Module org.jhotdraw8.geom
Package org.jhotdraw8.geom.intersect

Class IntersectCircleLine

java.lang.Object
org.jhotdraw8.geom.intersect.IntersectCircleLine
public class IntersectCircleLine extends Object

  • Method Details

    • intersectCircleLineEx

      public static IntersectionResultEx intersectCircleLineEx(double cx, double cy, double r, double a0x, double a0y, double a1x, double a1y)

    • intersectCircleLineEx

      public static IntersectionResultEx intersectCircleLineEx(Point2D c, double r, Point2D a0, Point2D a1)
      Computes the intersection between a circle and a line.

      FIXME actually computes line intersection with parameter t of line, and not t of circle.

      Parameters:
      c - the center of the circle
      r - the radius of the circle
      a0 - point 1 of the line
      a1 - point 2 of the line
      Returns:
      computed intersection

    • intersectLineCircleEx

      public static IntersectionResultEx intersectLineCircleEx(Point2D a0, Point2D a1, Point2D c, double r)
      Computes the intersection between a line and a circle.

      The intersection will contain the parameters 't' of the line in range [0,1].

      Parameters:
      a0 - point 0 of the line
      a1 - point 1 of the line
      c - the center of the circle
      r - the radius of the circle
      Returns:
      computed intersection

    • intersectLineCircleEx

      public static IntersectionResultEx intersectLineCircleEx(Point2D a0, Point2D a1, Point2D c, double r, double epsilon)

    • intersectLineCircle

      public static IntersectionResult intersectLineCircle(Point2D a0, Point2D a1, Point2D c, double r, double epsilon)

    • intersectLineCircleEx

      public static IntersectionResultEx intersectLineCircleEx(double x0, double y0, double x1, double y1, double cx, double cy, double r)
      Computes the intersection between a line and a circle.

      The intersection will contain the parameters 't' of the line in range [0 - epsilon, 1 + epsilon].

      The intersection will have one of the following status:

      This method solves the following equation: 

       x0 + (x1 - x0) · t, y0 + (y1 - y0) · t, with t in range [0,1] : line equation
 (x - cx)² + (y - cy)² = r² : circle equation
 (x0 + (x1 - x0) · t - cx)² + (y0 + (y1 - y0) · t - cy)² - r² =0 : intersection equation
 (x0 + x1·t - x0·t - cx)² + (y0 + y1· t - y0· t - cy)² - r² =0
 -2·x0·x1·t²  + 2·x0·(cx+x1)·t - 2·x0*cx +(x0²+x1²)·t² - 2·(x0² - x1·cx)·t + x0² + cx²  ...+same for y...   - r² =0
 (x0²+-2·x0·x1+x1²)·t²  + (2·x0·(cx+x1)- 2·(x0² - x1·cx))·t  - 2·x0*cx + x0² + cx²  ...+same for y...   - r² =0
 (x1 - x0)²·t²  + 2·((x1 - x0)·(x0 - cx))·t  - 2·x0*cx + x0² + cx²  ...+same for y...   - r² =0
 (x1 - x0)²·(y1 - y0)²·t²  + 2·((x1 - x0)·(x0 - cx)+(y1 - y0)·(y0 - cy))·t - 2·(x0·cx + y0·cy) + cx² + cy² + x0² + y0²  - r² =0
 Δx²·Δy²·t²  + 2·(Δx·(x0 - cx)+Δy·(y0 - cy))·t - 2·(x0·cx + y0·cy) + cx² + cy² + x0² + y0²  - r² =0
 a·t² + b·t + c = 0 : quadratic polynomial, with t in range [0,1]
      Parameters:
      x0 - point 0 of the line
      y0 - point 0 of the line
      x1 - point 1 of the line
      y1 - point 1 of the line
      cx - the center of the circle
      cy - the center of the circle
      r - the radius of the circle
      Returns:
      computed intersection

    • intersectLineCircleEx

      public static IntersectionResultEx intersectLineCircleEx(double x0, double y0, double x1, double y1, double cx, double cy, double r, double epsilon)
      This method computes the argument of the circle function with atan2 and thus may be unnecessarily slow if you only need the argument of the line function.
      Parameters:
      x0 - point 0 of the line
      y0 - point 0 of the line
      x1 - point 1 of the line
      y1 - point 1 of the line
      cx - the center of the circle
      cy - the center of the circle
      r - the radius of the circle
      epsilon - epsilon value
      Returns:
      intersection result

    • intersectLineCircle

      public static IntersectionResult intersectLineCircle(double x0, double y0, double x1, double y1, double cx, double cy, double r)

    • intersectLineCircle

      public static IntersectionResult intersectLineCircle(double x0, double y0, double x1, double y1, double cx, double cy, double r, double epsilon)