#include <stdlib.h>

#include "text-flags.h"

#define DIV (TEXTFLAG_XF & ~(TEXTFLAG_XF-1))

#if TEXTFLAG_XF & (TEXTFLAG_XF + DIV)
#error "TEXTFLAG_XF is not a contiguous set of bits"
#endif

#define NIL  (TEXTFLAG_XF_NONE/DIV)
#define FL_X (TEXTFLAG_XF_FLIP_X/DIV)
#define FL_Y (TEXTFLAG_XF_FLIP_Y/DIV)
#define R180 (TEXTFLAG_XF_ROT180/DIV)
#define XY   (TEXTFLAG_XF_FLIP_XY/DIV)
#define CCW  (TEXTFLAG_XF_ROT_CW/DIV)
#define CW   (TEXTFLAG_XF_ROT_CCW/DIV)
#define XMY  (TEXTFLAG_XF_FLIP_XMY/DIV)
/* compose[1st][2nd] */
static unsigned int compose[8][8]
 = { { NIL,  FL_X, FL_Y, R180, XY,   CCW,  CW,   XMY  },
     { FL_X, NIL,  R180, FL_Y, CCW,  XY,   XMY,  CW   },
     { FL_Y, R180, NIL,  FL_X, CW,   XMY,  XY,   CCW  },
     { R180, FL_Y, FL_X, NIL,  XMY,  CW,   CCW,  XY   },
     { XY,   CW,   CCW,  XMY,  NIL,  FL_Y, FL_X, R180 },
     { CCW,  XMY,  XY,   CW,   FL_X, R180, NIL,  FL_Y },
     { CW,   XY,   XMY,  CCW,  FL_Y, NIL,  R180, FL_X },
     { XMY,  CCW,  CW,   XY,   R180, FL_X, FL_Y, NIL  } };
static unsigned int invert[8]
 = { NIL,  FL_X, FL_Y, R180, XY,   CW,   CCW,  XMY  };

unsigned int textflag_xf_compose(unsigned int a, unsigned int b)
{
 return(compose[(a&TEXTFLAG_XF)/DIV][(b&TEXTFLAG_XF)/DIV]*DIV);
}

unsigned int textflag_xf_invert(unsigned int xf)
{
 return(invert[(xf&TEXTFLAG_XF)/DIV]*DIV);
}

unsigned int textflag_xf_sx(unsigned int xf, unsigned int sx, unsigned int sy)
{
 switch (xf & TEXTFLAG_XF)
  { case TEXTFLAG_XF_NONE:
    case TEXTFLAG_XF_FLIP_X:
    case TEXTFLAG_XF_FLIP_Y:
    case TEXTFLAG_XF_ROT180:
       return(sx);
       break;
    case TEXTFLAG_XF_FLIP_XY:
    case TEXTFLAG_XF_ROT_CW:
    case TEXTFLAG_XF_ROT_CCW:
    case TEXTFLAG_XF_FLIP_XMY:
       return(sy);
       break;
  }
 abort();
}

unsigned int textflag_xf_sy(unsigned int xf, unsigned int sx, unsigned int sy)
{
 switch (xf & TEXTFLAG_XF)
  { case TEXTFLAG_XF_NONE:
    case TEXTFLAG_XF_FLIP_X:
    case TEXTFLAG_XF_FLIP_Y:
    case TEXTFLAG_XF_ROT180:
       return(sy);
       break;
    case TEXTFLAG_XF_FLIP_XY:
    case TEXTFLAG_XF_ROT_CW:
    case TEXTFLAG_XF_ROT_CCW:
    case TEXTFLAG_XF_FLIP_XMY:
       return(sx);
       break;
  }
 abort();
}

int textflag_xf_x(unsigned int xf, int ix, int iy, unsigned int sx, unsigned int sy)
{
 switch (xf & TEXTFLAG_XF)
  { case TEXTFLAG_XF_NONE:
    case TEXTFLAG_XF_FLIP_Y:
       return(ix);
       break;
    case TEXTFLAG_XF_FLIP_X:
    case TEXTFLAG_XF_ROT180:
       return(((int)sx)-1-ix);
       break;
    case TEXTFLAG_XF_FLIP_XY:
    case TEXTFLAG_XF_ROT_CCW:
       return(iy);
       break;
    case TEXTFLAG_XF_ROT_CW:
    case TEXTFLAG_XF_FLIP_XMY:
       return(((int)sy)-1-iy);
       break;
  }
 abort();
}

int textflag_xf_y(unsigned int xf, int ix, int iy, unsigned int sx, unsigned int sy)
{
 switch (xf & TEXTFLAG_XF)
  { case TEXTFLAG_XF_NONE:
    case TEXTFLAG_XF_FLIP_X:
       return(iy);
       break;
    case TEXTFLAG_XF_FLIP_Y:
    case TEXTFLAG_XF_ROT180:
       return(((int)sy)-1-iy);
       break;
    case TEXTFLAG_XF_FLIP_XY:
    case TEXTFLAG_XF_ROT_CW:
       return(ix);
       break;
    case TEXTFLAG_XF_ROT_CCW:
    case TEXTFLAG_XF_FLIP_XMY:
       return(((int)sx)-1-ix);
       break;
  }
 abort();
}