' Copyright (c) 2021 Thomas Hugo Williams
' For Colour Maximite 2, MMBasic 5.06

Option Explicit On
Option Default None

Const chm.BLACK%   = 0
Const chm.RED%     = 1
Const chm.GREEN%   = 2
Const chm.YELLOW%  = 3
Const chm.BLUE%    = 4
Const chm.MAGENTA% = 5
Const chm.CYAN%    = 6
Const chm.WHITE%   = 7

Dim chm.col_map$(255) ' map of attribute values to VT100 control codes
Dim chm.mem%(5000)    ' memory buffer for character and attribute data
Dim chm.max_num%      ' max number of windows allowed
Dim chm.num%          ' current number of windows created

' For the currently selected window:
Dim chm.id% = -1 ' id
Dim chm.a%       ' x-coordinate of left hand side
Dim chm.b%       ' y-coordinate of top
Dim chm.w%       ' width
Dim chm.h%       ' height
Dim chm.x%       ' x cursor-position
Dim chm.y%       ' y cursor-position
Dim chm.at%      ' attributes to use for printing
Dim chm.pc%      ' pointer to the character data
Dim chm.pa%      ' pointer to the attribute data

Cls

Option Console Serial
Print Chr$(27) "[?25l"; ' hide cursor

moses()
End

Sub moses()
 chm.init(2)
 Dim win1% = chm.new_win%(10, 5, 40, 25)
 Dim i%
 chm.switch(win1%) : chm.border()
 chm.bold(1)
 chm.print_at(0, 0)
 For i% = 1 To 100
   chm.foreground(1 + i% Mod 6)
   chm.print("Moses supposes his toeses are roses, but moses supposes eroneously.")
   chm.print(" For nobody's toeses are roses as moses supposes his toeses to be. ")
   Pause 200
 Next
End Sub

Sub chm.init(max_num%)
 If max_num% < 1 Or max_num% > 10 Then Error "invalid number of windows: " + Str$(max_num%)
 Dim chm.a_%(max_num% - 1)
 Dim chm.b_%(max_num% - 1)
 Dim chm.w_%(max_num% - 1)
 Dim chm.h_%(max_num% - 1)
 Dim chm.x_%(max_num% - 1)
 Dim chm.y_%(max_num% - 1)
 Dim chm.pc_%(max_num% - 1)
 Dim chm.at_%(max_num% - 1)
 chm.max_num% = max_num%

 Local i%, s$
 For i% = 0 To 255
   ' Foreground
   s$ = Chr$(27) + "[0m" + Chr$(27) + "["
   If i% And &b01000000 Then Cat s$, "1;"
   Select Case i% And &b00000111
     Case chm.BLACK%   : Cat s$, "30"
     Case chm.RED%     : Cat s$, "31"
     Case chm.GREEN%   : Cat s$, "32"
     Case chm.YELLOW%  : Cat s$, "33"
     Case chm.BLUE%    : Cat s$, "34"
     Case chm.MAGENTA% : Cat s$, "35"
     Case chm.CYAN%    : Cat s$, "36"
     Case chm.WHITE%   : Cat s$, "37"
     Case Else         : Error "unexpected"
   End Select
   Cat s$, "m" + Chr$(27) + "["

   ' Background
   Select Case (i% And &b00111000) >> 3
     Case chm.BLACK%   : Cat s$, "40"
     Case chm.RED%     : Cat s$, "41"
     Case chm.GREEN%   : Cat s$, "42"
     Case chm.YELLOW%  : Cat s$, "43"
     Case chm.BLUE%    : Cat s$, "44"
     Case chm.MAGENTA% : Cat s$, "45"
     Case chm.CYAN%    : Cat s$, "46"
     Case chm.WHITE%   : Cat s$, "47"
     Case Else         : Error "unexpected"
   End Select
   Cat s$, "m"

   ' Reverse video
   If i% And &b10000000 Then Cat s$, Chr$(27) + "[7m"

   chm.col_map$(i%) = s$
 Next
End Sub

Sub chm.foreground(col%)
 chm.at% = (chm.at% And &b11111000) Or col%
End Sub

Sub chm.background(col%)
 chm.at% = (chm.at% And &b11000111) Or (col% << 3)
End Sub

Sub chm.bold(z%)
 chm.at% = (chm.at% And &b10111111) Or (z% << 6)
End Sub

Sub chm.inverse(z%)
 chm.at% = (chm.at% And &b01111111) Or (z% << 7)
End Sub

Function chm.new_win%(x%, y%, w%, h%)
 If chm.num% > Bound(chm.a_%(), 1) Then Error "maximum number of windows reached: " + Str$(chm.num%)
 chm.a_%(chm.num%) = x% + 1 ' To account for VT100 using 1,1 as root instead of 0,0.
 chm.b_%(chm.num%) = y% + 1
 chm.w_%(chm.num%) = w%
 chm.h_%(chm.num%) = h%
 chm.x_%(chm.num%) = 0
 chm.y_%(chm.num%) = 0
 If chm.num% = 0 Then
   chm.pc_%(chm.num%) = Peek(VarAddr chm.mem%())
 Else
   chm.pc_%(chm.num%) = chm.pc_%(chm.num% - 1) + chm.w_%(chm.num% - 1) * chm.h_%(chm.num% - 1) * 2
 EndIf
 chm.at_%(chm.num%) = chm.WHITE%

 Memory Set chm.pc_%(chm.num%), 32, w% * h%
 Memory Set chm.pc_%(chm.num%) + w% * h%, chm.WHITE%, w% * h%

 chm.new_win% = chm.num%
 Inc chm.num%
End Function

Sub chm.switch(id%)
 If chm.id% > -1 Then
   chm.at_%(chm.id%) = chm.at%
   chm.x_%(chm.id%) = chm.x%
   chm.y_%(chm.id%) = chm.y%
 EndIf
 chm.id% = id%
 chm.a% = chm.a_%(id%)
 chm.b% = chm.b_%(id%)
 chm.w% = chm.w_%(id%)
 chm.h% = chm.h_%(id%)
 chm.x% = chm.x_%(id%)
 chm.y% = chm.y_%(id%)
 chm.at% = chm.at_%(id%)
 chm.pc% = chm.pc_%(id%)
 chm.pa% = chm.pc% + chm.w% * chm.h%
End Sub

Sub chm.print(s$)
 chm.print_at(chm.x%, chm.y%, s$)
End Sub

Sub chm.print_at(x%, y%, s$)
 Local x_% = x%, y_% = y%
 Local i% = 1
 Local ls% = Len(s$)
 Local nc% = Min(chm.w% - x_%, ls% - i% + 1)
 Local of%
 Local ps% = Peek(VarAddr s$)

 Do While nc% > 0
   If y_% = chm.h% Then
     chm.scroll_up()
     Inc y_%, -1
   EndIf

   of% = y_% * chm.w% + x_%
   Memory Copy ps% + i%, chm.pc% + of%, nc%
   Memory Set chm.pa% + of%, chm.at%, nc%

   Print chm.col_map$(chm.at%);
   Print Chr$(27) "[" Str$(chm.b% + y_%) ";" Str$(chm.a% + x_%) "H" Mid$(s$, i%, nc%);

   Inc i%, nc%
   Inc x_%, nc%
   If x_% = chm.w% Then x_% = 0 : Inc y_%
   nc% = Min(chm.w% - x_%, ls% - i% + 1)
 Loop

 ' Leaves chm.x% and chm.y% at the last printed char position.
 chm.x% = x_%
 chm.y% = y_%
End Sub

Sub chm.scroll_up()
'  Local tmpa%(chm.w%), tmpc%(chm.w%)
 Local pa% = chm.pa%
 Local pc% = chm.pc%

 ' Copy attribute and character data from first line (y = 0) to tmp{a|c}%.
'  Memory Copy pa%, Peek(VarAddr tmpa%()), chm.w%
'  Memory Copy pc%, Peek(VarAddr tmpc%()), chm.w%

 Local y%
 For y% = 1 To chm.h% - 1
   ' Copy attribute and character data from line y + 1 to line y.
   Memory Copy pa% + chm.w%, pa%, chm.w%
   Memory Copy pc% + chm.w%, pc%, chm.w%
   Inc pa%, chm.w%
   Inc pc%, chm.w%
 Next

 ' Paste attribute and character data from original first line to last line.
'  Memory Copy Peek(VarAddr tmpa%()), pa%, chm.w%
'  Memory Copy Peek(VarAddr tmpc%()), pc%, chm.w%
 Memory Set pa%, chm.WHITE%, chm.w%
 Memory Set pc%, 32, chm.w%

 chm.redraw()
End Sub

Sub chm.redraw()
 Local a% = -1, b%, x%, y%
 Local pa% = chm.pa%
 Local pc% = chm.pc%
 For y% = 0 To chm.h% - 1
   Print Chr$(27) "[" Str$(chm.b% + y%) ";" Str$(chm.a%) "H";
   For x% = 0 To chm.w% - 1
     b% = Peek(Byte pa% + x%)
     If a% <> b% Then a% = b% : Print chm.col_map$(a%);
     Print Chr$(Peek(Byte pc% + x%));
   Next x%
   Inc pa%, chm.w%
   Inc pc%, chm.w%
 Next y%
End Sub

Sub chm.border()
 Local s1$ = "+" + String$(chm.w%, "-") + "+"
 Local s2$ = "|" + Space$(chm.w%) + "|")
 Print Chr$(27) "[" Str$(chm.b% - 1) ";" Str$(chm.a% - 1) "H" s1$
 Local i%
 For i% = 0 To chm.h% - 1
   Print Chr$(27) "[" Str$(chm.b% + i%) ";" Str$(chm.a% - 1) "H" s2$
 Next
 Print Chr$(27) "[" Str$(chm.b% + chm.h%) ";" Str$(chm.a% - 1) "H" s1$
End Sub