stella/src/emucore/TrackBall.hxx

//============================================================================
//
//   SSSS    tt          lll  lll       
//  SS  SS   tt           ll   ll        
//  SS     tttttt  eeee   ll   ll   aaaa 
//   SSSS    tt   ee  ee  ll   ll      aa
//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
//  SS  SS   tt   ee      ll   ll  aa  aa
//   SSSS     ttt  eeeee llll llll  aaaaa
//
// Copyright (c) 1995-2012 by Bradford W. Mott, Stephen Anthony
// and the Stella Team
//
// See the file "License.txt" for information on usage and redistribution of
// this file, and for a DISCLAIMER OF ALL WARRANTIES.
//
// $Id$
//============================================================================

#ifndef TRACKBALL_HXX
#define TRACKBALL_HXX

#include "bspf.hxx"
#include "Control.hxx"
#include "Event.hxx"

/**
  The various trackball-like controllers supported by the Atari 2600.
  They're all placed in one class, since other than a few minor
  differences, they work almost exactly the same.  This code was
  heavily borrowed from z26.

  The supported controllers include:
    TrackBall22: Atari 2600 CX-22 Trakball
    TrackBall80: Atari ST CX-80 Trakball
    AmigaMouse:  Amiga Mouse

  @author  Stephen Anthony & z26 team
  @version $Id$
*/
class TrackBall : public Controller
{
  public:
    /**
      Create a new TrackBall controller plugged into the specified jack

      @param jack   The jack the controller is plugged into
      @param event  The event object to use for events
      @param system The system using this controller
      @param type   The type of trackball controller
    */
    TrackBall(Jack jack, const Event& event, const System& system, Type type);

    /**
      Destructor
    */
    virtual ~TrackBall();

  public:
    /**
      Read the entire state of all digital pins for this controller.

      Note that this method must take into account the location of the
      pin data in the bitfield, and zero the remaining data:

        Left port : upper 4 bits valid, lower 4 bits zero'ed
        Right port: lower 4 bits valid, upper 4 bits zero'ed

      This method completely takes over reading of the port;
      it doesn't call Controller::read() at all.

      @return The state of all digital pins
    */
    uInt8 read();

    /**
      Update the entire digital and analog pin state according to the
      events currently set.
    */
    void update();

  private:
    // Counter to iterate through the gray codes
    int myHCounter, myVCounter;

    // How many new horizontal and vertical values this frame
    int myTrakBallCountH, myTrakBallCountV;

    // How many lines to wait before sending new horz and vert val
    int myTrakBallLinesH, myTrakBallLinesV;

    // Was TrakBall moved left or moved right instead
    int myTrakBallLeft;

    // Was TrakBall moved down or moved up instead
    int myTrakBallDown;

    int myScanCountH, myScanCountV, myCountH, myCountV;

    // CX-22
    static const uInt32 ourTrakBallTableTB_H[2][2];
    static const uInt32 ourTrakBallTableTB_V[2][2];

    // ST mouse / CX-80
    static const uInt32 ourTrakBallTableST_H[4];
    static const uInt32 ourTrakBallTableST_V[4];

    // Amiga mouse
    static const uInt32 ourTrakBallTableAM_H[4];
    static const uInt32 ourTrakBallTableAM_V[4];
};

#endif