This article is the fourth of a serie of five about how to code a one-pixel sine scroll on Amiga, an effect commonly used by coders of demos and other cracktros. For example, in this this intro by Supplex (so beautiful, so vintage):
In the first article, we learned how to install a development environment on an Amiga emulated with WinUAE, and how to code a basic Copper list to display something on the screen. In the second article, we learned how to set up a 16×16 font to display the columns of pixels of its characters, and to use triple buffering to display the pictures on the screen without any flickering. In the third article, we learned how to draw and animate the sine scroll, first with the CPU then with the Blitter.
In this article, we shall add some bells and whistles to the sine scroll, namely a shadow and a mirror – this doesn’t cost much CPU time cycles because the Copper makes this happen. Also, we shall try to give control back to the OS as cleanly as we can.
Click here to download the archive of the source and data of the program hereby explained.
If you’re using Notepad++, click here to download and enhanced version of the UDL 68K Assembly (v3).
NB : This article may be best read while listening to the great module composed by Nuke / Anarchy for the diskmag part of Stolen Data #7, but this is just a matter of personal taste…
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