Polygon operations

[Anonymous]

Is there someone willing to show an example of use of the "polyoperations" functions?
Please!!!
I can't find my way in using this function.

[Laszlo Nagy]

Does this page help?
Would be helpful to put your AC version in your signature.

AC12:
http://www.graphisoft.com/ftp/techsupport/documentation/developer_docs/BasicLibraryDoc/12/Window-Mac...

AC13:
http://www.graphisoft.com/ftp/techsupport/documentation/developer_docs/BasicLibraryDoc/13/Window-Mac...

[Anonymous]

Thanks Laszlo,
but i was more thinking about the Polyop extension (ch=INITADDONSCOPE ("PolyOperations ", "", "")) which is said by Zsolt to be a more effective way to do such operations.
Although I will look with this macro.
But that would be very very very nice to see just a little example of use of the extension to see how we can use it. The source containers etc.. are a bit difficult to understand from scratch.
Maybe there is an object in the library using it?
Thanks in advance,
olivier

AC v13, winVista

[ztaskai]

There is an example object called PolyOperations_Example.gsm in the Sample Objects folder of the Basic Library.

You can download it from http://www.graphisoft.com/support/developer/downloads/

The extension is much more effective and capable than the macro indeed!

Regards,

[Anonymous]

Thanks a lot!
BTW I have been trying to use the polyoperations macro to calculate areas, but it appears to me that the results are bit different than what they should be. (if i draw a polygon and see the area)
Is that a bug?
You can't use the addon to calculate areas, can you?
(in that case it is not documented in the manual)
thanks,
regards,
olivier

[ztaskai]

Olivier wrote:
I have been trying to use the polyoperations macro to calculate areas, but it appears to me that the results are bit different than what they should be. (if i draw a polygon and see the area)
Is that a bug?

It can be considered as a bug, sure. Please report the details and we'll see about the priority.

Olivier wrote:
You can't use the addon to calculate areas, can you?
(in that case it is not documented in the manual)

The documentation is complete - consequently there is no area calculation. One reason to include it would be to completely replace the old macro...

Regards,

[Anonymous]

Here is the code from the Polygonoperations.gsm macro:

----
area=0

tempNumPnts = nsp/3

areaLX = get(1) ! Last point
areaLY = get(1)
!!ziiz=get(1)
areaFX = areaLX ! First point
areaFY = areaLY

for areaI=1 to tempNumPnts-1
areaX = get(1)
areaY = get(1)
!!ziiz=get(1)
area = area + (areaX + areaLX) * (areaY - areaLY) * 0.5

areaLX = areaX
areaLY = areaY
next areaI
area = area + (areaFX + get(1)) * (areaFY - get(1)) * 0.5


-------

I add this in the beginning to give my polygon:
-------
for i=1 to vardim1(ac_coords)
put ac_coords[2],ac_coords[3],0
next i

------
ac_coords comes from the accessories API

but the resulting area is totally false...

I don't understand this code anyway which should call 3 times "get" per loop but "gets" only 2 times per loop.
Is there something obvious that I missed?

Thanks in advance,
Olivier

[Anonymous]

Ok, I think I fixed the little bug in the macro:
--
for areaI=1 to tempNumPnts-1
---
should be
--
for areaI=1 to tempNumPnts-2
--
now it seems to work.

However it doesn't work if there are holes in the polygon.
Some more work should fix this second problem.

[Anonymous]

and added of course this ziiz=get(1) in the loop to get 3 times instead of 2

[ztaskai]

The macro is designed to handle 2D polygons defined by two coordinate points. You modified it to handle 3 coordinates per point:)

Regs,