/*===========================================================================
 *
 * File:	Bmpfile.CPP
 * Author:	Dave Humphrey (uesp@m0use.net)
 * Created On:	Monday, March 25, 2002
 *
 * Implements the CBmpFile class for handling standard BMP image files.
 *
 *=========================================================================*/

	/* Include Files */
#include "bmpfile.h"


/*===========================================================================
 *
 * Begin Local Variable Definitions
 *
 *=========================================================================*/
  DEFINE_FILE();
/*===========================================================================
 *		End of Local Variable Definitions
 *=========================================================================*/


/*===========================================================================
 *
 * Class CBmpFile Constructor
 *
 *=========================================================================*/
CBmpFile::CBmpFile () {
  //DEFINE_FUNCTION("CBmpFile::CBmpFile()");

	/* Initialize the BMP headers */
  InitBMPInfoHeader(m_InfoHeader);
  InitBMPFileHeader(m_FileHeader);

  m_pData     = NULL;
  m_ImageSize = 0;
  m_pPalette	= NULL;
  m_PaletteSize = 0;
 }
/*===========================================================================
 *		End of Class CBmpFile Constructor
 *=========================================================================*/


/*===========================================================================
 *
 * Class CBmpFile Method - void Destroy (void);
 *
 * Delete the contents of the BMP file.
 *
 *=========================================================================*/
void CBmpFile::Destroy (void) {
  DEFINE_FUNCTION("CBmpFile::Destroy()");

  	/* Clear the BMP headers */
  InitBMPInfoHeader(m_InfoHeader);
  InitBMPFileHeader(m_FileHeader);

	/* Unallocate any allocated pointer arrays */
  DestroyArrayPointer(m_pData);
  DestroyArrayPointer(m_pPalette);
  m_ImageSize   = 0;
  m_PaletteSize = 0;

	/* Chain to the base class method */
  CGenFile::Destroy();
 }
/*===========================================================================
 *		End of Class Method CBmpFile::Destroy()
 *=========================================================================*/


/*===========================================================================
 *
 * Class CBmpFile Method - boolean ExportLBM (pFilename, Width, Height, 
 *					      pImage,    pPalette);
 *
 * Attempts to save the input LBM type image to a BMP file.  Returns FALSE
 * on any error.  The input image data is assumed to be an array of size
 * Width*Height representing the color index in the palette.  The palette
 * data is assumed to be a regular RGB triplet array of 256 colors (768 bytes).
 *
 *=========================================================================*/
boolean CBmpFile::ExportLBM (const char* pFilename,  const int Width, const int Height,
			     const byte* pImageData, const byte* pPalette) {
  DEFINE_FUNCTION("CBmpFile::ExportLBM()");
  boolean Result;

	/* Ensure valid input */
  ASSERT(pImageData != NULL && pPalette != NULL);

	/* Delete the current BMP data, and initialize members */
  Destroy();
  m_pData     = (byte *) pImageData;
  m_ImageSize = (long) Width * (long) Height;
  m_pPalette    = (rgbpal_t *) pPalette;
  m_PaletteSize = 256;

	/* Initialize the file headers */
  m_InfoHeader.Height    = Height;
  m_InfoHeader.Width     = Width;
  m_InfoHeader.SizeImage = (uint) m_ImageSize;
  m_InfoHeader.BitCount  = 8;
  m_FileHeader.Size       = ComputeSize();
  m_FileHeader.OffsetBits = ComputeOffsetBits();

	/* Attempt to save the BMP file */
  Result = Save(pFilename);

	/* Reset the image data */
  m_pData    = NULL;
  m_pPalette = NULL;

  return (Result);
 }
/*===========================================================================
 *		End of Class Method CBmpFile::ExportLBM()
 *=========================================================================*/


/*===========================================================================
 *
 * Class CBmpFile Method - boolean Save (pFilename);
 *
 * Attempt to save the current BMP image to the given filename.  Returns
 * FALSE on any error.
 *
 *=========================================================================*/
boolean CBmpFile::Save (const char* pFilename) {
  DEFINE_FUNCTION("CBmpFile::Save()");
  boolean Result;

	/* Ensure valid object state */
  ASSERT(m_pData != NULL && m_pPalette != NULL);
  ASSERT(m_ImageSize >= (long)UINT_MAX);

	/* Attempt to open and output file */
  Result = Open(pFilename, "wb");
  if (Result) Result = Write((char *)&m_FileHeader, sizeof(bmpfileheader_t));
  if (Result) Result = Write((char *)&m_InfoHeader, sizeof(bmpinfoheader_t));
  if (Result) Result = WriteQuadPalette();
  if (Result) Result = Write((char *)m_pData,       (size_t)m_ImageSize);
  Close();

  return (Result);
 }
/*===========================================================================
 *		End of Class Method CBmpFile::Save()
 *=========================================================================*/


/*===========================================================================
 *
 * Class CBmpFile Method - boolean WriteQuadPalette (void);
 *
 * Protected helper class method to output the current RGB palette to
 * the current position in the BMP file.  BMP file usually output a quad
 * RGBA palette with an alpha component in addition to the standard 3
 * colors.  BMP palettes are also backwards to the usual with the format:
 *		
 *			Blue Green Red Alpha
 *
 * Palette entries should be byte values ranging from 0 to 255.
 *
 *=========================================================================*/
boolean CBmpFile::WriteQuadPalette (void) {
  //DEFINE_FUNCTION("CBmpFile::WriteQuadPalette()");
  int       LoopCounter;
  boolean   Result;
  rgbpal_t* pPal = m_pPalette;

	/* Output each entry in the palette */
  for (LoopCounter = 0; LoopCounter < m_PaletteSize; LoopCounter++) {
    Result  = WriteChar(pPal->B);
    Result &= WriteChar(pPal->G);
    Result &= WriteChar(pPal->R);
    Result &= WriteChar((byte)0);
    pPal++;
    if (!Result) return (FALSE);
   }

  return (TRUE);
 }
/*===========================================================================
 *		End of Class Method CBmpFile::WriteQuadPalette()
 *=========================================================================*/


/*===========================================================================
 *
 * Function - void InitBMPFileHeader (FileHeader);
 *
 * Initializes the given BMP file header with the default values.
 *
 *=========================================================================*/
void InitBMPFileHeader (bmpfileheader_t& FileHeader) {
  FileHeader.Type = BMPFILE_TYPE_WORD;
  FileHeader.OffsetBits = 0;
  FileHeader.Size = 0;
  FileHeader.Reserved1 = 0;
  FileHeader.Reserved2 = 0;
 }
/*===========================================================================
 *		End of Function InitBMPFileHeader()
 *=========================================================================*/


/*===========================================================================
 *
 * Function - void InitBMPInfoHeader (InfoHeader);
 *
 * Initializes the given BMP info header with the default values.
 *
 *=========================================================================*/
void InitBMPInfoHeader (bmpinfoheader_t& InfoHeader) {
  InfoHeader.Size      = sizeof(bmpinfoheader_t);
  InfoHeader.SizeImage = 0;
  InfoHeader.Height    = 0;
  InfoHeader.Width     = 0;
  
  InfoHeader.XPelsPerMeter = 6000;
  InfoHeader.YPelsPerMeter = 6000;

	/* Use all colors in BMP */  
  InfoHeader.ColorImportant = 0;
  InfoHeader.ColorUsed      = 0;

	/* Standard RGB uncompressed */
  InfoHeader.Compression = BMPCOMPRESS_RGB;
  InfoHeader.BitCount = 24;	
  InfoHeader.Planes   = 1;
 }
/*===========================================================================
 *		End of Function InitBMPInfoHeader()
 *=========================================================================*/