Нарисовать линию без зазубринок Оформил: DeeCo Автор: http://www.swissdelphicenter.ch ```{ This code draws an anti-aliased line on a bitmap This means that the line is not jagged like the lines drawn using the LineTo() function } uses Graphics, Windows; type TRGBTripleArray = array[0..1000] of TRGBTriple; PRGBTripleArray = ^TRGBTripleArray; // anti-aliased line procedure WuLine(ABitmap : TBitmap ; Point1, Point2 : TPoint ; AColor : TColor); var deltax, deltay, loop, start, finish : integer; dx, dy, dydx : single; // fractional parts LR, LG, LB : byte; x1, x2, y1, y2 : integer; begin x1 := Point1.X; y1 := Point1.Y; x2 := Point2.X; y2 := Point2.Y; deltax := abs(x2 - x1); // Calculate deltax and deltay for initialisation deltay := abs(y2 - y1); if (deltax = 0) or (deltay = 0) then begin // straight lines ABitmap.Canvas.Pen.Color := AColor; ABitmap.Canvas.MoveTo(x1, y1); ABitmap.Canvas.LineTo(x2, y2); exit; end; LR := (AColor and \$000000FF); LG := (AColor and \$0000FF00) shr 8; LB := (AColor and \$00FF0000) shr 16; if deltax > deltay then begin // horizontal or vertical if y2 > y1 then // determine rise and run dydx := -(deltay / deltax) else dydx := deltay / deltax; if x2 < x1 then begin start := x2; // right to left finish := x1; dy := y2; end else begin start := x1; // left to right finish := x2; dy := y1; dydx := -dydx; // inverse slope end; for loop := start to finish do begin AlphaBlendPixel(ABitmap, loop, trunc(dy), LR, LG, LB, 1 - frac(dy)); AlphaBlendPixel(ABitmap, loop, trunc(dy) + 1, LR, LG, LB, frac(dy)); dy := dy + dydx; // next point end; end else begin if x2 > x1 then // determine rise and run dydx := -(deltax / deltay) else dydx := deltax / deltay; if y2 < y1 then begin start := y2; // right to left finish := y1; dx := x2; end else begin start := y1; // left to right finish := y2; dx := x1; dydx := -dydx; // inverse slope end; for loop := start to finish do begin AlphaBlendPixel(ABitmap, trunc(dx), loop, LR, LG, LB, 1 - frac(dx)); AlphaBlendPixel(ABitmap, trunc(dx) + 1, loop, LR, LG, LB, frac(dx)); dx := dx + dydx; // next point end; end; end; // blend a pixel with the current colour procedure AlphaBlendPixel(ABitmap : TBitmap ; X, Y : integer ; R, G, B : byte ; ARatio : Real); Var LBack, LNew : TRGBTriple; LMinusRatio : Real; LScan : PRGBTripleArray; begin if (X < 0) or (X > ABitmap.Width - 1) or (Y < 0) or (Y > ABitmap.Height - 1) then Exit; // clipping LScan := ABitmap.Scanline[Y]; LMinusRatio := 1 - ARatio; LBack := LScan[X]; LNew.rgbtBlue := round(B*ARatio + LBack.rgbtBlue*LMinusRatio); LNew.rgbtGreen := round(G*ARatio + LBack.rgbtGreen*LMinusRatio); LNew.rgbtRed := round(R*ARatio + LBack.rgbtRed*LMinusRatio); LScan[X] := LNew; end;```
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Автор проекта: USU Software
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