# Environment variables in VCL ## General These are the general environment variables used in the VCL: * `SAL_USE_VCLPLUGIN` - use a VCL plugin * `SAL_RTL_ENABLED` - Enable RTL UI * `SAL_NO_NWF` - disable native widgets * `SAL_FORCEDPI` - force a specific DPI (gtk3 & qt5/kf5 plugins only) * `SAL_FORCE_HC` - force high-contrast mode * `SAL_USE_SYSTEM_LOOP` - calls std::abort on nested event loop calls. Currently just for Qt with many crashes. WIP. * `SAL_NO_FONT_LOOKUP` - disable font search and fallback and always use a hard-coded font name (for some unit tests) * `LO_COLLECT_UIINFO` - enable the uitesting logging, value is expected to be a relative file name that will be used to write the log under `instdir/uitest/`. * `VCL_DOUBLEBUFFERING_AVOID_PAINT` - don't paint the buffer, useful to see where we do direct painting * `VCL_DOUBLEBUFFERING_FORCE_ENABLE` - enable double buffered painting * `VCL_DOUBLEBUFFERING_ENABLE` - enable a safe subset of double buffered painting (currently in Writer, not in any other applications) * `VCL_DEBUG_DISABLE_PDFCOMPRESSION` - disable compression in the PDF writer * `SAL_DISABLE_WATCHDOG` - don't start the thread that watches for broken GL/Vulkan/OpenCL drivers * `SAL_NO_MOUSEGRABS` - for debugging - stop blocking UI if a breakpoint is hit ## Gtk+ * `VCL_GTK3_PAINTDEBUG` - in debug builds, if set to `1` then holding down `shift+0` forces a redraw event, `shift+1` repaints everything, and `shift+2` dumps cairo frames to pngs as `/tmp/frame.png` * `GDK_SCALE=2` - for HiDPI scaling (just supports integers) ## Bitmap * `VCL_NO_THREAD_SCALE` - disable threaded bitmap scale * `VCL_NO_THREAD_IMPORT` - disable threaded bitmap import * `EMF_PLUS_DISABLE` - use EMF rendering and ignore EMF+ specifics ## OpenGL * `SAL_DISABLEGL` - disable OpenGL use * `SAL_GL_NO_SWAP` - disable buffer swapping if set (should show nothing) * `SAL_GL_SLEEP_ON_SWAP` - sleep for half a second on each swap-buffers. ## Skia * `SAL_DISABLESKIA=1` - force disabled Skia * `SAL_ENABLESKIA=1` - enable Skia, unless denylisted (and if the VCL backend supports Skia) * `SAL_FORCESKIA=1` - force using Skia, even if denylisted * `SAL_SKIA=raster|vulkan|metal` - select Skia's drawing method, by default Vulkan or Metal are used if available * `SAL_DISABLE_SKIA_CACHE=1` - disable caching of complex images * `SAL_SKIA_KEEP_BITMAP_BUFFER=1` - `SkiaSalBitmap` will keep its bitmap buffer even after storing in `SkImage` ## OpenGL,Skia * `SAL_WITHOUT_WIDGET_CACHE` - disable LRU caching of native widget textures ## Qt * `QT_SCALE_FACTOR=2` - for HiDPI testing (also supports float) * `SAL_VCL_QT5_NO_FONTCONFIG` - ignore fontconfig provided font substitutions * `SAL_VCL_QT5_NO_NATIVE` - disable `QStyle`'d controls * `SAL_VCL_QT5_USE_CAIRO` - use cairo for text rendering and fonts (default for kf5, but not qt5) ## Kf5 * `SAL_VCL_KF5_USE_QFONT` - use `QFont` for text rendering (default for qt5, but not kf5) ## Mac * `SAL_FORCE_HIDPI_SCALING` - set to 2 to fake HiDPI drawing (useful for unittests, windows may draw only top-left 1/4 of the content scaled) abora/co-24.04.6