========================= ShowGIF V2.1 ========================= Feb. 10, 1995 Copyright (c) 1994/95 by Roman Hiestand Copyright notice ---------------- The program ShowGIF and its documentation are written and copyrighted by Roman Hiestand. They may be distributed freely providing the following restrictions are satisfied: - Distributors may not charge more than the cost of a diskette used in the distribution of this program. - Distributors may only distribute the unmodified copy of the original program, along with it's documentation, and copyright notices intact. - Commercial distribution is only possible with written permission from the author. Disclaimer ---------- This program and its documentation is provided "as is". No warranties are made with respect to the accuracy, reliability, performance or operation of this software and information. You are using this program at your own risk. The author is not liable for any damages that may have been caused by using this software. Description ----------- ShowGIF is, as the name says, a GIF viewer for the Picasso-II graphics board of VillageTronic. The program can be started from CLI or Workbench with one or more file names/icons. If the program cannot load an image (because you didn't submit a filename or the file doesn't exist), a file requester pops up. Usage ----- From CLI: ShowGIF Image [...] Template: FILES/M,BUF/N,DELAY/N,NOCENTER/S,VERBOSE/S,ALL/S FILES/M: One or more filenames to be viewed If no filenames are given or the files weren't GIFs, a file-requester pops up. BUF/N: Specify the FileBufferSize in KB, like BUF 100 DELAY/N: Specifies the delay in seconds after showing the picture. If none is given, the program waits for a key or a mousebutton. Remember: during this delay, the program can't be stopped ! NOCENTER:Normally, a picture is centered on the screen. If you don't want this behaviour, set NOCENTER. VERBOSE: Display name and resolution of the image and the screen. ALL: Search all subdirectories for the specified pattern. (see also Pattern matching below) Examples: ShowGIF BUF=5 SYS:Images/Globe.gif ShowGIF DF0:Pictures/Mercedes.gif DF0:Pictures/Family.GIF BUF 10 DELAY 5 From Workbench: - Default Tool: Specify ShowGIF as the default tool of an image - Multiple selection: With the shift-key pressed, select an image and double-click on ShowGIF's icon. The arguments DELAY, NOCENTER and VERBOSE can also be accessed from WB via ToolTypes. Features -------- - fully programmed in assembler - uses a file buffer (50 KB by default) - CLI or WB start - very system-friendly - (nearly) pure - can be aborted at anytime (except during a crash ... :-) ) (with Ctrl-C, since V2.1 also with Escape) - no 'light' background (since V1.1) - file requester (since V1.2) - FileBufSize can be specified (since V1.3) - supports entire GIF87a standard (local color maps, interlaced images, multiple images, since V1.5) - supports partly GIF89a standard (comment/plain text extension) - Parameters via WB/ToolTypes (since V1.8) - Pattern matching (since V2.0) - NoDrop feature (since V2.1, see below) About being 'nearly' pure: You can safely make this program resident. You can run ShowGIF as many times as you want, if you run one *after* the other. A problem *can* arise when you run two or more ShowGIF's at the same time. The only part that is not pure is where it opens the screen and the window. This time is quite short, and it is very unlikely to happen that two ShowGIF's interfere. By the way, have you ever tried to view two images at the very same time ? (Not very useful, ay ?) The NoDrop feature ------------------ ShowGIF tries to open a screen above the previous one. This avoids 'flickering' by switching back to the Workbench resolution. Your monitor will be thankful... If the memory is low and a second screen can't be opened, the first one is closed first and the screen is opened again. Pattern Matching ---------------- (NB: * only works if you use WildStar or a similar program. Use #? instead) Since V2.0 pattern matching is implemented. As this is a complex matter and it's not really the same in every program, I describe it in this chapter. ShowGIF splits your supplied pattern into two parts: ShowGIF DF0:Pictures/*.gif | Path || pattern \ - The easy case: the path is not a pattern ShowGIF just searches the pattern in the supplied path and displays every picture found. Example: ShowGIF DF0:Pictures/*.gif displays every picture in DF0:Pictures with .gif at the end. ShowGIF DF0:Pictures/A* displays every picture in DF0:Pictures starting with A or a. If you add 'ALL', the supplied path is taken as a starting point. Every subdirectory is now searched for the pattern. Example: ShowGIF DF0:*.gif ALL displays every picture in DF0: and its subdirectories with .gif at the end. - The complex case: the path is a pattern ShowGIF searches now every path that matches the path pattern for the file pattern. The same with 'ALL', but now every subdirectory is searched too. Example: ShowGIF DH0:G*/A*.gif displays every picture in DH0:Graphics, DH0:Games ... that matches A*.gif (A at the beginning and .gif at the end) ShowGIF DH0:G*/A*.gif displays every picture in all subdirectories of DH0:Graphics, DH0:Games ... that matches A*.gif Of course, every standard pattern matching characters can be used: ? Matches any single character # Matches zero or more of the following character | Separates OR clauses * Matches any number of arbitrary characters (only with WildStar) Examples: - *.gif matches Mercedes.gif, Family.gif ... - #a.gif matches .gif, a.gif, aa.gif, aaa.gif ... - A* matches Ape.gif, a.gif, Amiga.gif (but also: Amiga.gif.info !) - a(b|c).gif matches ab.gif and ac.gif Pattern matching is NOT case sensitive. Requirements ------------ Kick 2.0 and vilintuisup.library version > 2.0. Bugs ---- - VERBOSE may display data in wrong order with multiple images The problem is: I haven't got any GIFs with local colors, multiple images or plain text extensions. So I couldn't test it. I think, it works, but I'm not sure. If you find a bug, please report it to me together with as much information as possible that could help me to fix it: your computer, configuration, kick version and so on. Future plans ------------ - view images larger than the largest screen available - reduce colors (NB: don't expect anything in the near future !) Notes about this program ------------------------ The Graphics Interchange Format(c) is the Copyright property of CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe Incorporated. This program has been fully written in assembler. It is therefore very short and quite fast. The GIF decoding algorithm is mainly based on the c-source (jrdgif.c) of the jpeg software (version 4 of the jpeg software release), which itself is based on giftoppm. Many thanks to the JPEG group ! (Even if their real goal is to provide the JPEG-standard, not software for GIF :-) ) ShowGIF is pretty much optimised. Not only by the assembler (PhxAss is GREAT! Thanks to F. Wille), but also by hand. At this time, I can't think of another optimisation. When I compared ShowGIF to VT, I was pretty surprised because I didn't expect VT being so fast. Maybe I overlooked a couple of optimisations ... Comparison table ---------------- (Not representative) ShowGIF V2.0 ViewGIF 1.6 VT_Picasso V2.1 ReadGIF V1.249 from VillageTronic (J.Weinelt) ------------------------------------------------------------ Executable size 3848 19376 84584 12276 display time (~,secs) 11 33 15 24 Mem needed (~) 1.12 MB 1.18 MB 2.41 MB 1.17 MB Time & mem are measured with 'globe.gif' (547365 bytes, 912x900), a beautiful picture of the Venus from NASA. Program & image are on harddisk. The memory is measured including display memory (~1.03 MB). These are just typical values. The differences in speed become smaller with smaller images and larger if the image is on ram-disk. Revisions --------- 1.0 - first public release 1.1 - added support for interlaced images now fills background with darkest color 1.2 - file requester added 1.3 - now checks for Ctrl-C (requested by Markus Illenseer) corrected a bug in GetCode added CLI-option BUF 1.4 - Multiple images supported Output window for workbench Faster ~10 % 1.5 - Doesn't quit anymore if GIF-revision is >89a Supports Local color table Correctly processes (skips) GIF89a extension blocks CLI-option DELAY some small optimisations 1.6 - Now supports some GIF89a extensions even faster ! 1.7 - Slightly faster (~10%) and shorter 1.8 - Added Center-behaviour, NOCENTER option VERBOSE option added ToolTypes parsing 2.0 - Pattern matching (this is worth skipping 1.9 :-) 2.1 - Added NoDrop behaviour (requested a long time ago by Christian A. Weber and Henning Sauer) Escape now quits the program like Ctrl-C Address ------- I can be reached at Roman Hiestand Luziaweg 15 CH-8807 Freienbach Switzerland Fax: CH-055/48 26 37 email: rhiestan@iiic.ethz.ch