Provides a BitmapDevice: the vcl software renderer Provides algorithms and data types for bitmap graphics e.g. line and fill polygon scan conversion, bitmap format iterators, and a SalGraphics-compatible software renderer Used for example for wmf / svm files. E.g. used when you do --headless, and have no DISPLAY set - it's an all-software backend for the LibO graphic backend. also see [git:vcl/headless].