在 https://github.com/ocornut/imgui 上写着：
不需要特定的构建过程。您可以将 .cpp 文件添加到现有项目中。
我尝试使用带有相关
.cppUndefined Reference to ... errorsimgui.cpp|1994|undefined reference to `ImGui::InputText(char const*, char*, unsigned long, int, int (*)(ImGuiInputTextCallbackData*), void*)'
这是我尝试过的代码：
#include "imgui.h"
int main()
{
bool my_tool_active = true;
float my_color = 0.5;
// Create a window called "My First Tool", with a menu bar.
ImGui::Begin("My First Tool", &my_tool_active, ImGuiWindowFlags_MenuBar);
if (ImGui::BeginMenuBar())
{
if (ImGui::BeginMenu("File"))
{
if (ImGui::MenuItem("Open..", "Ctrl+O")) { /* Do stuff */ }
if (ImGui::MenuItem("Save", "Ctrl+S")) { /* Do stuff */ }
if (ImGui::MenuItem("Close", "Ctrl+W")) { my_tool_active = false; }
ImGui::EndMenu();
}
ImGui::EndMenuBar();
}
// Edit a color (stored as ~4 floats)
ImGui::ColorEdit4("Color", &my_color);
// Plot some values
const float my_values[] = { 0.2f, 0.1f, 1.0f, 0.5f, 0.9f, 2.2f };
ImGui::PlotLines("Frame Times", my_values, IM_ARRAYSIZE(my_values));
// Display contents in a scrolling region
ImGui::TextColored(ImVec4(1,1,0,1), "Important Stuff");
ImGui::BeginChild("Scrolling");
for (int n = 0; n < 50; n++)
ImGui::Text("%04d: Some text", n);
ImGui::EndChild();
ImGui::End();
return 0;
}
我错过了什么？我在网页上找不到任何链接器命令（根据我的经验，“未定义的引用...”通常是缺少链接器选项的结果）
我在编译 imgui 时遇到了一些问题，但一旦你得到它，事情就没那么复杂了。
首先你需要了解你需要什么样的设置，在我的例子中，我在 gentoo linux 上使用 gnome 和 wayland，所以我想将 imgui 与 opengl 和 glfw 一起使用，所以通过 https://github 上的入门文档。 com/ocornut/imgui/wiki/Getting-Started 我知道我需要包含以下内容
backends/imgui_impl_glfw.hbackends/imgui_impl_opengl3.h然后我实际上只是复制了其中一个示例以使其正常工作，只需将 main 函数更改为 imgui_main 以便在我的原始 cpp 文件上手动运行它：
#include "my_imgui.h"
// Dear ImGui: standalone example application for GLFW + OpenGL 3, using programmable pipeline
// (GLFW is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
// Learn about Dear ImGui:
// - FAQ https://dearimgui.com/faq
// - Getting Started https://dearimgui.com/getting-started
// - Documentation https://dearimgui.com/docs (same as your local docs/ folder).
// - Introduction, links and more at the top of imgui.cpp
#include "imgui.h"
#include "backends/imgui_impl_glfw.h"
#include "backends/imgui_impl_opengl3.h"
#include <cstdio>
#define GL_SILENCE_DEPRECATION
#if defined(IMGUI_IMPL_OPENGL_ES2)
#include <GLES2/gl2.h>
#endif
#include <GLFW/glfw3.h> // Will drag system OpenGL headers
// [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
// This example can also compile and run with Emscripten! See 'Makefile.emscripten' for details.
#ifdef __EMSCRIPTEN__
#include "../libs/emscripten/emscripten_mainloop_stub.h"
#endif
static void glfw_error_callback(int error, const char* description)
{
fprintf(stderr, "GLFW Error %d: %s\n", error, description);
}
// Main code
int imgui_main(int, char**)
{
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", nullptr, nullptr);
if (window == nullptr)
return 1;
glfwMakeContextCurrent(window);
glfwSwapInterval(1); // Enable vsync
// 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::StyleColorsLight();
// 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 a nullptr. 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.
// - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
// - 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 \\ !
// - Our Emscripten build process allows embedding fonts to be accessible at runtime from the "fonts/" folder. See Makefile.emscripten for details.
//io.Fonts->AddFontDefault();
//io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
//ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
//IM_ASSERT(font != nullptr);
// 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
#ifdef __EMSCRIPTEN__
// For an Emscripten build we are disabling file-system access, so let's not attempt to do a fopen() of the imgui.ini file.
// You may manually call LoadIniSettingsFromMemory() to load settings from your own storage.
io.IniFilename = nullptr;
EMSCRIPTEN_MAINLOOP_BEGIN
#else
while (!glfwWindowShouldClose(window))
#endif
{
// 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, or clear/overwrite your copy of the mouse data.
// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
// 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 create 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 / io.Framerate, io.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);
}
#ifdef __EMSCRIPTEN__
EMSCRIPTEN_MAINLOOP_END;
#endif
// Cleanup
ImGui_ImplOpenGL3_Shutdown();
ImGui_ImplGlfw_Shutdown();
ImGui::DestroyContext();
glfwDestroyWindow(window);
glfwTerminate();
return 0;
}
因此，如果我将此示例写入
features/imgui/my_imgui.cppmy_imgui.h我将外部imgui库放置在
PROJECT_SRC/extern/imgui现在是
CMakeList.txt你可以按照你想要的方式做，我是新手
CMakeList.txt所以我创建了一个默认启用的选项
imguioption(F_IMGUI "imgui Support" ON)
在我的 make cmakelists 文件中，我找到 opengl 和 glfw3 软件包，并将
extern/imguiif (F_IMGUI)
find_package(OpenGL REQUIRED)
find_package(glfw3 3.3 REQUIRED)
include_directories(${PROJECT_SOURCE_DIR}/extern/imgui)
endif()
在
srcif (F_IMGUI)
target_link_libraries(tux_music_studio_server_cpp PRIVATE
OpenGL::GL)
target_link_libraries(tux_music_studio_server_cpp PRIVATE
glfw)
target_sources(tux_music_studio_server_cpp PRIVATE
${PROJECT_SOURCE_DIR}/extern/imgui/imgui.cpp
${PROJECT_SOURCE_DIR}/extern/imgui/imgui_demo.cpp
${PROJECT_SOURCE_DIR}/extern/imgui/imgui_draw.cpp
${PROJECT_SOURCE_DIR}/extern/imgui/imgui_widgets.cpp
${PROJECT_SOURCE_DIR}/extern/imgui/imgui_tables.cpp
${PROJECT_SOURCE_DIR}/extern/imgui/backends/imgui_impl_glfw.cpp
${PROJECT_SOURCE_DIR}/extern/imgui/backends/imgui_impl_opengl3.cpp
)
target_sources(tux_music_studio_server_cpp PRIVATE
features/imgui/my_imgui.cpp
features/imgui/my_imgui.h
)
endif()
现在，如果你得到
undefined reference如果您遇到分段错误，只要您正确遵循他们的入门指南，我会尝试不同的选项，vulkan 而不是 opengl，或任何其他可用的选项（我不太确定您在什么操作系统上）开）。
在我的示例中，我将 gtx3060 与 wayland 一起使用，因此除了 opengl 和 glfw 与 imgui 之外，我实际上没有太多选择，但如果在我的情况下它也会导致分段错误，那么我会创建一个简单的 hello world 示例每种技术单独，在这种情况下，我将尝试分别编译和运行 opengl 和 glfw 的 hello world 示例，也许其中之一会出现段错误，所以至少我会获得更多信息并从那里继续。
我真的很喜欢imgui，我相信你也会玩得开心。
DearImgui 需要一个“渲染器”才能在屏幕上实际绘制内容。从源代码的外观来看，您没有在源代码中的 imgui.h 之后包含那些“渲染器”的实现
有很多事情可能会出错。这是一个简单的清单：
imgui(.cpp & .h)
imgui_internal.h
imgui_draw.cpp
imgui_widgets.cpp
imgui_tables.cpp
2）选择您的后端，并包含相应的 .cpp 文件（它们位于“backends”文件夹中。 例如，对于 opengl3 + glfw，您需要将它们添加到 CB 项目中：
imgui_impl_openlg3(.cpp & .h)
imgui_impl_opengl3_loader.h
imgui_impl_glfw(.cpp & .h)
#include "imgui.h"
/* this block of code will change depending on the renderer you use
#include "imgui_impl_opengl3.h"
#include "imgui_impl_glfw.h"
#include "GLFW/glfw"
*/
//your code here
4）如果您是第一次这样做，链接错误很可能来自您正在使用的渲染器。 例如，对于 opengl3+glfw，将以下参数添加到 CB 中的链接器设置中：
libopengl32.a
libgflw3.a
libgdi32.a