Club Amiga de Montreal - CAM/CAM_CD_1.iso/files/403.lha/Zhow_v1.2/Zhow.doc

Text File | 1990-07-27 | 8KB | 188 lines

            Zhow 1.2 - The ILBM Glider
            ==========================

          ® Jonas Petersson & Absolut Software (aka Sirius Soft)


"Oh no, yet another show program..."

  Well, you're right. I HAD to write it since no other program seemed to
be written with any USEFULNESS in mind. Ok, there are quite a few that
probably works well with a 640x200 Amiga but how about Europe? Not to
mention the really BIG pictures, you know that the Amiga officially
supports resolutions that is 1Kx1K? Wouldn't it be nice to be able to
look at them too...? As a bonus from the calculations needed to accomplish
these things you have the possibility to "ZOOM" into pictures that are hires
and/or interlaced.

  Another nice thing with this one is that it supports overscan and
(yeach) workbench - even multiselections. It also shows the picture on
a separate SCREEN, not only in a View, which means that it lets you
do other things on some other screen, like showing other pictures...

  1.1 doesn't show the workbench screen between the pictures but rather
an (almost) blank screen to make it serve better as a primitive slideshow.
The blank screen uses your workbench colors 0 and 1, so you can
choose your favorite colors (or make them the same if you don't like my
little commercial ;-).


Usage
-----

 Like any other show program but with a little feature:


   Zhow [-wWidth] [-hHeight] [-tTime] [-l] pictures

 When started with only the filename it will examine the picture size
and from that and the workbench screen size decide what size the new
screen containing the picture should be.

 When width and/or height are specified it will try to show the picture in
a screen of THAT size. The Time is the maximum no of seconds that the
picture will be shown. There is a little kludge if you happen to like naming
your file something beginning with a '-' and then 'w', 'h', 't' or 'l'. Solution
#1: rename you file ;-) , #2 give an illegal option (like '--') to terminate
the option parsing. BTW, you may specify as many options as you like -
only the last one counts...

 When the picture is bigger than the screen, you will be able to
scroll around so that your mouse pointer always is on the spot it should
have been if the picture had been the size of the screen. It might sound
a bit strange but once you've tried it, you'll like it.

 There is really one more difference using height&depth or not: If you
DON'T specify them, maximum screen usage is determined from the workbench
screen as described above, but if you DO specify you'll be able to look
att pictures in overscan. That is: any width up to 376 is shown in LORES
on a screen of suitable size. HAM pictures can, of course,be any width
they like, since there is no such thing as a HIRES HAM picture. Scrolling
in HAM pictures gives nice effects on the left side of the screen as anyone
with some knowledge of HAM understands.


 You can FREEZE the scrolling anytime by clicking the left mouse button.
Click it again to UNFREEZE. There is an invisible dragbar and also the
screen depth gadgets. They might be a bit hard to find on very small and
very big pictures though...

 You end by pressing the right mouse button or by pressing the ESC key
or by waiting for the timeout (if you specified one). Space key is also
a way to stop looking at a picture from v1.2 and onwards.

 NOTE: By specifying -l (for loop mode) you make the program loop through
the pictures for ever. This together with the -tTime option is useful for
a slide show. Also note that the one and only way out of this loop is
pressing the 'DEL' key - thus removing the keyboard makes the demo unstopable.
This 'DEL' key can also be used to terminate a 'nonlooping' script in case
you realise you don't want to see all of the pictures.


 Since it checks the workbench screen rather than doing some strange
assumptions, it doesn't matter whether you have NTSC or PAL och have
MOREROWed etc. You'll get the size you LIKE! Personnally I have two
"aliases":

    ILBM file  =>  zhow file
    ZOOM file  =>  zhow -w320 -h256 file

 The first one works like any ordinary show while the other one makes it
possible to examine a picture that is bigger than 320x256 closer.
On small pictures it won't matter which I use.


Notes:
------

 There seems to be a problem with screens that are smaller than about
32x32 pixels. The picture ends up like garbage all over the first 32 lines.
Seems like the problem isn't mine but rather CBM's... Not very much of
a picture anyway.

 These very small pictures may cause another problem: If the height is less
than the dragbar you will have trouble activating the picture once you
dectivate it. I use wKeys to avoid this.

 Another inconvenience shows up when scrolling around in an overscanned
picture: CBM seems to stop the mouse pointer from moving to positions
outside the workbench screen rectangle and thus prevents you from
scrolling to the corners. On the other hand - why should you ever want
to BOTH overscan AND scroll around? ONE of the alternatives is quite
enough to look at the whole picture...

 Right now it doesn't support color cycling. Let me know if you think
it's needed.

 No serious bugs found (yet?). It might even work nice with the new chip set
(that was my intention anyway). I've tried it with pictures as high as
1008 (maybe 1024) and as wide as 4096 - no problem.


Future enhancements
-------------------

 Possibly colorcycling and maybe scripts if there is an interest.
This version is a FAST one, but that means that it uses a lot of memory
when unpacking a big picture. I've been thinking of using a slower
unpacker in case the last AllocMem() for the work space fails. Unfortunatly,
that will make the program at bit bigger... We'll see. Argumentation for
leaving it out now goes something like this: If you don't have enough
memory to unpack it FAST, then you can't even THINK of loading it into
a paint program, so the picture isn't of much use for you anyway...

Next release will support the new 1.4 resolutions etc.

Revision history
----------------
1.1    Added ESC, timeout and (almost) blank screen during
    picture switches on demand from Matt Dillon, plus
    changed the option parsing.
1.1b    Fixed a problem concerning "double" masks and hires
        in pictures with too many colors due to too much overscan.
        (Poor Amy gets upset when you ask her to show a HIRES HAM)
1.2     Added SPACE as an alternative to ESC, the loop mode and
        DEL to terminate a slideshow on request from Jamie Zawinski
        <teak.Berkeley.EDU!jwz>. The reason for this version beeing
        some 1.5K bigger isn't that a lot of code was added but
        that I upgraded to Aztec 5.0 - compiling with 3.6a makes it
        just ~100 bytes bigger than 1.1b, but we're better safe than
        sorry, right?

Distribution
------------

 Zhow is not public domain. A friend of mine advised me to call it
"Freely Distributable Copyrighted" instead. That's close enough.
If You wish to include it with a commercial program feel free provided
that You send me a registered copy.

 Source code? You mean there is something to IMPROVE??? Right, send
me a message then and I'll think about it...


 Here is a list of "message ports" to me:

    Jonas 'Zaphod' Petersson
    Ö Farmvägen 36 B
    S-214 41 MALMÖ
    SWEDEN
    Phone: [phone]

    Sysop on Amiga User Group Sweden's BBS2 (AbsExecBase)
    IFNA 2:501/414  [phone], 300-14400 8N1 (HST)

    zaphod@{magrathea.sirius.se,slaka.UUCP}     /* These are Amigas! */
    [e-mail]            /* At work  */
    [e-mail]        /* Postgrad */
    [e-mail]        /* -- " --  */
    [e-mail]            /* Project  */
    [e-mail]            /* Not very reliable */


Feel free to send comments, bug reports (huh?), money, coke, beer, girls...

Just a "Hi, I liked your program" is just as good as a few bucks - I didn't
write this to make money out of it...