Implemented Hierarchical LOD system and associated FBX Importer functionality.

KREngine/kraken/KRLODGroup.cpp

@@ -0,0 +1,91 @@
+//
+//  KRLODGroup.cpp
+//  KREngine
+//
+//  Created by Kearwood Gilbert on 2012-12-06.
+//  Copyright (c) 2012 Kearwood Software. All rights reserved.
+//
+
+#include "KRLODGroup.h"
+#include "KRContext.h"
+
+KRLODGroup::KRLODGroup(KRScene &scene, std::string name) : KRNode(scene, name)
+{
+    m_min_distance = 0.0f;
+    m_max_distance = 0.0f;
+}
+
+KRLODGroup::~KRLODGroup()
+{
+}
+
+std::string KRLODGroup::getElementName() {
+    return "lod_group";
+}
+
+tinyxml2::XMLElement *KRLODGroup::saveXML( tinyxml2::XMLNode *parent)
+{
+    tinyxml2::XMLElement *e = KRNode::saveXML(parent);
+    e->SetAttribute("min_distance", m_min_distance);
+    e->SetAttribute("max_distance", m_max_distance);
+    return e;
+}
+
+void KRLODGroup::loadXML(tinyxml2::XMLElement *e)
+{
+    KRNode::loadXML(e);
+
+    m_min_distance = 0.0f;
+    if(e->QueryFloatAttribute("min_distance", &m_min_distance) != tinyxml2::XML_SUCCESS) {
+        m_min_distance = 0.0f;
+    }
+    
+    m_max_distance = 0.0f;
+    if(e->QueryFloatAttribute("max_distance", &m_max_distance) != tinyxml2::XML_SUCCESS) {
+        m_max_distance = 0.0f;
+    }
+}
+
+bool KRLODGroup::getLODVisibility(const KRViewport &viewport)
+{
+    // Compare square distances as sqrt is expensive
+    float sqr_distance = (viewport.getCameraPosition() - getWorldTranslation()).sqrMagnitude();
+    return ((sqr_distance >= m_min_distance * m_min_distance || m_min_distance == 0) && (sqr_distance < m_max_distance * m_max_distance || m_max_distance == 0));
+}
+
+void KRLODGroup::updateLODVisibility(const KRViewport &viewport)
+{
+    bool new_visibility = getLODVisibility(viewport);
+    if(!new_visibility) {
+        hideLOD();
+    } else {
+        if(!m_lod_visible) {
+            getScene().notify_sceneGraphCreate(this);
+            m_lod_visible = true;
+        }
+        for(std::vector<KRNode *>::iterator itr=m_childNodes.begin(); itr < m_childNodes.end(); ++itr) {
+            (*itr)->updateLODVisibility(viewport);
+        }
+    }
+}
+
+float KRLODGroup::getMinDistance()
+{
+    return m_min_distance;
+}
+
+float KRLODGroup::getMaxDistance()
+{
+    return m_max_distance;
+}
+
+void KRLODGroup::setMinDistance(float min_distance)
+{
+    m_min_distance = min_distance;
+}
+
+void KRLODGroup::setMaxDistance(float max_distance)
+{
+    m_max_distance = max_distance;
+}
+