MD_Parola.cpp

/*
MD_Parola - Library for modular scrolling text and Effects
  
See header file for comments
This file contains methods to implement core functions
  
Copyright (C) 2013 Marco Colli. All rights reserved.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <MD_Parola.h>
#include <MD_Parola_lib.h>
#include <MD_MAX72xx.h>

MD_Parola::MD_Parola(uint8_t dataPin, uint8_t clkPin, uint8_t csPin, uint8_t numDevices):
_D(dataPin, clkPin, csPin, numDevices),
_fsmState(END), _suspend(false),
_pText(NULL)
{
  // Set up the MAX72XX library
  // The MAX72XX is in power-saving mode on startup,
  // we have to do a wakeup call, set the brightness, enable updates and clear the display
  _D.control(MD_MAX72XX::SHUTDOWN, MD_MAX72XX::OFF);
  _D.control(MD_MAX72XX::INTENSITY, MAX_INTENSITY/2);
  _D.control(MD_MAX72XX::UPDATE, MD_MAX72XX::ON);

  // initialise options in this library using methods supplied
  setSpeed(10);
  setPause(10*getSpeed());
  setCharSpacing(1);
  setTextAlignment(LEFT);
  setTextEffect(PRINT, NO_EFFECT);
  displayClear();

  // Now set the default viewing parameters for this library
  _D.setFont(MD_MAX72XX::SYS_VAR);
}

MD_Parola::~MD_Parola(void)
{
}

void MD_Parola::displayScroll(char *pText, textPosition_t align, textEffect_t effect, uint16_t speed)
{
  setTextAlignment(align);
  setSpeed(speed);
  setPause(0);
  setTextEffect(effect, effect);
  setTextBuffer(pText);

  displayReset();
}

void MD_Parola::displayText(char *pText, textPosition_t align, uint16_t speed, uint16_t pause, textEffect_t effectIn, textEffect_t effectOut)
{
  setTextAlignment(align);
  setSpeed(speed);
  setPause(pause);
  setTextEffect(effectIn, effectOut);
  setTextBuffer(pText);

  displayReset();
}

bool MD_Parola::displayAnimate(void)
{
  // work through things that stop us running this at all
  if (((_fsmState == PAUSE) && (millis() - _lastRunTime < _pauseTime)) ||
    (millis() - _lastRunTime < _tickTime) ||
    (_suspend))
    return(false);

  // save the time now, before we run the animation, so that the animation is part of the 
  // delay between animations giving more accurate frame timing.
  _lastRunTime = millis();  

  // suspend the display while we animate a frame
  _D.update(MD_MAX72XX::OFF);

  // any text to display?
  if (_pText != NULL)
  {
    switch (_fsmState)
    {
    case END:   // do nothing in this state
      PRINT_STATE("ANIMATE");
    break;

    case INITIALISE:
      PRINT_STATE("ANIMATE");

      setInitialConditions();
      _moveIn = true;
      // fall through to process the effect, first call will be with INITIALISE

    default: // All state except END are handled by the special effect functions
      switch (_moveIn ? _effectIn : _effectOut)
      {
        case PRINT:       effectPrint(_moveIn);   break;
        case SLICE:       effectSlice(_moveIn);   break;
        case WIPE:        effectWipe(false, _moveIn); break;
        case WIPE_CURSOR:   effectWipe(true, _moveIn);  break;
        case OPENING:     effectOpen(false, _moveIn); break;
        case OPENING_CURSOR:  effectOpen(true, _moveIn);  break;
        case CLOSING:     effectClose(false, _moveIn);  break;
        case CLOSING_CURSOR:  effectClose(true, _moveIn); break;
        case BLINDS:      effectBlinds(_moveIn);    break;
        case DISSOLVE:      effectDissolve(_moveIn);  break;
        case SCROLL_UP:
        case SCROLL_DOWN:   effectVScroll((_moveIn ? _effectIn : _effectOut), _moveIn); break;
        case SCROLL_LEFT:
        case SCROLL_RIGHT:    effectHScroll((_moveIn ? _effectIn : _effectOut), _moveIn); break;
        default:
          _fsmState = END;
      }

      // one way toggle for input to output, reset on Initialise
      _moveIn = _moveIn && !(_fsmState == PAUSE);
    break;
    }
  }

  TIME_PROFILE("\nAnimation time ");

  // re-enable and update the display
  _D.update(MD_MAX72XX::ON);

  TIME_PROFILE(": Cycle time ");

  return(_fsmState == END);
}

void MD_Parola::displayReset(void)
{
  _suspend = false;
  _fsmState = INITIALISE;
}

void MD_Parola::setInitialConditions(void)
// set the global variables initial conditions for all display effects
{
  PRINTS("\nsetInitialConditions");

  if (_pText == NULL)
    return;

  _pCurChar = _pText;
  _limitOverflow = !calcTextLimits(_pText);
}

uint16_t MD_Parola::getTextWidth(char *p)
// Get the width in columns for the text string passed to the function
// This is the sum of all the characters and the space betwen them.
{
  uint16_t  sum = 0;

  PRINTS("\ngetTextWidth");

  while (*p != '\0')
  {
    sum += _D.getChar(*p++, ARRAY_SIZE(_cBuf), _cBuf);
    if (*p)
      sum += _charSpacing;
  }

  PRINT(": W=", sum);

  return(sum);
}

bool MD_Parola::calcTextLimits(char *p)
// Work out left and right sides for the text to be displayed, 
// depending on the text alignment. If the message will not fit 
// in the current display the return false, otherwise true.
{
  bool b = true;
  uint16_t  displayWidth = _D.getColumnCount();
  
  _textLen = getTextWidth(p);

  PRINTS("\ncalcTextLimits");

  switch (_textAlignment)
  {
  case LEFT:
    _limitLeft = displayWidth-1;
    if (_textLen > displayWidth)
    {
      _limitRight = 0;
      b = false;
    }
    else
    {
      _limitRight = _limitLeft - _textLen;
    }
    break;

  case RIGHT:
    _limitRight = 0;
    if (_textLen > displayWidth)
    {
      _limitLeft = displayWidth-1;
      b = false;
    }
    else
    {
      _limitLeft = _limitRight + _textLen;
    }
    break;

  case CENTER:
    if (_textLen > displayWidth)
    {
      _limitLeft = displayWidth-1;
      _limitRight = 0;
      b= false;
    }
    else
    {
      _limitRight = (displayWidth - _textLen)/2;
      _limitLeft = _limitRight + _textLen;
    }
    break;
  }

  PRINT(" L:", _limitLeft);
  PRINT(" R:", _limitRight);
  PRINT(" O:", !b);

  return (b);
}

uint8_t MD_Parola::makeChar(char c)
// Load a character bitmap and add in trailing char spacing blanks
{
  uint8_t len;

  PRINTX("\nmakeChar 0x", c);

  len = _D.getChar(c, ARRAY_SIZE(_cBuf), _cBuf);
  for (uint8_t i = 0; i<_charSpacing; i++)
  {
    if (len < ARRAY_SIZE(_cBuf))
    _cBuf[len++] = 0;
  }

  PRINT(", len=", len);

  return(len);
}

uint8_t MD_Parola::reverseBuf(uint8_t *p, uint8_t size)
// reverse the elements of the specified buffer
// useful when we are scrolling right and want to insert the columns in reverse order
{
  for (uint8_t i=0; i<size/2; i++)
  {
    uint8_t t;

    t = p[i];
    p[i] = p[size-1-i];
    p[size-1-i] = t;
  }
}

#define SFX(s)  ((_moveIn && _effectIn == (s)) || (!_moveIn && _effectOut == (s)))

void MD_Parola::moveTextPointer(void)
// This method works when increment is done AFTER processing the character
// the _endOfText flag is set as a look ahead (ie, when the last character 
// is still valid)
// We need to move a pointer forward or back, depending on the way we are 
// travelling through the text buffer.
{
  PRINTS("\nMovePtr"); 

  if (SFX(SCROLL_RIGHT))
  {
    PRINTS(" --");
    _endOfText = (_pCurChar == _pText);
    _pCurChar--;
  }
  else 
  {
    PRINTS(" ++");
    _pCurChar++;
    _endOfText = (*_pCurChar == '\0');
  }

  PRINT(": endOfText ", _endOfText); 
}

uint8_t MD_Parola::getFirstChar(void)
// load the first char into the char buffer
// return 0 if there are no characters
{
  uint8_t len = 0;

  PRINTS("\ngetFirst");

  // initialise pointers and make sure we have a good string to process
  _pCurChar = _pText;
  if ((_pCurChar == NULL) || (*_pCurChar == '\0'))
  {
    _endOfText = true;
    return(0);
  }
  _endOfText = false;
  if (SFX(SCROLL_RIGHT))
    _pCurChar += strlen(_pText) - 1;

  // good string, get the first char into the current buffer
  len = makeChar(*_pCurChar);

  if (SFX(SCROLL_RIGHT))
    reverseBuf(_cBuf, len);
  
  moveTextPointer();

  return(len);
}

uint8_t MD_Parola::getNextChar(void)
// load the next char into the char buffer
// return 0 if there are no characters
{
  uint8_t len = 0;

  PRINTS("\ngetNext ");

  if (_endOfText)
    return(0);

  len = makeChar(*_pCurChar);

  if (SFX(SCROLL_RIGHT))
    reverseBuf(_cBuf, len);

  moveTextPointer();

  return(len);
}