At the entrance, two polygons are given (the coordinates of the vertices of these polygons are listed in the order of their traversal; however, the traversal order for different polygon angles can be chosen different). Can one polygon be transformed into another using only parallel translation and proportional scaling?
I have following idea So, find some common peak for two polygons and make the transfer of one polygon so that these vertices lie on one point then Scaling so that the neighboring point matches the corresponding point of another polygon, but I think it's wrong , at least I can't write it in code
Is there some special formula or theorem for this problem?
Compute the axis-aligned bounding boxes of the two polygons.
If the aspect ratios do not match, the answer is negative. Otherwise the ratio of corresponding sides is your scaling factor. The translation is obtained by linking the top left corners and the transformation equations are
X = s.(x - xtl) + Xtl
Y = s.(y - ytl) + Ytl
where s
is the scaling factor and (xtl, ytl)
, (Xtl, Ytl)
are the corners.
Now choose a vertex of the first polygon, predict the coordinates in the other and find the matching vertex. If you can't, the answer is negative. Otherwise, you can compare the remaining vertices*.
*I assume that the polygons do not have overlapping vertices. If they can have arbitrary self-overlaps, I guess that you have to try matching all vertices, with all cyclic permutations.