Download this example
procedure
TForm1.FormCreate(Sender: TObject);
{ Draw 1 pixcel
width line }
procedure DrawLine(W,Y,H,L,RGBV:Integer;
Step:Real);
Var
R, C : Integer;
Begin
For R:=0
To H Do
Begin
{
Change fill color }
If
R<=L Then
Begin
C:=Round(R*Step);
Case
RGBV Of
1:Image1.Canvas.Pen.Color:=RGB(C,0,0);
2:Image1.Canvas.Pen.Color:=RGB(0,C,0);
3:Image1.Canvas.Pen.Color:=RGB(0,0,C);
End;
End
Else
If R<=2*L Then
Begin
C:=Round((R-L)*Step);
Case
RGBV Of
1:Image1.Canvas.Pen.Color:=RGB(255-C,0,0);
2:Image1.Canvas.Pen.Color:=RGB(0,255-C,0);
3:Image1.Canvas.Pen.Color:=RGB(0,0,255-C);
End;
End;
{
Fill area by drawing lines }
Image1.Canvas.MoveTo(0,Y+R);
Image1.Canvas.LineTo(W,Y+R);
End;
End;
Var
Row, X, Y, H, H2, W, L : Integer;
Step : Real;
begin
{ Get form size
}
H:=Image1.Height;
W:=Image1.Width;
{ Fill image area
by form color }
Image1.Canvas.Brush.Color:=clBlack;
Image1.Canvas.Pen.Color:=clBlack;
Image1.Canvas.Rectangle(0,0,W,H);
{ Set fill size
}
H2:=100;
L:=H2 Div 2;
{ Set fill step
size }
Step:=255/L;
For Row:=1 To 3 Do
Begin
Y:=(Row-1)*150;
DrawLine(W,Y,H2,L,Row,Step);
End;
end;
DOWNLOAD this example
Click
here
to download this complete example for Delphi 6. (File size 4KB)
