F64 MySin(F64 d)
{//Sin() does not have an address.
  return Sin(d);
}

F64 MyCos(F64 d)
{//Cos() does not have an address.
  return Cos(d);
}

U0 FunDraw1(CDC *dc,F64 (*f)(F64 t))
{
  I64 i,w=Fs->pix_width,h=Fs->pix_height;
  F64 scale=h/5.0;
  for (i=-w/2; i<=w/2; i++)
    GrLine(dc,w/2+i,h/2-scale*f(i/scale*2*pi),
           w/2+i+1,h/2-scale*f((i+1)/scale*2*pi));
}

U0 FunDraw2(CDC *dc,F64 (*f)(F64 t,F64 p),F64 T)
{
  I64 i,w=Fs->pix_width,h=Fs->pix_height;
  F64 scale=h/5.0;
  for (i=-w/2; i<=w/2; i++)
    GrLine(dc,w/2+i,h/2-scale*f(i/scale,T),w/2+i+1,h/2-scale*f((i+1)/scale,T));
}

U0 Init(CDC *dc)
{
  I64 i,w=Fs->pix_width,h=Fs->pix_height;
  F64 scale=h/5.0;
  DocClear;
  DCFill(dc);
  dc->color=BLACK;
  GrLine(dc,0,h/2,w-1,h/2);
  GrLine(dc,w/2,0,w/2,h-1);
  for (i=-2; i<=2; i++)
  {
    dc->color=BLACK;
    GrLine(dc,w/2-3,h/2-scale*i,w/2+3,h/2-scale*i);
    if (i)
    {
      dc->color=DKGRAY;
      GrPrint(dc,w/2+5,h/2-scale*i-FONT_HEIGHT/2,"%5.1f",ToF64(i));
    }
  }
  for (i=-4; i<=4; i++)
  {
    dc->color=BLACK;
    GrLine(dc,w/2+scale*i,h/2-3,w/2+scale*i,h/2+3);
    if (i)
    {
      dc->color=DKGRAY;
      GrPrint(dc,
              w/2+scale*i-7*FONT_WIDTH/2,h/2+5+FONT_HEIGHT,"%5.1f*T",ToF64(i));
    }
  }
}

U0 SndMathDemo()
{
  CDC *dc=DCAlias;
  Init(dc);
  dc->color=RED;
  FunDraw1(dc,&MySin);
  "$RED$Sin$FG$\n";
  PressAKey;
  dc->color=BLUE;
  FunDraw2(dc,&Saw,1.0);
  "$BLUE$Saw$FG$\n";
  PressAKey;
  dc->color=GREEN;
  FunDraw2(dc,&FullSaw,1.0);
  "$GREEN$FullSaw$FG$\n";
  PressAKey;
  Init(dc);
  dc->color=RED;
  FunDraw1(dc,&MyCos);
  "$RED$Cos$FG$\n";
  PressAKey;
  dc->color=BLUE;
  FunDraw2(dc,&Caw,1.0);
  "$BLUE$Caw$FG$\n";
  PressAKey;
  dc->color=GREEN;
  FunDraw2(dc,&FullCaw,1.0);
  "$GREEN$FullCaw$FG$\n";
  PressAKey;
  Init(dc);
  dc->color=RED;
  FunDraw1(dc,&MySin);
  "$RED$Sin$FG$\n";
  PressAKey;
  dc->color=BLUE;
  FunDraw2(dc,&Tri,1.0);
  "$BLUE$Tri$FG$\n";
  PressAKey;
  dc->color=GREEN;
  FunDraw2(dc,&FullTri,1.0);
  "$GREEN$FullTri$FG$\n";
  PressAKey;
  DCFill(dc);
  DCDel(dc);
}

SndMathDemo;