/*
-----------------------------------------------------
File:    Keyboard.Pas
By:      Ronny Wester, ronny@rat.se
Passat a C by: JailDoctor

Unit to check up/down status of individual key flags.
Written from code I got off rec.games.programmer.
Sorry, I lost the name of the poster.
As most of this code is scancode-dependent some keys
may not be where they "should" on your keyboard.
-----------------------------------------------------
*/
/* unit Keyboard;


interface

  uses Dos;
*/

#include <SDL2/SDL.h>
//const

#define keySysReq      SDL_SCANCODE_SYSREQ
#define keyCapsLock    SDL_SCANCODE_CAPSLOCK
#define keyNumLock     0x45
#define keyScrollLock  0x46
#define keyLeftCtrl    0x1D
#define keyLeftAlt     0x38
#define keyLeftShift   0x2A
#define keyRightCtrl   0x9D
#define keyAltGr       0xB8
#define keyRightShift  0x36
#define keyEsc         0x01
#define keyBackspace   0x0E
#define keyEnter       0x1C
#define keySpace       0x39
#define keyTab         0x0F
#define keyF1          0x3B
#define keyF2          0x3C
#define keyF3          0x3D
#define keyF4          0x3E
#define keyF5          0x3F
#define keyF6          0x40
#define keyF7          0x41
#define keyF8          0x42
#define keyF9          0x43
#define keyF10         0x44
#define keyF11         0x57
#define keyF12         0x58
#define keyA           0x1E
#define keyB           0x30
#define keyC           0x2E
#define keyD           0x20
#define keyE           0x12
#define keyF           0x21
#define keyG           0x22
#define keyH           0x23
#define keyI           0x17
#define keyJ           0x24
#define keyK           0x25
#define keyL           0x26
#define keyM           0x32
#define keyN           0x31
#define keyO           0x18
#define keyP           0x19
#define keyQ           0x10
#define keyR           0x13
#define keyS           0x1F
#define keyT           0x14
#define keyU           0x16
#define keyV           0x2F
#define keyW           0x11
#define keyX           0x2D
#define keyY           0x15
#define keyZ           0x2C
#define key1           0x02
#define key2           0x03
#define key3           0x04
#define key4           0x05
#define key5           0x06
#define key6           0x07
#define key7           0x08
#define key8           0x09
#define key9           0x0A
#define key0           0x0B
#define keyMinus       0x0C
#define keyEqual       0x0D
#define keyLBracket    0x1A
#define keyRBracket    0x1B
#define keySemicolon   0x27
#define keyTick        0x28
#define keyApostrophe  0x29
#define keyBackslash   0x2B
#define keyComma       0x33
#define keyPeriod      0x34
#define keySlash       0x35
#define keyInsert      0xD2
#define keyDelete      0xD3
#define keyHome        0xC7
#define keyEnd         0xCF
#define keyPageUp      0xC9
#define keyArrowLeft   0xCB
#define keyArrowRight  0xCD
#define keyArrowUp     0xC8
#define keyArrowDown   0xD0
#define keyKeypad0     0x52
#define keyKeypad1     0x4F
#define keyKeypad2     0x50
#define keyKeypad3     0x51
#define keyKeypad4     0x4B
#define keyKeypad5     0x4C
#define keyKeypad6     0x4D
#define keyKeypad7     0x47
#define keyKeypad8     0x48
#define keyKeypad9     0x49
#define keyKeypadComma 0x53
#define keyKeypadStar  0x37
#define keyKeypadMinus 0x4A
#define keyKeypadPlus  0x4E
#define keyKeypadEnter 0x9C
#define keyCtrlPrtScr  0xB7
#define keyShiftPrtScr 0xB7
#define keyKeypadSlash 0xB5

const char *keyNames[256] {
      /* $00 */ NULL, "Esc", "1", "2", "3", "4", "5", "6",
      /* $08 */ "7", "8", "9", "0", "+", "Apostrophe", "Backspace", "Tab",
      /* $10 */ "Q", "W", "E", "R", "T", "Y", "U", "I",
      /* $18 */ "O", "P", "�", "?", "Enter", "Left Ctrl", "A", "S",
      /* $20 */ "D", "F", "G", "H", "J", "K", "L", "�",
      /* $28 */ "�", "'", "Left shift", "<", "Z", "X", "C", "V",
      /* $30 */ "B", "N", "M", ",", ".", "-", "Right shift", "* (pad)",
      /* $38 */ "Alt", "Space", "Caps Lock", "F1", "F2", "F3", "F4", "F5",
      /* $40 */ "F6", "F7", "F8", "F9", "F10", "Num Lock", "Scroll Lock", "7 (pad)",
      /* $48 */ "8 (pad)", "9 (pad)", "- (pad)", "4 (pad)", "5 (pad)", "6 (pad)", "+ (pad)", "1 (pad)",
      /* $50 */ "2 (pad)", "3 (pad)", "0 (pad)", ", (pad)", "SysRq", NULL, NULL, "F11", "F12",
      /* $59 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL,
      /* $60 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
      /* $70 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
      /* $80 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
      /* $90 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, "Enter (pad)", "Right Ctrl", NULL, NULL,
      /* $A0 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
      /* $B0 */ NULL, NULL, NULL, NULL, NULL, "/ (pad)", NULL, "PrtScr", "Alt Gr", NULL, NULL, NULL, NULL, NULL, NULL, NULL,
      /* $C0 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL, "Home",
      /* $C8 */ "Up arrow", "Page Up", NULL, "Left arrow", NULL, "Right arrow", NULL, "End",
      /* $D0 */ "Down arrow", NULL, "Insert", "Delete", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
      /* $E0 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
      /* $F0 */ NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
};


procedure InstalarKb;
procedure DesinstalarKb;
function  TeclaPuls( b : byte ) : Boolean;
function  QTeclaPuls : Boolean;
function  AgarrarTecla : Byte;
procedure BorrarKb;
procedure EscriuKb;


implementation


var

  uOldInt9  : Pointer;                   { saves location of old OldInt9 vector }
  uKeys     : array [0..255] of Boolean; { array that holds key values }
  e0Flag    : Byte;
  uExitProc : Pointer;


{$F+}
procedure NewInt9; interrupt; assembler;
asm
  cli
  in      al, $60                       { get scan code from keyboard port }
  cmp     al, $E0                       { al = $E0 key ? }
  jne     @@SetScanCode
  mov     [e0Flag], 128
  mov     al, 20h                       { Send 'generic' EOI to PIC }
  out     20h, al
  jmp     @@exit
@@SetScanCode:
  mov     bl, al                        { Save scancode in BL }
  and     bl, 01111111b
  add     bl, [e0Flag]
  xor     bh, bh
  and     al, 10000000b                 { keep break bit, if set }
  xor     al, 10000000b                 { flip bit, 1 means pressed, 0 no }
  rol     al, 1                         { move breakbit to bit 0 }
  mov     [offset uKeys + bx], al
  mov     [e0Flag], 0
  mov     al, 20h                       { send EOI to PIC }
  out     20h, al
@@exit:
  sti
end;
{$F-}


procedure InstalarKb;
begin
  GetIntVec( $09, uOldInt9);           { save old location of INT 09 handler }
  SetIntVec( $09, Addr( NewInt9));     { point to new routine }
  FillChar( uKeys, SizeOf( uKeys), 0); { clear the keys array }
end;


procedure DesinstalarKb;
begin
  SetIntVec( $09, uOldInt9);         { point back to original routine }
  uOldInt9 := nil;
end;


function TeclaPuls( b : byte ) : Boolean;
begin
  TeclaPuls := uKeys[b];
end;


function QTeclaPuls : Boolean;
var b : Integer;
begin
  QTeclaPuls := True;
  for b := 0 to 255 do
    if uKeys[b] and (keyNames[b] <> nil) then
      Exit;
  QTeclaPuls := False;
end;


function AgarrarTecla : Byte;
var b : Integer;
begin
  AgarrarTecla := 0;
  for b := 1 to 255 do
    if uKeys[b] and (keyNames[b] <> nil) then
    begin
      AgarrarTecla := b;
      Exit;
    end;
end;


procedure BorrarKb;
begin
  FillChar( uKeys, SizeOf( uKeys), 0); { clear the keys array }
end;


{$F+}
procedure CleanUp;
begin
  ExitProc := uExitProc;
  if uOldInt9 <> nil then
    DesinstalarKb;
end;

procedure EscriuKb;
var b:byte;
begin
     for b := 0 to 255 do
         if uKeys[b] and (keyNames[b] <> nil) then
            write(keyNames[b],' | ');
     writeln;
end;

{$F-}


begin
  uExitProc := ExitProc;
  ExitProc := @CleanUp;
  uOldInt9 := nil;
end.