A One Pixel Long Line

[Martijn Mulder]

I try to define a line with the length of 1 unit (1 pixel) that is, in fact,
just a point on the screen. But when I draw it with a wide pen with the
appropriate StartCap and EndCap (Round), it will appear as a dot.

I can think of a way to define a 1-pixel long line but it is ugly and
clumsy.
I subtract .5 from the given pixel's X and Y coordinate for the first
System.Drawing. PointF structure, and add .5 to the other PointF stucture. It
seems to work (see the code below), but it doesn't feel good.

Is there a standard way to obtain a line with unit length 1?

//namespace OnePixelLine
namespace OnePixelLine
{
//class Form
class Form:System.Win dows.Forms.Form
{
//one integer type point that won't produce output
System.Drawing. Point point0=new System.Drawing. Point(50,50);
//two integer type points that produce 2-pixels long line
System.Drawing. Point point1=new System.Drawing. Point(100,100);
System.Drawing. Point point2=new System.Drawing. Point(101,101);

//two float type points that produce 1-pixel long line, but it is ugly
System.Drawing. PointF pointf1=new System.Drawing. PointF(149.5f,1 49.5f);
System.Drawing. PointF pointf2=new System.Drawing. PointF(150.5f,1 50.5f);

//a pen
System.Drawing. Pen pen=new System.Drawing. Pen(System.Draw ing.Color.Red);

//constructor
Form()
{

//widen pen. Remove this to check the length of the lines
pen.Width=9;
//set StartCap and EndCap both to Round
pen.StartCap=Sy stem.Drawing.Dr awing2D.LineCap .Round;
pen.EndCap=Syst em.Drawing.Draw ing2D.LineCap.R ound;
//prepare for paint
Paint+=new System.Windows. Forms.PaintEven tHandler(OnPain t);
}


//OnPaint
void OnPaint(object a,System.Window s.Forms.PaintEv entArgs b)
{

//this outputs nothing
b.Graphics.Draw Line(pen,point0 ,point0);
//this outputs a line 2 pixels long
b.Graphics.Draw Line(pen,point1 ,point2);
//this outputs a line 1 pixel long, but it is clumsy
b.Graphics.Draw Line(pen,pointf 1,pointf2);
}

//Main
public static void Main()
{
System.Windows. Forms.Applicati on.Run(new Form());
}
}
}

[Martijn Mulder]

>> SetStyle

(
System.Windows. Forms.ControlSt yles.AllPaintin gInWmPaint|
System.Windows. Forms.ControlSt yles.DoubleBuff er|
System.Windows. Forms.ControlSt yles.ResizeRedr aw|
System.Windows. Forms.ControlSt yles.UserPaint,
true
);

Ever heard of the using statement? :-)

The using statement? Not using it makes it easier to look up different
classes since I know where they reside. I am an ardent typer :-)

[Michael C]

"Martijn Mulder" <i@m> wrote in message
news:44******** *************** @news.wanadoo.n l...

SetStyle
(
System.Windows. Forms.ControlSt yles.AllPaintin gInWmPaint|
System.Windows. Forms.ControlSt yles.DoubleBuff er|
System.Windows. Forms.ControlSt yles.ResizeRedr aw|
System.Windows. Forms.ControlSt yles.UserPaint,
true
);

Ever heard of the using statement? :-)

The using statement? Not using it makes it easier to look up different
classes since I know where they reside. I am an ardent typer :-)

It would make everything else harder though, typing, reading, maintaining.
:-)

Michael

[Martijn Mulder]

>>>> SetStyle

(
System.Windows. Forms.ControlSt yles.AllPaintin gInWmPaint|
System.Windows. Forms.ControlSt yles.DoubleBuff er|
System.Windows. Forms.ControlSt yles.ResizeRedr aw|
System.Windows. Forms.ControlSt yles.UserPaint,
true
);

Ever heard of the using statement? :-)

The using statement? Not using it makes it easier to look up different
classes since I know where they reside. I am an ardent typer :-)

It would make everything else harder though, typing, reading, maintaining.
:-)

I don't agree.

- Typing: My editor makes it very easy to copy a line. All editors do
- Reading: When a long name shows up (i.e. System.Drawing. ..,
System.Windows. Forms...) I know it is SDK-defined, all else is user defined.
The eye is wandering for repitition, for redundancy
- Maintaining: Maintaining code is a nightmare, any kind of code

Never using using (no, never!) makes the code self-documenting, so to speak.
Only thing is that I am new to C# so I start out typing javax.swing... when
I mean System.Drawing. ..

[Michael C]

"Martijn Mulder" <i@m> wrote in message
news:44******** *************** @news.wanadoo.n l...

I don't agree.

- Typing: My editor makes it very easy to copy a line. All editors do
You can't disagree there. You type more than me, full stop.
- Reading: When a long name shows up (i.e. System.Drawing. ..,
System.Windows. Forms...) I know it is SDK-defined, all else is user
defined. The eye is wandering for repitition, for redundancy
You read more also. Personally I found your code much more difficult to
read. I know Point is in System.Drawing so don't need to be reminded over
and over. Besides, where it is isn't so important to me that I need see it
every time it is used.
- Maintaining: Maintaining code is a nightmare, any kind of code
That's a cop out. Some code is easier to maintain than other.
Never using using (no, never!) makes the code self-documenting, so to
speak. Only thing is that I am new to C# so I start out typing
javax.swing... when I mean System.Drawing. ..

I doubt you'll find many developers who agree :-)

Michael