XProfan

English

p.specht

both, namely Bezierkurven 2. Order and Splines 3. Order (aka Kubische Splines) are engstens akin and ineinander überführbar. both are namely in reality kubische Polynomfunktionen. so go incidentally today skalierbare Schriften created: Duch Eckpunk-indicated. and legal protected is the Result then too!

Compile Mark Separation

Window Title "Parametrisch explizit gesteuerte 4-spots-Kurve"
'(DW) Demoware 2015-01-02 by P.woodpecker, Wien (Austria). without jedwede Gewähr!
Windowstyle 24:font 2:randomize:Window 0,0-%maxx,%maxy
Var xh&=width(%hwnd)/2:Var yh&=height(%hwnd)/2

proc fy :parameters y0!,y1!,y2!,y3!,a!:var a2!=sqr(a!):var a3!=a2!*a!

    '*********************************************************************************
    return a3!*y3!+(3*a2!-3*a3!)*y2!+(3*a3!-6*a2!+3*a!)*y1!+(-a3!+3*a2!-3*a!+1)*y0!
    '*********************************************************************************

endproc

Declare i&,j&,k&,f!, x!,y!,x0!,y0!,x1!,y1!,x2!,y2!,x3!,y3!, a!
REPEAT :locate 2,2:print "1. point klicken"

whileloop 0,3

    waitmouse

    if %mousepressed=1

        x!=%mousex:y!=%mousey

        if (&Loop=0) or (&Loop=3):usepen 0,16,200

            else :usepen 0,9,rgb(0,200,0)
            endif : moveto x!,y!:lineto x!,y!:sound 500,10

            if     &Loop=0: x0!=x!:y0!=y!:locate 2,2:print "2"

            elseif &Loop=1: x1!=x!:y1!=y!:locate 2,2:print "3"

            elseif &Loop=2: x2!=x!:y2!=y!:locate 2,2:print "4"

            elseif &Loop=3: x3!=x!:y3!=y!:locate 2,2:print "Drawing           "

                else : print "Huh?"

            endif

        endwhile

        a!=0:x!=fy(x0!,x1!,x2!,x3!,a!):y!=fy(y0!,y1!,y2!,y3!,a!)
        usepen 0,6,rgb(0,0,200):moveto x!,y!

        whileloop 0,100:a!=&Loop/100

            x!=fy(x0!,x1!,x2!,x3!,a!):y!=fy(y0!,y1!,y2!,y3!,a!):lineto x!,y!

        endwhile

    Until %Key=27:END