开发语言 【C++】开源：ImGui图形用户界面库配置与使用

★,°:.☆(￣▽￣)/$:.°★  这篇文章主要介绍ImGui图形用户界面库配置与使用。 无专精则不能成，无涉猎则不能通。——梁启超 欢迎来到我的博客，一起学习，共同进步。 喜欢的朋友可以关注一下，下次更新不迷路丹

文章目录

:smirk:1. 项目介绍:blush:2. 环境配置:satisfied:3. 使用说明

1. 项目介绍

项目Github地址：https://github.com/ocornut/imgui

Dear ImGui (ImGui) 是一个开源的、用 C++ 编写的图形用户界面（GUI）库。它由OCornut创建，旨在为应用程序和工具提供创建用户界面的简单高效的方式。

以下是 Dear ImGui 的一些主要特性和特点：

1.即时模式 GUI：ImGui 遵循即时模式 GUI 的范例，用户界面不是通过保留模式或对象层次结构构建的。相反，每一帧都需要重新创建和绘制用户界面。这种设计使得创建和更新界面变得非常灵活和直观。

2.轻量级和可嵌入性：ImGui 是一个轻量级库，只有几个文件组成，可轻松嵌入到现有项目中。它没有任何外部依赖，使得集成和部署变得非常简单。

3.跨平台支持：ImGui 可以在多个平台上运行，包括 Windows、MacOS、Linux 和其他一些操作系统。它提供了与底层图形 API（如OpenGL、DirectX）的集成，以便在不同平台上绘制用户界面。

4.简单易用的 API：ImGui 提供了一个简单直观的 API，使得创建用户界面变得非常容易。您可以使用各种控件（如按钮、文本框、滑块等）来构建界面，并通过监听用户输入和响应事件来实现交互。

5.自定义性强：ImGui 具有强大的自定义能力，您可以自定义主题、样式和控件外观以满足您的需求。此外，您还可以编写自定义的渲染器，以实现与不同图形 API 的集成。

Dear ImGui 是一个简单、灵活且强大的 GUI 库，适用于各种应用程序和工具的用户界面开发。无论是创建原型、调试工具还是构建实际应用程序，它都提供了一套方便的工具和框架来简化界面开发过程。

2. 环境配置

下面进行环境配置：

# windows vs

# windows端需要预装directx，VS的Kit中默认会有

# 源码中的example下有示例VS工程(.sln)，下载源码后直接用VS打开运行

# windows clion

# CMakeLists.txt示例，提前装好了glfw+glad+freeglut+opencv

cmake_minimum_required(VERSION 3.19)

project(opengl_demo)

set(CMAKE_CXX_STANDARD 14)

include_directories("./env/include")

link_directories("./env/lib")

include_directories("./env/imgui")

include_directories("./env/imgui/backends")

set(OpenCV_DIR "D:/develop/opencv341_mingw/x64/mingw/lib")

find_package(OpenCV 3 REQUIRED)

MESSAGE("OpenCV version : ${OpenCV_VERSION}")

include_directories(${OpenCV_INCLUDE_DIRS})

link_directories(${OpenCV_LIBRARIES}) # ${OpenCV_LIB_DIR}

file(GLOB IMGUI "./env/imgui/*.cpp") # 1.80

add_executable(opengl_demo main.cpp env/glad.c ${IMGUI})

target_link_libraries(opengl_demo

glfw3 # 3.3.9

opengl32

freeglut # 3.4.0

glu32

${OpenCV_LIBRARIES}

xinput

)

# ubuntu cmake

sudo apt install libglfw3 libglfw3-dev # 安装glfw

# 一个博主已经写了一个基于cmake的示例，这里引用一下 http://t.csdnimg.cn/LDY5H

https://github.com/tashaxing/imgui_cmake_starter

# 包含了imgui 1.83的源码和示例程序，直接编译即可

3. 使用说明

运行示例：

windows VS直接生成运行即可，ubuntu下cmake编译指令如下：

mkdir build && cd build

cmake ..

make

./imgui_cmake_starter

Imgui的示例代码：

#include "imgui.h"

#include "imgui_impl_glfw.h"

#include "imgui_impl_opengl3.h"

#include

#if defined(IMGUI_IMPL_OPENGL_ES2)

#include

// About Desktop OpenGL function loaders:

// Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.

// Helper libraries are often used for this purpose! Here we are supporting a few common ones (gl3w, glew, glad).

// You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)

#include // Initialize with gl3wInit()

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)

#include // Initialize with glewInit()

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)

#include // Initialize with gladLoadGL()

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)

#include // Initialize with gladLoadGL(...) or gladLoaderLoadGL()

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)

#define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.

#include // Initialize with glbinding::Binding::initialize()

#include

using namespace gl;

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)

#define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.

#include // Initialize with glbinding::initialize()

#include

using namespace gl;

#else

#include IMGUI_IMPL_OPENGL_LOADER_CUSTOM

#endif

// Include glfw3.h after our OpenGL definitions

#include

// [Win32] Our example includes a copy of glfw3.lib pre-compiled with VS2010 to maximize ease of testing and compatibility with old VS compilers.

// To link with VS2010-era libraries, VS2015+ requires linking with legacy_stdio_definitions.lib, which we do using this pragma.

// 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.

#if defined(_MSC_VER) && (_MSC_VER >= 1900) && !defined(IMGUI_DISABLE_WIN32_FUNCTIONS)

#pragma comment(lib, "legacy_stdio_definitions")

#endif

static void glfw_error_callback(int error, const char* description)

{

fprintf(stderr, "Glfw Error %d: %s\n", error, description);

}

int main(int argc, char** argv)

{

// Setup window

glfwSetErrorCallback(glfw_error_callback);

if (!glfwInit())

return 1;

// Decide GL+GLSL versions

#if defined(IMGUI_IMPL_OPENGL_ES2)

// GL ES 2.0 + GLSL 100

const char* glsl_version = "#version 100";

glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);

glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);

glfwWindowHint(GLFW_CLIENT_API, GLFW_OPENGL_ES_API);

#elif defined(__APPLE__)

// GL 3.2 + GLSL 150

const char* glsl_version = "#version 150";

glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);

glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);

glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // 3.2+ only

glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // Required on Mac

#else

// GL 3.0 + GLSL 130

const char* glsl_version = "#version 130";

glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);

glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);

//glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); // 3.2+ only

//glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE); // 3.0+ only

#endif

// Create window with graphics context

GLFWwindow* window = glfwCreateWindow(1280, 720, "Dear ImGui GLFW+OpenGL3 example", NULL, NULL);

if (window == NULL)

return 1;

glfwMakeContextCurrent(window);

glfwSwapInterval(1); // Enable vsync

// Initialize OpenGL loader

#if defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)

bool err = gl3wInit() != 0;

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)

bool err = glewInit() != GLEW_OK;

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)

bool err = gladLoadGL() == 0;

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)

bool err = gladLoadGL(glfwGetProcAddress) == 0; // glad2 recommend using the windowing library loader instead of the (optionally) bundled one.

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)

bool err = false;

glbinding::Binding::initialize();

#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)

bool err = false;

glbinding::initialize([](const char* name) { return (glbinding::ProcAddress)glfwGetProcAddress(name); });

#else

bool err = false; // If you use IMGUI_IMPL_OPENGL_LOADER_CUSTOM, your loader is likely to requires some form of initialization.

#endif

if (err)

{

fprintf(stderr, "Failed to initialize OpenGL loader!\n");

return 1;

}

// Setup Dear ImGui context

IMGUI_CHECKVERSION();

ImGui::CreateContext();

ImGuiIO& io = ImGui::GetIO(); (void)io;

//io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls

//io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad; // Enable Gamepad Controls

// Setup Dear ImGui style

ImGui::StyleColorsDark();

//ImGui::StyleColorsClassic();

// Setup Platform/Renderer backends

ImGui_ImplGlfw_InitForOpenGL(window, true);

ImGui_ImplOpenGL3_Init(glsl_version);

// Load Fonts

// - 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.

// - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.

// - 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).

// - 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.

// - Read 'docs/FONTS.md' for more instructions and details.

// - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !

//io.Fonts->AddFontDefault();

//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);

//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);

//io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);

//io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f);

//ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());

//IM_ASSERT(font != NULL);

// Our state

bool show_demo_window = true;

bool show_another_window = false;

ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);

// Main loop

while (!glfwWindowShouldClose(window))

{

// Poll and handle events (inputs, window resize, etc.)

// You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.

// - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.

// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.

// Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.

glfwPollEvents();

// Start the Dear ImGui frame

ImGui_ImplOpenGL3_NewFrame();

ImGui_ImplGlfw_NewFrame();

ImGui::NewFrame();

// 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!).

if (show_demo_window)

ImGui::ShowDemoWindow(&show_demo_window);

// 2. Show a simple window that we create ourselves. We use a Begin/End pair to created a named window.

{

static float f = 0.0f;

static int counter = 0;

ImGui::Begin("Hello, world!"); // Create a window called "Hello, world!" and append into it.

ImGui::Text("This is some useful text."); // Display some text (you can use a format strings too)

ImGui::Checkbox("Demo Window", &show_demo_window); // Edit bools storing our window open/close state

ImGui::Checkbox("Another Window", &show_another_window);

ImGui::SliderFloat("float", &f, 0.0f, 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f

ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color

if (ImGui::Button("Button")) // Buttons return true when clicked (most widgets return true when edited/activated)

counter++;

ImGui::SameLine();

ImGui::Text("counter = %d", counter);

ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);

ImGui::End();

}

// 3. Show another simple window.

if (show_another_window)

{

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)

ImGui::Text("Hello from another window!");

if (ImGui::Button("Close Me"))

show_another_window = false;

ImGui::End();

}

// Rendering

ImGui::Render();

int display_w, display_h;

glfwGetFramebufferSize(window, &display_w, &display_h);

glViewport(0, 0, display_w, display_h);

glClearColor(clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w);

glClear(GL_COLOR_BUFFER_BIT);

ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

glfwSwapBuffers(window);

}

// Cleanup

ImGui_ImplOpenGL3_Shutdown();

ImGui_ImplGlfw_Shutdown();

ImGui::DestroyContext();

glfwDestroyWindow(window);

glfwTerminate();

return 0;

}

以上。

参考文章

 您阅读本篇文章共花了：