Mathc initiation/a259

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	kbezier.h

/* ------------------------------------ */
/*  Save as :   kbezier.h               */
/* ------------------------------------ */
void G_Cubic_Bezier_2d(

CTRL_splot  w,

pt2d P0,
pt2d P1,
pt2d P2,
pt2d P3
)
{
tvalue t;

  t.min  =   0;  
  t.max  =   1;  
  t.step =  .01;

FILE   *fp = fopen("a_main.plt","w");
fprintf(fp," set zeroaxis lt 8\n"
           " set grid\n\n"
           " plot [%0.3f:%0.3f] [%0.3f:%0.3f] \\\n"
//           " \"circle\"  with linesp lt 1 pt 1,\\\n"
           " \"curve\"   with linesp lt 3 pt 1,\\\n"
           " \"ctrlpts\" with linesp lt 4 pt 4\n\n"
            ,w.xmin,w.xmax,w.ymin,w.ymax);
 fclose(fp);

        fp = fopen("curve","w");
 for(t.value=t.min; t.value<=t.max; t.value+=t.step)
     fprintf(fp," %6.5f   %6.5f\n",
                Cubic_Bezier_x_2d(t.value,P0,P1,P2,P3),
                Cubic_Bezier_y_2d(t.value,P0,P1,P2,P3));
             fclose(fp);

        fp = fopen("ctrlpts","w");
     fprintf(fp," %6.5f   %6.5f\n",P0.x,P0.y);
     fprintf(fp," %6.5f   %6.5f\n",P1.x,P1.y); /* try : \n\n */
     fprintf(fp," %6.5f   %6.5f\n",P2.x,P2.y);
     fprintf(fp," %6.5f   %6.5f\n",P3.x,P3.y);
             fclose(fp);
             
 fp = fopen("circle","w");
      for(t.value=0;t.value<2.01*PI;t.value+=.05)
          fprintf(fp," %6.5f %6.5f\n",
              5*cos(t.value)+0,5*sin(t.value)+0);
 fclose(fp);
}
/* ------------------------------------ */
void G_wp_Cubic_Bezier_2d(

CTRL_splot  w,

pt2d P0,
pt2d P1,
pt2d P2,
pt2d P3
)
{
tvalue t;

  t.min  =   0;  
  t.max  =   1;  
  t.step =  .01;

FILE   *fp = fopen("a_main.plt","w");
fprintf(fp," set zeroaxis lt 8\n"
           " set grid\n\n"
           " plot [%0.3f:%0.3f] [%0.3f:%0.3f]\\\n"
//           " \"circle\" with linesp lt 1 pt 1,\\\n"
           " \"curve\"  with linesp lt 3 pt 1\n\n",
           w.xmin,w.xmax,w.ymin,w.ymax);
  fclose(fp);

        fp = fopen("curve","w");
 for(t.value=t.min; t.value<=t.max; t.value+=t.step)
     fprintf(fp," %6.5f   %6.5f\n",
             Cubic_Bezier_x_2d(t.value,P0,P1,P2,P3),
             Cubic_Bezier_y_2d(t.value,P0,P1,P2,P3));
      fclose(fp);

 fp = fopen("circle","w");
      for(t.value=0;t.value<2.01*PI;t.value+=.05)
          fprintf(fp," %6.5f %6.5f\n",
              5*cos(t.value)+0,5*sin(t.value)+0);
 fclose(fp);
}
/* ------------------------------------ */
/* ------------------------------------ */

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