Option explicit
option default NONE
cls
'
' draw the image to be rotated
'
const image_width=100, image_height=100, image_left=80, image_top=80
box image_left,image_top,image_width,image_height,5,rgb(red),rgb(green)
text image_left+image_width/2,image_top+image_height/2,"A",CM,4,2,rgb(red),-1
'
'set up variables and constants
'
const xo=image_left+image_width/2,yo=image_top+image_height/2, xn=xo+400, yn=yo+200
dim float maxf=sqr(2.0)*image_width
if sqr(2.0)*image_height > maxf then maxf = sqr(2.0)*image_height
dim integer max= cint(maxf+1)/2
const rot=45.0
dim integer i,shear
dim float alpha= -tan(rad(rot/2))
dim float beta=sin(rad(rot))
print alpha,beta
'
' first shear
'
pause 4000
for i=-max to max
shear = cint(i*alpha)
blit xo-max,yo+i,xn-max+shear,yo+i,max*2,1
next i
pause 2000
'
' second shear
'
for i=-max to max
shear = cint(i*beta)
blit xn+i,yo-max,xn+i,yn-max+shear,1,max*2
next i
pause 2000
'
' third shear
'
for i=-max to max
shear = cint(i*alpha)
blit xn-max,yn+i,xo-max+shear,yn+i,max*2,1
next i
pause 2000