Janilabo | TPAFromEllipse() & TPAFromCircle2() [SCAR Divi]

{==============================================================================]
  Explanation: Generates a TPA containing all coordinates within the given ellipse,
               defined by the center point and radius. Coordinates are stored row-by-row.
[==============================================================================}
function TPAFromEllipse(center: TPoint; XRadius, YRadius: Extended): TPointArray;
var
  r, x, y, rx, ry: Integer;
  b: TBox;
begin
  if ((XRadius > 0) and (YRadius > 0)) then
  begin
    rx := Round(XRadius);
    ry := Round(YRadius);
    b := IntToBox((center.X - rx), (center.Y - ry), (center.X + rx), (center.Y + ry));
    SetLength(Result, Integer(((b.X2 - b.X1) + 1) * ((b.Y2 - b.Y1) + 1)));
    for y := b.Y1 to b.Y2 do
      for x := b.X1 to b.X2 do
        if (Sqr((x - center.X) / XRadius) + Sqr((y - center.Y) / YRadius) <= 1) then
        begin
          Result[r] := Point(x, y);
          Inc(r);
        end;
  end;
  SetLength(Result, r);
end;

{==============================================================================]
  Explanation: Returns true if point is inside the given ellipse,
               defined by the center point and radius.
[==============================================================================}
function InEllipse(pt, center: TPoint; XRadius, YRadius: Extended): Boolean;
begin
  Result := (Sqr((pt.X - center.X) / XRadius) + Sqr((pt.Y - center.Y) / YRadius) <= 1);
end;

{==============================================================================]
  Explanation: Generates a TPA containing all coordinates within the given circle,
               defined by the center point and radius. Coordinates are stored row-by-row.
[==============================================================================}
function TPAFromCircle2(center: TPoint; radius: Extended): TPointArray;
var
  r, x, y, v: Integer;
  b: TBox;
begin
  if (radius > 0) then
  begin
    v := Round(radius);
    b := IntToBox((center.X - v), (center.Y - v), (center.X + v), (center.Y + v));
    SetLength(Result, Integer(((b.X2 - b.X1) + 1) * ((b.Y2 - b.Y1) + 1)));
    for y := b.Y1 to b.Y2 do
      for x := b.X1 to b.X2 do
        if (Sqr((x - center.X) / radius) + Sqr((y - center.Y) / radius) <= 1) then
        begin
          Result[r] := Point(x, y);
          Inc(r);
        end;
  end;
  SetLength(Result, r);
end;

{==============================================================================]
  Explanation: Returns true if point is inside the given circle,
               defined by the center point and radius.
[==============================================================================}
function InCircle2(pt, center: TPoint; radius: Extended): Boolean;
begin
  Result := (Sqr((pt.X - center.X) / radius) + Sqr((pt.Y - center.Y) / radius) <= 1);
end;

var
  bmp: TSCARBitmap;

begin
  bmp := TSCARBitmap.Create('');
  bmp.SetSize(500, 500);
  WriteLn(TPAToStr(TPAFromCircle(Point(50, 50), 5)));
  WriteLn(TPAToStr(TPAFromCircle2(Point(50, 50), 5)));
  bmp.SetPixels(TPAFromCircle2(Point(50, 50), 25.5), clRed);
  bmp.SetPixels(TPAFromCircle2(Point(250, 250), 50.5), clBlue);
  bmp.SetPixels(TPAFromEllipse(Point(100, 250), 20.5, 10.5), clGreen);
  bmp.SetPixels(TPAFromEllipse(Point(350, 100), 40.55, 15.444), clYellow);
  bmp.SetPixels(TPAFromEllipse(Point(450, 350), 15, 45), clWhite);
  bmp.SetPixels(TPAFromEllipse(Point(60, 400), 35, 45), clGray);
  bmp.SetPixels(TPAFromEllipse(Point(270, 420), 30, 30), clBronze);
  DebugBitmap(bmp);
  bmp.Free;
end.