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include/framework/geometry/geometric_tools.h

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+/* -----------------------------------------------------------------------------
+	GSFramework
+	Copyright 2001-2013 Emmanuel Julien. All Rights Reserved.
+----------------------------------------------------------------------------- */
+
+
+#ifndef	__NGEOMETRICTOOLS__
+#define	__NGEOMETRICTOOLS__
+
+
+		#include "math/vector.h"
+
+
+namespace GS {
+	namespace Geometric {
+
+/// Compute 2d triangle area.
+float		TriArea2D(float x0, float y0, float x1, float y1, float x2, float y2);
+
+/*!
+	@short	Test intersection between a ray and a plane.
+
+	@param		a	Origin of the ray.
+	@param		v	Direction of the ray.
+	@param		n	Normal of the plane.
+	@param		p	A point on the plane.
+
+	@param		t	Output, the parametric 't' value of the point of
+					intersection.
+
+	@return		False if the ray is embedded in or coplanar to the plane.
+				True otherwise.
+*/
+bool		LineIntersectPlane(const Vector4 &a, const Vector4 &v, const Vector4 &n, const Vector4 &p, float &t);
+
+/*!
+	@short	Compute barycentric coordinates.
+*/
+void		Barycentric(const Vector4 &a, const Vector4 &b, const Vector4 &c, const Vector4 &p, float &u, float &v, float &w);
+
+/*!
+	@short	Test intersection between a ray and a plane.
+
+	@param		a	Origin of the ray.
+	@param		v	Normalized direction of the ray.
+	@param		c	Center of the sphere.
+	@param		r	Radius of the sphere.
+
+	@param		t	Output, the parametric 't' value of the points of
+					intersection. t[0] is the closest point of
+					intersection to the origin of the ray.
+
+	@return		False if no intersection.
+*/
+bool		LineIntersectSphere(const Vector4 &a, const Vector4 &v, const Vector4 &c, float r, float t[2]);
+
+/*!
+	@short	Determine the closest points between two lines.
+
+	@param		a	First point on first line.
+	@param		b	Second point on first line.
+	@param		u	First point on second line.
+	@param		v	Second point on second line.
+
+	@param		t	Output, the parametric 't' values of the closest
+					points on each line. t[0] belongs to (a;b), t[1]
+					belongs to (u;v).
+
+	@return		False if both lines are parallel.
+*/
+bool		LineClosestPointToLine(const Vector4 &a, const Vector4 &b, const Vector4 &u, const Vector4 &v, float t[2]);
+
+
+/*!
+	@short	Determine the closest point to a line from a position in space.
+
+	@param		a	First point on line.
+	@param		b	Second point on line.
+	@param		u	Location.
+	@param		i	Output the closest point on line to u.
+
+	@return		t	Parametric position of i on the [a;b] segment.
+					If t < 0 or t > 1 then i lies outside the [a;b] segment.
+*/
+float		LineClosestPoint(const Vector4 &a, const Vector4 &b, const Vector4 &u, Vector4 *p = 0);
+
+/*!
+	@short	Determine the closest point to a segment from a position in space.
+
+	@param		a	First point on segment.
+	@param		b	Second point on segment.
+	@param		u	Location.
+	@param		i	Output the closest point on segment to u.
+
+	@return		t	Parametric position of i on the [a;b] segment.
+*/
+float		SegmentClosestPoint(const Vector4 &a, const Vector4 &b, const Vector4 &u, Vector4 *p = 0);
+
+	} // Geometric
+} // GS
+
+
+#endif	// __NGEOMETRICTOOLS__