Line clipping: Difference between revisions

Revision as of 07:52, 20 February 2007

Revision as of 14:36, 5 March 2007

Line 46:

begin

code := [];

if y > ymax then code := [TOP]

else if y < ymin then code := [BOTTOM];

if x > xmax then code := code +[RIGHT]

else if x <> xminxmax then code := code + [LEFTRIGHT]

else if x >< xmaxxmin then code := code + [RIGHTLEFT]

end;

Line 70 ⟶ 71:

{Now find intersection point;

use formulas y=y0+slope*(x-x0),x=x0+(1/slope)*(y-y0).}

if TOP in outcodeOut then

begin {Divide line at top of clip rectangle}

Line 75 ⟶ 77:

y := ymax

end

else if BOTTOM in outcodeOut then

begin {Divide line at bottom of clip rectangle}

x := x0 + (x1 - x0) * (ymin - y0) / (y1 - y0);

y := ymin

end

else if RIGHT in outcodeOut then

begin {Divide line at right edge of clip rectangle}

y := y0 + (y1 - y0) * (xmax - x0) / (x1 - x0);

Line 90 ⟶ 93:

x := xmin

end;

{Now we move outside point to intersection point to clip,

and get ready for next pass.}