source: branches/simple/Devices/Screen.pas

unit Screen;

interface

uses
  Classes, SysUtils, Device, DeviceManager, Memory, Channel;

type
  TScreenMode = (smText);

  { TScreen8 }

  TScreen8 = class(TDevice8)
  private
    FOnChange: TNotifyEvent;
    function ReadData8: Byte;
    function ReadAddr8: Byte;
    function ReadWidth8: Byte;
    function ReadHeight8: Byte;
    procedure WriteData8(Data: Byte);
    procedure WriteAddr8(Data: Byte);
    procedure WriteWidth8(Data: Byte);
    procedure WriteHeight8(Data: Byte);
    procedure DoChange;
    procedure UpdateMode;
  public
    Memory: TMemory8;
    Width: Byte;
    Height: Byte;
    Mode: TScreenMode;
    constructor Create;
    destructor Destroy; override;
    function GetHandlerCount: Integer; override;
    function GetHandler(Address: Integer): TChannel8; override;
    property OnChange: TNotifyEvent read FOnChange write FOnChange;
  end;

  { TScreen16 }

  TScreen16 = class(TDevice16)
  private
    FOnChange: TNotifyEvent;
    function ReadData8: Byte;
    function ReadData16: Word;
    function ReadAddr16: Word;
    function ReadWidth16: Word;
    function ReadHeight16: Word;
    procedure WriteData8(Data: Byte);
    procedure WriteData16(Data: Word);
    procedure WriteAddr16(Data: Word);
    procedure WriteWidth16(Data: Word);
    procedure WriteHeight16(Data: Word);
    procedure DoChange;
    procedure UpdateMode;
  public
    Memory: TMemory16;
    Width: Word;
    Height: Word;
    Mode: TScreenMode;
    constructor Create;
    destructor Destroy; override;
    function GetHandlerCount: Integer; override;
    function GetHandler(Address: Integer): TChannel16; override;
    property OnChange: TNotifyEvent read FOnChange write FOnChange;
  end;

  TScreen = class(TDevice)
    BitWidth: TBitWidth;
    Screen8: TScreen8;
    Screen16: TScreen16;
    constructor Create(BitWidth: TBitWidth; Screen8: TScreen8; Screen16: TScreen16);
  end;


implementation

{ TScreen }

constructor TScreen.Create(BitWidth: TBitWidth; Screen8: TScreen8;
  Screen16: TScreen16);
begin
  Self.BitWidth := BitWidth;
  Self.Screen8 := Screen8;
  Self.Screen16 := Screen16;
end;

{ TScreen16 }

procedure TScreen16.WriteData8(Data: Byte);
begin
  Memory.WritePos8(Data);
  DoChange;
end;

procedure TScreen16.WriteData16(Data: Word);
begin
  Memory.WritePos16(Data);
  DoChange;
end;

function TScreen16.ReadData8: Byte;
begin
  Result := Memory.ReadPos8;
end;

function TScreen16.ReadData16: Word;
begin
  Result := Memory.ReadPos16;
end;

procedure TScreen16.WriteAddr16(Data: Word);
begin
  Memory.Position := Data;
  DoChange;
end;

function TScreen16.ReadAddr16: Word;
begin
  Result := Memory.Position;
end;

procedure TScreen16.WriteWidth16(Data: Word);
begin
  Width := Data;
  DoChange;
end;

function TScreen16.ReadWidth16: Word;
begin
  Result := Width;
end;

procedure TScreen16.WriteHeight16(Data: Word);
begin
  Height := Data;
  DoChange;
end;

function TScreen16.ReadHeight16: Word;
begin
  Result := Height;
end;

procedure TScreen16.DoChange;
begin
  if Assigned(FOnChange) then FOnChange(Self);
end;

procedure TScreen16.UpdateMode;
begin
  Memory.Size := Width * Height;
end;

constructor TScreen16.Create;
begin
  Memory := TMemory16.Create;
  Width := 80;
  Height := 50;
  Mode := smText;
  UpdateMode;
end;

destructor TScreen16.Destroy;
begin
  FreeAndNil(Memory);
  inherited;
end;

function TScreen16.GetHandlerCount: Integer;
begin
  Result := 4;
end;

function TScreen16.GetHandler(Address: Integer): TChannel16;
begin
  if Address = 0 then begin
    Result := TChannel16.Create;
    Result.Read16 := ReadData16;
    Result.Write16 := WriteData16;
  end else
  if Address = 1 then begin
    Result := TChannel16.Create;
    Result.Read16 := ReadAddr16;
    Result.Write16 := WriteAddr16;
  end else
  if Address = 2 then begin
    Result := TChannel16.Create;
    Result.Read16 := ReadWidth16;
    Result.Write16 := WriteWidth16;
  end else
  if Address = 3 then begin
    Result := TChannel16.Create;
    Result.Read16 := ReadHeight16;
    Result.Write16 := WriteHeight16;
  end;
end;

{ TScreen8 }

procedure TScreen8.WriteData8(Data: Byte);
begin
  Memory.WritePos8(Data);
  DoChange;
end;

function TScreen8.ReadData8: Byte;
begin
  Result := Memory.ReadPos8;
end;

procedure TScreen8.WriteAddr8(Data: Byte);
begin
  Memory.Position := Data;
  DoChange;
end;

function TScreen8.ReadAddr8: Byte;
begin
  Result := Memory.Position;
end;

procedure TScreen8.WriteWidth8(Data: Byte);
begin
  Width := Data;
  DoChange;
end;

function TScreen8.ReadWidth8: Byte;
begin
  Result := Width;
end;

procedure TScreen8.WriteHeight8(Data: Byte);
begin
  Height := Data;
  DoChange;
end;

function TScreen8.ReadHeight8: Byte;
begin
  Result := Height;
end;

procedure TScreen8.DoChange;
begin
  if Assigned(FOnChange) then FOnChange(Self);
end;

procedure TScreen8.UpdateMode;
begin
  Memory.Size := Width * Height;
end;

constructor TScreen8.Create;
begin
  Memory := TMemory8.Create;
  Width := 20;
  Height := 12;
  Mode := smText;
  UpdateMode;
end;

destructor TScreen8.Destroy;
begin
  FreeAndNil(Memory);
  inherited;
end;

function TScreen8.GetHandlerCount: Integer;
begin
  Result := 4;
end;

function TScreen8.GetHandler(Address: Integer): TChannel8;
begin
  if Address = 0 then begin
    Result := TChannel8.Create;
    Result.Read8 := ReadData8;
    Result.Write8 := WriteData8;
  end else
  if Address = 1 then begin
    Result := TChannel8.Create;
    Result.Read8 := ReadAddr8;
    Result.Write8 := WriteAddr8;
  end else
  if Address = 2 then begin
    Result := TChannel8.Create;
    Result.Read8 := ReadWidth8;
    Result.Write8 := WriteWidth8;
  end else
  if Address = 3 then begin
    Result := TChannel8.Create;
    Result.Read8 := ReadHeight8;
    Result.Write8 := WriteHeight8;
  end;
end;

end.