Almathera Ten Pack 3: CDPD 3/Almathera Ten on Ten - Disc 3: CDPD3.iso/scope/076-100/scopedisk88/mostra/mostra.doc

Text File | 1995-03-19 | 18.6 KB | 422 lines

                                Mostra

                        A Universal IFF Viewer



There are many utilities for viewing IFF ILBM files, but none I'd seen
until now met the goal of displaying every IFF picture; each had its
idiosyncrasies.  If one viewer could display overscan pictures, then
every picture with more than 640 pixels on a line would be shifted
like there were 700 pixels; some programs could only show a directory
of pictures by forcing the user to enter all the filenames; some
programs would crash with PAL pictures; others would do the same with
pictures larger than any screen; it was rare to have an option to
force a screen mode (for the tech-folks out there:  old IFF ILBM files
don't have the CAMG chunk!); there were no comfortable file requesters
for use when you didn't know the exact name of the file (who can
remember GRABBiT file names?); pressing the right mouse button could
cause a useless drag bar to corrupt the picture...

If a program had one feature, it lacked another, so I decided to write
a show utility.  I never would have succeeded without the best friend
of an Amiga programmer:  the ARP library.  If I have been able to
write Mostra, it's only to ARP's credit.  Pattern matching, resource
tracking, powerful resident functions...  The only drawback is that
you MUST have the arp.library (V39!) in your libs:  directory in order
to run Mostra.  Otherwise, a message will be displayed, and Mostra
will refuse to run.  Mostra is also a pure program, i.e.  it can be
made resident.

Note that you can run Mostra from Workbench:  called by itself it will
pop the file requester and will show you pictures until you select
CANCEL or close the file requester window.  Otherwise, you can select
multiple icons, or you can change the default tool of your pictures.
Note that if you do this with a CAT or a LIST you will have an
automatic little slideshow.

Mostra can process ANY IFF ILBM file (including Photon Paint files,
excellence!  files etc.); this means not only IFF ILBM FORMs, but also
nested ILBM, FTXT, FORMs, CATs, LISTs and PROPs!  It will always try
to find the screen type that fits the best, and won't give up if you
want to see 1x1 brushes or VERY large pictures:  Tom tried up to
5120x4096 (Thanks Tom).  In any case, you can force the screen type
with several options.

One of the major features in this release is direct support for SHAM
and indirect support for Dynamic HAM and Dynamic Hi-Res.  Note that
you get *FULL* SHAM support--you can scroll around SHAM pictures in
little screens!  Of course vertical movement requires a *LOT* of work
for your Amiga.  For Dynamic Hi-Res and Dynamic HAM Mostra will call
NewTek's Dyna-Show, that must be in one of your search paths (the
simplest way to accomplish this is putting Dyna-Show in your C:
directory).  You can this way look to every kind of picture, but with
Dynamic modes you lose some of Mostra's powerful features, e.g.  the
screen sizing.  However, all principal functions are implemented.
Including Dyna-Show-like code in Mostra would have increased its size
too much.  Maybe the next release I'll think about it.


To get the syntax in AmigaDOS/ARP style type:

     M ?

This will produce the input template:

     Files/...,A=ALL/s,R=REPEAT/s,Q=QUIET/s,NOFASTDRAW/s,
     C=CENTER/s,B=BLACKBACKGROUND/s,W=Width/k,H=Height/k,CYCLE/s,
     Secs/k,Fade/k,NO=NOSTARTUP/s,Batch/k,
     N=NOMOUSE/s,F=FREEMOUSE/s,NA=NOACTIVATE/s,DB=DOUBLEBUFFERING/s,
     HIRES/s,LACE/s,LORES/s,NOLACE/s,HAM/s,HALFBRITE/s:

If you ask for more help by typing "?" again, you will see:

Mostra 1.0 © 1990 Sebastiano Vigna
Usage: M <wildcards [...] | !> [ALL] [REPEAT] [QUIET] [NOFASTDRAW]
        [CENTER] [BLACKBACKGROUND] [WIDTH n] [HEIGHT n] [CYCLE]
        [SECS time] [FADE speed] [NOSTARTUP] [BATCH file]
        [NOMOUSE] [FREEMOUSE] [NOACTIVATE] [DOUBLEBUFFERING]
        [HIRES | LORES] [LACE | NOLACE] [HAM | HALFBRITE]

The same help is displayed if you call Mostra with no arguments.

Mostra's first argument is a list of patterns (or file names) as long
as you want; you will get every picture whose name matches one of the
patterns.

Alternatively, you can type only the "!" character, and Mostra will
display the famous Heath File Requester, allowing you to scan the
entire file system.

When you're tired of looking at the picture, move the mouse pointer to
the very top of the screen and press the right button (you can also
press the RETURN, SPACE or ESCAPE keys).  You can drag or depth-
arrange the screen with the left mouse button (the gadgets are
invisible, but they really are there!).  TAB will toggle on/off color
cycling.  To stop pattern matching or IFF scanning use CTRL-C at any
moment.

If the screen size is less than the size of the picture, you can move
around with cursor keys by themselves (moving by 8 pixels) or in
combination with the ALT (16 pixels, lowest=weakest), SHIFT (64
pixels), or CTRL (128 pixels, highest=strongest) keys.  A noteworthy
feature of Mostra is that the picture is NOT decrunched all at one
time in a very large chunk of memory; instead, a fast LM routine
decrunches the file in real-time every time you move (the routine
could be faster, but it has lots of controls to get rid of damaged IFF
BODY chunks; safety always first).  This is not as fast as the
memory-eating method, but I think it's MUCH better!  Very large
pictures (like 800x900) will be shown in a full screen (generated on
the fly at Workbench size) which you can move around.  Overscan
pictures will retain their size of it's not greater than 400x300
lo-res pixels (400x250 on a NTSC Amiga).  For hi-res pictures, there
is also a 704 pixel width limit due to Intuition.  Small brushes will
be shown in a minimum 256x128 pixel screen.  Of course, moving
vertically with SHAM pictures involves a high system overhead, since
CopperLists are continuously built and deleted.

A weird effect of this method is that you can see pictures that can't
even be *LOADED* into your Amiga.  Let's suppose you have a really
crunched picture; the BODY chunk and a 256x256 lo-res screen could
take much less space than the decrunched picture, so you could create
pictures that only Mostra could let you see in all of their parts.
Why you would want to do this, well, that's another matter.

If you're looking at a Dynamic HAM/Dynamic Hi-Res picture, remember
that you're dealing with Dyna-Show, and not with Mostra.  To exit you
must simply press a key or a mouse button.  Remember also that all
other task are frozen.


Then we have a lot of options (parentheses show how to shorten 'em):

 -  ALL (A) recursively scans all of the subdirectories during the
    wildcard search.

 -  REPEAT (R) will endlessly restart from the first pattern when it
    has finished with the last; if you used the "!" line arguments,
    the file requester will pop up after every picture until you
    CANCEL or close.

 -  QUIET (Q) turns off all messages except in case of error.

 -  NOFASTDRAW leaves the program at priority 0; by default, Mostra
    will surround the BODY decrunching operations with a
    SetTaskPri(1).  This will not lock the system, but in a
    multitasking situation Mostra will perform quickly when needed.

 -  CENTER (C) will force the screen to be centered (640x200 pictures
    on PAL screens look so ugly...) and will use overscan if
    necessary.

 -  BLACKBACKGROUND (B) will create a 0-bitplane (almost no memory
    consumed!) black screen that will stay until you saw the last
    picture.  This is for aesthetic purposes only.

 -  WIDTH and HEIGHT (W,H) want an argument that specifies the
    dimensions of the viewing screen.  However, Mostra is an
    intelligent program, and will almost always find the correct
    screen by itself.  WARNING:  dimensions allowed are from 64 to
    1024, at your own risk.  Your Amiga won't crash, but weird things
    can happen...  (Please note that SHAM vertical sizes will be
    rounded to the next even number).

 -  CYCLE will automatically activate color cycling on every picture.
    Usually this happens only by request, through TAB.

 -  SECS must be followed by a number between 0 and 1000 (the zero
    delay was a request from a BIXen).  Mostra will display the
    picture for the number of seconds specified, but you can skip it
    with mouse, RETURN, SPACE, and ESCAPE keys as always or stop the
    show with CTRL-C.  Cursor keys are disabled.  Greatly reworked on
    Warren's request.

 -  FADE lets you specify a speed for pictures to FADE in and out.
    Valid numbers are 1 to 4, with four the slowest.  Note that HAM
    pictures can't be faded.

 -  NOMOUSE (N) will hide the mouse pointer while Mostra is displaying
    a picture.

 -  FREEMOUSE (F) will let you pass from one picture to another by
    clicking either of the mouse buttons at any position on the
    screen.

 -  NOACTIVATE (NA) will inhibit the activation of the picture
    screens, so you can keep on typing on your current screen.  This
    was a request from Tom.

 -  DOUBLEBUFFERING (DB) sets a double buffering show mode:  while a
    new picture is being loaded you see the old one, no Workbench
    pop-up or black screens.  Eats lots of memory, too.  Again, a
    request from Tom.  (NOTE:  it's canceled if you call the file
    requester; if a picture requiring Dyna-Show is encountered, the
    current screen will be closed, in order to get as much free memory
    as possible:  you may consider using also BLACKBACKGROUND to
    prevent Workbench appereance.)

Centering is no longer performed via Preferences, so if you move the
screen the centering will go away.  NOSTARTUP and BATCH options will
be discussed later.

Now, the graphics options.  You can force all screens to be HIRES or
LORES, LACE or NOLACE, HAM or HALFBRITE.  Note that if Mostra finds a
six bitplane picture with no indications (no CAMG chunk), it won't set
the HAM flag by default.  These flags are "dumb," that is, they'll do
exactly what you say, even if it is meaningless.  However, if you use
both HALFBRITE and HAM together, only the former will take place.

Note that all of the options after QUIET won't have any effect on
pictures shown through Dyna-Show, except for BLACKBACKGROUND and SECS.

And now, some examples:


M MyPics:* SECS 5 FADE 1 NOMOUSE BLACKBACKGROUND REPEAT CENTER ALL

will generate a real (and endless!) slide show of the pictures in the
MyPics: dir and in all its subdirs, centered and with no mouse pointer
hanging around.  In order to stop the slide show, you must press
CTRL-C.


M df0:*.image df0:pictures/*.pic HIRES LACE

will show the files ending with .image on the drive df0: and the
files ending with .pic in the directory df0:pictures.  Mostra will be
forced to use high resolution, interlaced screens.  Setting the HIRES
flag on pictures with more than 4 bitplanes usually leads you to see
absolutely nothing.


M dh0:hirespic LORES NOLACE

will show a hi-res picture in lo-res ("zooming in").  You can move
around with the cursor keys as described above.

WIDTH and HEIGHT can be useful when you have a picture that cannot be
displayed because there's not enough Chip RAM (you get the "Can't open
Screen" error message).  In such a case, try:


M pic WIDTH 128 HEIGHT 128

This will usually allow you to at least get a peek at something.




                          Advanced features

For maximum flexibility, Mostra allows you to use "startup" files and
"startup" ToolTypes, with which you can configure the program to suit
your tastes.

There is a standard startup file, called S:Startup-Mostra.  Mostra
will search for it when run from CLI.  The format of this file is
*EXACTLY* the same as the Mostra line format minus the command name
("M").  Commands may be spread out over several lines or gathered
together onto a single line.  Every switch or keyword in the startup
file will act as a default, and will be toggled or superseded by any
command line arguments.  Command line switches will act as toggles (if
your startup file has the keyword ALL and you say "M * ALL", you
*WON'T* go into subdirectories), while keywords simply assert the new
value (if you have "fade 1" in your startup file and you say "fade 3"
in the command line, your pictures will be faded at speed 3).

Two options concern startup files:

 -  NOSTARTUP inhibit the search for startup files, useful if you have
    one of them and you want to specify your options from scratch; it
    can be shortened with "NO".

 -  BATCH wants a complete path/filename that Mostra will use as
    startup file.

From the WB side, you can write the startup options in the ToolTypes
of the Mostra icon, and it will use them.  The format is the same of
Startup-Mostra.  Please note that "FADE=1", "WIDTH=352" are valid, but
"FREEMOUSE=ON" is not; use only "FREEMOUSE".

Or you can set the first ToolType of a project icon to STARTUP and put
your options in the following lines; the project picture file will be
shown with those options when you double-click its icon.  You can do
the same thing with an icon that has no related file, and put some
wildcards in the ToolType.  The wildcards will then be shown with
those options.  If you don't put in wildcards, you get a "style" icon:
you can SHIFT click some icons, SHIFT click the "style" icon (in
*THIS* order) and then SHIFT double-click the Mostra icon (or directly
SHIFT double-click the last icon, if its default tool is Mostra):  you
will see the selected picture files with the options specified in the
style icon.  The style icon by itself will pop up the file requester.
Please note that even an icon with wildcards can be used as a style
icon because multiple selections supersede wildcards.

I know, it seems a little twisted, but using it you'll find, instead,
that it's the way you'd think.

WARNING:  strange interactions can take place.  If you have some
picture icons, and you SHIFT click all but one of them and then you
SHIFT double click the last *AND* the last picture icon you clicked
had some STARTUP options, you will see *ALL* of the pictures with
those options.  Right?

For curious/tech/interested people, here is the exact algorithm:

1) If sm_NumArgs > 1 (the user started Mostra with al least an icon
argument), check if sm_ArgList[1] (the first "real" argument) has
ToolTypes with first ToolType = "STARTUP".  If so, scan the whole
ToolTypes list like a command line, accepting mixed commands on a
single ToolType as well as separated commands in separated ToolTypes.

2) If 1) goes wrong, check the Mostra icon ToolTypes, and take them as
a command line.  (Note:  STARTUP is not requested.)

3) Now, if sm_NumArgs > 1, check every sc_ArgList[i] with i>0 and if
there is a related file (*NOT* a .info file!) generate a list of
arguments as if the user entered them manually, *SUPERSEDING* eventual
filenames/wildcards found in 1) and 2).

Now, examples, by means of common problems:


1) "I have a hundred pictures on my 360M hard disk, and I've organized
them in a few groups.  How can I make simple slideshows, with each
group separate?"

Simple:  Create a project icon for each group, and add a ToolType
"STARTUP".  Then add a ToolType like "PICS:Group1/* ALL SECS 5 CENTER"
to choose your options, set the default tool to "C:M" (or wherever you
put it) and double-click (of course, this must be done with every
group icon).  DON'T give the icons the same name as a directory, or
Mostra will collapse in confusion.


2) "I want to always see the black screen when I start from WB."

Set a Mostra ToolType to "BLACKBACKGROUND".


3) "I have some pictures.  Sometimes I want to see a few of them with
a full screen and no mouse, sometimes with a 128x128 screen, sometimes
centered."

Create three "style" icons.  Each icon must have as its first ToolType
"STARTUP", and the following ones must be something like "NOMOUSE",
"WIDTH 128 HEIGHT 128" and "CENTER".  The default tool must be "C:M".
When you want to see in a certain style, SHIFT click the picture icons
and *THEN* SHIFT double-click the style icon you desire.


4) "I'd like to click my pics one at a time, each one with different
options.  I'd like also to see them in irregular groups, each picture
with its options."

You need a psycho-analyst, not Mostra.



                            Credits, etc.

I am proud to announce that Mostra worked perfectly with .LBM files
from an MS-DOS game, loaded directly from the original disk (via
CrossDos, of course).

I wish to thank some people, first of all the ARP team for the
arp.library and John Toebes at Lattice for the best Amiga C.  Speed
and compactness of Mostra come from the fabulous 5.04 release.  Dulcis
in fundo (I like *SO* much the Latin!) thanks to Luca Spada (the
SkyLink SysOp) for his enthusiasm about my previous Show program; he
persuaded me to create Mostra 1.0.

Also I would thank all of the BIXens that encouraged me someway or
helped me to find bugs.  Great help with SHAM came from Warren Block
and Jamie Purdon (something still has to be fixed...).  The new
centering code comes from an example by Willy Langeveld.  Erik
Quackenbush made me aware of a big bug.  Dan Ten Ton suggested the new
name (don't wonder, he knows the Italian!) but the pointer came also
from Dave Quick (only, he doesn't know the Italian...).  Wes Howe
pushed me to improve the diagnostics.  Tom Rokicki, Roger Uzun, Dan,
Warren and Luca helped me to beta-test and they suggested new options.
Warren also checked the docs.  Keith Hopkins gave me the icon.
Finally, Tom sent me the greatest compliments 8-).  Etc.  etc., I
surely missed someone...  it's the *BEST* programming environment in
the world!

If you find any bugs please write me or leave me a message at BIX.

This software is not public domain.  It is shareware:  you should send
me $20 (or more, why not?) if you find it useful (BIXfriends are of
course free).  Please don't send checks drawn on a US bank, they're
almost impossible to cash.  I'd prefer postal money orders, currency
or checks drawn on an italian bank.

If you have access to a TeX system, you can print a copy of the TeX
"Mostra.tex" file that comes with the program.  Anyway, if you spent a
good part of your time preparing and printing documents, I'd suggest
you to take a look at AmigaTeX, a wonderful package from Radical Eye
Software.

This software is provided "AS IS" without warranty of any kind, either
expressed or implied.  By using Mostra, you agree to accept the entire
risk as to the quality and performance of the program.  Any liability
will be limited exclusively to product replacement.  Mostra is freely
distributable as long as all of its files are included in their
original form without additions, deletions, or modifications of any
kind.  (I *HATE* all of this legal stuff, but one never knows...)

Dyna-Show © 1990 NewTek is a show program that features Dynamic modes
display.

I hope Mostra will help you to enjoy your Amiga even more (if
possible).


Sebastiano Vigna
BIX: svigna
Via Valparaiso, 18
20144 MILANO Italia