tilted rectangle

[tsh73]

It started as attempt to create warped weave.
So I got mesh warped OK... didn't got weave right.
Got this instead.

'spinoff of rotated weave
'tsh73 may 2018
nomainwin
open "Errr... Windows?" for graphics_nsb_nf as #gr
#gr "trapclose [quit]"
#gr "down"
#gr "fill white; flush"
#gr "home; posxy cx cy"

'#gr "home; circle 50"
side= 20
pi = acs(-1)

#gr "size 3"
scale1 =.85
scale2 =.7
for x = 0 to 2*cx step side
   for y = 0 to 2*cy step side
       xx=x'+side*sin(x/cx*pi)
       xx=side+(x+side*sin(y/cy*pi))*scale1
       yy=side+(y+side*sin(0-x/cx*pi))*scale1
       aDeg=atan2(side*(sin(0-x/cx*pi)-sin(0-(x-side)/cx*pi)),side)/pi*180
       col=2*int(sin(y/cy*pi)+1)+int(sin(x/cx*pi)+1)+1
       #gr "color ";word$(" yellow blue green red", col)

       call drawfilledrectangle aDeg, xx, yy, scale2*side, scale2*side
   next
next

#gr "flush"
wait

[quit]
timer 0
close #gr
end

'-----by B+
sub drawfilledrectangle a, x, y, w, h 'tsh fixed
   #gr "size 2;north;turn 180;turn ";a
   for i = 1 to h  'draw *part of* bigger and bigger rectangles
       #gr "place ";x;" ";y;";go ";i;";turn -90;go ";w;";turn 90"
   next
   #gr "size 1"
end sub

'---------------------------
function atan2(y,x)
   pi = acs(-1)    'could be made global to save some ticks
   if x <> 0 then arctan = atn(y/x)

   select case
       case x > 0
       atan2 = arctan

       case y>=0 and x<0
       atan2 = pi + arctan

       case y<0 and x<0
       atan2 = arctan - pi

       case y>0 and x=0
       atan2 = pi / 2

       case y<0 and x=0
       atan2 = pi / -2
   end select
end function


[B+]

Cool! I bet this might come in handy drawing Rubic cubes... ;-))