# 
#                             C o n n e c t  4 !
#
# by Tom Wheeley.
#
# A semi-graphical Connect 4 program for the fx9700 calculator, make sure
# you also enter the correct names in programs A and B.
#
# This program is CaS compatible!

@@ Prog A ( )
"Player 1"


@@ Prog B ( )
"Player 2"


@@ Prog C ( )

"Connect 4"

# Draw screen

Prog Z
127->X:Lbl 1
Plot X,2
Plot X,62:Line 
X-18->X:X>0=>Goto 1
62->Y:Lbl 2
Plot 1,Y
Plot 126,Y:Line 
Y-10->Y:Y>0=>Goto 2

# Initialise
0->B~H:T<>0=>1->T
4->R

#Program loop
Lbl 3
  T=0=>"[O]":T<>0=>"[0]"
  T=0=>Prog A
  T<>0=>Prog B
  "Column (1-7)"?->A        ; Enter column number
  A<>Abs Int A=>Goto 3         
  A>7=>Goto 
  A=0=>Goto 4
  A[A]=6=>"Column full!"
  A[A]=6=>Goto 3
  Isz A[A]
  18A-8->P:10A[A]-3->Q      ; Calculate position on screen
  Prog O:1-T->T
  Lbl 4:Plot 0,0_           ; Show screen
Goto 3


@@ Prog O ( )

R->V:Lbl 1:\sqrt( R\sqr - V\sqr -> U    ; Circle drawing routine. It moves
Plot P+U,Q+V                            ; X from the Radius to 0, using
Plot P-U,Q-V                            ; Pythagorus to calculate Y.  To
T<>0=>Line                              ; save time 4 way symmetry is used.
Plot P+U,Q-V
Plot P-U,Q+V
T<>0=>Line 
Plot P+V,Q+U
Plot P-V,Q-U
T<>0=>Line 
Plot P+V,Q-U
Plot P-V,Q+U
T<>0=>Line 
Dsz V:Goto 1


@@ Prog Z ( )

Range 1,127,0,1,63,0                    ; Set Range
64->X:32->Y