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Mail Archives: djgpp/1998/12/25/19:19:08

Message-Id: <3.0.6.32.19981225161913.007beb10@tenforward.com>
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Date: Fri, 25 Dec 1998 16:19:13 -0800
To: djgpp AT delorie DOT com
From: Mad Cow <sw AT tenforward DOT com>
Subject: Re: StarMaps
In-Reply-To: <002701be305c$4794a140$ecf8c6c3@johans-dator>
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Reply-To: djgpp AT delorie DOT com

Ouch! My Brain Hurts!



>Hello sickness (Sorry, just a *sick* joke :)
>To calculate the distance between two points in 2D-space, you use the
>pythagorean theorem. I give you some code from X-type:
>
>int get_distance(int x1, int y1, int x2, int y2)
> {
> return(sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)));
> }
>
>This function returns the distance between x1,y1 and x2,y2...
>
> short int gox,goy,speed;
> float del;
>
> del=speed/sqrt((x-gx)*(x-gx)+(y-gy)*(y-gy));
> gox=-((float)((float)x-(float)gx)*del);
> goy=-((float)((float)y-(float)gy)*del);
>
> ...and this piece o' code returns the path for a bullet or something like
>that. Set the speedvariable to pixels it will move every time. Every time
>you want to move it, do x+=gox and y+=goy. Well good night as we say here
>00:12.
>
>

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