Additions:
~- [[FaqHDvideoPlayback How can I play back high-resolution high-speed video?]]
Deletions:
Additions:
~- [[FaqHDvideoPlayback tips and tricks for playing back high-resolution high-speed video]]
Additions:
~- [[FaqTTLTrigger How to send TTL triggers via parallel port (Win 2k/XP/Vista/7 only)?]]
Deletions:
Additions:
~- [[Faq64BitSupport Does Psychtoolbox work with 64-bit versions of Matlab or Octave?]]
Additions:
~- [[Faq10BitDACs Is it possible to get 10-bit DAC resolution with PTB-3 under WinXP or OS/X?]]
Deletions:
Additions:
~- [[FaqInitialScreen How do I make the initial screen black instead of white?]]
Additions:
~- [[FaqHowDoIExitScreen How do I close a screen and return to the command line (Mac or Win)?]]
~- [[FaqPerformanceTuning1 How can I try to improve timing and performance of PTB-3 code?]]
~- [[FaqMatlabFigureUpdate How can I update Matlab figures during the experiment?]]
~- [[FaqPerformanceTuning1 How can I try to improve timing and performance of PTB-3 code?]]
~- [[FaqMatlabFigureUpdate How can I update Matlab figures during the experiment?]]
Deletions:
~- [[FaqPerformanceTuning1 How can i try to improve timing and performance of PTB-3 code?]]
~- [[FaqMatlabFigureUpdate How can I during the experiment update Matlab figures?]]
Additions:
~- [[FaqScreenShots How can I take a screenshot of my stimuli?]]
Additions:
~- [[FaqMatlabFigureUpdate How can I during the experiment update Matlab figures?]]
Deletions:
Additions:
~- [[FaqAddFaq How do I add a FAQ & answer to this list?]]
Deletions:
Additions:
~- [[FaqMatlabFigureUpdate How can I during the experiment update Matlab figures between trials?]]
~- ~- [[FaqAddFaq How do I add a FAQ & answer to this list?]]
~- ~- [[FaqAddFaq How do I add a FAQ & answer to this list?]]
Deletions:
Revision [1455]
Edited on 2008-09-17 13:14:00 by DavidFencsik [Added FAQ about collecting responses during repeated stimulus presentation.]Additions:
~- [[FaqAnimationAndResponse How can I collect responses while repeatedly presenting/updating visual stimuli?]]
Revision [1454]
Edited on 2008-09-17 13:09:42 by DavidFencsik [Moved the Add-a-FAQ item to the end of the list.]No Differences
Additions:
~- [[FaqVista Are there known issues with Windows Vista and how to resolve them?]]
Additions:
~- [[FaqTTLTrigger How to send TTL triggers via parallel port (Win 2k/XP/Vista only)?]]
Deletions:
Additions:
~- [[FaqTTLTrigger How to send TTL triggers via parallel port (Win 2k/XP only)?]]
Additions:
~- [[FaqDownloadFails Why does DownloadPsychtoolbox persistently fail with svn CHECKOUT and PROPFIND errors?]]
Deletions:
Additions:
~- [[FaqAddFaq Why does the DownloadPsychtoolbox script persistently fail with CHECKOUT or PROPFIND errors?]]
Additions:
~- [[FaqGetSecsTestFails Psychtoolbox or the GetSecsTest script tell me that the clock and timers on my computer are broken! What now?!?]]
Additions:
~- [[FaqAddFaq How do I add a FAQ & answer to this list?]]
Deletions:
Additions:
~- [[FaqAddFaq How do I add a FAQ
Deletions:
Additions:
~- [[FaqQuickTimeTrouble When trying to play movies with Quicktime, Matlab crashes or gives Bus errors! What can i do?]]
Additions:
~- [[FaqHowDoIExitScreen How do I close the screen an return to the command line (Mac or Win)?]]
Additions:
~- [[FaqBlueScreen When opening an onscreen window, Psychtoolbox shows a blue or white screen and then nothing happens?!?]]
Deletions:
Additions:
~- [[FaqPerformanceTuning1 How can i try to improve timing and performance of PTB-3 code?]]
Additions:
~- [[FaqImageTransparency How to display images with transparent backgrounds?]]
Additions:
~- [[MultipleKbcheck How to perform keyboard check for multiple keyboards (Mac OS/X Only)?]]
Deletions:
Additions:
~- [[MultipleKbcheck How to perform keyboard check for multiple keyboards? (Mac OS/X Only)]]
Additions:
~- [[FaqAddFaq How do I add a FAQ & answer to this list?]]
Deletions:
Additions:
~- [[FaqAddFaq How do I add a Q&A to this list?]]
Deletions:
Additions:
~- [[Faq10BitDACs Is it possible to get 10-bit DAC resolution with PTB-3 under OS/X?]]
Deletions:
Additions:
~- [[Faq10BitDACs How can I get 10-bit DAC resolution under OS/X?]]
Additions:
~- [[IntelMacCurrentState Does the PTB-3 run on the new Intel-based Macintosh computers?]]
~- [[FaqWarningPrefs How can I skip the checks that Screen performs when it starts up?]]
~- [[FaqDuplicateOffscreen How do I duplicate an offscreen window?]]
~- [[FaqTextSize Can I set TextSize (and other parameters) for all windows/screens?]]
~- [[FaqVirusWin Windows: Why does my virus checker complain about the PTB-3 distribution?]]
~- [[FaqWarningPrefs How can I skip the checks that Screen performs when it starts up?]]
~- [[FaqDuplicateOffscreen How do I duplicate an offscreen window?]]
~- [[FaqTextSize Can I set TextSize (and other parameters) for all windows/screens?]]
~- [[FaqVirusWin Windows: Why does my virus checker complain about the PTB-3 distribution?]]
Deletions:
~- [[FaqWarningPrefs How do I control the debugging checks when Screen starts up?]]
~- [[FaqDuplicateOffscreen How do you create a duplicate of an offscreen window?]]
~- [[FaqTextSize Is there any simple way to set TextSize (or other such parameters) for all windows/screens?]]
~- [[FaqVirusWin Why does my virus checker complain about the PTB-3 distribution (Windows)?]]
Additions:
=== [[http://psychtoolbox.org Psychtoolbox-3]] Frequently Asked Questions (FAQ) ===
Deletions:
Additions:
~- [[FaqTextureWindow What's the difference between a texture, a window, and a screen?]]
Deletions:
Additions:
~- [[ContributeToWiki How do I add a Q&A to this list?]]
Deletions:
Additions:
~- [[PsychtoolboxWiki How do I add a Q&A to this list?]]
Additions:
~- [[FaqBlueScreen When opening an onscreen window, Psychtoolbox shows a blue screen and then nothing happens?!?]]
Additions:
~- [[FaqFlipTimestamps What do the timestamps returned by Screen('Flip') mean?]]
Additions:
~- [[IntelMacCurrentState Does the PTB-3 run on the new Intel based Macintosh computers?]]
Additions:
~- [[FaqScreenOpenWindow Why does it take 40 s to open my first window?]]
Additions:
~- [[FaqWarningPrefs How do I control the debugging checks when Screen starts up?]]
Additions:
~- [[FaqOffscreenMultipleBuffers Can offscreen windows (created with 'OpenOffScreenWindow') have multiple buffers?]]
Deletions:
Additions:
~- [[FaqOffscreenMultipleBuffers Can offscreen windows (created with ""OpenOffScreenWindow"") have multiple buffers?]]
Deletions:
Additions:
~- [[FaqDownload How do I get PTB-3?]]
~- [[FaqBackwardsCompatible Is PTB-3 backwards compatible with PTB-2 (Mac or Win)?]]
~- [[FaqTextureWindow What is the difference between a texture and a window and a screen?]]
~- [[FaqDuplicateOffscreen How do you create a duplicate of an offscreen window?]]
~- [[FaqTextSize Is there any simple way to set TextSize (or other such parameters) for all windows/screens?]]
~- [[FaqOffscreenMultipleBuffers Can offscreen windows (created with '""OpenOffScreenWindow""') have multiple buffers?]]
~- [[FaqVirusWin Why does my virus checker complain about the PTB-3 distribution (Windows)?]]
~- [[FaqBackwardsCompatible Is PTB-3 backwards compatible with PTB-2 (Mac or Win)?]]
~- [[FaqTextureWindow What is the difference between a texture and a window and a screen?]]
~- [[FaqDuplicateOffscreen How do you create a duplicate of an offscreen window?]]
~- [[FaqTextSize Is there any simple way to set TextSize (or other such parameters) for all windows/screens?]]
~- [[FaqOffscreenMultipleBuffers Can offscreen windows (created with '""OpenOffScreenWindow""') have multiple buffers?]]
~- [[FaqVirusWin Why does my virus checker complain about the PTB-3 distribution (Windows)?]]
Deletions:
[[FaqBackwardsCompatible Is PTB-3 backwards compatible with PTB-2 (Mac or Win)?]]
[[FaqTextureWindow What is the difference between a texture and a window and a screen?]]
[[FaqDuplicateOffscreen How do you create a duplicate of an offscreen window?]]
[[FaqTextSize Is there any simple way to set TextSize (or other such parameters) for all windows/screens?]]
[[FaqOffscreenMultipleBuffers Can offscreen windows (created with '""OpenOffScreenWindow""') have multiple buffers?]]
Additions:
[[FaqBackwardsCompatible Is PTB-3 backwards compatible with PTB-2 (Mac or Win)?]]
Additions:
[[FaqDownload How do I get PTB-3?]]
Additions:
=== [[http://psychtoolbox.org Psychtoolbox-3]] FAQ ===
Deletions:
Revision [204]
Edited on 2006-10-15 21:49:44 by DavidBrainard [Moved each Q/A to its own page, with back link at top]Additions:
[[FaqOffscreenMultipleBuffers Can offscreen windows (created with '""OpenOffScreenWindow""') have multiple buffers?]]
Deletions:
----
----
----
Revision [194]
Edited on 2006-10-15 21:43:41 by DavidBrainard [Moved each Q/A to its own page, with back link at top]Deletions:
A: Nope. It wouldn't make sense to have multiple buffers.
Revision [190]
Edited on 2006-10-15 21:41:35 by DavidBrainard [Moved each Q/A to its own page, with back link at top]Deletions:
A: No. You have to set it for each window via the Screen('TextSize', win, ...) command. But that's not much work, given that most people have at most two windows.
Revision [188]
Edited on 2006-10-15 21:40:46 by DavidBrainard [Moved each Q/A to its own page, with back link at top]Deletions:
A: You would first create an empty offscreen window of the same size and color depth as your original offscreen window, then copy the original windows content into the new window:
Be origWin the offscreen window you want to duplicate, then:
duplicateWin = Screen('OpenOffscreenWindow', origWin); Screen('CopyWindow', origWin, duplicateWin);
-> duplicateWin is a copy of origWin.
Revision [184]
Edited on 2006-10-15 21:39:33 by DavidBrainard [Moved each Q/A to its own page, with back link at top]Additions:
[[FaqTextureWindow What is the difference between a texture and a window and a screen?]]
[[FaqDuplicateOffscreen How do you create a duplicate of an offscreen window?]]
[[FaqTextSize Is there any simple way to set TextSize (or other such parameters) for all windows/screens?]]
[[FaqOffscreenMultipleBuffers Can 'OpenOffScreenWindow' windows have multiple buffers?]]
Q: Is there any simple way to set TextSize (or other such parameters) for all windows/screens?
[[FaqDuplicateOffscreen How do you create a duplicate of an offscreen window?]]
[[FaqTextSize Is there any simple way to set TextSize (or other such parameters) for all windows/screens?]]
[[FaqOffscreenMultipleBuffers Can 'OpenOffScreenWindow' windows have multiple buffers?]]
Q: Is there any simple way to set TextSize (or other such parameters) for all windows/screens?
Deletions:
A: A screen corresponds to a physically connected display device. Screen 0 is the display with the Dock and menu bar. Screen 1 (on a dual-display system) is the 2nd display, and so on... The Screen('Screens') command returns a vector of all available screens - the available, connected and powered on display devices. If you have a dual-display setup whose displays are switched into mirror-mode (both displays show same content), then this will appear to PTB as a single screen. The screen-number just defines on which physical output device you want to open/show your stimulus window.
An onscreen-window is used to display your stimulus. Each screen can have exactly one full-screen onscreen window - or no PTB window at all. All drawing commands expect a handle to an onscreen window so they know where to draw to.
Onscreen windows are double-buffered: They consist of a backbuffer and a frontbuffer. The backbuffer is where all drawing operations are performed -- where you build/prepare your stimulus for presentation. The frontbuffer is scanned out and displayed by your display - your beamer, flat-panel or CRT at the display refresh interval.
After you've finished drawing and your stimulus image is ready in the backbuffer, you issue the Screen('Flip',...) command. This command asks PTB to switch the role of the front- and back- buffer at the next vertical retrace of your display device. This way, the former backbuffer becomes the new frontbuffer and your new stimulus gets shown to the subject. The former frontbuffer becomes the new backbuffer and is ready for drawing the next stim. As the bufferswap is synchronized with vertical retrace and always happens in less than 1 microsecond, you'll get perfect, flickerfree, tearfree stimulus presentation timing, regardless how long drawing takes -- Unless obviously you try to draw something too complex in a too short period of time. The important point is that Flip decouples drawing (with its timing variabilities) and actual stimulus presentation - something not possible in the MacOS-9 and Win toolboxes.
Offscreen windows are the same as Textures in the Psychtoolboxes released since 2006. Internally they are the same thing, so you can always use a Psychtoolbox texture where you would use an Offscreen window and an offscreen window where you would use a texture. They only differ in creation and performance: Textures are created by Screen('MakeTexture') from a Matlab image matrix or automatically by the Quicktime movie playback engine or the videocapture engine. Creating them is very fast and efficient. They are also optimized for fastest possible drawing. Offscreen windows are created by the call Screen('OpenOffscreenWindow'); - they are initialized with a selectable size, color depth and initial uniform color, not with image content. They are optimized for fast drawing *into* them - Each Screen drawing command can not only draw to onscreen windows, but also into offscreen windows. After creation, they are (nearly) synonymous.
E.g.:
Say you have a image matrix I in Matlab, e.g., created via I=imread('myimage.png'):
Then:
tex=Screen('MakeTexture', win, I);
is the same as:
tex=Screen('OpenOffscreenWindow', win); Screen('PutImage', tex, I);
in, just that the former is much faster than the latter. The advantage is also that the Screen('DrawTexture') command allows to scale, zoom, filter and rotate textures while drawing, that texture drawing is extremely fast as it uses specialized hardware on your graphics card, and much more...
Q: Is there any simpe way to set TextSize (or other such parameters) for all windows/screens?
Additions:
Onscreen windows are double-buffered: They consist of a backbuffer and a frontbuffer. The backbuffer is where all drawing operations are performed -- where you build/prepare your stimulus for presentation. The frontbuffer is scanned out and displayed by your display - your beamer, flat-panel or CRT at the display refresh interval.
