/*
 *  Abuse - dark 2D side-scrolling platform game
 *  Copyright (c) 1995 Crack dot Com
 *  Copyright (c) 2005-2011 Sam Hocevar <sam@hocevar.net>
 *
 *  This software was released into the Public Domain. As with most public
 *  domain software, no warranty is made or implied by Crack dot Com, by
 *  Jonathan Clark, or by Sam Hocevar.
 */

#if defined HAVE_CONFIG_H
#   include "config.h"
#endif

#include "common.h"

#include "pcxread.h"
#include "specs.h"

enum PCX_type { not_PCX, PCX_8, PCX_24 };

struct PCX_header_type
{
  char manufactururer,version,encoding,bits_per_pixel;
  short xmin,ymin,xmax,ymax,hres,vres;
  char palette[48];
  char reserved,color_planes;
  short bytes_per_line,palette_type;
  char filter[58];
} PCX_header;

int read_PCX_header(FILE *fp)
{
  if (!fread(&PCX_header.manufactururer,1,1,fp)) return 0;
  if (!fread(&PCX_header.version,1,1,fp)) return 0;
  if (!fread(&PCX_header.encoding,1,1,fp)) return 0;
  if (!fread(&PCX_header.bits_per_pixel,1,1,fp)) return 0;
  PCX_header.xmin=read_uint16(fp);
  PCX_header.ymin=read_uint16(fp);
  PCX_header.xmax=read_uint16(fp);
  PCX_header.ymax=read_uint16(fp);
  PCX_header.hres=read_uint16(fp);
  PCX_header.vres=read_uint16(fp);
  if (!fread(PCX_header.palette,1,48,fp)) return 0;
  if (!fread(&PCX_header.reserved,1,1,fp)) return 0;
  if (!fread(&PCX_header.color_planes,1,1,fp)) return 0;
  PCX_header.bytes_per_line=read_uint16(fp);
  PCX_header.palette_type=read_uint16(fp);
  if (!fread(PCX_header.filter,1,58,fp)) return 0;
  return 1;
}

int write_PCX_header(FILE *fp)
{
  if (!fwrite(&PCX_header.manufactururer,1,1,fp)) return 0;
  if (!fwrite(&PCX_header.version,1,1,fp)) return 0;
  if (!fwrite(&PCX_header.encoding,1,1,fp)) return 0;
  if (!fwrite(&PCX_header.bits_per_pixel,1,1,fp)) return 0;
  write_uint16(fp,PCX_header.xmin);
  write_uint16(fp,PCX_header.ymin);
  write_uint16(fp,PCX_header.xmax);
  write_uint16(fp,PCX_header.ymax);
  write_uint16(fp,PCX_header.hres);
  write_uint16(fp,PCX_header.vres);
  if (!fwrite(PCX_header.palette,1,48,fp)) return 0;
  if (!fwrite(&PCX_header.reserved,1,1,fp)) return 0;
  if (!fwrite(&PCX_header.color_planes,1,1,fp)) return 0;
  write_uint16(fp,PCX_header.bytes_per_line);
  write_uint16(fp,PCX_header.palette_type);
  if (!fwrite(PCX_header.filter,1,58,fp)) return 0;
  return 1;
}

PCX_type PCX_file_type(char const *filename)
{
  FILE *fp=fopen(filename,"rb");
  if (!fp)
    return not_PCX;

  if (!read_PCX_header(fp))
  {
    fclose(fp);
    return not_PCX;
  }
  fclose(fp);
  if (PCX_header.manufactururer!=10)
    return not_PCX;
  if (PCX_header.color_planes==3 && PCX_header.bits_per_pixel==8)
    return PCX_24;
  else if (PCX_header.color_planes==1 && PCX_header.bits_per_pixel==8)
    return PCX_8;
  else return not_PCX;
}

void read_PCX_line(FILE *fp, unsigned char *start, short skip, int width)
{
  int c,n=0,i;

  do
  {
    c=fgetc(fp)&0xff;
    if ((c&0xc0)==0xc0)
    {
      i=c&0x3f;
      c=fgetc(fp);
      while (i--)
      {
    *start=c;
    start+=skip;
        n++;
      }
    }
    else
    {
      *start=c;
      start+=skip;
      n++;
    }
  } while (n<width);
}

image *read_PCX(char const *filename, palette *&pal)
{
  if (PCX_file_type(filename)!=PCX_8) return NULL;
  FILE *fp=fopen(filename,"rb");
  read_PCX_header(fp);

  image *im=new image(ivec2(PCX_header.xmax-PCX_header.xmin+1,
                            PCX_header.ymax-PCX_header.ymin+1));
  int y;
  for (y=0;y<im->Size().y;y++)
    read_PCX_line(fp,im->scan_line(y),1,PCX_header.bytes_per_line);
  unsigned char palette_confirm;
  if (!fread(&palette_confirm,1,1,fp) || palette_confirm!=12)
  {
    pal=new palette;
    pal->defaults();
  }
  else
  {
    pal=new palette;
    fread(pal->addr(),1,256*3,fp);
  }
  fclose(fp);
  return im;
}

void write_PCX(image *im, palette *pal, char const *filename)
{
  FILE *fp=fopen(filename,"wb");
  if (!fp)
    return ;

  PCX_header.manufactururer=10;
  PCX_header.version=5;
  PCX_header.encoding=1;
  PCX_header.bits_per_pixel=8;
  PCX_header.xmin=0;
  PCX_header.ymin=0;
  PCX_header.xmax=im->Size().x-1;
  PCX_header.ymax=im->Size().y-1;
  PCX_header.hres=320;
  PCX_header.vres=200;
  PCX_header.reserved=0;
  PCX_header.color_planes=1;
  PCX_header.bytes_per_line=im->Size().x;
  PCX_header.palette_type=0;
  memset(PCX_header.filter,0,58);

  if (!write_PCX_header(fp))
  {
    fclose(fp);
    return;
  }

  int y,run_length,x;
  unsigned char *sl,code;
  for (y=0; y<im->Size().y; y++)
  {
    sl=im->scan_line(y);
    for (x=0; x<im->Size().x; )
    {
      run_length=1;
      while (x+run_length<im->Size().x && sl[x]==sl[x+run_length])
        run_length++;
      if (run_length==1 && sl[x]<64)
        fputc(sl[x],fp);
      else
      {
        if (run_length>=64)
      run_length=63;
    code=0xc0 | run_length;
    fputc(code,fp);
    fputc(sl[x],fp);

      }
      x+=run_length;

    }
  }
  fputc(12,fp);  // note that there is a palette attached
  fwrite(pal->addr(),1,256*3,fp);
  fclose(fp);
}