openGL UIs for LV2 plugins

Robin Gareus

linuxaudio.org, CiTu.fr

Linux Audio Conference 2013, Graz

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.

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

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

but..

• 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

• 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?!)

• openGL

• 3D FPS..

• 3D FPS..
• Audio Effects!

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

• Simple setup - plugin inside host

• Simple setup - plugin inside host

• Simple setup - plugin inside host

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

• 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..

Possible solutions to the API + ABI conflict:

• Compile plugin and host with same version of the library

Possible solutions to the API + ABI conflict:

• Compile plugin and host with same version of the library
• Run plugin as separate process

Possible solutions to the API + ABI conflict:

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

• 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

• 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

• 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

• 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

• 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

• 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

• 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*).

Problems:

• No widgets at all.

Problems:

• No widgets at all.
• No default fonts.

Problems:

• No widgets at all.
• No default fonts.
• No Desktop integration.

Advantages:

• Cross-platform

Advantages:

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

Advantages:

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

Advantages:

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

Advantages:

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

• 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.

Some screenshots first..

..audio examples right after.

Thanks for your attention.

Questions?!

(while I prepare/launch the demo)