Recent versionsof SMSQ/E from about version 3.00 feature high colour and
high resolution screens along with the new Window Manager. This makes them
very suitable for displaying colourful and attractive background images
behind your program windows.
These images are called wallpaper. SBASIC provides a convenient to use
command called BGIMAGE which lets you display saved screens as background
wallpaper. With the wealth and variety of free images available on the
internet as JPEG, GIF and PNG files, for example, I decided to write a
program which converts these images to the type of QL screens which the
BGIMAGE command can use.
My Wallpaper program uses David Westbury’s PHGTK toolkit which shoulders the
burden of the work in converting these files and resizing images to fit your
system or emulator’s screen. It can convert the graphics to mode 16 (Aurora
and QPC2), mode 32 (QPC2, SMSQmulator and QXL), or mode 33 (Q40, Q60, Q68
and possibly even a registered QemuLator with its own customised mode 33
version of SMSQ/E).
Simply select a JPEG, PNG or GIF file using the pointer driven file
selection menu, then select whether it needs to be rotated, and how to
resize the image (e.g. preserve aspect ratio, stretch, crop) and wait a few
seconds for the conversion to take place. Small previews help you view the
screens. Once the conversion is done, you can see a preview in full-screen
mode, apply it as a BGIMAGE wallpaper, save as a screen in the current
screen mode for future use and even get help editing your boot program to
add or amend a BGIMAGE command so that the wallpaper is loaded at startup.
The program can even select a background colour to use in place of wallpaper
if you wish (e.g. apply a dark background colour late at night to save your
eyes from a bright screen).
The downside of using wallpaper on a high-colour system is the amount of
memory it takes. On a 16-bit colour system such as QPC2 each pixel needs two
bytes of memory, so a 1024×768 pixel display in mode 32 or 33 could need up
to 1,572,864 bytes just to hold the uncompressed wallpaper – at the time of
writing SMSQ/E does not support compressed wallpaper screen images. Couple
this with the copious amounts of memory needed during conversion, and you
can see that you will need to set your emulator to have quite a generous
amount of memory! So, the Wallpaper program lets you choose whether the
graphics are converted more quickly in RAM, or as files on your hard disk if
you keep running out of memory.
The Wallpaper program uses the system palette so will follow whatever colour
theme you’ve applied to your system (colour themes can be designed using the
Q-CoCo program from Wolfgang Uhlig and Bob Spelten Jr.)
A Quill _doc file is included which explains a lot about wallpaper on SMSQ/E
systems,the file formats used, the BGIMAGE command, use of programs such as
Photon and so on.
Download the Wallpaper software and a few example graphic files from
QL-Users Mailing List