ANN: Stars
Alejandro Tejada
capellan2000 at gmail.com
Sat Jun 23 21:08:59 CDT 2012
Hi Francois,
François Chaplais-3 wrote
>
> Thanks Alejandro. The actual link is
> http://www.jamesphurley.com/RunRev/BezierLine.rev
> I will have a deep look at the stack and how it relates to interpolation.
> Best regards
>
I used these 3 different Bezier drawing handlers in this stack:
http://andregarzia.on-rev.com/alejandro/stacks/Eps_Import_V04.zip
One handler is based in Don Lancaster's code,
other handler uses Matrices and another
handler uses the very first code that
I published many, many years ago...
Could you guess which is faster? :-)
Although I have not looked in detail, the stack
SVGL must have different handlers to draw
Quadratic and Bezier curves.
http://revonline2.runrev.com/stack/112/SVGL
NOTE:
global varBezierSegment contains
a series of coordinates points
that draw the graphic on the card.
for example:
145,234
146,236
148,239
149,241
150,244
etc...
global variables named a,b,c,d
contains four coordinates points
of the bezier segment
for example:
A segment of an Adobe illustrator file:
96 62 m
96 69 101 1555 107 1555 C
a = 96,62
b = 96,69
c = 101,1555
d = 107,1555
The field named fld "BezierResolution" and
the variable named "cde" should contain
a number from 16 to 800.
This is the number of rectilinear segments
in a bezier segment...
on bezier1
global varBezierSegment,a,b,c,d
put the first item of a into x1
put the first item of d into x2
put the first item of b into xa
put the first item of c into xb
put the second item of a into y1
put the second item of d into y2
put the second item of b into ya
put the second item of c into yb
put 0 into v1
if there is a fld "BezierResolution" then put fld "BezierResolution" into
cde
if cde is not a number then put "32" into cde
Repeat with i = 1 to cde -- a number from 16 to 800
put i * ( 1 / cde ) into v1
put 1 - v1 into v2
put (x1 * (v2 ^ 3) + (3 * xa * v1 * v2 * v2) + (3 * xb * v1 * v1 * v2) +
(x2 * (v1 ^ 3))) into x
put (y1 * (v2 ^ 3) + (3 * ya * v1 * v2 * v2) + (3 * yb * v1 * v1 * v2) +
(y2 * (v1 ^ 3))) into y
if varBezierSegment is not empty then put last line of varBezierSegment
into varTemp
if x div 1,y div 1 <> varTemp then put x div 1,y div 1 & return after
varBezierSegment
end repeat
end bezier1
----------------------------------------------------------------
on bezier2
/* this is the custom property bm1
1,1 -1
1,2 3
1,3 -3
1,4 1
2,1 3
2,2 -6
2,3 3
2,4 0
3,1 -3
3,2 3
3,3 0
3,4 0
4,1 1
4,2 0
4,3 0
4,4 0
*/
/* this is the custom property bm2
[p0]
[p1]
[p2]
[p3]
1,1 0
1,2 0
1,3 0
1,4 0
*/
/* this is the custom property bm3
1,1 0
2,1 0
3,1 0
4,1 0
*/
global varBezierSegment,a,b,c,d
put the first item of a into x1
put the second item of a into y1
put the first item of b into xa
put the second item of b into ya
put the first item of c into xb
put the second item of c into yb
put the first item of d into x2
put the second item of d into y2
put 0 into v1
put the bm1 of me into qwe12
split qwe12 by return and space
put the bm2 of me into qwy12
put the bm2 of me into qwx12
put x2 into word 2 of line 1 of qwx12
put xb into word 2 of line 2 of qwx12
put xa into word 2 of line 3 of qwx12
put x1 into word 2 of line 4 of qwx12
put y2 into word 2 of line 1 of qwy12
put yb into word 2 of line 2 of qwy12
put ya into word 2 of line 3 of qwy12
put y1 into word 2 of line 4 of qwy12
split qwx12 by return and space
split qwy12 by return and space
if there is a fld "BezierResolution" then put fld "BezierResolution" into
cde
if cde is not a number then put "32" into cde
Repeat with i = 1 TO cde
put i * (1/cde) into v1
put 1 - v1 into v2
put the bm3 of me into qws12
put v2^3 into word 2 of line 1 of qws12
put v2^2 into word 2 of line 2 of qws12
put v2 into word 2 of line 3 of qws12
put 1 into word 2 of line 4 of qws12
split qws12 by return and space
put matrixMultiply(qwe12,qws12) into qwz12
put matrixMultiply(qwx12,qwz12) into pX
put matrixMultiply(qwy12,qwz12) into pY
combine pX using space
combine pY using space
if varBezierSegment is not empty then put last line of varBezierSegment
into varTemp
if pX div 1,pY div 1 <> varTemp then put pX div 1,pY div 1 & return
after varBezierSegment
end repeat
end bezier2
----------------------------------------------------------------
on bezier3
global varBezierSegment,a,b,c,d
put the first item of a into x3
put the second item of a into y3
put the first item of b into x2
put the second item of b into y2
put the first item of c into x1
put the second item of c into y1
put the first item of d into x0
put the second item of d into y0
put 0 into v1
put (x3 - 3 * x2 + 3 * x1 - x0) into A
put (3 * x2 - 6 * x1 + 3 * x0) into B
put (3 * x1 - 3 * x0) into C
put (x0) into D
put (y3 - 3 * y2 + 3 * y1 - y0) into E
put (3*y2 - 6 * y1 + 3 * y0) into F
put (3 * y1 - 3 * y0) into G
put (y0) into H
if there is a fld "BezierResolution" then put fld "BezierResolution" into
cde
if cde is not a number then put "32" into cde
Repeat with i = 1 to cde -- a number from 16 to 800
put i * ( 1 / cde ) into v1
put 1 - v1 into t
put ((((A * t) + B)* t) + C) * t + D into x
put ((((E* t) + F)* t) + G) * t + H into y
if varBezierSegment is not empty then put last line of varBezierSegment
into varTemp
if x div 1,y div 1 <> varTemp then put x div 1,y div 1 & return after
varBezierSegment
end repeat
end bezier3
Have a nice weekend!
Al
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