freebsd-nq/release/picobsd/tinyware/view

Warsaw, 1998.08.18

			VIEW - small PNG viewer
			-----------------------

This program is intended to serve as a simple console viewer for PNG
graphics. It also features some scripting abilities, which allow you to
build simple presentation.

In fact, using even this initial version I was able to build a nice
presentation of PicoBSD abilities which I used in real-life situation (you
can see for yourself one of the presentation's screens, fbsd.png).

The audience was impressed :-), especially when I asked them politely what
are requirements and cost to make that kind of presentation using M$
products...

Simple Viewing
--------------

Usage is as follows:

	view [-g nnn.nnn] [-r x] filename.png

where
	-g nnn.nnn	screen gamma (you can adjust how bright is the
			picture)
	-r x		resolution:
			0 - 640x480x16
			1 - 640x200x256
			2 - 320x240x256

Under right mouse button you can find a simple menu, which tells you also
the hotkeys. You can shift, rotate and zoom the picture.

Presentation
------------

Usage is as above, but the file you give as argument is a (unix) text file
of the following format:

	1	VIEW SCRIPT
	2	5
	3	welcome.png
	4	/home/clipart/logo.png
	5	/home/present/title.png
	6	/home/present/outline.png
	7	/home/present/end.png

(of course without the line numbering or the leading space!). The line number
1 is magic, and must be present in order to recognize the file properly.

The second line tells how many pictures consist the presentation. The
following lines tell the file names containing the images themselves.

See the example in file picobsd.vu.

Command line arguments (gamma and resolution) are as above. You can also use
the pop-up menu to adjust image parameters, as well as go forward or
backward in the presentation.

Bugs, caveats, missing features
-------------------------------

* there are some bugs in libvgl which require strange workarounds, and even
  then it doesn't work quite right. See the source for the 'XXX' comments...

* I didn't have time to add gamma adjustment to the pop-up menu. It's
  simple, though, and I leave it as an exercise for the reader :-))

* it would be great if someone would add GIF and jpeg support.

* the error checking is probably weak. A bad PNG file or script file will
  probably cause a coredump.

* pop-up menu facilities need more abstraction to be usable in other cases.

Anyway, as it is even now it's quite usable.

Have fun!

Andrzej Bialecki

<abial@freebsd.org>

$FreeBSD$