Solved

Line intersects rectangle?

Posted on 2009-04-03
6
274 Views
Last Modified: 2012-05-06
Hi,

How can I test if a line (defined by two x,y endpoints) intersects a rectangle?

I have a bunch of rectangles draw on a screen, and want to know if a user's mouse intersects any of them when they move the mouse. I only get mouse move messages every so often, so if the user moves the mouse fast enough, most of the mouse location points are missed. So I'm looking to figure out which rectangles could have been intersected between two mouse points.

Thanks
0
Comment
Question by:DJ_AM_Juicebox
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3
6 Comments
 
LVL 84

Accepted Solution

by:
ozo earned 250 total points
ID: 24065536
0
 
LVL 31

Assisted Solution

by:GwynforWeb
GwynforWeb earned 250 total points
ID: 24065595
0
 
LVL 84

Expert Comment

by:ozo
ID: 24065652
http://www.siggraph.org/education/materials/HyperGraph/scanline/clipping/cliplb.htm
says that Liang-Barsky is a 36% speed improvement over  Cohen -Sutherland for 2D lines
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 31

Expert Comment

by:GwynforWeb
ID: 24065826
...the questioner is not clipping,  just detecting incidence with the rectangular.
0
 
LVL 84

Expert Comment

by:ozo
ID: 24066020
that's what line clipping algorithms do
0
 
LVL 31

Expert Comment

by:GwynforWeb
ID: 24066221
...line clipping gives the clipped line segment. That is different than just detecting if the line crosses the rectangle.
0

Featured Post

Enroll in June's Course of the Month

June's Course of the Month is now available! Every 10 seconds, a consumer gets hit with ransomware. Refresh your knowledge of ransomware best practices by enrolling in this month's complimentary course for Premium Members, Team Accounts, and Qualified Experts.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

How to Win a Jar of Candy Corn: A Scientific Approach! I love mathematics. If you love mathematics also, you may enjoy this tip on how to use math to win your own jar of candy corn and to impress your friends. As I said, I love math, but I gu…
This article seeks to propel the full implementation of geothermal power plants in Mexico as a renewable energy source.
This is a video describing the growing solar energy use in Utah. This is a topic that greatly interests me and so I decided to produce a video about it.
Finds all prime numbers in a range requested and places them in a public primes() array. I've demostrated a template size of 30 (2 * 3 * 5) but larger templates can be built such 210  (2 * 3 * 5 * 7) or 2310  (2 * 3 * 5 * 7 * 11). The larger templa…

690 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question