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 http://www.dilwyn.me.uk/graphics/index.html