Bug 1315

Summary:	Broadcom VC IV overlay when windowed does not take HDMI overscan setting into account
Product:	[JogAmp] Jogl	Reporter:	Gottfried Haider <gottfried.haider>
Component:	embedded	Assignee:	Sven Gothel <sgothel>
Status:	RESOLVED FIXED
Severity:	normal	CC:	gottfried.haider
Priority:	P4
Version:	2.4.0
Hardware:	embedded_arm
OS:	linux
Type:	FEATURE	SCM Refs:	jogl 51d301875a65f511b6a9846fc3bf661e50a48a68
Workaround:	---

Description Gottfried Haider 2016-07-02 13:04:54 CEST

By default, the Raspberry Pi firmware applies an overscan setting for connected HDMI displays (which can manually disabled by setting disable_overscan=1 in the config.txt).

When overscan is enabled, the size of the desktop is reduced by a number of pixels. So for example, on a 1280x720 display, with overscan enabled, running "fbset -s" will report a geometry of only 1184x624 pixels.

Now with Processing, when running a windowed sketch that uses the JOGL renderer, the overlayed GL surface is offset to the window decoration. I presume that is because the GL part is working with the native resolution of the display, while the X part is not.

I spotted this behavior with Raspbian Jessie version May 2016, and with the latest firmware of today. Disabling overscan fixes this artifact for me. I will check with older releases of the Raspbian distribution to see if this perhaps a regression on their side.

Please let me know if you think that this should be handled differently on Rasbpian's side - I can try to take it up with them. Thanks!

Comment 1 Sven Gothel 2019-03-27 03:56:20 CET

I have merged your patch.
Since I don't test this platform - I trust you here.

Please reopen this bug if required.