07 - Make An Amp Plugin UI With B.Widgets

May 12, 2023 ยท View on GitHub

See video: https://youtu.be/1MP2Y1g6KCY

Introduction into a new widget tookit designed for graphical user interfaces for music production: B.Widgets. And create an UI for myAmp with this toolkit.

Topics

Get started

git submodule add https://github.com/sjaehn/BWidgets.git myAmp_BWidgets/BWidgets
git submodule update --init --recursive

Build BWidgets

cd BWidgets
make bwidgets

UI header file

  • Inherit the MyAmpUI class from BWidgets::Window
  • Declare:
    • BWidgets::ValueDial dial
    • Constructor
    • (Destructor)
    • getTopLevelWidget()
    • portEvent()
    • valueChangedCallback()

UI cpp file

  • Constructor
    • Initialize parent class BWidgets::Window
    • Initialize dial
    • setBackground()
    • dial
      • add()
      • setClickable()
      • setCallbackfunction()
    • getTopLevelWidget()
      • Get widget from the pugl backend of B.Widgets using puglGetNativeView(getView())
  • portEvent()
    • Set the dial value using setValue()
  • valueChangedCallback()
    • Get the event-emitting widget from the passed BWidgets::Event* event by event->getWidget()
    • Get the main window from this widget using getMainWindow()
    • Get the dial value using getValue()
    • Pass the dial value to the host using LV2 write_function()
  • Idle interface (ui_idle())
    • Call the BWidgets::Window event handler using handleEvents()

DSP

gcc myAmp.c -fvisibility=hidden -fPIC -DPIC -shared -pthread `pkg-config --cflags lv2` -Wl,-Bstatic `pkg-config --libs --static lv2` -Wl,-Bdynamic -lm -o myAmp.so

UI

g++ -fPIC -DPIC -DPUGL_HAVE_CAIRO -fvisibility=hidden -std=c++17 -IBWidgets/include myAmp_BWidgets.cpp `pkg-config --cflags lv2 cairo x11` -c
g++ -shared -pthread -LBWidgets/build myAmp_BWidgets.o -lbwidgetscore -lcairoplus -lpugl `pkg-config --libs lv2 cairo x11` -o myAmp_BWidgets.so

Test

  • Create a new folder inside your LV2 directory
  • Copy all .so, .ttl, and .png files
  • And run
jalv.gtk3 https://github.com/sjaehn/lv2tutorial/myAmp_BWidgets