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Changing round bezier example.

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This commit is contained in:
Brad Nelson
2022-03-11 09:18:25 -08:00
parent 85824c8b04
commit 2099d1a3d8
1 changed files with 30 additions and 19 deletions
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49
examples/bezier_test.fs
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@ -65,42 +65,53 @@ scanlines max-scanlines cells erase
; ;
: draw-spans max-scanlines 0 do i draw-row loop ; : draw-spans max-scanlines 0 do i draw-row loop ;
: 0.<< 16 lshift ;
: 0.>> 16 rshift ;
: 2span { a b -- n } a b max a b min - ; : 2span { a b -- n } a b max a b min - ;
: 3span { a b c -- n } a b max c max a b min c min - ; : 3span { a b c -- n } a b max c max a b min c min - ;
: bezier 0 0 0 0 0 0 { x1 y1 x2 y2 x3 y3 x1.5 x2.5 y1.5 y2.5 xn yn } : raw-bezier 0 0 { x1 y1 x2 y2 x3 y3 d xn yn }
y1 y2 y3 3span 2 < if y1 d rshift y2 d rshift y3 d rshift 3span 2 < if
y1 y3 2span if y1 d rshift y3 d rshift 2span if
x1 x3 + 2/ 0.>> y1 y2 min y3 min add-edge y1 y3 = if
x1 x3 + 2/ d lshift y1 d rshift add-edge
exit
then
y1 y3 < if
x1 x3 x1 - y1 1 d lshift 1- and y3 y1 - */ - d rshift
y1 d rshift add-edge
else
x3 x1 x3 - y3 1 d lshift 1- and y1 y3 - */ - d rshift
y3 d rshift add-edge
then
then then
else else
x1 x2 + 2/ to x1.5 x2 x3 + 2/ to x2.5 x1 x2 2* + x3 + to xn
y1 y2 + 2/ to y1.5 y2 y3 + 2/ to y2.5 y1 y2 2* + y3 + to yn
x1 x2 2* + x3 + 2/ 2/ to xn x1 4* y1 4* x1 x2 + 2* y1 y2 + 2* xn yn d 2 + recurse
y1 y2 2* + y3 + 2/ 2/ to yn xn yn x2 x3 + 2* y2 y3 + 2* x3 4* y3 4* d 2 + recurse
x1 y1 x1.5 y1.5 xn yn recurse
xn yn x2.5 y2.5 x3 y3 recurse
then then
; ;
(
: line 0 0 { x1 y1 x2 y2 dx dy } : line 0 0 { x1 y1 x2 y2 dx dy }
y1 y2 > if y1 y2 > if
y1 y2 to y1 to y2 y1 y2 to y1 to y2
x1 x2 to x1 to x2 x1 x2 to x1 to x2
then then
y2 y1 - to dy y2 y1 - 0.>> to dy
x2 x1 - to dx x2 x1 - to dx
dy 0 ?do dy 0 ?do
x1 dx i dy */ + 0.>> y1 i + add-edge x1 dx i dy */ + 0.>> y1 0.>> i + add-edge
loop loop
; ;
\ : line ( x1 y1 x2 y2 ) 2dup bezier ; )
: bezier 0 raw-bezier ;
: line ( x1 y1 x2 y2 ) 2dup bezier ;
0 value pen-x 0 value pen-y 0 value pen-x 0 value pen-y
: move-to { x y } x 0.<< to pen-x y to pen-y ; : move-to { x y } x to pen-x y to pen-y ;
: line-to { x y } pen-x pen-y x 0.<< y line x y move-to ; : line-to { x y } pen-x pen-y x y line x y move-to ;
: bezier-to { x' y' x y } pen-x pen-y x' 0.<< y' x 0.<< y bezier x y move-to ; : bezier-to { x' y' x y } pen-x pen-y x' y' x y bezier x y move-to ;
-1 -1 window -1 -1 window