Solved

Draw ARC

Posted on 2004-03-29
4
1,087 Views
Last Modified: 2013-11-20
I need  to find Start angle and End angle for the ARC with known Radius(r),Center point(x0,y0),Start(x1,y1) and End(x2,y2) points of the ARC.


Please help me.

Thank you.
0
Comment
Question by:shean85
[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
  • 2
4 Comments
 
LVL 16

Expert Comment

by:nonubik
ID: 10711679
Hi shean85,
Are you using ObjectArx? Cause if so, you can :

dStartAngle = (Start - Center).angleTo(AcGeVector2d::kXAxis);
dEndAngle = (End - Center).angleTo(AcGeVector2d::kXAxis);

where Start, Center, End are AcGePoint2d.
Radius information is useless/redundant.
0
 
LVL 31

Accepted Solution

by:
Zoppo earned 250 total points
ID: 10712142
Hi shean85,

with this function you can calc the angle between two points (in degrees):

double CalcAngle( CPoint& p1, CPoint& p2 )
{
      if ( p1.x == p2.x )
      {
            if ( p1.y < p2.y )
                  return 90.0;
            else
                  return 270.0;
      }
      else if ( p1.y == p2.y )
      {
            if ( p1.x < p2.x )
                  return 0.0;
            else
                  return 180.0;
      }

      return atan2( p2.y - p1.y, p2.x - p1.x ) * 180.0 / 3.14159265358;
}

// if you need it in radians you can simply calc it from result with
r = d * PI / 180; // d = angle in degrees, r in radians

With this you can easily calc angles from center to start- and endpoint.

hope this helps,

ZOPPO
0
 
LVL 31

Expert Comment

by:Zoppo
ID: 10712148
hm ... just forgot to mention you'll have to include <math.h> if not yet included ...

ZOPPO
0

Featured Post

Announcing the Most Valuable Experts of 2016

MVEs are more concerned with the satisfaction of those they help than with the considerable points they can earn. They are the types of people you feel privileged to call colleagues. Join us in honoring this amazing group of Experts.

Question has a verified solution.

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

Suggested Solutions

Title # Comments Views Activity
iSeries FTP Exit Program 8 174
windows 10 how make picture as desktop background 2 73
withoutTen challenge 14 142
Path of Workbook 3 88
Exception Handling is in the core of any application that is able to dignify its name. In this article, I'll guide you through the process of writing a DRY (Don't Repeat Yourself) Exception Handling mechanism, using Aspect Oriented Programming.
In this post we will learn different types of Android Layout and some basics of an Android App.
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

710 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