo_window); // Edit bools storing our window open/close state
101 ImGui::Checkbox("Another Window", &show_another_window);
102
103 ImGui::SliderFloat("float", &f, 0.0f, 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f
104 ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color
105
106 if (ImGui::Button("Button")) // Buttons return true when clicked (most widgets return true when edited/activated)
107 counter++;
108 ImGui::SameLine();
109 ImGui::Text("counter = %d", counter);
110
111 ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
112 ImGui::End();
113 }
114
115 // 3. Show another simple window.
116 if (show_another_window)
117 {
118 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)
119 ImGui::Text("Hello from another window!");
120 if (ImGui::Button("Close Me"))
121 show_another_window = false;
122 ImGui::End();
123 }
124
125 // Rendering
126 ImGui::Render();
127 int display_w, display_h;
128 glfwGetFramebufferSize(window, &display_w, &display_h);
129 glViewport(0, 0, display_w, display_h);
130 glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
131 glClear(GL_COLOR_BUFFER_BIT);
132 //glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound, but prefer using the GL3+ code.
133 ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
134
135 glfwMakeContextCurrent(window);
136 glfwSwapBuffers(window);
137 }
138
139 // Cleanup
140 ImGui_ImplOpenGL2_Shutdown();
141 ImGui_ImplGlfw_Shutdown();
142 ImGui::DestroyContext();
143
144 glfwDestroyWindow(window);
145 glfwTerminate();
146
147 return 0;
148 }
149