{---------------------------------------------------------------------------}
{ Unit Wrel1    Funzioni/procedure di supporto per la grafica in coordinate
{               relative in Delphi 1.0 -  By Claudio Fin (C) 1997
{---------------------------------------------------------------------------}

unit Wrel1;

interface

uses
  SysUtils, WinTypes, WinProcs, Messages, Classes, Graphics, Controls,
  Forms, Dialogs, ExtCtrls, StdCtrls;


type
  TFinestraFunzioni=object
    xmin,xmax,ymin,ymax:real;    { Valori sugli assi }
    xsegm,ysegm:real;
    paper,ink:TColor;            { Colori fondo e inchiostro }
    Foglio:TImage;
    procedure DefiWnd(a:TImage; const xxmin,yymin,xxmax,yymax:real);
    procedure Cls;
    procedure SetInk(a:Tcolor);
    procedure SetPaper(a:Tcolor);
    procedure Plotta(const xx,yy:real);
    procedure Linea(const xx1,yy1,xx2,yy2:real);
    procedure Cerchio(const xx,yy,Raggio:real);
    procedure Testo(const s:string; const xx1,yy1:real);
    end;


implementation


{--------------------------------------------------------------------------}

procedure TFinestraFunzioni.Testo(const s:string; const xx1,yy1:real);
var xq,yq:integer;
begin
  xq:=trunc( ( xx1 - xMIN ) / xSEGM );
  yq:=foglio.height-1-trunc( ( yy1 - yMIN ) / ySEGM );
  Foglio.canvas.textout(xq,yq,s);
end;

{--------------------------------------------------------------------------}

procedure TFinestraFunzioni.Cerchio(const xx,yy,Raggio:real);
var lun,xq,yq:integer;
begin
  xq:=trunc( ( xx - xMIN ) / xSEGM );
  yq:=foglio.height-1-trunc( ( yy - yMIN ) / ySEGM );
  lun:=1+trunc(raggio/xsegm);
{  Foglio.Canvas.Brush.Style:=BsClear;}
  Foglio.Canvas.Brush.Color:=paper;
  Foglio.Canvas.Pen.Color:=ink;
  Foglio.Canvas.Ellipse(xq-lun,yq+lun,xq+lun,yq-lun);
end;

{--------------------------------------------------------------------------}

procedure TFinestraFunzioni.Linea(const xx1,yy1,xx2,yy2:real);
var xx1q,yy1q,xx2q,yy2q:integer;
begin
  xx1q:=trunc( ( xx1 - xMIN ) / xSEGM );
  xx2q:=trunc( ( xx2 - xMIN ) / xSEGM );
  yy1q:=foglio.height-1-trunc( ( yy1 - yMIN ) / ySEGM );
  yy2q:=foglio.height-1-trunc( ( yy2 - yMIN ) / ySEGM );
  foglio.canvas.moveto(xx1q,yy1q);
  foglio.canvas.pen.color:=ink;
  foglio.canvas.lineto(xx2q,yy2q);
  foglio.canvas.pixels[xx2q,yy2q]:=ink;
end;

{--------------------------------------------------------------------------}

procedure TFinestraFunzioni.Plotta(const xx,yy:real);
var xq,yq:integer;
begin
  xq:=trunc( ( xx - xMIN ) / xSEGM );
  yq:=foglio.height-1-trunc( ( yy - yMIN ) / ySEGM );
  foglio.canvas.pixels[xq,yq]:=ink;
end;

{--------------------------------------------------------------------------}

procedure TFinestraFunzioni.DefiWnd(a:TImage; const xxmin,yymin,xxmax,yymax:real);
begin
  Foglio:=a;
  xmin:=xxmin; xmax:=xxmax; ymin:=yymin; ymax:=yymax;
  xsegm:= ( xMAX - xMIN )  /  ( Foglio.Width  - 1 );
  ysegm:= ( yMAX - yMIN )  /  ( Foglio.Height - 1 );
  ink:=ClWhite; paper:=ClBlack;
  Foglio.canvas.font.name:='fixedsys';
  Foglio.canvas.font.color:=clwhite;

end;

{--------------------------------------------------------------------------}

procedure TFinestraFunzioni.Cls;
begin
  Foglio.Canvas.Pen.Color:=paper;
  Foglio.Canvas.Brush.Color:=paper;
  Foglio.Canvas.Brush.Style:=BsSolid;
  Foglio.Canvas.Rectangle(0,0,Foglio.width,Foglio.Height);
  Foglio.Canvas.Pen.Color:=Ink;
end;

{--------------------------------------------------------------------------}

procedure TFinestraFunzioni.SetInk(a:Tcolor);
begin ink:=a; end;

{--------------------------------------------------------------------------}

procedure TFinestraFunzioni.SetPaper(a:Tcolor);
begin paper:=a; end;

{--------------------------------------------------------------------------}



end.