Нарисовать линию, не используя функции LineTo

Delphi , Графика и Игры , Canvas

Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

{ 
  Enables you do draw a line if for some reason you 
  cannot use the delphi LineTo procedure. 
  For example, for drawing higher resolution lines 
  or drawing lines in 2D arrays. 
}

 procedure DrawLine(APoint1, APoint2: TPoint; ACanvas: TCanvas);
 var
   Lpixel, LMaxAxisLength: integer;
   LRatio: Real;
 begin
   LMaxAxisLength := Max(abs(APoint1.X - APoint2.X), abs(APoint1.Y - APoint2.Y));
   for Lpixel := 0 to LMaxAxisLength do
    begin
     LRatio := Lpixel / LMaxAxisLength;
     ACanvas.Pixels[APoint1.X + Round((APoint2.X - APoint1.X) * LRatio),
       APoint1.Y + Round((APoint2.Y - APoint1.Y) * LRatio)] :=
       ACanvas.Pen.Color;
   end;
 end;

 // Draw a double resolution line 
procedure DrawLineDouble(APoint1, APoint2: TPoint; ACanvas: TCanvas);
 var
   Lpixel, LMaxAxisLength: integer;
   LRatio: Real;
   LPoint: TPoint;
 begin
   LMaxAxisLength := max(abs(APoint1.X - APoint2.X), abs(APoint1.Y - APoint2.Y));
   for Lpixel := 0 to LMaxAxisLength do
    begin
     LRatio := Lpixel / LMaxAxisLength;
     LPoint.X := APoint1.X + Round((APoint2.X - APoint1.X) * LRatio);
     LPoint.Y := APoint1.Y + Round((APoint2.Y - APoint1.Y) * LRatio);
     with ACAnvas do
      begin
       Pixels[LPoint.X * 2, LPoint.Y * 2] := clBlack;
       Pixels[(LPoint.X * 2) + 1, LPoint.Y * 2] := clBlack;
       Pixels[LPoint.X * 2, (LPoint.Y * 2) + 1] := clBlack;
       Pixels[(LPoint.X * 2) + 1, (LPoint.Y * 2) + 1] := clBlack;
     end;
   end;
 end;

Статья Нарисовать линию, не используя функции LineTo раздела Графика и Игры Canvas может быть полезна для разработчиков на Delphi и FreePascal.

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