Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.sys.apple2.programmer > #3156

Re: hi-res graphics animation, dynamically generated shape tables

X-Received by 10.157.45.200 with SMTP id g66mr10290921otb.84.1477330224923; Mon, 24 Oct 2016 10:30:24 -0700 (PDT)
X-Received by 10.36.238.131 with SMTP id b125mr106829iti.3.1477330224868; Mon, 24 Oct 2016 10:30:24 -0700 (PDT)
Path csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.glorb.com!g45no2240401qte.1!news-out.google.com!w25ni31797qtc.0!nntp.google.com!g45no2240398qte.1!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail
Newsgroups comp.sys.apple2.programmer
Date Mon, 24 Oct 2016 10:30:24 -0700 (PDT)
In-Reply-To <067e080a-f706-41a8-a3aa-414b82375a2d@googlegroups.com>
Complaints-To groups-abuse@google.com
Injection-Info glegroupsg2000goo.googlegroups.com; posting-host=67.168.182.173; posting-account=9Dd-GgoAAAAjVgCPcBurQ6c4EXW6Wi8v
NNTP-Posting-Host 67.168.182.173
References <78d160d0-2aef-49e5-a6b4-5af5aacc2db5@googlegroups.com> <3162a740-1ea8-4835-8afa-be8322709228@googlegroups.com> <067e080a-f706-41a8-a3aa-414b82375a2d@googlegroups.com>
User-Agent G2/1.0
MIME-Version 1.0
Message-ID <5ea5f29f-a456-4165-afe6-ddfc8d3dcafe@googlegroups.com> (permalink)
Subject Re: hi-res graphics animation, dynamically generated shape tables
From Michael Pohoreski <michael.pohoreski@gmail.com>
Injection-Date Mon, 24 Oct 2016 17:30:24 +0000
Content-Type text/plain; charset=UTF-8
Xref csiph.com comp.sys.apple2.programmer:3156

Show key headers only | View raw

On Monday, October 24, 2016 at 9:01:44 AM UTC-7, Michael Pohoreski wrote:

Part 3b -- Supplement

> Our **integer** line drawing function ends up like:
> 
> function line2( x0, y0, x1, y1, color )
> {
>     var x, y = y0;
>     var dx = x1 - x0;
>     var dy = y1 - y0;
>     var s  = 2*dy - dx;
> 
>     for( x = x0; x <= x1; ++x )
>     {
>         putpixel( x, y, color );
> 
>         if (s > 0)
>         { 
>             s -= dx;
>             y++;
>         }
>         s += dy;
>     }
> }

Update:

In order to preserve symmetry, the compare should be: >= instead of >

if (s >= 0)

Check out linei() and linej() in line.js

Back to comp.sys.apple2.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

hi-res graphics animation, dynamically generated shape tables Mark Lemmert <mark.lemmert@gmail.com> - 2016-09-28 12:20 -0700
  Re: hi-res graphics animation, dynamically generated shape tables Michael J. Mahon <mjmahon@aol.com> - 2016-09-28 16:15 -0500
    Re: hi-res graphics animation, dynamically generated shape tables Mark Lemmert <mark.lemmert@gmail.com> - 2016-09-28 21:47 -0700
      Re: hi-res graphics animation, dynamically generated shape tables Michael J. Mahon <mjmahon@aol.com> - 2016-09-29 12:50 -0500
  Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-09-28 16:27 -0700
    Re: hi-res graphics animation, dynamically generated shape tables Mark Lemmert <mark.lemmert@gmail.com> - 2016-09-28 21:54 -0700
    Re: hi-res graphics animation, dynamically generated shape tables qkumba <peter.ferrie@gmail.com> - 2016-09-29 21:21 -0700
      Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-09-30 00:06 -0700
  Re: hi-res graphics animation, dynamically generated shape tables Mark Lemmert <mark.lemmert@gmail.com> - 2016-10-07 10:23 -0700
    Re: hi-res graphics animation, dynamically generated shape tables Nick Westgate <nick.westgate@gmail.com> - 2016-10-09 16:55 -0700
      Re: hi-res graphics animation, dynamically generated shape tables Mark Lemmert <mark.lemmert@gmail.com> - 2016-10-10 18:07 -0700
        Re: hi-res graphics animation, dynamically generated shape tables Nick Westgate <nick.westgate@gmail.com> - 2016-10-10 19:43 -0700
      Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-10-17 10:19 -0700
        Re: hi-res graphics animation, dynamically generated shape tables Mark Lemmert <mark.lemmert@gmail.com> - 2016-10-17 11:55 -0700
          Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-10-19 18:54 -0700
            Re: hi-res graphics animation, dynamically generated shape tables Mark Lemmert <mark.lemmert@gmail.com> - 2016-10-20 11:17 -0700
              Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-10-20 18:52 -0700
                Re: hi-res graphics animation, dynamically generated shape tables Mark Lemmert <mark.lemmert@gmail.com> - 2016-10-21 15:41 -0700
              Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-10-24 19:15 -0700
    Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-10-17 10:15 -0700
  Re: hi-res graphics animation, dynamically generated shape tables Mark Lemmert <mark.lemmert@gmail.com> - 2016-10-21 15:43 -0700
    Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-10-24 09:01 -0700
      Re: hi-res graphics animation, dynamically generated shape tables 6502workshop@gmail.com - 2016-11-05 10:29 -0700
    Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-10-24 09:01 -0700
      Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-10-24 10:30 -0700
    Re: hi-res graphics animation, dynamically generated shape tables Michael Pohoreski <michael.pohoreski@gmail.com> - 2016-10-24 10:18 -0700

csiph-web