# ImGUI

###### tags: `software` `electrical_system` `NTURT`

## References

* [Dear ImGUi](https://github.com/ocornut/imgui)
* [imgui-SFML](https://github.com/eliasdaler/imgui-sfml) <參考用>

> Note: ImGUI only draw the image and not displaying it, it requires backends that are specific to platforms to actual display to the screen. Since `OpenGL` is one of the most popular cross-plafrom display library, we will use it here.

## How to start using ImGUI ?

### Ubuntu

Install glfw

sudo apt install libglfw3
sudo apt install libglfw3-dev

### On Raspberry Pi

Install glfw

sudo apt install libglfw3
sudo apt install libglfw3-dev

:::warning
Note: Since Raspberry Pi (1~4) only supports OpenGL 2, the backend should choose `imgui_impl_opengl2.h`.
:::

### macOS

1. download **brew** in terminal

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

echo '# Set PATH, MANPATH, etc., for Homebrew.' >> /Users/work/.zprofile                         
echo 'eval "$(/opt/homebrew/bin/brew shellenv)"' >> /Users/work/.zprofile
eval "$(/opt/homebrew/bin/brew shellenv)"

2. install glfw

brew install glfw

3. download **cmake** in terminal

brew install cmake
brew install cmake-docs

### Using cmake to build

From: [csdn](https://blog.csdn.net/u012234115/article/details/118961206)

Add your application at the end of the file

cmake_minimum_required(VERSION 3.8)
project(imgui_test)
set(CMAKE_BUILD_TYPE Release)
set(CMAKE_CXX_STANDARD 17)

if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
        add_compile_options(-Wall -Wextra -Wpedantic)
endif()

# find apple specific graphics library
if(APPLE)
        find_library(OPENGL_LIBRARY OpenGL REQUIRED)
        find_library(COCOA_LIBRARY Cocoa REQUIRED)
        find_library(IOKIT_LIBRARY IOKit REQUIRED)
        find_library(COREVID_LIBRARY CoreVideo REQUIRED)
endif()

# imgui includes
include_directories(
        imgui
        imgui/backends
)

# pull apple global includes
if(APPLE)
        include_directories(
                /usr/local/include
                /opt/local/include
                /opt/homebrew/include
        )
endif()

# set common imgui sources
file(GLOB IMGUI_SRC
        imgui/*.h
        imgui/*.cpp
)

# set platform specific imgui sources
if(WIN32)
        file(GLOB IMGUI_PLATFORM_SRC
                imgui/backends/imgui_impl_win32.*
                imgui/backends/imgui_impl_dx12.*
        )
elseif(UNIX)
        add_definitions(-DIMGUI_IMPL_OPENGL_LOADER_GL3W)

        include_directories(
                imgui/examples/libs/gl3w
        )

        file(GLOB IMGUI_PLATFORM_SRC
                imgui/examples/libs/gl3w/GL/gl3w.*
                imgui/backends/imgui_impl_glfw.*
                imgui/backends/imgui_impl_opengl2.*
        )
endif()

# link apple globle libraries
if(APPLE)
        link_directories(
                /usr/local/lib
                /opt/local/lib
                /opt/homebrew/lib
        )
endif()

# library: imgui
add_library(imgui
        ${IMGUI_SRC}
        ${IMGUI_PLATFORM_SRC}
)

# link to platform specific libraries
if(WIN32)
        target_link_libraries(imgui
                d3d12.lib
                d3compiler.lib
                dxgi.lib
        )
elseif(APPLE)
        target_link_libraries(imgui
                ${OPENGL_LIBRARY}
                ${COCOA_LIBRARY}
                ${IOKIT_LIBRARY}
                ${COREVID_LIBRARY}
                glfw
        )
elseif(UNIX AND NOT APPLE)
        target_link_libraries(imgui
                GL
                glfw
                dl
        )
endif()

add_executable(${PROJECT_NAME}
        src/main.cpp
)
target_link_libraries(${PROJECT_NAME}
        imgui
)