3 Point Arc

[ceaser]

Hi Dennishea

How about we work together on this "CAD" program? I send you what I have done so far and we can exchange ideas and routines?

Thanks
Michael

[dennishea]

Hi ceaser. It is ok by me. Have you had a chance to look at what I've tried so far? I hope we can find better solution for snap to intersection, mid point, end point, ect, ect. The more gray matter the better. Looking forward to working with you ceaser.

[ceaser]

Hi Dennishea

I did not have a change to look at your snap options, I am busy with surveying Stockpiles and checking bolts on a bridge, but I will have a look this weekend and then also send you what I have so far.

Thanks
Michael

[dennishea]

Thanks for the quik reply ceaser. Will wait for weekend to get here. Be safe and will type at you later.

p.s. I will try to program in table for recording.

[dennishea]

Colin9876

I tried your solution for arc's and I think yours takes longer to draw. I don't know if it's I'm using pixels and your using line or what. Like I have stated in other post's I am not a Programmer so maybe you can help me understand the speed difference. If you get time maybe you could take a look at what I have done so far and point out what I need to do to make the code more ledgeable. There is a link in post 10 that has a zip file with a wordpad file and source code. Thanks for any and all comments.

[colin9876]

Hi,
Yes - unfortunately due to the fact that you cant plot a single point with the .NET libary I have to draw it with connecting lines.
(form.line(0,0,1,0,cblack) wont draw just one pixel long - this is a flaw in .NET library - smallest lines being 0 points long or 2 pixels long!)

Its not slow on my device but if you want to speed it up you can double the step line to

s=2/r
because you dont really need the steps to be as small as 1/r

I looked at your code and it looks good, no major problems.
I wouldnt have done it writing to a bitmap because it seems an extra step, but given there is the .NET line bug (that you cant plot a single point) it means there is one advantage of doing it ur way

Just as a minor critique, on circle you use lable name txtr but this is actually the diameter not the radius so txtdiam would be better name! Thats why u divide it by two when calculating the radius.
In future I would tighten up the variable naming - as I said before use x,y,x1,y1 etc for co-ordinates but try and use something like l,length,ylen etc etc for lengths. Theres a few places where one minute x,y is a co-ordinate then the next its lengths lol! e.g
y2 = (y2 / 2) + Min(txty2.Text,txty1.Text)

ylen might be a clearer variable name here! Other than that its a good start!

[dennishea]

Hi colin9876. I think the main reason I use very small variables is because I'm not a typist. Erel has done such a good job with basic4ppc that even a bad programmer like me has alot less problems finding his or hers spelling mistakes and I use the term programmer loosely. I hope you keep track of what I'm trying to do and let me know when I can do better. I will go back thru my program and rename my variables with more meaningful names and repost source code. Again thanks very much for your time.

[agraham]

Originally Posted by colin9876

unfortunately due to the fact that you cant plot a single point with the .NET libary I have to draw it with connecting lines

You can using the ImageLib library.

If you're going to bit-twiddle (or pixel-twiddle) don't overlook the "fast" methods in dzts' library http://www.basic4ppc.com/forum/addit....html#post8181 The not very good (written by me!) help is here dzImage

Depending upon the amount of pixel work you need doing it could be faster to assign your bitmap to a dztImage Image property, use the FastSetPixel method and then assign your image back. The fast method locks the bitmap for access only at the beginning and unlocks it at the end. ImageLib effectively locks and unlocks it for every pixel access. For many pixels the speed difference could be significant.

[colin9876]

Point taken but Im all for keeping it simple and drawing direct to the screen. Theres no reason to use dlls or bitmaps for this.
My method is fast if the raw .net line command is used.
Also I stand by what I said that the .NET line command doesn't follow convention that line(0,0,0,0) should plot a single point if line(0,0,1,0) plots 2

in fact theres no way I know with .NET to plot a single pixel, the circle fn won't do it either with r=0. Its crazy - there must b a way without using a dll?!

[klaus]

Hi ceaser,

For the 3 point arc, is this what you are looking for ?

Best regards