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     Date: 08-01-95    Time: 11:24p     Number: 155    
     From: Jan_Reidar Jørgensen          Refer: 154     
       To: Bjørn Stærk                Board ID: ROLVSOY         Reply: 06-29-95
  Subject: Linjer                           34: TEAM/Program   Status: Public 
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BS│ Er det noen som kan skaffe meg en rask linjerutine, helst i
BS│ ASM eller C++?
Denne skal visst være en Bresenham algoritme for linje:

Forklaring:
CUR_X : Initial x-axis coordinate
CUR_Y : ........y................
MAJ_AXIS_PCNT : Length of line projected onto major axis (dmajor)
DESTX_DIASTP : 2*dminor-2*dmajor
DESTY_AXSTP : 2*dminor
ERROR_TERM : 2*dminor-dmajor

Programrutine:
draw_line()
{
int xstep,ystep,i;
if (INC_Y)     ystep = 1; else     ystep = -1;
if (INC_X)     ystep = 1; else     ystep = -1;   ---> xstep???
for (i=0; i0) {
          CUR_X += xstep
          CUR_Y += ystep
          ERROR_TERM += DESTX_DIASTP;
          }
     else {
          // if YMAJAXIS==1 then y axis is the major axis
          if(YMAJAXIS) CUR_Y += ystep;     else CUR_X += xstep;
          ERROR_TERM += DESTY_AXSTP;
          }
     }
}

HENTET FRA Programmer's Guide to the EGA, VGA and Super VGA Cards
av Richard F. Ferraro.  ISBN 0-201-62490-7

╔═╗─╔═╗─╔═╗─╔═╗─>  Jan Reidar Jørgensen - jare@rol.bbs.no
──║─╠═╣─╠╦╝─╠═──>  SigOp på Rolvsøy BBS: Programmering og Hoved/Dataprat
╚═╝─╝─╚─╝╚╝─╚═╝─>  Det er Kjell, det!
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