diff Resources/Computations/IntersectSegmentAndVerticalLine.py @ 132:35c2b85836ce wasm

fix rtstruct projections
author Sebastien Jodogne <s.jodogne@gmail.com>
date Fri, 17 Nov 2017 18:01:31 +0100
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Resources/Computations/IntersectSegmentAndVerticalLine.py	Fri Nov 17 18:01:31 2017 +0100
@@ -0,0 +1,20 @@
+#!/usr/bin/env python
+
+from sympy import *
+
+# Intersection between the 2D line segment (prevX,prevY)-(curX,curY) and the
+# vertical line "x = x0" using homogeneous coordinates
+
+prevX, prevY, curX, curY, x0 = symbols('prevX prevY curX curY x0')
+
+p1 = Matrix([prevX, prevY, 1])
+p2 = Matrix([curX, curY, 1])
+l1 = p1.cross(p2)
+
+h1 = Matrix([x0, 0, 1])
+h2 = Matrix([x0, 1, 1])
+l2 = h1.cross(h2)
+
+a = l1.cross(l2)
+
+pprint(a / a[2])