Ellipse2Poly sense on start / end angle changed ! (Bug #3421)

Added by Gary Gray over 11 years ago. Updated over 11 years ago.

Status:Cancelled Start date:2013-12-04
Priority:Normal Due date:
Assignee:- % Done:

0%
Category:core
Target version:2.4.8
Affected version:pre 2.4 (deprecated) Operating System:Any
Difficulty: HW Platform:Any
Pull request:

Description

I can see in the code that someone changed the follow line in Ellipse2Poly between V2.0 & V2.4.6

        pt.y = cvRound( cy - x * beta - y * alpha );

to 

        pt.y = cvRound( cy + x * beta - y * alpha );

This had massive repercussions in our code which we only just found,.., I searched and could not find any mention of this change! Surely people realize changing something like can silently break applications (we know the V2.0 was broke but it just meant a sign change on start and end angle)

Associated revisions

Revision eedde323
Added by Vadim Pisarevsky over 10 years ago

Merge pull request #3421 from SpecLad:ncv-algorithm

History

#1
Updated by Alexander Smorkalov over 11 years ago

  • Description changed from I can see in the code that someone changed the follow line in Ellipse2Poly be... to I can see in the code that someone changed the follow line in Ellipse2Poly be... More

#2
Updated by Daniil Osokin over 11 years ago

Hi! Thanks for report! Please, send a pull request with bugfix (http://code.opencv.org/projects/opencv/wiki/How_to_contribute). It will really help!

  • Target version set to 2.4.8
  • Category set to core
  • Assignee set to Gary Gray

#3
Updated by Steven Puttemans over 11 years ago

Actually, this was fixed with a reason. To find out why fixes have happened, you can browse a file in the GitHub repository and check it's commit history. Reason for this one: https://github.com/Itseez/opencv/commit/a937d9d43c7bc1345d6d43634a1731ec3d0330fa

Look at the second file that was changed. This was actually done for unifying the coordinate interpretation in the complete drawing in order to ensure the new RotatedRect functionality would work. It was submitted onto version 2.2 and thus you missed the update.

A single advice is to keep your openCV up to date. Doing this with each new stable release reduces the effort and makes sure your code isn't subdued to other terrible bugs and problems.

I will cancel the ticket. Reopen if you think this is still a valid problem.

  • Status changed from New to Cancelled
  • Assignee deleted (Gary Gray)

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