Thomas Jentzsch Posted January 29, 2014 Share Posted January 29, 2014 I recently found some time to have a closer look at the Cosmic Ark stars effect. While doing that, I found some regularity in the required timings. By using that insight, I was able to use the effect with three particles (M0, M1, BL) at once. The attached demo shows the code in action. Enjoy! BTW: It looks slightly different on read hardware than in Stella, but nevertheless it works there too. Cosmic3Stars.bin Cosmic3Stars.zip 4 Quote Link to comment Share on other sites More sharing options...
+Stephen Posted January 29, 2014 Share Posted January 29, 2014 Cool - Cosmic Ark was (still is) one of my all time favourite 2600 games. Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted January 29, 2014 Share Posted January 29, 2014 Amazing! Quote Link to comment Share on other sites More sharing options...
+Gemintronic Posted January 29, 2014 Share Posted January 29, 2014 I ask this because I really don't understand the underlying technique. Does this background use up the missiles and ball completely? Meaning: you couldn't have, say, 2 enemy lasers and 1 shot for the player? Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 29, 2014 Author Share Posted January 29, 2014 Yes, the particles are used completely. So you only have the playfield graphics and both sprites left. BTW: Of course the trick works with two particles too. 1 Quote Link to comment Share on other sites More sharing options...
+Gemintronic Posted January 29, 2014 Share Posted January 29, 2014 Could you interleave the Cosmic Ark effect such that normal missiles/ball are drawn on alternating lines? Or, is that too CPU intensive? Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 29, 2014 Author Share Posted January 29, 2014 (edited) BTW: By using GRP0 and GRP1 too, you can have 5 "stars". Cosmic5Stars.bin Edited January 29, 2014 by Thomas Jentzsch 1 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 29, 2014 Author Share Posted January 29, 2014 Could you interleave the Cosmic Ark effect such that normal missiles/ball are drawn on alternating lines? Or, is that too CPU intensive? You would have to reposition them every line. I can hardly think of a scenario where this is feasible. 1 Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 30, 2014 Author Share Posted January 30, 2014 Amazing!Thanks. Can you test on your "stock-standard Australian PAL '2600'" which shows problems with Boulder Dash? Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted January 30, 2014 Author Share Posted January 30, 2014 If you play with the number of scanlines, you can get some interesting effects. Scrolling Starfield.bin 2 Quote Link to comment Share on other sites More sharing options...
+Gemintronic Posted January 31, 2014 Share Posted January 31, 2014 Now the starfield is so thick it looks like yet another hardware defying example of smooth horizontal scrolling! I love this stuff! Quote Link to comment Share on other sites More sharing options...
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