OPTION ANGLE DEGREES
PRINT
PRINT "＜ 合わせ鏡による光の反射 ＞"
PRINT "後方観察用潜望鏡です。"
PRINT "後方観察用潜望鏡に映る背景像は 上下反転・左右反転しています。"
PRINT "後方観察用潜望鏡に映る背景像の上下反転は 合わせ鏡に因るものです。"
PRINT "後方観察用潜望鏡に映る背景像の左右反転は 観察者の相対的左右反転行為に因るものです。"
PRINT

SET WINDOW -4,4,-4,4
DRAW GRID
PLOT LINES : 2,-3;2,-1
PLOT LINES : 2,1;2,3
PLOT LINES : -2,-1;0,-3
PLOT LINES : -2,1;0,3
SET COLOR 4
DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(2,1)
SET COLOR 3
DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(2,2)
SET COLOR 2
DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(2,3)
WAIT DELAY 1

FOR t=0 TO 2 STEP 0.05
   SET DRAW mode hidden       ! ちらつき防止
   SET COLOR 4
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(2-t,1)
   SET COLOR 3
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(2-t,2)
   SET COLOR 2
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(2-t,3)
   WAIT DELAY 0.1    
   SET DRAW mode explicit   ! ちらつき防止 
NEXT t

FOR t=0 TO 1 STEP 0.05
   SET DRAW mode hidden       ! ちらつき防止
   SET COLOR 4
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0-t,1)
   SET COLOR 3
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0-t,2)
   SET COLOR 2
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0,3-t)
   WAIT DELAY 0.1    
   SET DRAW mode explicit   ! ちらつき防止 
NEXT t

FOR t=0 TO 1 STEP 0.05
   SET DRAW mode hidden       ! ちらつき防止
   SET COLOR 4
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(-1-t,1)
   SET COLOR 3
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(-1,2-t)
   SET COLOR 2
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0,2-t)
   WAIT DELAY 0.1    
   SET DRAW mode explicit   ! ちらつき防止 
NEXT t

FOR t=0 TO 2 STEP 0.05
   SET DRAW mode hidden       ! ちらつき防止
   SET COLOR 4
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(-2,1-t)
   SET COLOR 3
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(-1,1-t)
   SET COLOR 2
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0,1-t)
   WAIT DELAY 0.1    
   SET DRAW mode explicit   ! ちらつき防止 
NEXT t

FOR t=0 TO 1 STEP 0.05
   SET DRAW mode hidden       ! ちらつき防止
   SET COLOR 4
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(-2+t,-1)
   SET COLOR 3
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(-1,-1-t)
   SET COLOR 2
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0,-1-t)
   WAIT DELAY 0.1    
   SET DRAW mode explicit   ! ちらつき防止 
NEXT t

FOR t=0 TO 1 STEP 0.05
   SET DRAW mode hidden       ! ちらつき防止
   SET COLOR 4
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(-1+t,-1)
   SET COLOR 3
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(-1+t,-2)
   SET COLOR 2
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0,-2-t)
   WAIT DELAY 0.1    
   SET DRAW mode explicit   ! ちらつき防止 
NEXT t

FOR t=0 TO 2 STEP 0.05
   SET DRAW mode hidden       ! ちらつき防止
   SET COLOR 4
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0+t,-1)
   SET COLOR 3
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0+t,-2)
   SET COLOR 2
   DRAW DISK WITH SCALE(0.05,0.05)*SHIFT(0+t,-3)
   WAIT DELAY 0.1    
   SET DRAW mode explicit   ! ちらつき防止 
NEXT t

END