MeshManager.cpp

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/*
--------------------------------------------------------------------------------
This source file is part of SkyX.
Visit http://www.paradise-studios.net/products/skyx/
 
Copyright (C) 2009-2012 Xavier Vergu�n Gonz�lez <xavyiy@gmail.com>
 
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.
 
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 
You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.
--------------------------------------------------------------------------------
*/
 
#include "MeshManager.h"
 
#include "SkyX.h"
 
namespace SkyX
{
    MeshManager::MeshManager(SkyX *s)
        : mSkyX(s)
        , mCreated(false)
        , mMesh(static_cast<Ogre::Mesh*>(0))
        , mSubMesh(0)
        , mEntity(0)
        , mVertexBuffer()
        , mVertices(0)
        , mIndexBuffer()
        , mSceneNode(0)
        , mSteps(70)
        , mCircles(95)
        , mUnderHorizonCircles(12)
        , mUnderHorizonFading(true)
        , mUnderHorizonFadingExponent(0.75)
        , mUnderHorizonFadingMultiplier(2)
        , mRadiusMultiplier(0.95f)
        , mMaterialName("_NULL_")
    {
    }
 
    MeshManager::~MeshManager()
    {
        remove();
    }
 
    void MeshManager::remove()
    {
        if (!mCreated)
        {
            return;
        }
 
        mSceneNode->detachAllObjects();
        mSceneNode->getParentSceneNode()->removeAndDestroyChild(mSceneNode);
        mSceneNode = 0;
 
        Ogre::MeshManager::getSingleton().remove("SkyXMesh");
        mSkyX->getSceneManager()->destroyEntity(mEntity);
 
        mMesh.setNull();
        mSubMesh = 0;
        mEntity = 0;
        mVertexBuffer.setNull();
        mIndexBuffer.setNull();
        mMaterialName = "_NULL_";
 
        delete [] mVertices;
 
        mCreated = false;
    }
 
    void MeshManager::create()
    {
        if (mCreated)
        {
            return;
        }
 
        // Create mesh and submesh
        mMesh = Ogre::MeshManager::getSingleton().createManual("SkyXMesh",
            Ogre::ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);
        mSubMesh = mMesh->createSubMesh();
        mSubMesh->useSharedVertices = false;
 
        // Create mesh geometry
        _createGeometry();
 
        // Build edge list
        mMesh->buildEdgeList();
 
        // End mesh creation
        mMesh->load();
        mMesh->touch();
 
        mEntity = mSkyX->getSceneManager()->createEntity("SkyXMeshEnt", "SkyXMesh");
        mEntity->setMaterialName(mMaterialName);
        mEntity->setCastShadows(false);
        mEntity->setRenderQueueGroup(mSkyX->getRenderQueueGroups().skydome);
 
        mSceneNode = mSkyX->getSceneManager()->getRootSceneNode()->createChildSceneNode();
        mSceneNode->showBoundingBox(false);
        mSceneNode->attachObject(mEntity);
 
        mCreated = true;
    }
 
    void MeshManager::updateGeometry(Ogre::Camera* cam)
    {
        if (!mCreated)
        {
            return;
        }
 
        float Radius = getSkydomeRadius(cam);
 
        mVertices[0].x = 0; mVertices[0].z = 0; mVertices[0].y = Radius;
        mVertices[0].nx = 0; mVertices[0].nz = 0; mVertices[0].ny = 1; 
        mVertices[0].u = 4; mVertices[0].v = 4;
        mVertices[0].o = 1;
 
        float AngleStep = (Ogre::Math::PI/2) / (mCircles-mUnderHorizonCircles);
 
        float r, uvr, c, s, h;
        float currentPhiAngle, currentTethaAngle;
        int x, y;
 
        // Above-horizon
        for(y=0;y<mCircles-mUnderHorizonCircles;y++) 
        {
            currentTethaAngle = Ogre::Math::PI/2 - AngleStep*(y+1);
 
            r = Ogre::Math::Cos(currentTethaAngle);
            h = Ogre::Math::Sin(currentTethaAngle);
 
            uvr = static_cast<float>(y+1)/(mCircles-mUnderHorizonCircles);
 
            for(x=0;x<mSteps;x++) 
            {
                currentPhiAngle = Ogre::Math::TWO_PI * x / mSteps;
 
                c = Ogre::Math::Cos(currentPhiAngle) * r;
                s = Ogre::Math::Sin(currentPhiAngle) * r;
 
                mVertices[1+y*mSteps + x].x = c * Radius;
                mVertices[1+y*mSteps + x].z = s * Radius;
                mVertices[1+y*mSteps + x].y = h * Radius;
 
                mVertices[1+y*mSteps + x].nx = c;
                mVertices[1+y*mSteps + x].nz = s;
                mVertices[1+y*mSteps + x].ny = h;
 
                mVertices[1+y*mSteps + x].u = (1 + c*uvr/r)*4;
                mVertices[1+y*mSteps + x].v = (1 + s*uvr/r)*4;
 
                mVertices[1+y*mSteps + x].o = 1;
            }
        }
 
        float op; // Opacity
 
        // Under-horizon
        for(y=mCircles-mUnderHorizonCircles;y<mCircles;y++) 
        {
            currentTethaAngle = Ogre::Math::PI/2 - AngleStep*(y+1);
 
            r = Ogre::Math::Cos(currentTethaAngle);
            h = Ogre::Math::Sin(currentTethaAngle);
 
            uvr = static_cast<float>(y+1)/(mCircles-mUnderHorizonCircles);
 
            op = Ogre::Math::Clamp<Ogre::Real>(Ogre::Math::Pow(static_cast<Ogre::Real>(mCircles-y-1) / mUnderHorizonCircles, mUnderHorizonFadingExponent)*mUnderHorizonFadingMultiplier, 0, 1);
 
            for(x=0;x<mSteps;x++) 
            {
                currentPhiAngle = Ogre::Math::TWO_PI * x / mSteps;
 
                c = Ogre::Math::Cos(currentPhiAngle) * r;
                s = Ogre::Math::Sin(currentPhiAngle) * r;
 
                mVertices[1+y*mSteps + x].x = c * Radius;
                mVertices[1+y*mSteps + x].z = s * Radius;
                mVertices[1+y*mSteps + x].y = h * Radius;
 
                mVertices[1+y*mSteps + x].nx = c;
                mVertices[1+y*mSteps + x].nz = s;
                mVertices[1+y*mSteps + x].ny = h;
 
                mVertices[1+y*mSteps + x].u = (1 + c*uvr/r)*4;
                mVertices[1+y*mSteps + x].v = (1 + s*uvr/r)*4;
 
                mVertices[1+y*mSteps + x].o = op;
            }
        }
 
        // Update data
        mVertexBuffer->
                writeData(0,
                          mVertexBuffer->getSizeInBytes(),
                          mVertices,
                          true);
    
        // Update bounds
        Ogre::AxisAlignedBox meshBounds =
            Ogre::AxisAlignedBox(-Radius, 0,     -Radius,
                                  Radius, Radius, Radius);
 
        mMesh->_setBounds(meshBounds);
        mSceneNode->_updateBounds();
    }
 
    void MeshManager::_createGeometry()
    {
        int numVertices = mSteps * mCircles + 1;
        int numEle = 6 * mSteps * (mCircles-1) + 3 * mSteps;
 
        // Vertex buffers
        mSubMesh->vertexData = new Ogre::VertexData();
        mSubMesh->vertexData->vertexStart = 0;
        mSubMesh->vertexData->vertexCount = numVertices;
 
        Ogre::VertexDeclaration* vdecl = mSubMesh->vertexData->vertexDeclaration;
        Ogre::VertexBufferBinding* vbind = mSubMesh->vertexData->vertexBufferBinding;
 
        size_t offset = 0;
        vdecl->addElement(0, offset, Ogre::VET_FLOAT3, Ogre::VES_POSITION);
        offset += Ogre::VertexElement::getTypeSize(Ogre::VET_FLOAT3);
        vdecl->addElement(0, offset, Ogre::VET_FLOAT3, Ogre::VES_TEXTURE_COORDINATES, 0);
        offset += Ogre::VertexElement::getTypeSize(Ogre::VET_FLOAT3);
        vdecl->addElement(0, offset, Ogre::VET_FLOAT2, Ogre::VES_TEXTURE_COORDINATES, 1);
        offset += Ogre::VertexElement::getTypeSize(Ogre::VET_FLOAT2);
        vdecl->addElement(0, offset, Ogre::VET_FLOAT1, Ogre::VES_TEXTURE_COORDINATES, 2);
 
        mVertexBuffer = Ogre::HardwareBufferManager::getSingleton().
            createVertexBuffer(sizeof(VERTEX),
                               numVertices,
                               Ogre::HardwareBuffer::HBU_DYNAMIC_WRITE_ONLY);
 
        vbind->setBinding(0, mVertexBuffer);
 
        unsigned short *indexbuffer = new unsigned short[numEle];
 
        for (int k = 0; k < mSteps; k++)
        {
            indexbuffer[k*3] = 0;
            indexbuffer[k*3+1] = k+1;
 
            if (k != mSteps-1)
            {
                indexbuffer[k*3+2] = k+2;
            }
            else
            {
                indexbuffer[k*3+2] = 1;
            }
        }
 
        unsigned short *twoface;
 
        for(int y=0; y<mCircles-1; y++) 
        {
            for(int x=0; x<mSteps; x++) 
            {
                twoface = indexbuffer + (y*mSteps+x)*6 + 3 * mSteps;
 
                int p0 = 1+y * mSteps + x ;
                int p1 = 1+y * mSteps + x + 1 ;
                int p2 = 1+(y+1)* mSteps + x ;
                int p3 = 1+(y+1)* mSteps + x + 1 ;
 
                if (x == mSteps-1)
                {
                    p1 -= x+1;
                    p3 -= x+1;
                }
 
                // First triangle
                twoface[2]=p0;
                twoface[1]=p1;
                twoface[0]=p2;
 
                // Second triangle
                twoface[5]=p1;
                twoface[4]=p3;
                twoface[3]=p2;
            }
        }
 
        // Prepare buffer for indices
        mIndexBuffer =
            Ogre::HardwareBufferManager::getSingleton().createIndexBuffer(
            Ogre::HardwareIndexBuffer::IT_16BIT,
            numEle,
            Ogre::HardwareBuffer::HBU_STATIC, true);
 
        mIndexBuffer->
            writeData(0,
                      mIndexBuffer->getSizeInBytes(),
                      indexbuffer,
                      true);
 
        delete []indexbuffer;
 
        // Set index buffer for this submesh
        mSubMesh->indexData->indexBuffer = mIndexBuffer;
        mSubMesh->indexData->indexStart = 0;
        mSubMesh->indexData->indexCount = numEle;
 
        // Create our internal buffer for manipulations
        mVertices = new VERTEX[1+mSteps * mCircles];
    }
 
    void MeshManager::setGeometryParameters(const int &Steps, const int &Circles)
    {
        mSteps = Steps;
        mCircles = Circles;
 
        if (mCreated)
        {
            remove();
            create();
        }
    }
 
    void MeshManager::setUnderHorizonParams(const int& UnderHorizonCircles, const bool& UnderHorizonFading, const Ogre::Real& UnderHorizonFadingExponent, const Ogre::Real& UnderHorizonFadingMultiplier)
    {
        bool needToRecreate = (mUnderHorizonCircles != UnderHorizonCircles);
 
        mUnderHorizonCircles = UnderHorizonCircles;
        mUnderHorizonFading = UnderHorizonFading;
        mUnderHorizonFadingExponent = UnderHorizonFadingExponent;
        mUnderHorizonFadingMultiplier = UnderHorizonFadingMultiplier;
 
        if (needToRecreate)
        {
            remove();
            create();
        }
    }
 
    void MeshManager::setMaterialName(const Ogre::String& MaterialName)
    {
        mMaterialName = MaterialName;
 
        if (mCreated)
        {
            mEntity->setMaterialName(MaterialName);
        }
    }
 
    const float MeshManager::getSkydomeRadius(Ogre::Camera* c) const
    {
        float cameraFarClipDistance = c->getFarClipDistance();
 
        if (!cameraFarClipDistance)
        {
            cameraFarClipDistance = mSkyX->getInfiniteCameraFarClipDistance();
        }
 
        return cameraFarClipDistance*mRadiusMultiplier;
    }
}