ShowDT 1.3 (5.2.94) -- Scaling Datatypes Picture Viewer ======================================================= ShowDT is a 11K viewer for any datatypes-supported picture format. Currently, there are datatypes for ILBM (including HAM and HAM8, but not IFF24), PCX, GIF, JPEG, BMP and MacPaint format images, with more on the way (these datatypes are available separately; on Aminet, they are in the os30/dtype directory). This viewer also supports proportional scaling to screen size of pictures. This works best for scaling down (up to about 60 to 70%) and up (to about 120%). Further expansion and contraction produces distorted areas in the picture. The effect is best with pictures with many colors and which do not contain text. COPYRIGHT ========= ShowDT is Copyright (C) 1994 Chris Lawrence. This picture viewer is freely distributable, provided that the executable is not modified or renamed and that this documentation file is included. Permission is given to change the icons of the files to more accurately reflect your application and/or to improve appearance (MagicWB, etc). USAGE ===== From Workbench: --------------- Double-clicking on the ShowDT icon will bring up a file requester to select one or more files to view. Choose a file in the requester and then press RETURN or select "Ok". The picture (possibly after a few seconds of processing time) will be displayed. Once you are done with the picture, click the left mouse button, and the file requester will pop up again or the next picture will be displayed. Select "Cancel" in the file requester when you are done viewing pictures. Click once on the ShowDT icon and then shift-double-click on one or more picture icons for immediate display. You can also make ShowDT the default tool of a picture and launch ShowDT that way. This behavior can be modified by Tool Types; see below. From the Shell: --------------- Syntax: ShowDT [filename] [options] Type 'ShowDT' followed by one or more filenames. If you do not specify a filename, the file requester will be presented. This behavior can be modified by command line options; see below. WHILE A PICTURE IS BEING DISPLAYED ================================== While you are viewing a picture: Press 'N', the right cursor, or the left mouse button to show the next picture. Press 'P', the left cursor, or the right mouse button to show the previous picture. Press up cursor to see the first picture. Press down cursor to see the last picture. Press 'Q' or Escape to return to the file requester. Press 'R' to redraw the current picture. TOOL TYPES AND COMMAND LINE OPTIONS =================================== Tool Types must be entered in the ShowDT icon, as project Tool Types are not yet supported. Command line options can be entered on the command line after typing 'ShowDT' and an optional filename. The options supported are as follows: ONCE: Don't ask to any more files after those chosen the first time. SHOWINFO: Show picture name and resolution in the current Shell window or a Workbench Output window. If scaling is done, the size of the scaled output is also shown. SCALE: Enable bitmap scaling. The bitmap may not be scaled if one of the following conditions is met: 1) You run out of graphics memory. 2) The picture is already the maximum size for the selected display mode. 3) The picture is HAM or HAM8. SCALE works best with the BESTID and Monitor options. If SCALE is not enabled, the picture will be loaded as a autoscrolling bitmap if it exceeds the screen size. More control over scaling can be exercised by the SCALEMODE option. SCALEMODE: Gives more control over bitmap scaling. SCALEMODE=ALL -- Scale all pictures SCALEMODE=NONE -- Don't scale any pictures (default) SCALEMODE=UP -- Scale only pictures that are smaller than the displayed screen size. SCALEMODE=DOWN -- Scale only pictures that are larger than the displayed screen size. The bitmap may not be scaled if one of the following conditions is met: 1) You run out of graphics memory. 2) The picture is already the maximum size for the selected display mode. 3) The picture is HAM or HAM8. Scaling works best with the BESTID and Monitor options. If scaling is disabled, the picture will be loaded as a autoscrolling bitmap if it exceeds the screen size. MODEID: Allows the user to enter a 32-bit DisplayModeID for the picture. THIS MUST BE ENTERED IN DECIMAL. Useful for forcing higher resolution pictures to screen size. BESTID: Tells ShowDT to use the BestID function to determine the best available display mode for showing the picture. This will usually make ShowDT open a screen on the picture's native monitor that is closest to a Hires-Laced screen in aspect ratio. Mostly useful with Monitor options. MONITORID: Allows the user to enter a 32-bit monitor ID for the picture. This may be useful with the A2024 and RTG display boards. Most native Amiga monitors have a specific switch. Monitors: The following monitor names are shorthand for MONITORID= You may need to put these in Devs:Monitors before use. DEFAULT: The default monitor on your Amiga. With Mode Promotion off, this is the Boot Menu NTSC/PAL selection. With MP on, it is the DBLNTSC/DBLPAL equivalent of this selection. NTSC, PAL: Standard monitors. Useful for forcing a NTSC picture to PAL on a PAL monitor, for example. VGA or MULTISCAN: The Multiscan monitor. Useful for showing VGA GIF and VGA PCX pictures. EURO36: A European monitor that acts like NTSC. EURO72: A European monitor that acts like MULTISCAN. DBLNTSC, DBLPAL: Scan-doubled equivalents of NTSC and PAL. Useful for forcing pictures to be scan-doubled. SHOWMODEINFO: Tells ShowDT to display the ModeID of the picture and the mode that it is converted to (if applicable). DIRECTORY: Specify starting directory for file requester. SHOWTIME: Display the time it takes to obtain the picture and set up its display, including scaling. NOTE: It is not recommended that you use ShowDT with a pre-AGA system, as most Datatypes convert to 8 bitplane data. WARNING: ShowDT has problems with old-style ILBMs (ILBMs with 8-bit color information, rather than the current 32-bit). A conversion program may be helpful in this regard. OTHER STUFF =========== Contacting the author: ---------------------- Snail Mail: Chris Lawrence RHIT Box 1137 5500 Wabash Avenue Terre Haute, Indiana 47803-3999 BUG REPORTS: (Please give as much info as you can) Fastest response will be via EMail. Internet mail: Christopher.Lawrence@Rose-Hulman.Edu Future plans: ------------- * Hard-coded support for RTG monitors * Support for V40 animation.datatype (?) * Better/faster scaling algorithm (now uses BitMapScale()) * AppIcon and AppWindow * Docs in AmigaGuide format REVISION HISTORY ================ This is ShowDT 1.3 (5.2.94), the second public release of ShowDT. Changes from ShowDT 1.2 (30.1.94): ---------------------------------- * More control over bitmap scaling * Cleaned up information output * Optional time information * Multiple files (slideshow) implemented * Documented undocumented DIRECTORY option Changes from ShowDT 1.1 (29.1.94): ---------------------------------- * Bitmap scaling added * Workbench Tool Types support * Various bug fixes