/* Prints out "text" at world cooordinate (x,y). The text may be       */
/* at any angle "angle" relative to the horizontal. The parameter      */
/* "just" adjusts the horizontal justification of the string:          */
/*   just = 0.0 => left hand edge of string is at (x,y)                */
/*   just = 1.0 => right hand edge of string is at (x,y)               */
/*   just = 0.5 => centre of string is at (x,y) etc.                   */
/* N.B. Centreline of the string passes through (x,y)                  */

#include "plplot.h"
#include <math.h>

void plptex(x,y,dx,dy,just,text)
float x,y,dx,dy,just;
char *text;
{      
      int refx, refy;
      float shift, cc, ss;
      float xform[4],diag;
      float xscl, xoff, yscl, yoff;
   
      int level;
      glev(&level);
      if (level < 3) fatal("Please set up window before calling PLPTEX.");

      gwm(&xscl,&xoff,&yscl,&yoff);
      cc = xscl * dx;
      ss = yscl * dy;
      diag = sqrt(cc*cc + ss*ss);
      cc = cc/diag;
      ss = ss/diag;
      
      gmp(&xscl,&xoff,&yscl,&yoff);
      shift = 0.0;
      
      xform[0] = cc;
      xform[1] = -ss;
      xform[2] = ss;
      xform[3] = cc;

      if (just != 0.0) shift = plstrl(text) * just;
      refx = wcpcx(x) - shift * cc * xscl;
      refy = wcpcy(y) - shift * ss * yscl;
      plstr(0,xform,refx,refy,text);
}