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+---- Thread: bezier and cubic curves (/showthread.php?tid=390)
bezier and cubic curves - nitrofurano - 2011-10-25
finally i coded some snipets - two of them are about drawing bezier and cubic curves - btw, if someone can help them being faster, or part of the library, be welcome!
beziercurve.bas
Code:
dim x0,y0,x1,y1,x2,y2,x3,y3 as float
dim stpv,xi,xo,yi,yo,ir,i as float
dim xr1,yr1,xr2,yr2 as float
dim xsn,ycs as float
dim xa,ya,xb,yb,xc,yc as float
dim tw,t as float
x0=20:y0=30:x1=50:y1=80:x2=150:y2=40:x3=110:y3=10
xa=(x3)-(3*x2)+(3*x1)-(x0)
ya=(y3)-(3*y2)+(3*y1)-(y0)
xb=(3*x2)-(6*x1)+(3*x0)
yb=(3*y2)-(6*y1)+(3*y0)
xc=(3*x1)-(3*x0)
yc=(3*y1)-(3*y0)
stpv=32
for tw=0 to stpv
t=tw/stpv
x=(((((xa*t)+xb)*t)+xc)*t)+x0
y=(((((ya*t)+yb)*t)+yc)*t)+y0
if tw=0 then:xo=x:yo=y:end if
plot xo,yo:draw x-xo,y-yo :'- line (xo,yo,x,y):
xo=x:yo=y
next
pause 0cubiccurve.bas
Code:
dim x0,y0,x1,y1,x2,y2,x3,y3 as float
dim stpv,xi,xo,yi,yo,ir,i as float
dim xr1,yr1,xr2,yr2 as float
dim xsn,ycs as float
x0=20:y0=30:x1=50:y1=80:x2=150:y2=40
xr1=x1-x0:yr1=y2-y1
x3=x0+x2-x1:y3=y0+y2-y1
xr2=x2-x1:yr2=y3-y2
stpv=32
for i=0 to stpv
ir=i*(1.570796/stpv)
xsn=(xr1*sin(ir))-(xr2*cos(ir))
ycs=(yr1*(cos(ir)*-1))-(yr2*sin(ir))
xi=x3+xsn:yi=y3+ycs
if i=0 then:xo=xi:yo=yi:end if
if i<>0 then:
plot xo,yo:draw xi-xo,yi-yo :'- line (xo,yo,xi,yi)
end if
xo=xi
yo=yi
next i
pause 0circlefill.bas
Code:
dim x,y,r,xl as ubyte
dim yd as float
x=50:y=60:r=40
for yd=0 to r
xl=int((sin(acs(yd/r)))*r)
plot x-xl,y+yd:draw xl*2,0
if yd<>0 then:plot x-xl,y-yd:draw xl*2,0:end if
next yd
pause 0boxfill.bas
Code:
dim x1,y1,x2,y2 as integer
x1=20:y1=30:x2=50:y2=80
for y=y1 to y2
plot x1,y:draw x2-x1,0
next y
pause 0box.bas
Code:
dim x1,y1,x2,y2 as integer
x1=20:y1=30:x2=50:y2=80
plot x1,y1
draw x2-x1,0
draw 0,y2-y1
draw x1-x2,0
draw 0,y1-y2
pause 0line.bas
Code:
dim x1,y1,x2,y2 as integer
x1=20:y1=30:x2=50:y2=80
plot x1,y1
draw x2-x1,y2-y1
pause 0Re: bezier and cubic curves - britlion - 2011-10-25
They could be sped up by using faster trig functions, somewhat - though they would lose accuracy:
https://zxbasic.readthedocs.io/en/docs/library/fsin.bas/
Boriel has also optimized draw and circle to be much faster than Sinclair Basic already.
Floats are also the slowest data type - you should avoid for anything you want speed for.