I tried three methods:
1) Direct use of FBIO_DELTA_UPDATE_DISPLAY;
2) Use of erscribble (which uses FBIO_DELTA_UPDATE_DISPLAY) and;
3) Use of a label to force update
I have put all options in code, see scribble.c, which has the following comment that describes how to select a mode and what the current 'issues' are:
Code:
// Select only one of the following:
// USE_LL uses direct ioctl to update the complete screen
// issues: every update takes very long ~1s, so when drawing a lot the screen can
// not keep up
// USE_DRIVER uses the erscribble_driver functions from liberscribble.
// issues: erscribble uses real screen coordinates while xournal has 'translated'
// coordinates. The current code does not handle this, but it gives you an
// impresison of what should be possible
// Appart from the wrong positions, the reaction is also very slow, when drawing
// quickly, the updates appear late.
// USE_LABEL uses a label widget to force a screen update
// issues: the update will only happen when not touching the screen for ~2s.
All the modes have their own issues, so I attach my code (I use Anjuta) to allow more people to experiment.
Xournal is normally installed on the internal memory (not on SD) it takes some time to install it (you need an ipk file etc.). If you have already installed a version of xournal in your internal flash memory, then you can copy your experimental xournal version to SD, create a .desktop-file to point at it and run from SD. It will find the required resources(pixmaps) from internal flash. (Make sure you use --prefix=/usr/local when running configure!)
PS: All my changes as described earlier in this thread are also in the attachement.
PS2: make sure you install the libart-lgpl-2-2_2.3.20_arm.ipk and libgnomecanvas_2.14.0_arm.ipk in your Poky environment (Read the document it posted earlier!).
PS3: I would like a PS3 ;-)
PS4: When using USE_DRIVER you will not see anything in the emulator, only some error messages that the driver is not installed, this seems obvious since it would require emulating the wacom hardware.