Last Modified: Wed May 8 21:05:09 MST 2002

Table of Contents:


A new script automatically unpacks the distribution and installs files in the system (or user's directories for a private install), provides error checking and user interaction to skip parts of the process or change defaults. The 'install' script is packaged with both source and binary distribution files. To install for general use in the system directories the script must be run as root user, it may be run by any user to install to private directories.

To install from an unpacked source distribution:

     % xmkmf              build the package Makefile
     % make World         build binaries from sources
     % su                 become the root user
     # ./install          install the files (interactive)

Only the last two commands are required to install from an unpacked binary distribution.


Aside from general bug fixes most of the changes in this release are all new features for XImtool. Details on individual features are explained below, but in summary:

The most significant change in this version is the ability to access the displayed image pixels or header data to produce the real-pixel and WCS readouts. This is done using an external process called an ISM (Image Support Module) which communicates with ximtool as a "plug-in" module to enhance the features of the core program. In this case the ISM is written as an IRAF task (although any application that can send text over a socket can be used as an ISM regardless of the language/environment) run at the host level with the ability to access any supported image format. Any number of such ISM plug-ins can be developed to provide e.g. catalog overlay, animation, and so on.

For the WCS/pixel ISM to operate properly changes to the display protocol were required to pass the needed information. These changes are all backwards compatible with "older" display servers however for the ISM to work at all you will need to be running at least IRAF V2.12. Updates to external packages using image display (notably MSCRED) have already been completed. Details of the changes required are found in the technical notes at the end of this document.

Users should feel free to contact IRAF site support (iraf@noao.edu) with any questions.

2.1 Real-Time WCS/pixel Readout

XImtool now has the ability to display the actual pixel value of an image (as well as the scaled value previously shown) and the cursor position in image WCS values (e.g. RA/DEC, GLAT/GLONG, etc). This is done using an external task (the 'ism_wcspix.e' binary in the new distribution) to access the image and pass the coordinate/pixel information to the GUI.

WCS readout is enabled by default but can be toggled or reset using the 'WCS/Pix' button on the Coords tab in the control panel or the "ISM" toggle on the alt-gui menubar. When enabled, images currently in the server or subsequently displayed will be passed to the external process where they are cached for access. Cursor movements generate an event that maps the current frame buffer position to a position in the cached image. The ISM (ISM is Image Support Module) task then reads the image to determine the pixel value (or a small table of values around the current position), and computes one or more coordinates from the image position. The ISM task also has access to the associated BPM images and can optionally return bad pixel information during the cursor readout.

By default, the logical and world image coordinates are displayed to both the Coords panel readout as well as the main display window wcsbox text marker. Alternate coordinate systems (e.g. transformation of equatorial to galactic coordinates or some other sky system, physical coords, amplifier coords, etc) can be selected for display by hitting the "Options" toggle on the Coords panel. Available coordinate systems are chosen using the "Type" menu on the panel, the readout format (sexigesimal, degrees, etc) using the "Format" menu, and the display to the current panel or main image window using the remaining toggles for each WCS. Up to four systems may be displayed at one time, the coordinate panel and wcsbox marker will adjust size automatically depending on the display.

By selecting the "BPM Data" toggle from the Coords.Options panel ximtool is able to flag pixels in images with an associated bad pixel mask. This bad pixel mask is currently assumed to be named in the image header "BPM" keyword by convention. If the cursor passes over a bad pixel in the mask, the Coords bpm display as well as the main window wcsbox will change to a red background color. Only the Coords display will show the value, any non-zero value will be flagged with the color change.

With the ISM enabled the Compass indicator will display a set of arrows showing North-East if a WCS is available, otherwise just the current X-Y axes are shown. The pixel table will display actual pixel values from the image, with the ISM off the pixel table displays the scaled image values from the frame buffer.

2.2 "Peak-up" Cursor Centroid Positioning

Several new keystroke commands are available to reposition the cursor to a centroid or min/max pixel value within a bounding box of the cursor position, allowing you to approximate the position with the mouse and fine tune it quickly before typing an application keystroke command. The initial box size is controlled with a 'centerBoxSize' GUI resource (defaults to 5 pixels) but can be adjusted interactively using the Ctrl-[ and Ctrl-] commands to descrease andincrease the box size respectively. A marker will flash briefly to indicate the new box size.

The Ctrl-0 (zero) key finds either a centroid or the local maximum pixel value within this box region, Alt-Ctrl-0 (zero) will find the local minimum value. In either case the cursor is reposition to the computed value. The default peak-up action is to find the centroid position in the box however this can be changed to find the max pixel by selection the "Centroid Peaks" option from the main Display control panel or by resetting the "peakCentroid" GUI resource (defaults to True).

Centroiding is done using only the scaled screen pixel values and only pixels above the mean value within the box are used. It works best if the box size is set appropriately, the centroid position may appear to drift if the box is too large and includes too many background pixels.

2.2.1 Command Summary:

        Ctrl-0 (zero)           Reposition to centroid/max-pixel
    Alt-Ctrl-0 (zero)           Reposition to min-pixel
        Ctrl-[                  Decrease centering box size (min of 5)
        Ctrl-]                  Increase centering box size

2.2.2 Resource Summary:

        peakCentroid    True    Compute the box centroid position, a
                                'False' value force the max value to be used
        centerBoxSize   5       Size of the centroid box, used as cursor
                                position +/- this value

2.3 Auto-Registration of Images

The auto-register feature allows you specify a registration of two or more display frames with an offset. When enabled, this registration is maintained for all frames in the list if any one of them is panned or zoomed to a new location in the frame buffer. The list of frames to be registered is maintained in the Display panel.

For example, to use this feature do the following:

  1. Enable Auto-Register (either on the Display panel or the toolbar on the alt-gui) and pan/zoom to some star of interest.
  2. Use Mouse-Button-2 to center the star in the frame.
  3. Cycle through the frames and you may see a small shift of the star. For each frame, position the cursor on the star and type Ctrl-o to offset it to the center. Repeat as necessary. Small corrections will be cumulatively added so you can use the Ctrl-0 peak-up command to centroid each object in the frame before the Ctrl-o offset.
  4. Pan around the image in one display frame, then switch frames and the new frame should also be panned to the new image with the proper offset.
  5. A Ctrl-a command will toggle the feature, offsets are only allowed when Auto-Register is enabled.

Hitting "Register" will zero the offsets, as will toggling the auto-register function. What you should see is the object centered in the frame and as you blink through it remains registered but the panner box marker is moving around. Drag the panner around and all frames still remain registered with the given offset. The control/info panels also now display what the offset is for each frame.

The register display list is shared with the blink list and can be set using the Display control panel. By default all frames are included in the list. For accessing more than four frames, use the box icon in the Blink/Register box of the Display control panel to bring up a new window with access to all 16 available frames.

2.3.1 Command Summary:

        Ctrl-o         set the offset from center
        Ctrl-a         toggle the Auto-register feature

2.4 Integrated Control Panel

The separate windows previous used for Control/Print/Load/Save/etc have now been integrated into a single window with the appropriate control panel selectable with a Tab widget. There are also new Tab panels for setting the frame tile configuration (see below), more detailed information on the server status, and selecting the WCS readout options (see above).

All panels were updated as part of the integration, however some changes of note to each panels include:

2.4.1 Load Panel Changes

The Load panel was redesigned to make directory navigation easier as well as to provide new features. The file list box is now larger and implemented using a more natural directory listing format. The filename filter box can now accept a comma-delimited list of templates providing multiple matches to e.g. "*.fits" and "*.imh" images in the same listing. Sub-directories are always listed in the output.

A new options group was added to the panel with the following features:

2.4.2 Info Panel Changes

The Info panel was revised to provide a greater variety of status information. The type of output is controlled by the toggle buttons on the bottom of the frame, however all output is kept current as the program runs. Current info options include:

2.4.3 Tile Panel (NEW)

With the additional frames in this release, the default tiling scheme proved inadequate. A new control panel Tile frame now allows you to select from a number of tile configurations, the list of frames to be tiled, a "fill style" (left-to-right or top-to-bottom), as well as optional labels for each of the tiles (frame number, image title or image name).

Tile configuration will make use of all frames currently selected in the "Tile Frame" group in the following manner:

2.4.4 Coords Panel (NEW)

The Coords Panel is meant to provide a full-featured readout as well as serve as a control panel for the various options. The display window contains the image name/title and frame buffer info, and a selection of coordinate and image pixel readouts. The intent is provide more information than can fit comfortably on the main image window while still taking up as little screen space as possible. To this end the "Options" button is used to hide most of the feature controls when not in use (see below). Other options on the main panel include:

The "Readout Values" group controls the selection of WCS type, location and format to be displayed. The "Type" menu always provides a selection of the image Logical, Physical or World systems, which may be identical depending on the image header. If a World system is supplied in the image addition entries for transformations to other sky systems, (e.g. FK5 to ICRS or galactic/ecliptic) will also be available. The selection is dependent on whether the ISM is running as well as WCS information present in the image. The "Format" menu allows the use to select a sexigeimal display, conversion to degrees or radians, or whichever format is most natural for the coordinate being display. The two toggles to the right control whether this WCS is to be displayed on the Panel (i.e. the Coords Panel window) or the ImgWin (i.e. the text marker on the main image window).

Other options below this group control whether or not to display the WCS labels, the image name/title, and frame buffer information in the main Coords Panel display. The "BPM Data" option controls whether or not the ISM will try to map any bad-pixel mask associated with the image. If enabled, a bad-pixel mask specified by the image header BPM keyword (currently fixed by convention but this may be selectable later) will be mapped along with the image. Aside from wcs/pixel readouts at each cursor position, any BPM data values found will also be displayed. A non-zero value will cause the BPM field of the Coords Panel readout as well as the main image window marker to switch to a red background color to flag the value.

The last box allows the user to specify a different ISM task to be executed or to reinitialize the current one. In most cases this won't need to be changed, however a custom ISM could be started when using special data formats. This command string can also be controlled by the application "ism_task" resource.

2.5 Support for 16 Display Frames

As part of the extensive GUI changes, support for the full 16 frames allowed by the current IIS protocol is now available. IRAF V2.12 or later client tasks (and CDL library) are required to take advantage of these frames. All changes are backwards compatible, older versions of IRAF will continue to work but cannot access more than the original four frames. The new DISPLAY task will automatically sense whether the display server being used supports 16 frames or the original 4 and adjust the 'frame' parameter maximum accordingly. The changes are fully backwards compatible for other servers (e.g. SAOimage, DS9, etc).

More frames are possible if needed but will require further changes to the client IRAF code to be effective. Allowing creation of more than 16 frames by the Load panel can be done independently but would also require numerous code change to XImtool. Please contact site support (iraf@noao.edu) if there is a need for this, or for workaround suggestions depending on your application.

2.6 Magnifier

The magnifier marker appears to be stable and was moved into the default ximtool GUI and is now enabled by default. The ximtool-mag command has been removed.

2.7 Freezing Cursor Readout

Holding down the Alt key will now freeze the cursor display readout and draw crosshairs on the screen at the last position. This can be used for example to position the cursor but then allow the cursor to be moved to another window (to enter text, start a program, whatever) without losing the position information displayed on the screen.

2.8 Cut-Graphs

XImtool now has the ability to display horizontal and vertical cut-graphs of the display, these appear as "flip-out" panels that appear on the bottom and right side of the main display window and are controlled by the small "H" and "V" buttons in the lower right corner of the window. When both panels are enabled the corner area of the display also shows an options panel for the graphs. Current options include:

Graphs are (currently) drawn using only the scaled display values to avoid complications of accessing multiple images in a mosaic display. Both plots are labeled using the frame z1/z2 values and contain cursor indicators which update contuously.

2.9 Ruler Markers

Holding down the Ctrl key and the Left-Mouse-Button while moving the mouse will drag out a "ruler marker" measuring the distance from the initial point to the current mouse position. Releasing the Ctrl key before lifting the mouse button will leave the marker on the display, otherwise it will be erased automatically once the mouse button is released. Any number of ruler markers can be created in the frame.

Distances are measured by default in image logical pixels however the Right-Mouse-Button can be used inside the marker to popup a menu of options:

The marker can also be destroyed by hitting the Delete or Backspace key while the cursor is in the marker. There is presently no way to move the marker to a new position in the frame.

2.10 Summary of Cursor Commands
    * - indicates a new/changed command
Misc Functions
    Ctrl-b              Backward frame
    Ctrl-c              Center frame
    Ctrl-f              Forward frame
    Ctrl-i              Invert
    Ctrl-n              Normalize
*   Ctrl-m              Toggle Magnifier
*   Ctrl-p              Toggle Panner
    Ctrl-r              Register
*   Ctrl-s              Match LUTs
    Ctrl-t              Tile frames toggle
    Ctrl-u              Unzoom (zoom=1)
    Ctrl-x              Flip X
    Ctrl-y              Flip Y
    Ctrl-=              Print
    Ctrl-<              Decrease blink rate
    Ctrl->              Increase blink rate
    Ctrl-+              Zoom in
    Ctrl--              Zoom out

    Alt-1 thru Alt-4    Set frame displayed
    Ctrl-1 thru Ctrl-9  Set integer zoom factor

    Ctrl-Alt-q          Quit
    Ctrl-Alt-f          Fitframe
    Alt-b               Blink frames toggle
    Alt-c               Control panel
    Alt-h               Help panel
    Alt-i               Info box panel
    Alt-l               Load file panel
    Alt-p               Print panel
    Alt-s               Save panel
    Alt-t               Tcl Shell panel
*   Ctrl-a              Toggle Auto-Reg
*   Ctrl-o              Set offset
Cursor Positioning
*   Ctrl-h/Left_Arrow   move cursor 1 pixel left
*   Ctrl-j/Down_Arrow   move cursor 1 pixel down
*   Ctrl-k/Up_Arrorw    move cursor 1 pixel up
*   Ctrl-l/Right_Arrow  move cursor 1 pixel right

*   Shift-Ctrl-h        move cursor 10 pixels left
*   Shift-Left          move cursor 10 pixels left
*   Shift-Ctrl-j        move cursor 10 pixels down
*   Shift-Down          move cursor 10 pixels down
*   Shift-Ctrl-k        move cursor 10 pixels up
*   Shift-Up            move cursor 10 pixels up
*   Shift-Ctrl-l        move cursor 10 pixels right
*   Shift-Right         move cursor 10 pixels right
Frame Positioning
    Ctrl-Left           shift one full frame left
    Ctrl-Down           shift one full frame down
    Ctrl-Up             shift one full frame up
    Ctrl-Right          shift one full frame right

    Ctrl-Alt-Left       shift one half frame left
    Ctrl-Alt-Down       shift one half frame down
    Ctrl-Alt-Up         shift one half frame up
    Ctrl-Alt-Right      shift one half frame right
Peak-Up Centroiding
*   Ctrl-[              decrease centering box size
*   Ctrl-]              inrease centering box size
*   Ctrl-0 (zero)       centroid/find local max
*   Alt-Ctrl-0 (zero)   find local min
Mouse Button Actions
    Shift-Btn1Down      turn on magnifier
    Shift-Btn1Up        turn off magnifier
    Shift-Btn2Down      turn on crosshair cursor
    Shift-Btn2Up        turn off crosshair cursor
    Btn1Down            create marker
    Btn1Motion          resize marker being created
    Btn2Down            zoom on cursor position
    Btn3Down/Motion     brightness/contrast scaling

*   Ctrl-Btn1Down       create ruler marker
*   Ctrl-Btn1Motion     resize ruler marker
*   Ctrl-Btn1Up         destroy ruler marker

*   Alt-Motion          freeze cursor readout

2.11 Summary of Application Resources

Following is a summary of the task client and GUI resources, along with select resources defined for the main image display Gterm widget. All GUI elements can be controlled to some exten with resource definitions although not all resources are useful. Feel free to contact site-support (iraf@noao.edu) with questions about how to change the appearance of the GUI. Future versions of XImtool should feature a control panel to allow some of these more critical resources to be redefined at runtime.

Format for the listing is resource-name, default-value, and type, with an optional note appended. See the man page or online help for a full description of all resources. A '*' in the leftmost column indicates a new resource added with this release, some resource apply only to the alternative GUI. Client Program Resources

    defConfig            1                              Int
    defNFrames           0                              Int
    tileBorderWidth      3                              Int
    tileBorderColor      9                              Int
    autoscale            False                          Boolean
    antialias            False                          Boolean
    antialiasType        boxcar                         String          (1)
    tileFrames           False                          Boolean
    highlightFrames      True                           Boolean
    gui                  default                        String          (2)
    imtoolrc             /usr/local/lib/imtoolrc        String
    invert               False                          Boolean
    memModel             Fast                           String          (3)
    basePixel            64                             Int
    maxColors            216                            Int
    cmapInitialize       False                          Boolean
    cmap1                none                           String          (4)
    cmap2                none                           String          (4)
    cmapDir1             none                           String          (5)
    cmapDir2             /usr/local/lib/imtoolcmap      String          (5)
    input_fifo           /dev/imt1i                     String          (6)
    output_fifo          /dev/imt1o                     String          (6)
    unixaddr             /tmp/.IMT%d                    String          (7)
*   ism_addr             /tmp/.ISM%d                    String          (8)
*   ism_task             "ism_wcspix.e wcspix &"        String          (9)


  1. Options: nearest, bilinear, area, blkavg, boxcar, lowpass, gaussian
  2. Either the string 'default' or the path to a valid GUI file
  3. Options: fast, small, beNiceToServer
  4. Name of a colormap file in the cmapDir[1|2] directory
  5. Path to directory of valid colormaps
  6. Path to FIFO pipe
  7. Unix socket path, a '%d' is replaced with the uid
  8. Unix socket path, a '%d' is replaced with the uid. This is the socket used by plug-ins to negotiate a socket, once connected the actual communications use a different socket.
  9. Command used to start the default WCS/Pixel readout ISM task.

GUI Resources
    autoscale            True                           Boolean
    zoomfactors          1 2 4 8                        String
    displayCoords        True                           Boolean
    displayPanner        True                           Boolean
    displayMagnifier     False                          Boolean
    blinkRate            1.0                            Real            (1)
    pannerArea           150*150                        Geometry
    pannerGeom           -5+5                           Geometry
*   magnifierArea        100*100                        Geometry
*   magnifierGeom        +5+5                           Geometry
    wcsboxGeom           -5-5                           Geometry
    maxContrast          5.0                            Real
*   showToolBar          False                          Boolean
*   showPanelBar         False                          Boolean
    warnings             True                           Boolean
*   centerBoxSize        5                              Int
*   peakCentroid         True                           Boolean


  1. Value represents blink rate in seconds

Main Image Window (Gterm) Resources
    cmapName             image                          String          (1)
    basePixel            64                             Int
    warpCursor           True                           Boolean
    raiseWindow          True                           Boolean
    deiconifyWindow      True                           Boolean
    ginmodeCursor        circle                         Cursor
    ginmodeBlinkInterval 500                            Int             (2)
    color0               Black                          Pixel
    color1               White                          Pixel
    background           Black                          Pixel
    foreground           White                          Pixel
    width                512                            Int
    height               512                            Int


  1. Any user-defined name is acceptable
  2. Value represents blink rate in milliseconds

2.12 Summary of Command-Line Options
    -basePixel <num>                 Base colormap pixel
    -cmap1 <file>                    User colormap 1
    -cmap2 <file>                    User colormap 2
    -cmapDir1 <dir>                  User colormap directory
    -cmapDir2 <dir>                  Default colormap directory
    -cmapInitialize <bool>           initialize colormap
    -cmapName <name>                 Set Colormap name
    -config <num>                    Set initial config number
    -defgui                          Print default GUI and exit
    -displayPanner <bool>            Display Panner box
    -displayMagnifier <bool>         Display Magnifier box
    -displayCoords <bool>            Display WCS Coords box
    -fifo <pipe>                     Fifo pipe to use for connection
    -fifo_only                       Use fifo only for display
    -gui <file>                      GUI file
    -help                            Print help
    -imtoolrc <file>                 Set frame buffer configuration file
    -inet_only | -port_only          Use inet only for display
    -invert                          Start with inverted colormap 
    -ismdev <dev>                    ISM device (socket) template 
    -maxColors <num>                 Max number of image colors to allocate
    -memModel <type>                 Memory model (fast|small|beNiceToServer)
    -nframes <num>                   Number of frames to create at startup
    -port <num>                      Set inet port to use for connection
    -printConfig <name>              Set printer config file
    -tile                            Start in tile-frames mode
    -unix <name>                     Set unix socket to use for connection
    -unix_only                       Use only unix socket for display
    <file>                           File to load at startup


3.1 New Widgets

As part of the OBM modifications two new widgets were added to the toolkit. The widgets were also added to the LISTRES application in the X11IRAF sources which can be consulted for a complete list of resources. LISTRES is not normally built with the system but is installed locally on the NOAO/IRAF development machines. To build it yourself:

        % cd /<path>/x11iraf/obm/listres        # go to the source directory
        % xmkmf                                 # create the Makefile
        % make listres                          # compile the task

It may then be used as e.g. "listres <widget>" to print a full list of resources for the named widget.

3.1.1 Tabs Widget

The Tabs widget is a composite widget providing an "index tab" appearance to it's child widgets. The children will normally be layouts of more complex panels such as is done for the XImtool Control Panel. Only the children of the active Tab are visible, the contents of other Tabs are not displayed until that Tab is raised by selecting it with the mouse and the left mouse button.

A new Widget class command was added to allow GUI control of the active Tab (e.g. to programmatically raise a Tab). This command is of the form

        send <tab> setTop <name>

where <tab> is the name of the Tab widget, and <name> is the name of the child widget to be raised. Only one Tab widget is required to handle child widgets, the Tabs will be created automatically.

The widget code was also modified slightly to allow specific resource values to hide the appearance of the widget from the display, e.g. to completely change the appearance of a panel's layout by invisibly raising a different Tab. For instance, assuming we have a Tab widget called 'opPanels' with several child widgets containing layouts of other widgets, the following resource settings will hide the parent Tabs widget:

    *opPanels.font:                             nil2
    *opPanels.height:                           0
    *opPanels.width:                            0
    *opPanels.borderWidth:                      65535
    *opPanels.internalWidth:                    32765
    *opPanels.internalHeight:                   32765

Essentially we set NULL labels and sizes and values for the borderWidth and internalHeight/Width that have the same bit pattern as a negative value which internally means the borders are not drawn. The GUI callback code can then use the setTop Widget method to raise the desired Tab meaning the entire panel will change layouts automatically. This has advantages over simply unmapping/mapping the layouts as it doesn't create a window resize event which may cause the panel to "flash" during the change.

An example GUI for this widget is in x11iraf$guidemo/tabs.gui

3.1.2 ListTree Widget

The ListTree widget provides a nested list of items, where each item is either a terminal item in a list, or another list. Lists may be "open" meaning their contents are displayed, or "closed" meaning they are shown as an individual item. This widget can best be used to represent e.g. contents of a directory or sections/subsections of a document.

A new Widget class command was added to allow GUI control of the list contents. This command is of the form

        send <listree> setListTree <nested list>

where <listree> is the name of the widget, and <nested list> is a list of items to be displayed. This list should be a valid Tcl list, where items in the list may be lists themselves to produce the nested format. All ListTree widget are initially presented with the embedded lists "closed". There is presently no way to append the contents of the list, the entire list must be redefined with the above command. For example, the command

  send list setListTree {a1 {b1 { {a2 {a3 b3 c3 d3}} { b2 {z1 z2}} } } c1}

would produce a nested list such as


Specifying the lists is a bit complex, but this widget is a nice way to handle something like a table of contents in online documentation.

An example GUI for this widget is in x11iraf$guidemo/ltree.gui

3.2 Dynamic Widget Creation

In the original implementation of the OBM, the GUI is created or defined using the 'appInitialize' and 'createObjects' server commands. appInitialize initializes the X display but the 'resources' argument just sets the fallback resources for the application. A 'createObjects' call then queries the fallback resource database (either by a named resource o the 'objects' resource by default) to get the widget tree and then parses that as a string to actually create the widgets in the OBM.

The initial example GUIs all defined an "objects" resource as the way to define the widgets and all the subsequent GUI tasks followed that form, however appInitialize requires only a string of resource definitions ('object' resources or otherwise), and createObjects can take an argument as to which resource value specifies the widgets to create. For dynamic widget creation all that's really required is that we have a way to append the fallback resource database with a new list of widgets.

The solution then was implement a new 'appExtend' server command that simply sends a new resource string to the OBM to be merged into the fallback resource database. A plug-in would call this to load the widgets, then call createObjects naming the resource to realize the widgets. The new widgets are created as though they were specified from the start and can receive messages, be destroyed, etc. The appExtend server method essentially works by

  1. getting the fallback resource database
  2. convert resource string arg to a new resource database
  3. combine the two resource databases
  4. write the combined database back as the new fallback database

For example, the plug-in code for a "Hello, World" GUI panel would look something like

     appExtend {
             toplevel        TopLevelShell   testPanel\
             testPanel       Form            testForm\
             testForm        Label           testLabel\
             testForm        Command         testQuit
         *testLabel.label:                   Hello, world!
         *testQuit.fromHoriz:                testLabel
         *testQuit.label:                    Quit
     createObjects test_objects
     send testPanel map

This code could be uploaded by an ISM plug-in and sourced as Tcl code in a callback. It's also possible to define objects w/ existing parents meaning a plug-in can add buttons to menubars or panels when they first connect (e.g. a plug-in can add a new activation button for it to an existing menubar on the GUI).

The ability to dynamically create widgets means that plug-in modules can create their own GUI components, but it also means that meta-widgets such as Help panels, Image Display panels, etc can be recycled from a library of code. To use this effectively, however, some rules need to be established for an object naming convention, protocols for adding/deleting callbacks and event handlers, and some method of object orientation is desired in the Tcl code to make having multiple instances of a meta-widget in a GUI easier to handle. These details are still largely TBD, the basic functionality now exists in this version but may change as we take advantage of it and implement new plug-in tasks or meta-widgets.


4.1 Display Protocol Changes

The IIS display protocol used was modified to conform to the XImtool and IRAF changes implemented for the support of WCS mapping information. These are detailed in section 5.1 below.

Unlike the IRAF IMD interface changes though, the WCS version can be determined when the CDL is first opened so no explicit call to query this is required by CDL applications. Tasks may still set/retrieve mapping information and assume this is handled automatically by the interface. The hi-level routines for displaying FITS or IRAF images will also send the mapping information automatically, it's only when using the low-level cdl_displayPix() routine or setting the WCS explicitly where the mappings need to be set by the application.

Changes remain completely backwards compatible so client tasks need to be modified only to support the new XImtool features.

4.2 New Procedures

Three new public interface procedures were added in addition to the internal changes made to support image mappings:

4.2.1 C Calling Sequence

 valid = cdl_setMapping (cdl, region, sx,sy,snx,sny, dx,dy,dnx,dny, ref)
  stat = cdl_getMapping (cdl, region, sx,sy,snx,sny, dx,dy,dnx,dny, ref)
stat = cdl_queryMapping (cdl, wcs, region, sx,sy,snx,sny, dx,dy,dnx,dny, objref)

Where the arguments are defined as

    cdl               - CDL package pointer returned by cdl_open()
    region            - user-defined name for the region (e.g. 'image',
                        'subras1', 'ccd3', etc).
    sx, sy, snx, sny  - source rect in the object
    dx, dy, dnx, dny  - destinaton rect in the display frame buffer
    ref               - full node!/path/image[sec] image name, same as
                        was immap'd when the image was displayed.  Used
                        for access after the display
    wcs               - WCS number for a specified mapping

4.2.2 F77 Calling Sequence
           cfsetmapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, ref, ier)
           cfgetmapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, ref, ier)
         cfquerymapping (wcs, region, sx,sy,snx,sny, dx,dy,dnx,dny, objref, ier)

Where the arguments are defined as above and 'ier' is an error status code.

4.2.3 SPP Calling Sequence
         cdl_setMapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, ref, ier)
         cdl_getMapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, ref, ier)
       cdl_queryMapping (wcs, region, sx,sy,snx,sny, dx,dy,dnx,dny, objref, ier)

Where the arguments are defined as above and 'ier' is an error status code.

4.3 Demo Task Updates


5.1 IIS Protocol Changes

For backwards compatability none of the existing IIS protocols were modified completely, however we take advantage of unused registers to flag the new features in existing functions (like read/write WCS). The WCS mapping changes required only that the unused 'x' register be set to indicate the new behavior was desired, e.g. the wcs text containing the extra mapping data.

We also added two new WCS calls that allow us to query the WCS version, or query a WCS by a specific number corresponding to a mapping. The WCS version query will return a string such as "version=10" which can be parsed by the client to get a version number '10' (corresponding to version 1.0).

Because of the added mapping text the WCS string length was increased from 320 to 1024 bytes, the string length used internally depends on whether the 'x' register has been set.

Support for the full 16 frames allowed by the bit-flag 'z' register in the IIS header packet required the masking values be changed at various places in the code. This was more a limitation of the initial implementation than a required change to the protocol.

A complete summary of the XImtool IIS protocol implementation follows.

5.1.1 IIS Protocol Summary

                                   IIS Header Packet Summary

                      TID            Subunit     Tct   X   Y    Z   T    Data
Read Data     | IIS_READ|PACKED  | MEMORY      | -NB | x | y | fr | - | nbytes |
Write Data    | IIS_WRITE|PACKED | MEMORY      | -NB | x | y | fr | - | nbytes |
Read Cursor   | IIS_READ         | IMCURSOR    |  -  | - | - | wcs| - | -      |
Write Cursor  | IIS_WRITE        | IMCURSOR    |  -  | x | y | wcs| - | -      |
Set Frame     | IIS_WRITE        | LUT|COMMAND | -1  | - | - | -  | - | 2      |
Erase Frame   | IIS_WRITE | fb   | FEEDBACK    |  -  | - | - | fr | - | -      |
              |                  |             |     |   |   |    |   |        |
Old Read WCS  | IIS_READ         | WCS         |  -  | - | - | fr | - | 320    |
Old Write WCS | IIS_WRITE|PACKED | WCS         | -N  | - | - | fr |fb | 320    |
              |                  |             |     |   |   |    |   |        |
WCS Version?  | IIS_READ         | WCS         |  -  | 1 | 1 | -  | - | 320    |
WCS by Num.?  | IIS_READ         | WCS         |  -  | 1 | - | fr |wcs| 1024   |
New Read WCS  | IIS_READ         | WCS         |  -  | 1 | - | fr | - | 1024   |
New Write WCS | IIS_WRITE|PACKED | WCS         | -N  | 1 | - | fr |fb | 1024   |


        nbytes | NB  = number of bytes expected or written
        x            = x position of operation in frame buffer coords
        y            = y position of operation in frame buffer coords
        fr           = frame number (passed as bitflag (i.e. 1, 2 ,4 8, etc)
        fb           = frame buffer config number (zero indexed)
        N            = length of WCS string
        wcs          = WCS number (usually zero)
        Data         = the number of bytes of data to be read or written
                        following the header packet.

        IIS_WRITE    = 0400000
        IIS_READ     = 0100000
        COMMAND      = 0100000
        PACKED       = 0040000
        IMC_SAMPLE   = 0040000

        MEMORY       = 001
        LUT          = 002
        FEEDBACK     = 005
        IMCURSOR     = 020
        WCS          = 021

5.2 IRAF 'imd' Interface Changes.

In order for the XImtool ISM task map exactly the same image that was passed into the task displaying the image (i.e. the fully qualified node!path prefix including any image section or kernel args). It was necessary to modify the IIS SetWCS command to contain extra information at the end of the normal WCS text. This is passed from XImtool to the ISM at the time of the display if an ISM is already running, or when the ISM first connects thereafter.

To maintain complete backwards compatability it is not possible to bury this change in the internals of the interface, therefore it will be necessary for all tasks using the IMD interface to display images to make revisions to use the new features. Tasks which are not changed will continue to work, XImtool will simply disable the ISM when the display client connects without indicating it is able to pass mapping information. Client tasks, modified or not, will also continue to work when connecting to "mapping unaware" display servers since the interface only send the extra mapping information to servers which are expecting it.

To modify a task to make use these changes, there are just a few routines you need to be aware of:

    imd_wcsver()  - Query the server for new capabilities.  Returns a
                    non-zero version if the server can use the new
                    mapping functionality.

imd_setmapping()  - Set mapping data to be sent with next imd_putwcs() call

imd_getmapping()  - Get mapping data returned with last imd_getwcs() call.
                    returns a non-zero status if valid mapping available

 imd_query_map()  - Given a WCS number return the mapping data.  Returns a
                    non-zero status if valid mapping available

where the calling sequence is

         imd_setmapping (reg, sx,sy,snx,sny, dx,dy,dnx,dny, objref)
 valid = md_getmapping (reg, sx,sy,snx,sny, dx,dy,dnx,dny, objref)
 status = md_query_map (wcs, reg, sx,sy,snx,sny, dx,dy,dnx,dny, objref)
   version = md_wcsver ()

In order to maintain compatability with existing servers as well as take advantage of the new ximtool features, the idea is that all interfaces will remain the same and any program wishing to use these features will need a slight modification to 1) determine whether mappings are supported via a call to imd_wcsver(), and 2) use the new imd_[sg]etmapping() procedures to set and retrieve the mapping information. imd_query_map() can be used to query for the mapping using the wcs number returned from e.g. a cursor read. Details and examples of these modifications are included below.

5.2.1 Program Initialization

For a program to use mappings it must first query the server to see if this is supported, the reply also serves to initialize the imd interface. This is done using the imd_wcsver() call. For example, in the DISPLAY task during startup one would do something like

        # Query server to get the WCS version, this also tells us whether
        # we can use the all 16 supported frames.
        if (imd_wcsver() == 0)
            call clputi ("display.frame.p_max", 4)
            call clputi ("display.frame.p_max", 16)

The call to imd_wcsver() in this case is used to reset the number of allowed frames depending on the server capabilities.

This call is REQUIRED before mappings can be used by the interface. Internally, the interface defaults to a "version" of zero meaning the server does not support mappings, once the procedure is called the server reply value is stored in the interface common and returned as the function value. The return value is always an integer, zero means the server does not support mappings and a non-zero value is the WCS version number of the display change (e.g. a value of 10 is version 1.0, 11 is 1.1, etc).

A 'disable_wcs_maps' boolean environment variable can be set by the user to force this procedure to always return zero and disable mappings in case a problem is found after release or the old behavior is desired.

5.2.2 WCS Text Changes

Without getting into the details, if a server is found to be capable of using mappings in the imd_wcsver() call, the WCS string sent/read will have two additional lines of information to define the mapping. Specifically,

        name - title\n
        a b c d tx ty z1 z2 zt\n
        region_name sx sy snx sny dx dy dnx dny\n

where the new parameters are defined as

    region_name       - user-defined name for the region (e.g. 'image',
                        'subras1', 'ccd3', etc).
    sx, sy, snx, sny  - source rect in the object
    dx, dy, dnx, dny  - dest rect in the display frame buffer
    object_ref        - full node!/path/image[sec] image name, same as
                        was immap'd when the image was displayed.  Used
                        for access after the display

Since the interfaces remain the same a separate imd_setmapping() or imd_getmapping() call is required to set/get the additional mapping data. For example, to set the WCS:

    # Set the mapping info to be written with the WCS.
    call imd_setmapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, objref)

    # Write the WCS and mapping info to the data.
    call imd_putwcs (ds, frame, Memc[imname], Memc[title],
        a, b, c, d, tx, ty, W_ZS(wdwin), W_ZE(wdwin), W_ZT(wdwin))

To read the frame WCS:

    # Query the server for a wcs.
if (imd_getwcs (frame, server, image, sz_image, title, sz_title, a,b,c,d, tx,ty) == OK) { # If we got that okay, get the mapping information returned. if (imd_getmapping (reg, sx,sy,snx,sny, dx,dy,dnx,dny, obj) > 0) { : } }

In all cases if the imd_wcsver() initialization says the server can't do mappings these calls will be no-ops.

For multiple-image displays to a single frame it's important to remember that the default WCS for the frame will be the *last* WCS set by the client. For example, a mosaic display can set a wcs and mapping for each of the subrasters, but a final SetWCS call is required to define an overall WCS for the frame defining the "detector coords". Note that the 'objref' string should include the MEF extension number so it's mapped properly by the ISM.

5.2.3 Cursor Reads

The imd_query_map() procedure is used to return the mapping for a particular WCS number, such as that returned by a cursor read. It will do a new WCS query for this regardless of a previous imd_getwcs() call. Typical usage would be something like the following in IMEXAMINE:

procedure t_imexamine ()
    wcsver = imd_wcsver()
    while (ie_gcur (ie, curtype, x,y,wcs, key, cmd, SZ_LINE) != EOF) {
        if (imd_query_map (wcs,reg,sx,sy,snx,sny,dx,dy,dnx,dny,imname) > 0) {
            .... add image name to list

[NOTE: in this example the ie_gcur() procedure was modified to return the wcs from the cursor read.]

The WCS number returned by a cursor read now corresponds to the object id used in the server. It still contains the frame number as before, but the wcs number itself is used to identify the mapping.

5.3 ISM Communications

The ISM (Image Support Module) can be any external task which connects to XImtool over a socket. Communications are limited to simple null-terminated text strings. In most cases these strings are just the standard OBM messages sent to XImtool objects but can also include Tcl callback code (either ISM-specific callbacks, procedures which can be added to the callback list for existing XImtool objects, or even new GUI code to create panels and new objects).

5.3.1 Socket Connection

The ISM first requests a connection to XImtool on a dedicated socket whose default value is "/tmp/.ISM%d", where the '%d' is replaced by the userid allowing multiple users on a machine to have independent sockets. The XImtool 'ism_addr' resource or "-ismdev" command-line option can be used to change this address, a value of 'none' will disable ISM communications. The socket may also be set with an ISMDEV environment variable which will override the resource or command-line options.

Once a connection request is received, XImtool replies with a message telling the ISM to reconnect on a different socket, it then frees the initial connection allowing multiple other ISMs to request their own connection. The communications between XImtool and the ISM are carried out entirely over this second negotiated socket. Once connected, the ISM appears as just another named object which can receive OBM messages.

5.3.1 Communications Protocol

Messages from the ISM are written to the connection socket and must be preceeded by one of the following keywords:

    callback            Negotiate a connection on another socket
    ready               Client is ready to begin processing
    quit                Client is shutting down and disconnecting
    send                Send a message to another object

Messages are of the form:

All messages must be null-terminated. XImtool will buffer the text until a complete message is received. Once an ISM client has delivered a QUIT message no further messages will be sent the that ISM.

In OBM terminology the ISM is a named Client class object, where the name is set in the connection request. Messages sent to the ISM should use this name, messages sent to "client" are still interpreted to mean the XImtool client.

The content of messages delivered to the ISM are totally free-form and may contain any text the ISM is expected to understand.

5.3.3 GUI Objects

While the ISM can send a message to any object in the task, there is a GUI Parameter object called 'ism_msg' designed especially to process messages from the ISM. The callback in the GUI is expecting a message beginning with one of the following keywords:

    source        Source message text as Tcl code
    alert         Message contains error text to be displayed in the
                  GUI 'alert' box
    deliver       Message text should be passed to a callback routine
                  specific to that ISM.  This processing callback may
                  have been previously uploaded.  The message text
                  may be any form the processing callback is expected
                  to understand.
    info          Message text is status output intended for the
                  XImtool 'info' panel (connect/disconnect requests, etc)

In all cases the message is expected to be of the form

      <cmd> <ism_name> [ <arg1> <arg2> <...> ]

where <cmd> is one of the above keywords, <ism_name> is the name of the ISM sending the message. The remainder of the message is passed as an 'argv' list to the processing callback uploaded for the ISM. The ISM is responsible for formatting these messages.