Mesh.cpp

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/*
--------------------------------------------------------------------------------
This source file is part of Hydrax.
Visit ---
 
Copyright (C) 2008 Xavier Vergu�n Gonz�lez <xavierverguin@hotmail.com>
                                           <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 "Mesh.h"
 
#include "Hydrax.h"
#include <OgreMatrix4.h>
 
namespace Hydrax
{
    Mesh::Mesh(Hydrax *h)
            : mHydrax(h)
            , mCreated(false)
            , mMesh()
            , mSubMesh(0)
            , mEntity(0)
            , mNumFaces(0)
            , mNumVertices(0)
            , mVertexBuffer()
            , mIndexBuffer()
            , mSceneNode(0)
            , mMaterialName("_NULL_")
    {
    }
 
    Mesh::~Mesh()
    {
        remove();
    }
 
    void Mesh::remove()
    {
        if (!mCreated)
        {
            return;
        }
 
        mSceneNode->detachAllObjects();
        mSceneNode->getParentSceneNode()->removeAndDestroyChild(mSceneNode);
        mSceneNode = 0;
 
        Ogre::MeshManager::getSingleton().remove("HydraxMesh");
        mHydrax->getSceneManager()->destroyEntity(mEntity);
 
        mMesh.setNull();
        mSubMesh = 0;
        mEntity = 0;
        mNumFaces = 0;
        mNumVertices = 0;
        mVertexBuffer.setNull();
        mIndexBuffer.setNull();
        mMaterialName = "_NULL_";
 
        mCreated = false;
    }
 
    void Mesh::setOptions(const Options& Options)
    {
        if (mCreated)
        {
            Ogre::AxisAlignedBox meshBounds;
 
            if (Options.MeshSize.Width == 0 && Options.MeshSize.Height == 0)
            {
                meshBounds = Ogre::AxisAlignedBox(-1000000, -Options.MeshStrength/2,-1000000,
                                                   1000000,  Options.MeshStrength/2, 1000000);
            }
            else
            {
                meshBounds = Ogre::AxisAlignedBox(0,                     -Options.MeshStrength/2, 0,
                                                  Options.MeshSize.Width, Options.MeshStrength/2, Options.MeshSize.Height);
            }
 
            mMesh->_setBounds(meshBounds);
            mSceneNode->_updateBounds();
 
            if (mOptions.MeshSize.Width != Options.MeshSize.Width || mOptions.MeshSize.Height != Options.MeshSize.Height)
            {
                mSceneNode->setPosition(mHydrax->getPosition().x-Options.MeshSize.Width/2,mHydrax->getPosition().y,mHydrax->getPosition().z-Options.MeshSize.Height/2);
            }
        }
 
        mOptions = Options;
    }
 
    void Mesh::setMaterialName(const Ogre::String &MaterialName)
    {
        mMaterialName = MaterialName;
 
        if (mEntity)
        {
            mEntity->setMaterialName(mMaterialName);
        }
    }
 
    void Mesh::create()
    {
        if (mCreated)
        {
            return;
        }
 
        // Create mesh and submesh
        mMesh = Ogre::MeshManager::getSingleton().createManual("HydraxMesh",
                Ogre::ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);
        mSubMesh = mMesh->createSubMesh();
        mSubMesh->useSharedVertices = false;
 
        if (mHydrax->getModule())
        {
            if (!mHydrax->getModule()->_createGeometry(this))
            {
                _createGeometry();
            }
        }
 
        // End mesh creation
        Ogre::AxisAlignedBox meshBounds;
 
        if (mOptions.MeshSize.Width == 0 && mOptions.MeshSize.Height == 0)
        {
            meshBounds = Ogre::AxisAlignedBox(-1000000, -mOptions.MeshStrength/2,-1000000,
                                               1000000,  mOptions.MeshStrength/2, 1000000);
        }
        else
        {
            meshBounds = Ogre::AxisAlignedBox(0,                      -mOptions.MeshStrength/2, 0,
                                              mOptions.MeshSize.Width, mOptions.MeshStrength/2, mOptions.MeshSize.Height);
        }
 
        mMesh->_setBounds(meshBounds);
        mMesh->load();
        mMesh->touch();
 
        mEntity = mHydrax->getSceneManager()->createEntity("HydraxMeshEnt", "HydraxMesh");
        mEntity->setMaterialName(mMaterialName);
        mEntity->setCastShadows(false);
        mEntity->setRenderQueueGroup(Ogre::RENDER_QUEUE_1);
 
        mSceneNode = mHydrax->getSceneManager()->getRootSceneNode()->createChildSceneNode();
        mSceneNode->showBoundingBox(false);
        mSceneNode->attachObject(mEntity);
        mSceneNode->setPosition(mHydrax->getPosition().x-mOptions.MeshSize.Width/2,mHydrax->getPosition().y,mHydrax->getPosition().z-mOptions.MeshSize.Height/2);
 
        mCreated = true;
    }
 
    void Mesh::_createGeometry()
    {
        int& Complexity = mOptions.MeshComplexity;
 
        int numVertices = Complexity*Complexity;
        int numEle = 6 * (Complexity-1)*(Complexity-1);
 
        // 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;
 
        switch (mOptions.MeshVertexType)
        {
            case VT_POS_NORM_UV:
            {
                vdecl->addElement(0, 0, Ogre::VET_FLOAT3, Ogre::VES_POSITION);
                offset += Ogre::VertexElement::getTypeSize(Ogre::VET_FLOAT3);
                vdecl->addElement(0, offset, Ogre::VET_FLOAT3, Ogre::VES_NORMAL);
                offset += Ogre::VertexElement::getTypeSize(Ogre::VET_FLOAT3);
                vdecl->addElement(0, offset, Ogre::VET_FLOAT2, Ogre::VES_TEXTURE_COORDINATES);
 
                mVertexBuffer = Ogre::HardwareBufferManager::getSingleton().
                    createVertexBuffer(sizeof(POS_NORM_UV_VERTEX),
                                       numVertices,
                                       Ogre::HardwareBuffer::HBU_DYNAMIC_WRITE_ONLY);
            }
            break;
 
            case VT_POS_NORM:
            {
                vdecl->addElement(0, 0, Ogre::VET_FLOAT3, Ogre::VES_POSITION);
                offset += Ogre::VertexElement::getTypeSize(Ogre::VET_FLOAT3);
                vdecl->addElement(0, offset, Ogre::VET_FLOAT3, Ogre::VES_NORMAL);
 
                mVertexBuffer = Ogre::HardwareBufferManager::getSingleton().
                    createVertexBuffer(sizeof(POS_NORM_VERTEX),
                                       numVertices,
                                       Ogre::HardwareBuffer::HBU_DYNAMIC_WRITE_ONLY);
            }
            break;
 
            case VT_POS_UV:
            {
                vdecl->addElement(0, 0, Ogre::VET_FLOAT3, Ogre::VES_POSITION);
                offset += Ogre::VertexElement::getTypeSize(Ogre::VET_FLOAT3);
                vdecl->addElement(0, offset, Ogre::VET_FLOAT2, Ogre::VES_TEXTURE_COORDINATES);
 
                mVertexBuffer = Ogre::HardwareBufferManager::getSingleton().
                    createVertexBuffer(sizeof(POS_UV_VERTEX),
                                       numVertices,
                                       Ogre::HardwareBuffer::HBU_DYNAMIC_WRITE_ONLY);
            }
            break;
 
            case VT_POS:
            {
                vdecl->addElement(0, 0, Ogre::VET_FLOAT3, Ogre::VES_POSITION);
 
                mVertexBuffer = Ogre::HardwareBufferManager::getSingleton().
                    createVertexBuffer(sizeof(POS_VERTEX),
                                       numVertices,
                                       Ogre::HardwareBuffer::HBU_DYNAMIC_WRITE_ONLY);
            }
            break;
        }
 
        vbind->setBinding(0, mVertexBuffer);
 
        unsigned int *indexbuffer = new unsigned int[numEle];
 
        int i = 0;
        for(int v=0; v<Complexity-1; v++){
            for(int u=0; u<Complexity-1; u++){
                // face 1 |/
                indexbuffer[i++] = v*Complexity + u;
                indexbuffer[i++] = v*Complexity + u + 1;
                indexbuffer[i++] = (v+1)*Complexity + u;
 
                // face 2 /|
                indexbuffer[i++] = (v+1)*Complexity + u;
                indexbuffer[i++] = v*Complexity + u + 1;
                indexbuffer[i++] = (v+1)*Complexity + u + 1;
            }
        }
 
        // Prepare buffer for indices
        mIndexBuffer =
            Ogre::HardwareBufferManager::getSingleton().createIndexBuffer(
            Ogre::HardwareIndexBuffer::IT_32BIT,
            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;
    }
 
    bool Mesh::updateGeometry(const int &numVer, void* verArray)
    {
        if (numVer != mVertexBuffer->getNumVertices() || !mCreated)
        {
            return false;
        }
 
        if (verArray)
        {
            mVertexBuffer->
                writeData(0,
                          mVertexBuffer->getSizeInBytes(),
                          verArray,
                          true);
        }
 
        return true;
    }
 
    bool Mesh::isPointInGrid(const Ogre::Vector2 &Position)
    {
        Ogre::AxisAlignedBox WordMeshBox = mEntity->getWorldBoundingBox();
 
        // Get our mesh grid rectangle:
        // c-----------d
        // |           |
        // |           |
        // |           |
        // a-----------b
        Ogre::Vector3
            a = WordMeshBox.getCorner(Ogre::AxisAlignedBox::FAR_LEFT_BOTTOM),
            b = WordMeshBox.getCorner(Ogre::AxisAlignedBox::FAR_RIGHT_BOTTOM),
            c = WordMeshBox.getCorner(Ogre::AxisAlignedBox::NEAR_RIGHT_BOTTOM),
            d = WordMeshBox.getCorner(Ogre::AxisAlignedBox::NEAR_LEFT_BOTTOM);
 
        // Transform all corners to Ogre::Vector2 array
        Ogre::Vector2 Corners2D[4] =
           {Ogre::Vector2(a.x, a.z),
            Ogre::Vector2(b.x, b.z),
            Ogre::Vector2(c.x, c.z),
            Ogre::Vector2(d.x, d.z)};
 
        // Determinate if Position is into our rectangle, we use a line intersection detection
        // because our mesh rectangle can be rotated, if the number of collisions with the four
        // segments AB, BC, CD, DA is one, the Position point is into the rectangle, else(if number
        // of collisions are 0 or 2, the Position point is outside the rectangle.
        int NumberOfCollisions = 0;
        // Find a point wich isn't be inside the rectangle
        Ogre::Vector2 DestPoint = Corners2D[0] + (Corners2D[1]-Corners2D[0])*2;
        for (int k = 0; k < 3; k++)
        {
            if (Math::intersectionOfTwoLines(Corners2D[k], Corners2D[k+1], Position, DestPoint) != Ogre::Vector2::ZERO)
            {
                NumberOfCollisions ++;
            }
 
            if (k == 2)
            {
                if (Math::intersectionOfTwoLines(Corners2D[3], Corners2D[0], Position, DestPoint) != Ogre::Vector2::ZERO)
                {
                    NumberOfCollisions ++;
                }
            }
        }
        if (NumberOfCollisions == 1)
        {
            return true;
        }
 
        return false;
    }
 
    Ogre::Vector2 Mesh::getGridPosition(const Ogre::Vector2 &Position)
    {
        if (mOptions.MeshSize.Width == 0 && mOptions.MeshSize.Height == 0)
        {
            return Position;
        }
 
        if (!isPointInGrid(Position))
        {
            return Ogre::Vector2(-1,-1);
        }
 
        Ogre::AxisAlignedBox WordMeshBox = mEntity->getWorldBoundingBox();
 
        // Get our mesh grid rectangle: (Only a,b,c corners)
        // c
        // |
        // |
        // |
        // a-----------b
        Ogre::Vector3
            a = WordMeshBox.getCorner(Ogre::AxisAlignedBox::FAR_LEFT_BOTTOM),
            b = WordMeshBox.getCorner(Ogre::AxisAlignedBox::FAR_RIGHT_BOTTOM),
            c = WordMeshBox.getCorner(Ogre::AxisAlignedBox::NEAR_LEFT_BOTTOM);
 
        // Transform all corners to Ogre::Vector2 array
        Ogre::Vector2 Corners2D[3] =
           {Ogre::Vector2(a.x, a.z),
            Ogre::Vector2(b.x, b.z),
            Ogre::Vector2(c.x, c.z)};
 
        // Get segments AB and AC
        Ogre::Vector2 AB = Corners2D[1]-Corners2D[0],
                      AC = Corners2D[2]-Corners2D[0];
 
        // Find the X/Y position projecting the Position point to AB and AC segments.
        Ogre::Vector2 XProjectedPoint = Position-AC,
                      YProjectedPoint = Position-AB;
 
        // Fint the intersections points
        Ogre::Vector2 XPoint = Math::intersectionOfTwoLines(Corners2D[0],Corners2D[1],Position,XProjectedPoint),
                      YPoint = Math::intersectionOfTwoLines(Corners2D[0],Corners2D[2],Position,YProjectedPoint);
 
        // Find lengths
        Ogre::Real ABLength = AB.length(),
                   ACLength = AC.length(),
                   XLength  = (XPoint-Corners2D[0]).length(),
                   YLength  = (YPoint-Corners2D[0]).length();
 
        // Find final x/y grid positions in [0,1] range
        Ogre::Real XFinal = XLength / ABLength,
                   YFinal = YLength / ACLength;
 
        return Ogre::Vector2(XFinal,YFinal);
    }
 
    const Ogre::Vector3 Mesh::getObjectSpacePosition(const Ogre::Vector3& WorldSpacePosition) const
    {
        Ogre::Affine3 mWorldMatrix;
 
        if (mCreated)
        {
            mWorldMatrix = mEntity->getParentSceneNode()->_getFullTransform();
        }
        else
        {
            Ogre::SceneNode *mTmpSN = new Ogre::SceneNode(0);
            mTmpSN->setPosition(mHydrax->getPosition());
 
            mWorldMatrix = mTmpSN->_getFullTransform();
 
            delete mTmpSN;
        }
 
        return mWorldMatrix.inverse()*(WorldSpacePosition);
    }
 
    const Ogre::Vector3 Mesh::getWorldSpacePosition(const Ogre::Vector3& ObjectSpacePosition) const
    {
        Ogre::Affine3 mWorldMatrix;
 
        if (mCreated)
        {
            mWorldMatrix = mEntity->getParentSceneNode()->_getFullTransform();
        }
        else
        {
            Ogre::SceneNode *mTmpSN = new Ogre::SceneNode(0);
            mTmpSN->setPosition(mHydrax->getPosition());
 
            mWorldMatrix = mTmpSN->_getFullTransform();
 
            delete mTmpSN;
        }
 
        //return mWorldMatrix.transformAffine(ObjectSpacePosition);
        return mWorldMatrix*(ObjectSpacePosition);
    }
}