src/ssg/ssgLoadPCX.cxx

/*
     PLIB - A Suite of Portable Game Libraries
     Copyright (C) 2001  Steve Baker

     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 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
     Library General Public License for more details.

     You should have received a copy of the GNU Library General Public
     License along with this library; if not, write to the Free
     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

     For further information visit http://plib.sourceforge.net

     $Id: ssgLoadPCX.cxx 1963 2004-09-26 09:27:28Z bram $
*/

//===========================================================================
//
// File: ssgLoadPCX.cxx
//
// Created: 12.12.2003
//
// Author: Wolfram Kuss
//
// Revision: $Id: ssgLoadPCX.cxx 1963 2004-09-26 09:27:28Z bram $
//
// Description: Loads PCX texture files. Only 8 bit indexed for now.
//
//
//===========================================================================

#include "ssgLocal.h"
typedef unsigned char UByte,*UByteP;
#include "pcx.h"


#ifdef SSG_LOAD_PCX_SUPPORTED

int ReadFileIntoBuffer(const char *fname, UByte *&buffer, UByte *&bufferorig, unsigned long &file_length)
// Opens the file, allocates buffer of correct size to hold the file, reads it, closes it
{
  // **** open file ****
  FILE *tfile;
  if ( (tfile = fopen(fname, "rb")) == NULL) {
    ulSetError( UL_WARNING, "ssgLoadTexture: Failed to open file '%s' for reading.", fname );
    return false ;
  }

  // **** allocate buffer, read file into it and close file ****
  fseek(tfile, 0, SEEK_END);
  file_length = ftell(tfile);
  fseek(tfile, 0, SEEK_SET);

  buffer = new UByte[file_length];
  bufferorig = buffer;

  fread(buffer, file_length, 1, tfile);
  fclose(tfile);
  return true;
}

bool ssgLoadPCX ( const char *fname, ssgTextureInfo* info )
{
  UByte *buffer, *bufferorig;
  unsigned long file_length;
  if(!ReadFileIntoBuffer(fname, buffer, bufferorig, file_length))
    return false ;
  // **** "read" header and "analyse" it ****
  pcxHeaderType *ppcxHeader = (pcxHeaderType *) buffer;
  buffer += sizeof(pcxHeaderType);

  short width = ppcxHeader->xmax-ppcxHeader->x+1;
  short height = ppcxHeader->ymax-ppcxHeader->y+1;
  //p->isMasked = ((p->resOfRowanTexture & 0x200) != 0) ? 1 : 0;

  if ( info != NULL )
  {
    info -> width = width ;
    info -> height = height ;
    info -> depth = 4 ;
    info -> alpha = TRUE ;  //I think we have to set it to true always, since we always generate 4 bytes per pixel
  }

  // **** read body�; Do error checking ****
  long size = ((long)width)*height;
  UByte *pAlfa = NULL, * pBody = new UByte [size]; // 1 byte per texel
  UByte * pBodyorig = pBody;

  if(!ReadPCXBody(buffer, ppcxHeader, pBody))
// writes to pBody, which must have been allocated
  {
    delete [] buffer;
    delete [] pBody;
    ulSetError ( UL_WARNING,
      "ssgLoadTexture: '%s' - unsupported or broken PCX texture file", fname ) ;
    return false ;
  }
  if(*buffer++ != 12)
  { ulSetError ( UL_WARNING, "ssgLoadTexture: '%s' - PCX files needs a '12' byte", fname ) ;
    return false ;
  }
  assert(bufferorig + file_length - 768 == buffer);
  // starting at "buffer", you can find the palette, 256 entrys with 3 bytes each
  // only true for version 5 (and possible later versions)=

// start alfa handling
  // PCX does not allow alfa, so to enable alfa, you need two files :-(,
  // one for the body, for example abc.pcx and one for the alfa component, for example abc_trans.pcx
  if(fname[strlen(fname)-4]=='.')
  {
    char *t, *s = new char[strlen(fname)+15];
    strcpy(s, fname);
    t=&(s[strlen(s)-4]);
    strcpy(t, "_trans.pcx");
    if(ulFileExists(s))
    {
      UByte *alfaBuffer, *alfaBufferorig;
      if(!ReadFileIntoBuffer(s, alfaBuffer, alfaBufferorig, file_length))
        return false ;
      // **** "read" header and "analyse" it ****
      ppcxHeader = (pcxHeaderType *) alfaBuffer;
      alfaBuffer += sizeof(pcxHeaderType);

      if(width != ppcxHeader->xmax-ppcxHeader->x+1)
        ulSetError ( UL_WARNING, "ssgLoadTexture: '%s' - Width does not agree to 'body' width, so alfa is ignored", s ) ;
      else
      {

        if (height != ppcxHeader->ymax-ppcxHeader->y+1)
          ulSetError ( UL_WARNING, "ssgLoadTexture: '%s' - Height does not agree to 'body' height, so alfa is ignored", s ) ;
        else
        {
          // **** read body�; Do error checking ****
          pAlfa = new UByte [size]; // 1 byte per texel

          if(!ReadPCXBody(alfaBuffer, ppcxHeader, pAlfa))
          // writes to pBody, which must have been allocated
          {
            delete [] buffer;
            delete [] pAlfa;
            ulSetError ( UL_WARNING,
              "ssgLoadTexture: '%s' - unsupported or broken PCX texture file", fname ) ;
            return false ;
          }
        }
      }
    }
  }
// end alfa handling

  UByte *texels = new UByte [size * 4]; // 4 bytes per texel
  int c = 0;
  int iRunningIndex = 0;
  for (int y = 0; y < height; y++) {
    for (int x = 0; x < width; x++) {
      UByte a = pAlfa?pAlfa[iRunningIndex]:255;
      UByte b = pBody[iRunningIndex++];
      texels[c++] = buffer[b*3    ];
      texels[c++] = buffer[b*3 + 1];
      texels[c++] = buffer[b*3 + 2];
      texels[c++] = a;
    }
  }

  delete [] pBodyorig;
  delete [] bufferorig;
  if (pAlfa)
    delete [] pAlfa;
  return ssgMakeMipMaps ( texels, width, height, 4 ) ;
}
#else

bool ssgLoadPCX ( const char *fname, ssgTextureInfo* info )
{
  ulSetError ( UL_WARNING,
    "ssgLoadTexture: '%s' - PCX texture support not configured", fname ) ;
  return false ;
}

#endif