Line / Curve Tool - Length Fix Request

[Sugarfree]

Hi!

just a few days ago i started to use paint.net, everything is great (much more better than MS paint ), but there is one thing what i really don't like - "Line length bug" (at least i think that it is bug)

Now look, when i'm trying to draw a simple line, the real line length isn't correct: (watch example)

As you can see paint.net shows that line length is only 1px, but thats not correct... Should i have to every time remind myself that the line is for 1px longer? I don't know how the other people think, but for me this is pretty annoying. ;/

[Curmudgeon]

I'm guessing that depends on the brush width you choose for the line.

The default brush width is 2 pixels

[Sugarfree]

Brush width in that sample is 1px... You can test this trying to draw something with line / curve tool by yourself. Line length (what shows paint.net) always will be 1px shorter than it actually is.

[david.atwell]

I get the same result. I also notice that if I try to make it only 1px wide, it vanishes completely.

[Curmudgeon]

my only other guess is that a line isn't a line without a beginning and an ending meaning a beginning point, and an end point, so two pixels minimum with brush width of 1...

just a hypothetical guess

[BoltBait]

Moving to the troubleshooting forum...

[Sugarfree]

well 1px point we all can make with pencil tool or whatever, thats just not so important...

Line tool have to start counting length from "2" then everything would be OK. Or the other option - line / curve tool first px appears in moment when the mouse is pressed. (like in the MS Paint)

I hope you all understand what i mean...

Sorry for my English.

[Toli]

I think your Line is actually 1 pixel long, not 2.

Don't be surprised. It has 2 adjacent pixels. This means that its length is 1 pixel.

More general: If a line has N pixels, its length is N - 1 pixels.

Explanation: Just substract the pixels (horizontal) coordinates.

And, by the way: Why do you consider that the length should be mesured from the LEFT edge of the FIRST pixel to the RIGTH edge of the LAST pixel???

Paint.NET mesures it correctly, from the CENTER of the FIRST pixel to the CENTER of the LAST pixel.

If that line of yours would have been reported having a length of 2, I would have called it a bug.

Hope you understood...

[Sugarfree]

thats some kind of

I understand your explanation, but still...

I draw the line: "100px", then this lines length actually is 99px? If it's not the LINE LENGTH these 100px then what is it? Line WIDTH?

I'm little bit confused... ;/

EDIT: This is a family-friendly site. Let's keep it that way, OK? ~BoltBait

[jchunn]

I would have to agree that if a line "contains" two pixels in its' length, it is two pixels long.

A ruler is 12 inches long... it is measured from the beginning of the ruler to the end, and "contains" 12 full inches... you don't start from the end of the first inch.

Other graphics programs measure length in those terms. That does not mean that this is not by design, but if it is, it is less intuitive to me than I would like.

Just my two cents. The author of the software may have a reason for this that I am unaware of.

[Toli]

Actually, it is very simple.

The line which displays 100 pixels, is obviously 99 pixels long.

Any first grader knows that:

Problem:

There are 100 trees on a road's edge.

The distance between two of them is 1 meter.

What is the distance between the first and the last one?

Answer: 100 meters -> wrong, you failed.

Answer: 99 meters -> good, you passed.

EDIT: Be nice. ~BoltBait

[Toli]

Another answer - just try:

void Test()
{
   Image image = new Bitmap(16, 16);
   Graphics G = Graphics.FromImage(image);
   G.DrawLine(new Pen(Color.Red), 8, 1, 8, 2);
   image.Save(MyBitmap.bmp);
}

[jchunn]

Another answer - just try:

void Test()
{
   Image image = new Bitmap(16, 16);
   Graphics G = Graphics.FromImage(image);
   G.DrawLine(new Pen(Color.Red), 8, 1, 8, 2);
   image.Save(MyBitmap.bmp);
}

I'm not sure what you are trying to say here. The code you posted specifies the following:

Line Starting point: 8,1

Line Ending point: 8,2

None of the arguments provided to the Drawline method specify "length", they are x,y coordinates for the beginning and end of the line (x1, y1, x2, y2).

As for the tree analogy...

Tree = border of a pixel

Space between trees = pixel

100 "trees" would be 99 "spaces", right?

If that is true, then 3 "trees" would be 2 "spaces", right?

If that is true, then a line on the screen that has a length of 2 would have 3 "trees" (or borders) and 2 "spaces" (or pixels), right?