Re: A83: Re: line drawing algorithm

[Prev][Next][Index][Thread]

Re: A83: Re: line drawing algorithm


My 2 cents:

  Having studied the problem thoroughly (~2 minutes), I've concluded that:
A)Dan failed to properly impliment Harper's routine into his source code.
B)Harper failed to make his line drawing routine user-friendly, thus helping 
to incur Dan's blunder.

Dan's mistake:
He incorrectly defined the variables in his program. He defined them as 
words, not bytes, which is not usually a problem except that Harper had a 
line of code like this "ld (slope+1),a" instead of this "ld (remainder),a" 
In Dan's definitions, "slope+1" does not equal "remainder"

Harper's mistake:
He should not make the user define all of those variables (5). It is much 
much smarter to use self-modifying code that doesn't require such 
definitions (or temporary space).

Anyway, so Harper's routine works...
The modified routine for self-mod code is here:
void.calc.org/line.h

Here's a working version of Dan's source code (converted to ION)
void.calc.org/lines.zip

QED


>dan, try to run the program inside line.zip called freed.83p   its for sos,
>and it demonstrates that the routine works.  I don't know why it fails in
>your program, since i cut and pasted the "loop2" part of your program into
>mine and it was successful in drawing the same triangle as iline and your
>fastline
>
>-harper
>
>ps. this thread is getting kind of old.
>
>At 11:58 PM 8/24/00 -0400, you wrote:
>
>>I got the updated routine, but seem to still have the same problem...  
>>I've
>>reuploaded lines.zip file (http://tcpa.calc.org/members/dan/lines.zip) 
>>with
>>the updated source and binary for the program to test all the lines
>>routines.  The screen shots remain the same:
>>plotline/drawline (harper's routine) -
>>http://tcpa.calc.org/members/dan/plotline.bmp
>>fastline (my routine) - http://tcpa.calc.org/members/dan/fastline.bmp
>>iline (built in routine) - http://tcpa.calc.org/members/dan/iline.bmp
>>
>>-Dan
>>
>>----- Original Message -----
>>From: "Harper Maddox" <gte172i@prism.gatech.edu>
>>To: <assembly-83@lists.ticalc.org>
>>Sent: Thursday, August 24, 2000 10:50 PM
>>Subject: A83: line drawing algorithm
>>
>>
>> >
>> > Ok, I figured out what the problem with the line routine was, and I 
>>fixed
>>it.
>> > Once again, it is available at http://void.calc.org/programming
>> >
>> > -harper
>> >
>> >
>
>

________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com
Follow-Ups: