49 lines
1.3 KiB
Plaintext
49 lines
1.3 KiB
Plaintext
procedure DrawBar(Image: TImage; Bars,Rows,Row: integer; WhiteToBlack: boolean);
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{Draw horizontal bar according the following parameters:}
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{Bars = number of color bars to fit into the horizontal space}
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{Rows = number of rows to fit into the vertical space}
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{Row = the row to place the current bar - numbered 0..n, top to bottom}
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{WhiteToBlack - if true, bars in the row go from white to back}
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var X: integer;
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var Color: integer;
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var ColorStep: double;
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var BarHeight: integer;
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var R,R2: TRect;
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begin
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{Calculate bar dimensions}
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BarHeight:=Image.Height div Rows;
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R:=Rect(0,0,(Image.Width div Bars)+1, BarHeight);
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OffsetRect(R,0,BarHeight * Row);
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R2:=R;
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{Calculate color parameters}
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ColorStep:=255/(Bars-1);
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if WhiteToBlack then
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begin
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Color:=255;
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ColorStep:=-ColorStep
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end
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else Color:=0;
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{Draw bars}
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for X:=1 to Bars do
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begin
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{Set color}
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Image.Canvas.Brush.Color:=RGB(Color,Color,Color);
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Image.Canvas.Pen.Color:=RGB(Color,Color,Color);
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{Draw rectangular bar}
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Image.Canvas.Rectangle(R2);
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{Move rectangle and calculate color}
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OffsetRect(R2,R.Right,0);
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Color:=Round(X * ColorStep);
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end;
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end;
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procedure ShowGrayBars(Image: TImage);
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{Draw four bar, with alternating color scheme}
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begin
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DrawBar(Image,8,4,0,False);
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DrawBar(Image,16,4,1,True);
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DrawBar(Image,32,4,2,False);
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DrawBar(Image,64,4,3,True);
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end;
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