1 files changed, 106 insertions, 0 deletions
diff --git a/primedev/core/math/vplane.h b/primedev/core/math/vplane.h
new file mode 100644
index 00000000..8b8de423
--- /dev/null
+++ b/primedev/core/math/vplane.h
@@ -0,0 +1,106 @@
+#pragma once
+
+typedef int SideType;
+
+// Used to represent sides of things like planes.
+#define SIDE_FRONT 0
+#define SIDE_BACK 1
+#define SIDE_ON 2
+
+#define VP_EPSILON 0.01f
+
+class VPlane
+{
+public:
+	VPlane();
+	VPlane(const Vector3& vNormal, float dist);
+	VPlane(const Vector3& vPoint, const QAngle& ang);
+
+	void Init(const Vector3& vNormal, float dist);
+
+	// Return the distance from the point to the plane.
+	float DistTo(const Vector3& vVec) const;
+
+	// Copy.
+	VPlane& operator=(const VPlane& thePlane);
+
+	// Returns SIDE_ON, SIDE_FRONT, or SIDE_BACK.
+	// The epsilon for SIDE_ON can be passed in.
+	SideType GetPointSide(const Vector3& vPoint, float sideEpsilon = VP_EPSILON) const;
+
+	// Returns SIDE_FRONT or SIDE_BACK.
+	SideType GetPointSideExact(const Vector3& vPoint) const;
+
+	// Get a point on the plane (normal*dist).
+	Vector3 GetPointOnPlane() const;
+
+	// Snap the specified point to the plane (along the plane's normal).
+	Vector3 SnapPointToPlane(const Vector3& vPoint) const;
+
+public:
+	Vector3 m_Normal;
+	float m_Dist;
+};
+
+//-----------------------------------------------------------------------------
+// Inlines.
+//-----------------------------------------------------------------------------
+inline VPlane::VPlane() {}
+
+inline VPlane::VPlane(const Vector3& vNormal, float dist)
+{
+	m_Normal = vNormal;
+	m_Dist = dist;
+}
+
+inline VPlane::VPlane(const Vector3& vPoint, const QAngle& ang)
+{
+	m_Normal = ang.GetNormal();
+	m_Dist = vPoint.x * m_Normal.x + vPoint.y * m_Normal.y + vPoint.z * m_Normal.z;
+}
+
+inline void VPlane::Init(const Vector3& vNormal, float dist)
+{
+	m_Normal = vNormal;
+	m_Dist = dist;
+}
+
+inline float VPlane::DistTo(const Vector3& vVec) const
+{
+	return vVec.Dot(m_Normal) - m_Dist;
+}
+
+inline VPlane& VPlane::operator=(const VPlane& thePlane)
+{
+	m_Normal = thePlane.m_Normal;
+	m_Dist = thePlane.m_Dist;
+	return *this;
+}
+
+inline Vector3 VPlane::GetPointOnPlane() const
+{
+	return m_Normal * m_Dist;
+}
+
+inline Vector3 VPlane::SnapPointToPlane(const Vector3& vPoint) const
+{
+	return vPoint - m_Normal * DistTo(vPoint);
+}
+
+inline SideType VPlane::GetPointSide(const Vector3& vPoint, float sideEpsilon) const
+{
+	float fDist;
+
+	fDist = DistTo(vPoint);
+	if (fDist >= sideEpsilon)
+		return SIDE_FRONT;
+	else if (fDist <= -sideEpsilon)
+		return SIDE_BACK;
+	else
+		return SIDE_ON;
+}
+
+inline SideType VPlane::GetPointSideExact(const Vector3& vPoint) const
+{
+	return DistTo(vPoint) > 0.0f ? SIDE_FRONT : SIDE_BACK;
+}