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+include <math.h>
+
+# ME_ELLGEOM -- Given the semi-major axis, ratio of semi-minor to semi-major
+# axes, and position angle, compute the parameters of the equation of the
+# ellipse, where the ellipse is defined as A * X ** 2 + B * x * y +
+# C * Y ** 2 - F = 0.
+
+procedure me_ellgeom (a, ratio, theta, aa, bb, cc, ff)
+
+real    a                       #I the semi-major axis
+real    ratio                   #I the ratio of semi-minor to semi-major axes
+real    theta                   #I the position angle of the major axis
+real    aa                      #O the coefficient of x ** 2
+real    bb                      #O the coefficient of x * y
+real    cc                      #O the coefficient of y ** 2
+real    ff                      #O the constant term
+
+real    cost, sint, costsq, sintsq
+real    asq, bsq
+
+begin
+        # Get the angles.
+        cost = cos (DEGTORAD(theta))
+        sint = sin (DEGTORAD(theta))
+        costsq = cost ** 2
+        sintsq = sint ** 2
+
+        # Compute the parameters of the outer ellipse.
+        asq = a ** 2
+        bsq = (ratio * a) ** 2
+        aa = bsq * costsq + asq * sintsq
+        bb = 2.0 * (bsq - asq) * cost * sint
+        cc = asq * costsq + bsq * sintsq
+        ff = asq * bsq
+end
+
+
+# ME_RECTGEOM -- Construct a polygon representation of a rotated rectangle
+# givev the half-width of the long axis, the ratio of the half-width of the
+# short axis to the long axis, and the rotation angle.
+
+procedure me_rectgeom (hwidth, ratio, theta, xout, yout)
+
+real    hwidth          #I the half-width of the long axis of the rectangle
+real    ratio           #I the ratio of short to long axes of the rectangle
+real    theta           #I the rotation angle
+real    xout[ARB]       #O the x coordinates of the output vertices
+real    yout[ARB]       #O the y coordinates of the output vertices
+
+real    cost, sint, x, y
+
+begin
+        cost = cos (DEGTORAD(theta))
+        sint = sin (DEGTORAD(theta))
+        x = hwidth
+        y = ratio * x
+        xout[1] = x * cost - y * sint
+        yout[1] = x * sint + y * cost
+        x = -x
+        y = y
+        xout[2] = x * cost - y * sint
+        yout[2] = x * sint + y * cost
+        x = x
+        y = -y
+        xout[3] = x * cost - y * sint
+        yout[3] = x * sint + y * cost
+        x = -x 
+        y = y
+        xout[4] = x * cost - y * sint
+        yout[4] = x * sint + y * cost
+end
+