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## how determined they composed the coordinates of the area of all polygons?

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### #1zitao  Members

Posted 03 February 2013 - 01:09 AM

Several intersecting segments intersection coordinates are known how determined they composed the coordinates of the area of all polygons?

### #2CryoGenesis  Members

Posted 03 February 2013 - 05:28 AM

1. You're in the wrong section.

2. Your wording is sloppy, explain your question again. Do you want to found out the area of the intersection, the area of each polygon or the area of the entire thing?

### #3SuperVGA  Members

Posted 03 February 2013 - 06:02 AM

But in 2D intersections (being points) don't have areas... at least, normally they don't...
This looks like a 2D question, though. And it's a nice drawing. Is it a puzzle?
Would you like to determine the number of intersections between the rectangles?

Are all other rectangles overlapping rectangle #1?
If you want to find the coords at the intersections of "overlapping" rectangles,
you could use a parametric test between a point and all rectangles that the point does not belong to, and contain the point.

If you're going for the total area, and you know that every bit of the outermost rectangle will be filled,
go with

(max(all_coords[o..n-1].x) - min(all_coords[o..n-1].x))
*
(max(all_coords[o..n-1].y) - min(all_coords[o..n-1].y))

This doesn't sum overlapping areas, of course.

Edited by SuperVGA, 03 February 2013 - 12:28 PM.

### #4zitao  Members

Posted 04 February 2013 - 03:02 AM

But in 2D intersections (being points) don't have areas... at least, normally they don't...
This looks like a 2D question, though. And it's a nice drawing. Is it a puzzle?
Would you like to determine the number of intersections between the rectangles?

Are all other rectangles overlapping rectangle #1?
If you want to find the coords at the intersections of "overlapping" rectangles,
you could use a parametric test between a point and all rectangles that the point does not belong to, and contain the point.

If you're going for the total area, and you know that every bit of the outermost rectangle will be filled,
go with

(max(all_coords[o..n-1].x) - min(all_coords[o..n-1].x))
*
(max(all_coords[o..n-1].y) - min(all_coords[o..n-1].y))

This doesn't sum overlapping areas, of course.

thanks

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