Detect interception between line and arc or arc and arc

That function merely fixes axl_ol_ol, as you have found. What is needed is more robust function that can compare any two segments and return nil (if there is no intersection) or a list of intersection points, after you screened out the special cases where the lines or arcs are identical. Should easily be handled by basic trigonometry  and some equation-solving.

line-line  --  nil or 1 intersection point

line-arc   --  nil or 1 or 2 i-points

arc-line   --  nil or 1 or 2 i-points

arc-arc    --  nil or 1 or 2  i-points

Chris Walters

rusty former Cadence guru

Hi Christ,

Thanks for the suggestion. 

It seems like no existing function can achieve that and we need to write our own.

one of the algo i am thinking of is like this:

break the arcs into multiple (i) segments, then write a for i loop to:

1. get the start and end point of each segment.

2. use axl_ol_ol2 to get the intersection point and distance with the line or another arc's line segment.

3. store the interception points or distances (if no intersection). 

after the for loop, we can have the intersection points or min distance.

larger the i, more accurate the result.

See attached.

DEFn_arcLineSegmentIntersections - find the intersection points between an arc and a line segment

DEFn_arcArcIntersections - find the intersection points of two arcs

DEFn_circleLineIntersections - find the intersection points of an circle and a line

DEFn_circleCircleIntersections - find the intersection points of two circles

Hi eDave, Thank you very much. (I haven't tried out though)

you have always been very helpful.  =) 

Hi fxffxf, axlAirGap does NOT support lines dbid and always returns nil

you may want to tried out, assume aa and bb are two dbids of Lines on Etch/Surface,

Skill>axlAirGap(aa bb nil 'enhanced)

nil