Here is a short video about my proposed demonstration for the #Java devroom at #FOSDEM 2015. I'd like to get the audience to interactively play with drawing graphical FB primitives because it literally is that easy with Java.

My test setup uses VMWare Fusion along with my patches for vmwgfx that enable FB resizing (upstream) and double buffering (gentoo bugzilla).

The JVM in the demo is JamVM / GNU Classpath with my patch set that allows Java code to safely manage a map of /dev/fb0 using MappedByteBuffer. The raw memory is safely exposed using MappedByteBuffer.array() and therefore it is effectively just Java code writing to the FrameBuffer as an int[].

The same code can be used to obtain a direct array to any memory-mapped file for low-latency disk I/O in Java, or to map video memory from a camera device.
Shared publiclyView activity