A simple demo demonstrating different ways to display more than 4 colors on the Virtual Boy simultaneously.
1. Dither
OK, this is technically cheating since we do not really show more than 4 colors at once, but still, dithering creates a good illusion of a more color rich images, while not relying on any technical trickery.
2. Column Table
Through the Column Table's brightness repeat register, it is possible to change the amount of light emitted by the display LEDs (and thus the perceived brightness) every fourth pixel column.
This allows for a huge range of different shades of red on screen at the same time, but practical use cases are very limited, since you're bound to the grid of 4px columns and brightness changes always affecting the whole screen height.
3. Blending
This one exploits the laziness of the human eye to display 8 different colors on screen at the same time, by blending together two images.
It works by overlaying one image with another, half transparent one. Half transparency is achieved by simply displaying that image only every second frame.
Beware that this trick does not work very well on emulators but produces pretty stable colors on real hardware.
Copyright (C) 2007, 2018 by Jorge Eremiev jorgech3@gmail.com and Christian Radke chris@vr32.de
This software is licensed under the MIT License, which means you can basically do with it whatever you want as long as you include the original copyright and license notice in any copy of the software/source.
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