====== openGL UIs for LV2 plugins ======
~~SLIDESHOW~~

Robin Gareus

\\

linuxaudio.org, CiTu.fr

\\

Linux Audio Conference 2013, Graz

===== Definitions =====

**LV2** (LADSPA version 2) is an **open standard** for plugins (and hosts), targeted at audio processing.

**openGL** is a **cross-language**, multi-platform API for rendering 2D and 3D computer graphics.


===== Why LV2 GUIs =====

  * No custom UI is the preferred method
    * Host generated UI (common look&feel, UI guidelines,..)

===== Why LV2 GUIs =====

  * No custom UI is the preferred method
    * Host generated UI (common look&feel, UI guidelines,..)

but..

===== Why LV2 GUIs =====

  * No custom UI is the preferred method
    * Host generated UI (common look&feel, UI guidelines,..)

but

  * //Specialized// plugins
    * Important visual feedback
    * Huge number of controls
    * Dependencies between controls
    * Custom widgets e.g. 3D panning

===== Why LV2 GUIs =====

  * No custom UI is the preferred method
    * Host generated UI (common look&feel, UI guidelines,..)

but

  * //Specialized// plugins
    * Important visual feedback
    * Huge number of controls
    * Dependencies between controls
    * Custom widgets e.g. 3D panning
  *  //Corporate// look&feel (VST anyone?!)

===== LV2 GUIs =====

  * openGL

===== LV2 GUIs =====

  * 3D FPS..

===== LV2 GUIs =====

  * 3D FPS..
  * Audio Effects!

===== LV2 GUIs =====

  * 3D FPS..
  * Audio Effects!
  * WTF?!? :)

===== The toolkit + ABI issue 1 =====

{{  :wiki:wiki:lv2gl:pluginhost01.png?440}}

  * Simple setup - plugin inside host

~~CLEARFLOAT~~

===== The toolkit + ABI issue 2 =====

{{  :wiki:wiki:lv2gl:pluginhost02.png?440}}

  * Simple setup - plugin inside host
~~CLEARFLOAT~~

===== The toolkit + ABI issue 3 =====

{{  :wiki:wiki:lv2gl:pluginhost03.png?440}}

  * Simple setup - plugin inside host
~~CLEARFLOAT~~

===== The toolkit + ABI issue 4 =====

{{  :wiki:wiki:lv2gl:pluginhost04.png?440}}

  * Plugin and host use the same toolkit.
  * Toolkit is a shared lib
  * Identical version of library 
~~CLEARFLOAT~~

===== The toolkit + ABI issue 5 =====

{{ :wiki:wiki:lv2gl:pluginhost05.png?440}}

  * Plugin and host use the same toolkit.
  * ..but plugin & host were built with different versions
  * ABI (Application Binary Interface) does not match
  * -> conflicts of symbols
  * -> segfault..

~~CLEARFLOAT~~

===== The toolkit + ABI issue =====

Possible solutions to the API + ABI conflict:

  * Compile plugin and host with same version of the library

===== The toolkit + ABI issue =====

Possible solutions to the API + ABI conflict:

  * <del>Compile plugin and host with same version of the library</del>
  * Run plugin as separate process

===== The toolkit + ABI issue =====

Possible solutions to the API + ABI conflict:

  * <del>Compile plugin and host with same version of the library</del>
  * <del>Run plugin as separate process</del>
  * Use only libraries which are API and ABI compatible across versions

===== GUI Toolkits  =====

  * gdk/gtk (non relocatable, problematic on win, hard on OSX)
  * Qt (huge framework, many edge-cases)
  * libx11/xcb (no windows, not on OSX by default)
  * libclxclient (no windows, not on OSX by default)
  * FLTK (different back-ends depending on OS,..)
  * openGL 

===== GUI Toolkits  =====

  * <del>gdk/gtk (non relocatable, problematic on win, hard on OSX)</del>
  * Qt (huge framework, many edge-cases)
  * libx11/xcb (no windows, not on OSX by default)
  * libclxclient (no windows, not on OSX by default)
  * FLTK (different back-ends depending on OS,..)
  * openGL 

===== GUI Toolkits  =====

  * <del>gdk/gtk (non relocatable, problematic on win, hard on OSX)</del>
  * <del>Qt (huge framework, many edge-cases)</del>
  * libx11/xcb (no windows, not on OSX by default)
  * libclxclient (no windows, not on OSX by default)
  * FLTK (different back-ends depending on OS,..)
  * openGL 

===== GUI Toolkits  =====

  * <del>gdk/gtk (non relocatable, problematic on win, hard on OSX)</del>
  * <del>Qt (huge framework, many edge-cases)</del>
  * <del>libx11/xcb (no windows, not on OSX by default)</del>
  * libclxclient (no windows, not on OSX by default)
  * FLTK (different back-ends depending on OS,..)
  * openGL 

===== GUI Toolkits  =====

  * <del>gdk/gtk (non relocatable, problematic on win, hard on OSX)</del>
  * <del>Qt (huge framework, many edge-cases)</del>
  * <del>libx11/xcb (no windows, not on OSX by default)</del>
  * <del>libclxclient (no windows, not on OSX by default)</del>
  * FLTK (different back-ends depending on OS,..)
  * openGL 

===== GUI Toolkits  =====

  * <del>gdk/gtk (non relocatable, problematic on win, hard on OSX)</del>
  * <del>Qt (huge framework, many edge-cases)</del>
  * <del>libx11/xcb (no windows, not on OSX by default)</del>
  * <del>libclxclient (no windows, not on OSX by default)</del>
  * <del>FLTK (different back-ends depending on OS,..)</del>
  * openGL 

===== GUI Toolkits  =====

  * gdk/gtk (non relocatable, problematic on win, hard on OSX)
  * Qt (huge framework, many edge-cases)
  * libx11/xcb  (no windows, not on OSX by default)
  * libclxclient (no windows, not on OSX by default)
  * FLTK (different back-ends depending on OS,..)
  * openGL 

There are no dedicated audio related widgets in either toolkit by default
(with exception of libclxclient and some qt stuff*).

===== Pro/Cons of openGL =====

Problems:
  * No widgets at all.

===== Pro/Cons of openGL =====

Problems:
  * No widgets at all.
  * No default fonts.

===== Pro/Cons of openGL =====

Problems:
  * No widgets at all.
  * No default fonts.
  * No Desktop integration.

===== Pro/Cons of openGL =====

Advantages:
  * Cross-platform

===== Pro/Cons of openGL =====

Advantages:
  * Cross-platform
  * Minimal (no) library dependencies, API & ABI backwards compatible to ~1999.

===== Pro/Cons of openGL =====

Advantages:
  * Cross-platform
  * Minimal (no) library dependencies, API & ABI backwards compatible to ~1999.
  * Hardware accelerated.

===== Pro/Cons of openGL =====

Advantages:
  * Cross-platform
  * Minimal (no) library dependencies, API & ABI backwards compatible to ~1999.
  * Hardware accelerated.
  * 3D (!)

===== Pro/Cons of openGL =====

Advantages:
  * Cross-platform
  * Minimal (no) library dependencies, API & ABI backwards compatible to ~1999.
  * Hardware accelerated.
  * 3D (!)
  * UIs can be designed in e.g. blender.

===== State of the Art =====

  * August 2012: first LV2 + GL example plugin
  * March 2013: two //real// LV2 openGL plugins:
    * setBfree -- b_synth.lv2
    * balance.lv2
  * Spring 2013: widget model from blender & implementation in C
    * Dial aka rotary knob
    * Switch / Toggle Button
    * Radio Button / Push Button
    * Level Meter
    * Organ Drawbars
  * May 2013: started to break out openGL lv2 lib.
  * Last night: updates to libsuil to directly support openGL cross platform.
 
===== Examples =====

Some screenshots first..

\\

..audio examples right after.

===== setBfree Blender Model =====

{{ :wiki:wiki:lv2gl:screenshot-12.png?800 |}}

===== setBfree main UI =====
{{ :wiki:wiki:lv2gl:screenshot-14.png?800 |}}

===== setBfree main UI - rotated =====
{{ :wiki:wiki:lv2gl:sb3_gui_rotate.png?800 |}}

===== setBfree Program List =====
{{ :wiki:wiki:lv2gl:screenshot-15.png?800 |}}

===== setBfree - Text Entry =====
{{ :wiki:wiki:lv2gl:screenshot-16.png?800 |}}

===== setBfree - File Chooser =====
{{ :wiki:wiki:lv2gl:screenshot-17.png?800 |}}

===== balance.lv2  =====
{{ :wiki:wiki:lv2gl:screenshot-20.png?248 |}}

===== balance.lv2 - side-view =====

{{ :wiki:wiki:lv2gl:screenshot-18.png?800 |}}

===== Q&A =====

Thanks for your attention.

\\

Questions?!

\\

(while I prepare/launch the demo)