XProfan

Windowtitle "Gummiband-Pendel in the Wind"'(CL)CopyLeft 2014-03 by P.woodpecker, Wien
Windowstyle 24:Window 0,0-%maxx,%maxy-40' No however geartete Gewähr!
randomize:var col&=rgb(200+rnd(56),200+rnd(56),200+rnd(56))
var xx&=width(%hwnd):var yy&=height(%hwnd):var xh!=xx&/2:var yh!=yy&/2:var zoom!=2000
declare x!,y!,dx!,dy!,mx!,my!,r!,fk!,m!,f!,fx!,fy!,w!,a!,ax!,ay!,v!,vx!,vy!,g!,t!,wind!
g! =9.80665'm/s²
fk!=0.3'zoom*n/m
t! =0.01'Zeitschritt
m! =4.8'kg
MCls xx&,yy&

REPEAT

    StartPaint -1:ClS col&
    print Fx!:print Fy!
    usepen 0,1,0 : line xh!,0 - xh!,yy& : line 0,yh! - xx&,yh!
    usepen 0,3,0 : line %mousex,%mousey - xh!+x!*zoom!,yh!-y!*zoom!
    usepen 0,20,$9F0000 : line %mousex,%mousey - %mousex-1,%mousey
    usepen 0,47,200 : line xh!+x!*zoom!,(yh!-y!*zoom!-1) - xh!+x!*zoom!,yh!-y!*zoom!
    EndPaint
    MCopyBMP 0,0-xx&,yy& > 0,0;0
    mx!=%mousex-xh!-x!*zoom! : my!=yh!-%mousey-y!*zoom!
    dx!=mx!-x!   : dy!=my!-y!
    Fx!=dx!*fk!  : Fy!=dy!*fk!
    ax!=Fx!/m!   : ay!=Fy!/m! - g!'Gravitation
    wind!=(rnd(90)-rnd(70))/zoom!
    vx!=vx!+.5*ax!*t!+wind! : vy!=vy!+0.5*ay!*t!
    vx!=vx!*0.97 : vy!=vy!*0.97
    x!=x!+vx!*t!: y!=y!+vy!*t!
    waitinput 4

UNTIL %key=27

end