; XAS ;--------------------------------------------------------------- ;! Information about TV-Servers ;# INFORMATION TV ;----------------------------------------------------------------------- ;; Copyright (C) 1995-1996, 1998, 2004, 2008 ;; Associated Universities, Inc. Washington DC, USA. ;; ;; This program is free software; you can redistribute it and/or ;; modify it under the terms of the GNU General Public License as ;; published by the Free Software Foundation; either version 2 of ;; the License, or (at your option) any later version. ;; ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public ;; License along with this program; if not, write to the Free ;; Software Foundation, Inc., 675 Massachusetts Ave, Cambridge, ;; MA 02139, USA. ;; ;; Correspondence concerning AIPS should be addressed as follows: ;; Internet email: aipsmail@nrao.edu. ;; Postal address: AIPS Project Office ;; National Radio Astronomy Observatory ;; 520 Edgemont Road ;; Charlottesville, VA 22903-2475 USA ;--------------------------------------------------------------- XAS LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC ---------------------------------------------------------------- XAS Type: XAS is the preferred TV (image display) server for AIPS. Use: XAS is started automatically by the procedures that run on your host machine when you start up AIPS. It uses the basic X-Windows package to talk to the X-Window server on workstation in order to provide the functional equivalent of a TV-display device. XAS has eight graphics overlay planes and one to 16 (usually 16) grey-scale channels. On most workstations it uses "24-bit" or "true" color, in which XAS emulates the old IIS Model 70 in its ability to show multiple images at once (including 3-color images, hue-intensity, etc.) XAS is slower in this mode but still plenty fast enough, so that this mode is the default. On a few workstations, XAS must run in pseudo-color mode, using 199 grayscale levels or colors, though you can extend or reduce this. If the workstation does not support TrueColor, XAS willl revert to pseeudo-color, or you may request that mode with an .Xdefaults parameter (see below). You may control the number of gray-scale planes to some number < 16, with another of the .Xdefaults parameters. Unlike the older and less portable XVSS, XAS has no "button" widgets. When AIPS and its tasks specify "press button ..", you instead press the key corresponding to that letter, e.g. press key "a" when asked to press "button A". You can also use the X11 function keys F3, F4, F5, and F6 for AIPS Buttons A, B, C, and D, respectively. Keypad keys F1, F2, F3, and F4 are used by some other computers. To switch between full-sized and a smaller window (whose size you set with your window manager's tools), press the F2, F7, or keypad-plus keys. There are also 2 debug states which may be turned on and off by hitting the F8 and F9 keys. The former shows the commands coming from AIPS and friends, while the latter shows the window-manager interupts. Finally, pressing the ESCAPE key with the mouse cursor in the XAS window will cause it to shut down cleanly. XAS has the ability to tell AIPS what its window size and other basic parameters are. In fact, XAS now keeps the image catalog and TV parameter information inside itself. As a consequence, a new XAS display is already initialized and TVINITs are normally not required. Options: If you want to use the buffered I/O feature of XAS, you should define an environment variable AIPS_TV_BUFFERED to be "YES". For bash, bourne, or korh shell users this can be done thus: AIPS_TV_BUFFERED="YES"; export AIPS_TV_BUFFERED and for c-shell or tcsh users: setenv AIPS_TV_BUFFERED "YES" This should be done *before* starting the XAS TV server, and ideally should be placed in your login (.login or .profile) file. Using buffered I/O can considerably improve performance when the X display is being projected across a slow link such as a modem. In your home directory, the X-Window Manager will usually read a file called .Xdefaults when it starts up. It can be ordered to re-read it with the command xrdb -merge where refers to your home-directory .Xdefaults or to any other appropriate file. You could put this in your login command file. When XAS starts, it asks the Window Manager if the user has specified certain parameters in his .Xdefaults or other xrdb file. They control the initial size and placement of the window and the initial placement of its icon. They also control the cursor shape and color and the colors of the graphics channels. The XAS part of your file might look like: AIPStv*geometry: 518x518+0+0 AIPStv*iconGeometry: -0+0 AIPStv*xPixels: 1270 (actually size of local screen-10) AIPStv*yPixels: 924 (actually size of local screen-100) AIPStv*cursorShape: 34 AIPStv*cursorR: 255 AIPStv*cursorG: 0 AIPStv*cursorB: 255 AIPStv*graphics1R: 255 AIPStv*graphics1G: 255 AIPStv*graphics1B: 0 AIPStv*graphics2R: 16 AIPStv*graphics2G: 255 AIPStv*graphics2B: 0 AIPStv*graphics3R: 255 AIPStv*graphics3G: 171 AIPStv*graphics3B: 255 AIPStv*graphics4R: 0 AIPStv*graphics4G: 255 AIPStv*graphics4B: 255 AIPStv*graphics5R: 255 AIPStv*graphics5G: 45 AIPStv*graphics5B: 45 AIPStv*graphics6R: 153 AIPStv*graphics6G: 153 AIPStv*graphics6B: 255 AIPStv*graphics7R: 255 AIPStv*graphics7G: 204 AIPStv*graphics7B: 102 AIPStv*graphics8R: 0 AIPStv*graphics8G: 0 AIPStv*graphics8B: 0 AIPStv*nPlanes: 16 AIPStv*useSharedMemory: 1 AIPStv*useTrueColor: 1 AIPStv*maxGreyLevel: 199 AIPStv*maxCommDelay: 16384 AIPStv*gamma 220 where the names of things are obvious, the case is important, and the values shown here are the defaults. Colors must be between 0 and 255 for the cursor and graphics channels 1 through 7. Graphics channel 8 is used as a background and is limited to 0 through 63. The cursor shape numbers are defined in the Xlib Reference Manual (Volume Two of The Definitive Guides to the X Window System). Even numbers from 0 through 154 are legal, but not all are desirable. Possibilities include 30 (a cross with 2 lines in each direction), 40 (a square with a central dot), 128 (an ellipse with a central dot), 132 (arrow like the default cursor) and many others. 34 is a simple plus sign. In 31DEC08, XAS has acquired more memory planes, 16 by default. Each plane uses Xpixels times yPixels bytes, but this is trivial in modern computers. Nonetheless, the option to allocate fewer is offerred. We have added control over the screen x and y sizes. This means you can make them smaller than the default or bigger than the visible screen. The latter may or may not play well with your screen manager. The default sizes are the screen size less 10 in x and 100 in y. The latter allows room for the top window bar and 69 pixels minimum room to type in a window beneath the TV. The gamma correction is in integer 100'ths; i.e. the default 220 means a gamma correction of 2.20. The maxGreyLevel is used only in pseudo-color visuals. The default is the maximum for the workstation device minus 56. XAS is able to use higher limits than this, usually the maximum minus 18, or 237 for most workstations. The maxGreyLevel parameter is offered because users have different numbers of colors in what X-Windows calls the default color table. If XAS requires more levels (colors) than are left over in the default table it will create one of its own. Then, when the cursor moves into the XAS window the XAS table is used for the whole workstation and when the cursor is not in the XAS window the default table is used for the whole workstation, including the XAS window. This creates undesirable flashing of colors and can even render your text windows unreadable. Using a lower maxGreyLevel may avoid this problem, but then limits the dynamic range of your display. These considerations do NOT apply to TrueColor displays and a max grey level of 255 is always used. The use of Shared memory is important for speed when it is available. Turn it off (value = 0) at your peril. It will be automatically disabled if the X server and X client (XAS) are not running on the same host, or if XAS was not built with the shared MIT shared memory extension enabled (some sites don't have the libraries). XAS now also supports the concept of asynchronous execution of AIPS' TV commands. maxCommDelay is the maximum number of screen update requests that can occur before the screen is updated automatically. AIPS code usually forces this update whenever it is needed. However, over slow links, you may wish to reduce this to 50 or so, or even turn it off with values <= 1. The geometry and iconGeometry code require more explanation. The string is x[+-]xoff[+-]yoff where + offsets refer to the top and left and - offsets refer to the bottom and right. The default icon position is the top right corner of the screen and the default window position is the top left corner. Note that the width and height of the icon are set by its designer and cannot be changed. They may be omitted. The width and height set for the display window are just those which it will take at the beginning. You may resize and move the window, and move the icon, afterwards. As XAS starts up iconified, it is often useful to make its iconGeometry location somewhere other than a corner, so you don't miss it because it's under a clock or something... When XAS begins it asks the workstation for its dimensions and available intensities and then tells you the parameters it will use. These have been entered already in the TV parameters file by your AIPS Manager, but may be of interest to you as well. A TVINIT command in AIPS will make sure that AIPS knows what these values are. ----------------------------------------------------------------