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Scanline effects

Started by mysoft, Feb 05, 2024, 03:43 AM

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so, since 86box accurately emulates gfx cards... and dosbox-x improved on such low-level emulation (but dosbox-x requires changing the "refresh rate to 20" for some of those to work), i made a few scanline rendering tricks demo in qbasic... (

1) it's just a simple demo changing a text mode palette every scanline, changing one color to make a hue rainbow on left, and some sequential chopped color on right... the program also shows it's own source code as a text viewer while also playing a music (it's a low quality 1 bit/sample music playing at HSYNC rate, over covox/DSS (i could make it trough PC-Speaker but the scanline effect is what matter :P)

2) i decided to take that to the next level... and made it display a image in VGA/EGA 16 color modes changing palette every scanline to achieve up to 8k colors on the screen, and at same time i made a .bmp converter to generate the special .bmp files with extra information "per scanline palette", but on a regular image viewer you can still see a BW preview of the image.
the ( have some sample images to be viewed in the DOS 640x480x4bpp .bmp viewer, and the generator in freebasic (that can be compiled for dos/windows/linux, as it's all standard)