[HN Gopher] Row scrolling for parallax effects in Street Fighters 2
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       Row scrolling for parallax effects in Street Fighters 2
        
       Author : kryptonomist
       Score  : 43 points
       Date   : 2020-10-23 16:23 UTC (6 hours ago)
        
 (HTM) web link (sf2platinum.wordpress.com)
 (TXT) w3m dump (sf2platinum.wordpress.com)
        
       | percentcer wrote:
       | There's a more detailed writeup on this technique here:
       | http://www.extentofthejam.com/pseudo/
       | 
       | You can get some really cool effects with minimal code, here's a
       | shader I wrote that makes use of it:
       | https://www.shadertoy.com/view/wdcSWf
        
       | vernie wrote:
       | Mod please fix title (Street Fighter II)
        
       | qwertox wrote:
       | Here's a video showing the scene in action:
       | https://youtu.be/6OlenbCC4WI?t=373
        
       | JohnBooty wrote:
       | These simple techniques were really, really effective in 2D
       | games.
       | 
       | When done well (as they were in SF2) they created a wonderful
       | illusion of depth.
       | 
       | From a programmer's perspective, creating these sorts of effects
       | surely gave you a true feeling of "racing the beam" - ie the nuts
       | and bolts of the CRT itself.
       | 
       | The way scrolling worked on this systems was that you defined
       | your tilemaps and then changed the _scroll register_ to change
       | the position at which they were drawn.
       | 
       | By changing the scroll register in the _vertical blanking
       | interval_ (the time between the bottom line was drawn) and before
       | the topmost row was redrawn, you could shift the entire tile map
       | left, right, up, or down en masse. That would move the entire
       | tilemap like a flat sheet of paper.
       | 
       | However, if you changed the scroll register during the
       | _horizontal blanking interval_ - the time between individual
       | horizontal lines were drawn on the screen - you could achieve
       | fancier effects like the row scrolling effect described in the
       | linked article.
        
         | city41 wrote:
         | Another common trick with horizontal blanking is simulating
         | water, such as this stage in Sonic the Hedgehog:
         | https://www.youtube.com/watch?v=EV9PSaw2Q0c
         | 
         | At the specific horizontal line, change the color palette.
        
         | goatinaboat wrote:
         | _These simple techniques were really, really effective in 2D
         | games._
         | 
         | ISTR Altered Beast made excellent use of it
        
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       (page generated 2020-10-23 23:01 UTC)