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CMap.cpp

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// Copyright 2002 Kenneth Guy,
// 
// You are free to take the source and do as you wish with it.
// However it would be nice if you let me know if the code was useful
// to you and give me an acknowledgement if you use a significant portion
// of the code in an application.
// 
// CMap.cpp

#include "CMap.h"
#include "CGame.h"

#include <e32svr.h>
#include <e32base.h>

#include "TMapLineType.h"

CMap::CMap(CGame &aGame,const TUint16* aMapSprites,const TInt16* aMapData)
  : iMapData(aMapData), iMapSprites(aMapSprites), iGame(aGame) {

};

CMap* CMap::NewL(CGame &aGame,const TUint16* aMapSprites,
                 const TInt16* aMapData) {
  CMap* self= new (ELeave) CMap(aGame,aMapSprites,aMapData);
  CleanupStack::PushL(self);
  self->ConstructL();
  CleanupStack::Pop(self);
  return(self);
}

void CMap::ConstructL() {
  // get the base address of screen memory
  RScreenUtils screen;
  User::LeaveIfError(screen.Open());
  iScreenBase=screen.ScreenBase();
  screen.Close();

  // offscreen map,
  // longer than the screen so we can scroll one set of map sprites
  // off while the next is scrolling on, also space above and bellow
  // so that we can move sprites on and off
  iOffScreenMap=new (ELeave) TUint16[(11*64)*248];
  for(TInt i=0;i<(11*64)*248;i++)
    iOffScreenMap[i]=0x0000;

  iDrawArea=iOffScreenMap+((11*64)*24);

  // Point at which to draw the next line of map sprites
  iMapDrawPoint=iDrawArea;
  // where to start copying to the screen
  iBlitStart=iDrawArea;
  // end of the draw area,
  iDrawEnd=iDrawArea+((11*64)*224);

  // keeps track of when we need to plot a new line of map sprites
  iBlitPoint=0;

  // draw first screen full of map
  for(TInt i=0;i<11;i++) 
    ProcessMapLine();
}


CMap::~CMap() {
  delete [] iOffScreenMap;
}

TUint16* CMap::BlitStart() {
  return iBlitStart;
}

TUint16* CMap::DrawEnd() {
  return iDrawEnd;
}

TBool CMap::Finished() {
  return iFinished;
}

void CMap::ScrollMap() {

  if(!(iMapData[0] & EMapLineEndOfMap)) {
    iBlitStart+=4;
    if(iBlitStart >= iDrawEnd)
      iBlitStart=iDrawArea;
    
    // every 16*4 pixels (a map sprite is 64 pixels wide), we need to plot
    // another line of map sprites
    iBlitPoint++;
    if(iBlitPoint>=16) {
      iBlitPoint=0;
      ProcessMapLine();
    }
  } else {
    // scroll last line of sprites all the way onto the screen.
    if(iBlitPoint <24) {
      iBlitPoint++;
      iBlitStart+=4;
      if(iBlitStart >= iDrawEnd)
        iBlitStart=iDrawArea;
    } else {
      iFinished=ETrue;
    }
  }
};

void CMap::ProcessMapLine() {
  PlotMapLineAsm();
  while(iMapData[0] & EMapLineObject) {
    iGame.AddBadGuy(iMapData[0],iMapData+1);                 
    iMapData+=8;
  }
}

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