Preparing for Color Printout

Colored pictures that descend from a standard multicolor-, a hires-, or an FLI original needn't be prepared. They result in very good color printouts.

Whereas pictures that come from loaders ldr.GIF resp. ldr.PCXprep4IFLI have to be processed because of their special color mode. When loading, these modules will interpret the data so that they later can be saved as IFLI pictures (svr.FunPaintII). IFLI is a (multicolor) mode of the C64 that seems to allow more colors than actually exist. In fact, when displaying IFLI, two FLI pictures in memory will be alternately shown in fast succession shifted by one pixel. Adjacent dots of different colors will mix up to a 'new' color in the eye of the onlooker.

GoDot keeps both of the FLI half-pictures on hand in that way that they are interweaved. The data of either picture alternates pixel by pixel. The first dot comes from the first picture, the second from the second, the third from the first again, etc., thus generating stripes of one pixel width. The magnification on the right shows the principle (the complete picture can be found at head-word mod.RasterIFLI). The advantage of this two stripes order is that GoDot can also render the picture in hires- or multicolor mode without being forced to invest efforts. After printout these stripes would be distinctly visible, however, and therefore unfavourable. RasterIFLI 8x vergrößert

You get rid of them by using mod.OddSwap. This module will exchange the pixels of every second raster line of either half-picture, and thereby create a tesselated pattern of one pixel width (you'll find an example picture at the named head-word). The striation will be completely cleared, and a printout will look quite natural. The colors being close together will even produce seemingly more colors than actually technically available for a C64.


Arndt Dettke

Copyright © 1997, A. Dettke, Last Updated - 08/07/97