CIRCLE's Intersection point

Hi,

Is it a method or routine in AutoLISP to check
if a CIRCLE is intersected of a line or even other object.
The CIRCLE is known but what I want here is to check if
it's intersected by any line and retrieve this point
to further programming.

Thank in advance
Mac

 

Hi Mac,
Using ActiveX methods with VLisp this is relatively simple.
First get the boundingbox of the circle, create a 'fenced' selection set,
using the boundingbox as the fence, step through the selection set and use
the IntersectWith method.

If you need more help than that just post what you do have and I'll try to
help out.

Jeff

 

Form the AutoCAD help files:

Sub Example_IntersectWith()
' This example creates a line and circle and finds the points at
' which they intersect.

' Create the line
Dim lineObj As AcadLine
Dim startPt(0 To 2) As Double
Dim endPt(0 To 2) As Double
startPt(0) = 1: startPt(1) = 1: startPt(2) = 0
endPt(0) = 5: endPt(1) = 5: endPt(2) = 0
Set lineObj = ThisDrawing.ModelSpace.AddLine(startPt, endPt)

' Create the circle
Dim circleObj As AcadCircle
Dim centerPt(0 To 2) As Double
Dim radius As Double
centerPt(0) = 3: centerPt(1) = 3: centerPt(2) = 0
radius = 1
Set circleObj = ThisDrawing.ModelSpace.AddCircle(centerPt, radius)
ZoomAll

' Find the intersection points between the line and the circle
Dim intPoints As Variant
intPoints = lineObj.IntersectWith(circleObj, acExtendNone)

' Print all the intersection points
Dim I As Integer, j As Integer, k As Integer
Dim str As String
If VarType(intPoints) <> vbEmpty Then
For I = LBound(intPoints) To UBound(intPoints)
str = "Intersection Point[" & k & "] is: " & intPoints(j)
& "," & intPoints(j + 1) & "," & intPoints(j + 2)
MsgBox str, , "IntersectWith Example"
str = ""
I = I + 2
j = j + 3
k = k + 1
Next
End If
End Sub

 

Hi Jeff & Scott!

Thank you very much for your contribution.
I'm wondering if you are satisfied with 20(!) years of AutoCAD's
development on the market.
Fence(?????????????????????????????),
Boundingbox(??????????????????????????)
it should be a 'CIRCLE' directly!!!!!!!!!
I've got enough of 'Fence' thinking.
My routines like ´Circle trimmer' are probably known.
What I'm looking for here is a new technology.
But everything seems to be out of date as usual at AutoDesk.
In our time what many of older AutoLisp developers are looking for is not
'Select first', 'Select second' ...bla, bla, bla, but full 'Automation' for
whole drawing, because many drawings have already been created!
I'm warning you DO NOT try to be a new AutoDesk Slave (like Microsoft
Slaves).
Think independently and claim 'value for money'.
Basic AutoLISP & commands from 1986 has not been developed at all!
Except of command 'COPY' f...... 'Multiple' is removed.
In my opinion it's too weak for $3000:-

Best regards
Mac

 

Just out of shear curiosity, WTF are you rambling about?
Do want help or not?
If so, please state what you are looking for in a clear and concise manner.
If not, please just go away.

And FWIW, the $3000+ price tag for this is cheap, considering the
alternatives. I came from hand drafting and design to using Autocad and
LandDesktop over the years. I know that I can produce more than enough to
pay for the software in less than a week!

Jeff

 

OK!

What I need is a lisp routine that will
rotate all reference texts inside circles & 2 rectangle-lines
from 90 grade to zero but all at once on each drawing.
The method 'select first' & 'select second'
is hopeless here because there is ca 1000 texts on each drawing.
Some of the texts inside the circles or lines (together with them)
have to be magnified to the height pre-definied by the user.
All texts and references lines are simple drawing-entities(no blocks)
First outline is as follows:
- Open dialog for setup values: text height, rotation angle from and
rotation angle to.
- ssget procedure with filter
- then I can imagine two procedures: one for the text inside a circle
& second one for the text inside two rectangle lines.
- the key of the first procedure is to find the intersection point
between circle and arrow-line. Then probably this primitive
ssget'fence' circumscribed about the circle to find all lines
close to the circle. Then intercestWith to find intersection point
with the arrow-line.
From this point magnify the circle and reference text if needed.
And finally rotate the text at the centerpoint of the circle.
- the key of the second procedure is similar however the text is
always positioned
between two lines: one to the right of the text and second under the
text.
What has to be done here is to find the intersection point between
these two
lines and arrow-line and then rotate whole group at this point and
'scale' if needed.

Best regards
Mac Lukas

 

Well, that was much better. Now, to make this a little more clear, would it
be possible for you to place a copy of a sample drawing in R2002 or below
format to a place I could download it? Or you could send it to me at
miffATsonicDOTnet (replace the AT and DOT with the proper symbols).

Is the text always contained entirely within the circle? Is the text always
Text and not MText?

The text edjacent to 2 perpendicular line will be a little more
difficult......what is the arrow line? Is it a Leader object?

Does this have to be done in Lisp? Can VBA be used instead? IMHO, dialogs
are MUCH simpler in VBA than lisp.

Jeff