From 593fec134d041a3c8929ca1d8b57f17f6b3bad26 Mon Sep 17 00:00:00 2001
From: Lynix <lynix680@gmail.com>
Date: Wed, 13 Mar 2013 17:10:58 +0100
Subject: [PATCH] Added lights bounding box

Former-commit-id: 9ab45181c8b0586e9d4040d48d756683e88dd8fe
---
 include/Nazara/3D/Light.hpp |   7 ++-
 src/Nazara/3D/Light.cpp     | 111 ++++++++++++++++++++++++++++++++++--
 2 files changed, 110 insertions(+), 8 deletions(-)

diff --git a/include/Nazara/3D/Light.hpp b/include/Nazara/3D/Light.hpp
index 3342c02a5..278829a90 100644
--- a/include/Nazara/3D/Light.hpp
+++ b/include/Nazara/3D/Light.hpp
@@ -47,17 +47,18 @@ class NAZARA_API NzLight : public NzSceneNode
 		NzLight& operator=(const NzLight& light);
 
 	private:
+		void Invalidate();
 		void Register();
 		void Unregister();
-		void UpdateFrustum();
+		void UpdateBoundingBox() const;
 		bool VisibilityTest(const NzFrustumf& frustum);
 
 		nzLightType m_type;
-		NzBoundingBoxf m_boundingBox;
+		mutable NzBoundingBoxf m_boundingBox;
 		NzColor m_ambientColor;
 		NzColor m_diffuseColor;
 		NzColor m_specularColor;
-		bool m_boundingBoxUpdated;
+		mutable bool m_boundingBoxUpdated;
 		float m_attenuation;
 		float m_innerAngle;
 		float m_outerAngle;
diff --git a/src/Nazara/3D/Light.cpp b/src/Nazara/3D/Light.cpp
index 5d15cfc05..c00130416 100644
--- a/src/Nazara/3D/Light.cpp
+++ b/src/Nazara/3D/Light.cpp
@@ -5,6 +5,7 @@
 #include <Nazara/3D/Light.hpp>
 #include <Nazara/Core/Error.hpp>
 #include <Nazara/Math/Basic.hpp>
+#include <Nazara/Math/Sphere.hpp>
 #include <Nazara/Renderer/Renderer.hpp>
 #include <Nazara/Renderer/Shader.hpp>
 #include <cstring>
@@ -130,8 +131,10 @@ void NzLight::Apply(const NzShader* shader, unsigned int lightUnit) const
 
 const NzBoundingBoxf& NzLight::GetBoundingBox() const
 {
-	static NzBoundingBoxf dummy(nzExtend_Null);
-	return dummy;
+	if (!m_boundingBoxUpdated)
+		UpdateBoundingBox();
+
+	return m_boundingBox;
 }
 
 NzColor NzLight::GetAmbientColor() const
@@ -202,11 +205,17 @@ void NzLight::SetInnerAngle(float innerAngle)
 void NzLight::SetOuterAngle(float outerAngle)
 {
 	m_outerAngle = outerAngle;
+
+	m_boundingBox.MakeNull();
+	m_boundingBoxUpdated = false;
 }
 
 void NzLight::SetRadius(float radius)
 {
 	m_radius = radius;
+
+	m_boundingBox.MakeNull();
+	m_boundingBoxUpdated = false;
 }
 
 void NzLight::SetSpecularColor(const NzColor& specular)
@@ -221,6 +230,13 @@ NzLight& NzLight::operator=(const NzLight& light)
 	return *this;
 }
 
+void NzLight::Invalidate()
+{
+	NzSceneNode::Invalidate();
+
+	m_boundingBoxUpdated = false;
+}
+
 void NzLight::Register()
 {
 }
@@ -229,10 +245,95 @@ void NzLight::Unregister()
 {
 }
 
+void NzLight::UpdateBoundingBox() const
+{
+	if (m_boundingBox.IsNull())
+	{
+		switch (m_type)
+		{
+			case nzLightType_Directional:
+				m_boundingBox.MakeInfinite();
+				m_boundingBoxUpdated = true;
+				return; // Rien d'autre à faire
+
+			case nzLightType_Point:
+			{
+				NzVector3f radius(m_radius);
+				m_boundingBox.Set(-radius, radius);
+				break;
+			}
+
+			case nzLightType_Spot:
+			{
+				// On forme un cube sur l'origine
+				NzCubef cube(NzVector3f::Zero());
+
+				// On calcule le reste des points
+				float height = m_radius;
+				NzVector3f base(NzVector3f::Forward()*height);
+
+				// Il nous faut maintenant le rayon du cercle projeté à cette distance
+				// Tangente = Opposé/Adjaçent <=> Opposé = Adjaçent*Tangente
+				float radius = height*std::tan(NzDegreeToRadian(m_outerAngle));
+				NzVector3f lExtend = NzVector3f::Left()*radius;
+				NzVector3f uExtend = NzVector3f::Up()*radius;
+
+				// Et on ajoute ensuite les quatres extrêmités de la pyramide
+				cube.ExtendTo(base + lExtend + uExtend);
+				cube.ExtendTo(base + lExtend - uExtend);
+				cube.ExtendTo(base - lExtend + uExtend);
+				cube.ExtendTo(base - lExtend - uExtend);
+
+				m_boundingBox.Set(cube);
+				break;
+			}
+		}
+	}
+
+	switch (m_type)
+	{
+		case nzLightType_Directional:
+			break;
+
+		case nzLightType_Point:
+			if (!m_derivedUpdated)
+				UpdateDerived();
+
+			m_boundingBox.Update(NzMatrix4f::Translate(m_derivedPosition)); // Notre BoundingBox ne changera que selon la position
+			break;
+
+		case nzLightType_Spot:
+			if (!m_transformMatrixUpdated)
+				UpdateTransformMatrix();
+
+			m_boundingBox.Update(m_transformMatrix);
+			break;
+	}
+
+	m_boundingBoxUpdated = true;
+}
+
 bool NzLight::VisibilityTest(const NzFrustumf& frustum)
 {
-	NazaraUnused(frustum);
+	switch (m_type)
+	{
+		case nzLightType_Directional:
+			return true; // Toujours visible
 
-	///FIXME: Pour l'instant toujours visible
-	return true; // Toujours visible
+		case nzLightType_Point:
+			if (!m_derivedUpdated)
+				UpdateDerived();
+
+			// Un test sphérique est bien plus rapide et précis que celui de la bounding box
+			return frustum.Contains(NzSpheref(m_derivedPosition, m_radius));
+
+		case nzLightType_Spot:
+			if (!m_boundingBoxUpdated)
+				UpdateBoundingBox();
+
+			return frustum.Contains(m_boundingBox);
+	}
+
+	NazaraError("Invalid light type (0x" + NzString::Number(m_type, 16) + ')');
+	return false;
 }