mjkosmic / jimgui

:sparkling_heart: Pure Java binding for dear-imgui

jimgui

Linux Build	Windows Build

Cross-platform efficient pure Java binding for dear-imgui, Kotlin is used as code generation tool.

This project is created for a code editor and a game engine, both not open-sourced currently. You can find jimgui on Maven Repositories.

For macOS users, add -XstartOnFirstThread JVM argument when running programs built with jimgui.

Demo

• Partly re-implementation of imgui_demo.cpp.
• A sample text editor

Progress

• ImGui namespace getter/setter/function/javadoc generation
• ImGuiFontAtlas/ImGuiStyle/ImGuiFont/ImGuiIO/ImGuiDrawList properties getter/setter/function/javadoc generation
• ImGui*Flags copy-pasted constant/javadoc
• ImStyleVar keys using generic parameter as type constraint (type safe!)
• Functions to access and modify platform window size/pos
• Use MagicConstant annotation to specify where the constant parameters are from (IntelliJ IDEA understands this!)
  • Generate functions with MagicConstant annotation
• Native value pointer (bool *, int *, float *) wrappers, providing accessValue and modifyValue
• ImVec4 wrapper with optional mutability
• Critical Native function generations
• ImTextureID wrapper with platform-dependent implementations
  • LPDIRECT3DTEXTURE9 on WindowsXP+
  • GLuint on MacOS/Linux
• Linux native library with glfw3 + opengl3 implementation
  • 32-bit hosted on ?
  • 64-bit hosted on CircleCI
• WindowsXP+ native library
  • with glfw + opengl3 implementation
    • 32-bit hosted on ?
    • 64-bit hosted on my laptop
  • with directX9 implementation
    • 32-bit hosted on AppVeyor
    • 64-bit hosted on AppVeyor
• MacOS native library with Cocoa, glut as additions to Linux implementation
  • hosted on @zxj5470 's Mac laptop

Usage

Remember to add jcenter to your repositories.

Code example

import org.ice1000.jimgui.JImGui;
import org.ice1000.jimgui.util.JniLoader;

public class Main {
	public static void main(String... args){
		JniLoader.load();
		try (JImGui imGui = new JImGui()) {
			// load fonts, global initializations, etc.
			imGui.initBeforeMainLoop();
			while (!imGui.windowShouldClose()) {
				// some drawing-irrelated initializations
				// mostly do nothing here
				imGui.initNewFrame();
				// draw your widgets here, like this
				imGui.text("Hello, World!");
				imGui.render();
			}
		}
	}
}

Notice that jimgui uses a not-very-efficient way to convert java.lang.String into byte arrays that C++ is happy with. You can customize the string-to-bytes function yourself by using org.ice1000.jimgui.util.JImGuiUtil.setStringToBytes, or use the more efficient alternative to java.lang.String -- org.ice1000.jimgui.JImStr, which is supposed to be created as global constants.

Using Unicode strings

You can use ImGuiFontAtlas in order to extend glyph ranges for your font, which is needed if you want to display Unicode characters. You can find more info about glyph ranges at the dear-imgui repository.

Notice that in order to display Unicode characters you need to have your Java sources encoded and compiled as UTF-8. To compile the sources as UTF-8, add the following line to your build.gradle:

compileJava.options.encoding = 'UTF-8'

Gradle

import org.gradle.internal.os.OperatingSystem
// ...
repositories {
    // ...
    jcenter()
}
// ...
dependencies {
  String jimgui_version = 'v0.9'
  compile "org.ice1000.jimgui:core:$jimgui_version" // basic functionality
  compile "org.ice1000.jimgui:kotlin-dsl:$jimgui_version" // kotlin dsl wrapper
}
// ...
run {
  if (OperatingSystem.current() == OperatingSystem.MAC_OS) {
    jvmArgs "-XstartOnFirstThread"
  }
}

Gradle Kotlin DSL

dependencies {
  val jimguiVersion = "v0.9"
  compile("org.ice1000.jimgui:core:$jimguiVersion") // basic functionality
  compile("org.ice1000.jimgui:kotlin-dsl:$jimguiVersion") // kotlin dsl wrapper
}

Maven

<dependency>
  <groupId>org.ice1000.jimgui</groupId>
  <!-- basic functionality -->
  <artifactId>core</artifactId>
  <version>v0.9</version>
  <type>pom</type>
</dependency>

Build

First you need to make sure you have cmake newer than 3.14 and the following software installed:

• For Linux
  • make
  • pkg-config
  • libglfw3-dev
• For Windows (>= XP)
  • Visual Studio 2019 with msbuild
  • DirectX 9 Libraries (should be pre-installed on Windows or with Visual Studio)
  • DirectX SDK
• For Mac OS X
  • Everything needed on Linux
  • Cocoa
  • GLUT
  • OpenGL
  • Run with JVM Argument: -XstartOnFirstThread
    • You can use export _JAVA_OPTIONS='-XstartOnFirstThread'.

To compile a jar library, run:

$ ./gradlew assemble

To run tests, run:

$ ./gradlew test