TOC

• LEGUI - What is it?
• Contribution to LEGUI
• System requirements
• OpenGL state touched by the backend
• Usage
• • Dependencies
• • • Add dependency repo
• • • Add dependency (Maven)
• • • Add dependency (Gradle)
• • Demos
• Projects using LEGUI
• • Modeler by Cout970
• Links

LEGUI - What is it?

GUI implementation for using with LWJGL3.

This gui library made for using with OpenGL port (LWJGL) to allow programmers fast and easy integrate user interface to their OpenGL apps written in Java or Kotlin.
API is close to Swing API.

Examples

Radio button and text input	Widgets	TextArea
Button, togglebutton, checkbox, selectbox	Sliders	ScrollPanel

Contribution to LEGUI

See the contribution guide for more information.

System requirements

LEGUI requires Java 11+.

OpenGL state touched by the backend

Default renderer made on top of NanoVG which touches following states:

When textures are uploaded or updated, the following pixel store is set to defaults: GL_UNPACK_ALIGNMENT, GL_UNPACK_ROW_LENGTH, GL_UNPACK_SKIP_PIXELS, GL_UNPACK_SKIP_ROWS. Texture binding is also affected. Texture updates can happen when the user loads images, or when new font glyphs are added. Glyphs are added as needed start and end of render() method.

The data for the whole frame is buffered and flushed in end of rendering. The following code illustrates the OpenGL state touched by the rendering code:

    glUseProgram(prog);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glEnable(GL_CULL_FACE);
    glCullFace(GL_BACK);
    glFrontFace(GL_CCW);
    glEnable(GL_BLEND);
    glDisable(GL_DEPTH_TEST);
    glDisable(GL_SCISSOR_TEST);
    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glStencilMask(0xffffffff);
    glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
    glStencilFunc(GL_ALWAYS, 0, 0xffffffff);
    glActiveTexture(GL_TEXTURE0);
    glBindBuffer(GL_UNIFORM_BUFFER, buf);
    glBindVertexArray(arr);
    glBindBuffer(GL_ARRAY_BUFFER, buf);
    glBindTexture(GL_TEXTURE_2D, tex);
    glUniformBlockBinding(... , GLNVG_FRAG_BINDING);

Usage

Dependencies

Add dependency repo

For using this library you should add these urls as repositories:
For LWJGL and JOML dependencies
https://oss.sonatype.org/content/repositories/snapshots/ - for snapshots
https://oss.sonatype.org/content/repositories/releases/ - for releases
Also you can add your own versions of these libraries using LWJGL form.

For LEGUI and CBCHAIN dependency
https://raw.github.com/SpinyOwl/repo/releases

And add this dependency to your build script:

Add dependency (Maven):

```xml

org.liquidengine legui ${legui_version} ```

Add dependency (Gradle):

groovy // LEGUI - https://github.com/SpinyOwl/legui compile group: 'org.liquidengine', name: 'legui', version: "${legui_version}";

Demos:

All examples located under demo package.

Projects using LEGUI:

Modeler by Cout970

Open 3D Modeling Tool (Cout970/Modeler)
This tool is written in Kotlin, using LWJGL3 for rendering and Legui to build user interfaces

FMT by Fexcraft

Fex's Modelling Toolbox (Fexcraft/FMT)
A Tool to create Models basing on the "TMT" (updated and maintained version of Fex/FCL) Library.

Links

LWJGL - Lightweight Java Game Library 3
JOML – Java OpenGL Math Library
CBCHAIN - Callback Chain for LWJGL3
NanoVG -Small antialiased vector graphics rendering library for OpenGL.