rscreenutils.cpp

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// Copyright 2002 Kenneth Guy,
// 
// RScreenUtils.cpp

/** \file RScreenUtils.cpp

    implementation of class RScreenUtils */

#include <e32std.h>
#include <e32svr.h>

//data
#include "numbers.h"

#include "RScreenUtils.h"

/** Draw a picture on the screen.

    \param aPicture picture to draw */
void RScreenUtils::DrawPicture(TPicture &aPicture) {
  DrawPictureAsm(&aPicture);
}

/** Blank an area of the screen

    \param aBlank area to blank */
void RScreenUtils::BlankArea(TBlank &aBlank) {
  BlankAreaAsm(&aBlank);
}

/** constuctor */
RScreenUtils::RScreenUtils() : iScreenBase(NULL) {
}


/** Initialize class.

    Gets the screen info and works out the screen base address.

    \return KErrNone if successful, KErrNotSupported if: the screen is not 640x200 or the screen info is not available.

*/

TInt RScreenUtils::Open() {
  // get the screen info so we can work out the base address of the screen
  TPckgBuf<TScreenInfoV01> info;
  UserSvr::ScreenInfo(info);
  if(info().iScreenAddressValid==EFalse ||
     info().iScreenSize.iWidth!=640 ||
     info().iScreenSize.iHeight!=200) {
    return KErrNotSupported;
  }
    
  // screen memory is 2 bytes per pixel, top 4 bits unused,
  // 4 bits green, 4 bits blue.
  iScreenBase=STATIC_CAST(TUint16*,info().iScreenAddress);
  // there is palette information at the start of the screen
  // memory, for 12 bits per pixel this is 16 2 byte entries,
  // the first of which defines that the pixel size is 12 bits.
  // actual pallete information is ignored.
  iScreenBase += 16;
  return (KErrNone);
}


/** Base address of screen memory */
TUint16 *RScreenUtils::ScreenBase() {
  return iScreenBase;
}

/** Close */
void RScreenUtils::Close() {
  iScreenBase=NULL;
}

/** Draw a number in decimal.

    Converts the number to binary coded decimal then calls HexNumber()
    to plot it.

    \param aX X position to draw at (0-319)
    \param aY Y position to draw at (0-199)
    \param aNumber number to draw (0-999999), will wrap after that
    \param aForeColor foreground color
    \param aBackColor background color
*/
void RScreenUtils::Number(TUint aX,TUint aY,TUint32 aNumber,
                          TUint16 aForeColor,TUint16 aBackColor){
  HexNumber(aX,aY,BCDNumber(aNumber),aForeColor,aBackColor);
}

/** Draw a number in hexdecimal.

    \param aX X position to draw at (0-319)
    \param aY Y position to draw at (0-199)
    \param aNumber number to draw (0-FFFFFFF), will wrap after that
    \param aForeColor foreground color
    \param aBackColor background color
*/
void RScreenUtils::HexNumber(TUint aX,TUint aY,TUint32 aNumber,
                             TUint16 aForeColor,TUint16 aBackColor){
                             
  if(iScreenBase==NULL)
    return;
  TUint offset=aX+aY*640;
  NumberAsm(iScreenBase+offset,aNumber,aForeColor,aBackColor);
}

/** Clear screen to color.

    \param aColor color to fill the screen with
    */
void RScreenUtils::Blank(TUint16 aColor) {
  if(iScreenBase==NULL)
    return;
  BlankAsm(aColor);
}

/** Convert a number to BCD */
TUint32 RScreenUtils::BCDNumber(TUint32 aNumber) {
  TUint32 out=0;
  TInt digit=0;
  while(aNumber!=0) {
    out += (aNumber%10) << (4*digit);
    digit++;
    aNumber /= 10;
  }
  return out;
}


/** \fn   static void RScreenUtils::NumberAsm(TUint16 *aPos,TUint32 aNumber, TUint16 aForeColor,TUint16 aBackColor)

    Draws a hex number on the screen.

    \param aPos memory location to draw number
    \param aNumber number to draw (0-FFFFFFF), will wrap after that
    \param aForeColor foreground color
    \param aBackColor background color

    defined in the file number.s
*/



/** \fn void RScreenUtils::BlankAsm(TUint16 aColor);

    Blank the whole screen

    \param aColor color to fill the screen with

    defined in the file blank.s
*/


/** \fn void RScreenUtils::BlankAreaAsm(TBlank *aBlank)

    Blank an area of the screen

    \param aBlank area and color to clear

    defined in the file blankarea.s
*/


  

  
/** \fn void RScreenUtils::DrawPictureAsm(TPicture *aPicture)

    Draw a picture on the screen

    \param aPicture sprite information and location

    defined in the file drawpicture.s
 */