Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

Draw ARC

Posted on 2004-03-29
4
Medium Priority
?
1,094 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
  • 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 750 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

Hire Technology Freelancers with Gigs

Work with freelancers specializing in everything from database administration to programming, who have proven themselves as experts in their field. Hire the best, collaborate easily, pay securely, and get projects done right.

Question has a verified solution.

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

Introduction: Displaying information on the statusbar.   Continuing from the third article about sudoku.   Open the project in visual studio. Status bar – let’s display the timestamp there.  We need to get the timestamp from the document s…
Introduction: Finishing the grid – keyboard support for arrow keys to manoeuvre, entering the numbers.  The PreTranslateMessage function is to be used to intercept and respond to keyboard events. Continuing from the fourth article about sudoku. …
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.
Are you ready to place your question in front of subject-matter experts for more timely responses? With the release of Priority Question, Premium Members, Team Accounts and Qualified Experts can now identify the emergent level of their issue, signal…
Suggested Courses
Course of the Month10 days, 22 hours left to enroll

885 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