//
//  KRModel.cpp
//  KREngine
//
//  Copyright 2012 Kearwood Gilbert. All rights reserved.
//  
//  Redistribution and use in source and binary forms, with or without modification, are
//  permitted provided that the following conditions are met:
//  
//  1. Redistributions of source code must retain the above copyright notice, this list of
//  conditions and the following disclaimer.
//  
//  2. Redistributions in binary form must reproduce the above copyright notice, this list
//  of conditions and the following disclaimer in the documentation and/or other materials
//  provided with the distribution.
//  
//  THIS SOFTWARE IS PROVIDED BY KEARWOOD GILBERT ''AS IS'' AND ANY EXPRESS OR IMPLIED
//  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
//  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL KEARWOOD GILBERT OR
//  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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//  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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//  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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//  
//  The views and conclusions contained in the software and documentation are those of the
//  authors and should not be interpreted as representing official policies, either expressed
//  or implied, of Kearwood Gilbert.
//

#include "KREngine-common.h"

#include "KRModel.h"
#include "KRContext.h"
#include "KRMesh.h"
#include "KRQuaternion.h"

KRModel::KRModel(KRScene &scene, std::string instance_name, std::string model_name, std::string light_map, float lod_min_coverage, bool receives_shadow, bool faces_camera) : KRNode(scene, instance_name) {
    m_lightMap = light_map;
    m_pLightMap = NULL;
    m_model_name = model_name;
    m_min_lod_coverage = lod_min_coverage;
    m_receivesShadow = receives_shadow;
    m_faces_camera = faces_camera;
}

KRModel::~KRModel() {

}

std::string KRModel::getElementName() {
    return "model";
}

tinyxml2::XMLElement *KRModel::saveXML( tinyxml2::XMLNode *parent)
{
    tinyxml2::XMLElement *e = KRNode::saveXML(parent);
    e->SetAttribute("mesh", m_model_name.c_str());
    e->SetAttribute("light_map", m_lightMap.c_str());
    e->SetAttribute("lod_min_coverage", m_min_lod_coverage);
    e->SetAttribute("receives_shadow", m_receivesShadow ? "true" : "false");
    e->SetAttribute("faces_camera", m_faces_camera ? "true" : "false");
    return e;
}

void KRModel::loadModel() {
    if(m_models.size() == 0) {
        std::vector<KRMesh *> models = m_pContext->getModelManager()->getModel(m_model_name.c_str()); // The model manager returns the LOD levels in sorted order, with the highest detail first
        std::map<KRMesh *, std::vector<KRBone *> > bones;
        if(models.size() > 0) {
            bool all_bones_found = true;
            for(std::vector<KRMesh *>::iterator model_itr = models.begin(); model_itr != models.end(); model_itr++) {
                KRMesh *model = *model_itr;
                std::vector<KRBone *> model_bones;
                int bone_count = model->getBoneCount();
                for(int bone_index=0; bone_index < bone_count; bone_index++) {
                    KRBone *matching_bone = dynamic_cast<KRBone *>(getScene().getRootNode()->find<KRNode>(model->getBoneName(bone_index)));
                    if(matching_bone) {
                        model_bones.push_back(matching_bone);
                    } else {
                        all_bones_found = false; // Reject when there are any missing bones or multiple matches
                    }
                }
                bones[model] = model_bones;
            }
            if(all_bones_found) {
                m_models = models;
                m_bones = bones;
                getScene().notify_sceneGraphModify(this);
            }
        }
    }
}

void KRModel::render(KRCamera *pCamera, std::vector<KRLight *> &lights, const KRViewport &viewport, KRNode::RenderPass renderPass) {

    
    KRNode::render(pCamera, lights, viewport, renderPass);
    
    if(renderPass != KRNode::RENDER_PASS_DEFERRED_LIGHTS && (renderPass != KRNode::RENDER_PASS_FORWARD_TRANSPARENT || this->hasTransparency()) && renderPass != KRNode::RENDER_PASS_ADDITIVE_PARTICLES && renderPass != KRNode::RENDER_PASS_PARTICLE_OCCLUSION && renderPass != KRNode::RENDER_PASS_VOLUMETRIC_EFFECTS_ADDITIVE) {
        // Don't render meshes on second pass of the deferred lighting renderer, as only lights will be applied
    
        loadModel();
        
        if(m_models.size() > 0) {
            float lod_coverage = getBounds().coverage(viewport.getViewProjectionMatrix(), viewport.getSize()); // This also checks the view frustrum culling
            if(lod_coverage > m_min_lod_coverage) {
                
                // ---===--- Select the best LOD model based on screen coverage ---===---
                std::vector<KRMesh *>::iterator itr=m_models.begin();
                KRMesh *pModel = *itr++;
                
                while(itr != m_models.end()) {
                    KRMesh *pLODModel = *itr++;
                    if((float)pLODModel->getLODCoverage() / 100.0f > lod_coverage && pLODModel->getLODCoverage() < pModel->getLODCoverage()) {
                        pModel = pLODModel;
                    } else {
                        break;
                    }
                }
                
                if(m_pLightMap == NULL && m_lightMap.size()) {
                    m_pLightMap = getContext().getTextureManager()->getTexture(m_lightMap.c_str());
                }
                
                if(m_pLightMap && pCamera->settings.bEnableLightMap && renderPass != RENDER_PASS_SHADOWMAP && renderPass != RENDER_PASS_GENERATE_SHADOWMAPS) {
                    m_pContext->getTextureManager()->selectTexture(5, m_pLightMap);
                }
                
                KRMat4 matModel = getModelMatrix();
                if(m_faces_camera) {
                    KRVector3 model_center = KRMat4::Dot(matModel, KRVector3::Zero());
                    KRVector3 camera_pos = viewport.getCameraPosition();
                    matModel = KRQuaternion(KRVector3::Forward(), KRVector3::Normalize(camera_pos - model_center)).rotationMatrix() * matModel;
                }
                
                pModel->render(pCamera, lights, viewport, matModel, m_pLightMap, renderPass, m_bones[pModel]);
            }
        }
    }
}

bool KRModel::hasTransparency() {
    if(m_models.size() > 0) {
        return m_models[0]->hasTransparency();
    } else {
        return false;
    }
}

KRAABB KRModel::getBounds() {
    loadModel();
    if(m_models.size() > 0) {
        if(m_faces_camera) {
            KRAABB normal_bounds = KRAABB(m_models[0]->getMinPoint(), m_models[0]->getMaxPoint(), getModelMatrix());
            float max_dimension = normal_bounds.longest_radius();
            return KRAABB(normal_bounds.center()-KRVector3(max_dimension), normal_bounds.center() + KRVector3(max_dimension));
        } else {
            return KRAABB(m_models[0]->getMinPoint(), m_models[0]->getMaxPoint(), getModelMatrix());
        }
    } else {
        return KRAABB::Infinite();
    }
}