Line Drawing... Bresenham?

[Agamemnus]

DX=x2-x1
dy=y2-y1

L!=sqr(DX*dx+dy*dy)

NX!=DX/L!
NY!=dy/L!


For I=0 to L!

X1=x1+NX!
Y1=Y1+NY!
Pset(x1!,Y1!),15
Next I

[Jkl]

Thanks Agamemnus

[pr0gger]

:o that's it? It's that simple? you do realize, of course, that I once spent days trying to figure that out, and ended up with a hunk of code, 30 lines.... life before i used the forums...

[na_th_an]

That is the slow, floating point algorithm. The bresenham approach only uses interger math and several optimizations, thus it is more complicated, but heaps faster.

[relsoft]

Yeah, its what you call a vector line. I used that for some of my games.

YOu could also try to use DDA. The one with error Code.

[Jkl]

Well then by all means tell me the faster way to do it!

[Agamemnus]

Code:

DIM SHARED x2b(8) AS INTEGER, y2b(8) AS INTEGER
x2b(1) = 0: y2b(1) = 1
x2b(2) = 0: y2b(2) = -1
x2b(3) = 1: y2b(3) = 0
x2b(4) = -1: y2b(4) = 0
x2b(5) = -1: y2b(5) = 1
x2b(6) = 1: y2b(6) = 1
x2b(7) = 1: y2b(7) = -1
x2b(8) = -1: y2b(8) = -1

FUNCTION try.straight% (x0 AS INTEGER, y0 AS INTEGER, x1 AS INTEGER, y1 AS INTEGER)
DIM diff AS INTEGER, cost.min AS INTEGER, x0b AS INTEGER, y0b AS INTEGER
DO
cost.min = 32767
FOR i = 1 TO 8
diff = (x1 - x0 - x2b(i)) ^ 2 + (y1 - y0 - y2b(i)) ^ 2
IF diff < cost.min THEN cost.min = diff: x0b = x0 + x2b(i): y0b = y0 + y2b(i)
NEXT i
x0 = x0b: y0 = y0b
IF x0 = x1 THEN IF y0 = y1 THEN try.straight% = 1: EXIT DO
LOOP
END FUNCTION

[relsoft]

Here:

http://relsoft.wrq.cjb.net/files/relgfx.zip

Rel.Line

Just change the PutPixel to Psets...