X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Fyoink;a=blobdiff_plain;f=src%2FMoof%2FPlane.hh;h=06e4abdce63f59398f961a531942d7b63ec667ea;hp=797edc05c39fe13283c4a52088502fcb6e2f132c;hb=7e898e8ec0ff716e2fc722b883a626a6c346f107;hpb=29e3d45f7bbbf31eadf793c41ff2b3d9c47b7539

diff --git a/src/Moof/Plane.hh b/src/Moof/Plane.hh
index 797edc0..06e4abd 100644
--- a/src/Moof/Plane.hh
+++ b/src/Moof/Plane.hh
@@ -35,11 +35,65 @@
 namespace Mf {
 
 
-class Plane
+class Aabb;
+class Sphere;
+
+
+/*
+ * A plane in 3-space defined by the equation Ax + By + Cz = D, where [A, B, C]
+ * is normal to the plane.
+ */
+
+struct Plane
 {
-	Vector4 components;
+	Vector3	normal;
+	Scalar	d;
+
+	typedef enum
+	{
+		NEGATIVE	= -1,
+		INTERSECT	=  0,
+		POSITIVE	=  1
+	} Halfspace;
+
+	Plane() {}
+	Plane(const Vector3& vector, Scalar scalar) :
+		normal(vector),
+		d(scalar) {}
+	Plane(Scalar a, Scalar b, Scalar c, Scalar scalar) :
+		normal(a, b, c),
+		d(scalar) {}
+
+
+	/* Causes the normal of the plane to become normalized.  The scalar may also
+	 * be changed to keep the equation true. */
+	void normalize()
+	{
+		Scalar mag = normal.length();
+
+		normal /= mag;
+		d /= mag;
+	}
+
+	/**
+	 * Determine the shortest distance between a point and the plane. */
+
+	Scalar getDistanceToPoint(const Vector3& point) const
+	{
+		return cml::dot(point, normal) + d;
+	}
+
+	Halfspace intersects(const Vector3& point) const
+	{
+		Scalar distance = getDistanceToPoint(point);
+
+		if (isEqual(distance, 0.0)) return INTERSECT;
+		else if (distance < 0.0)    return NEGATIVE;
+		else                        return POSITIVE;
+	}
 
-public:
+	Halfspace intersects(const Aabb& aabb) const;
+	Halfspace intersects(const Sphere& sphere) const;
 };