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# The system Sprite Pool

The RISC-OS Window Manager maintains a common pool of sprites which can be used by any WIMP program. The sprite pool is split in two: one area is held in ROM and the other is held in the RMA. The ROM area contains many of the sprites seen on the desktop e.g. floppy disc, file types, default pointer, etc and the RMA sprite area contains any sprites that have been put there by programs. When a sprite (in the pool) is accessed, the Window Manager will first look in the RMA area and if the required sprite is not found there, it will look in the ROM area. This means that the standard definitions can be 'redefined'. To force the system to re-read a sprite file you must issue a *Iconsprites command, with a parameter telling the system which file to re-read. use !GRAB2 - to view sprites in the system sprite pool

# Sprite files and sizes for applications

Sprites files names indicate the size if the sprite image: !Sprites 34x17 - 3316 bytes mode 15 !Sprites22 34x34 - 4 k bytes mode 21 !Sprites11 68x68 - 7 k bytes 256 colours the numbers are the x and y resolutions, 22 90dpix90dpi, 24 90x45 11 180x180dpi :-) Icons that appear on the iconbar should have a width and height of 68 OS units square according to the PRM

# Sprite Sources

View Sprite files !NoPaint not !Paint as it supports drag and drop Run !Grab2 to see system sprites from Resources:$.Resources.Wimp Ovation button sprites are in: RES.Ovation.DavidPilling.OvationPro.!OvnPro.!OvnResDir.UK.Buttons JR sprite collection is ADFS::Panto.$.CLIPS.IconSprites

# To create sprites in Artworks -

make sure AW is showing pixel units size graphic to required sprite size - useful size 34x34 16 colours you can do this by putting a rectangle of the correct size behind it. the recatangle should have fill colour and line colour of none this will allow the mask option to produce a transparent background export sprite using bitmap sprite export from Artworks set (masked) set number of colours to 256 or 16 After changing the name of a sprite double click on !boot - which runs !Sprites Note - if you want system to generate small sprites then name of app must be short enough to allow "sm" to be inserted in the name

# to find a sprite

the sprites are named by file type - eg file_fff is the sprite for text files. to extract a sprite copy the sprite11 file to RAM - drop on to Paint - select and save the sprite u want to use the new sprites in artworks use photodesk to convert to RGB and save as jpeg

© JR 2013