source: GTP/trunk/Lib/Vis/OnlineCullingCHC/OGRE/src/OgreSolidBoundingBox.cpp @ 2455

#include "OgreStableHeaders.h"
#include "OgreSolidBoundingBox.h"

#include <OgreSimpleRenderable.h>
#include <OgreHardwareBufferManager.h>
#include <OgreCamera.h>
#include <OgreMaterialManager.h>
#include <OgreMaterial.h>
#include <OgrePass.h>
#include <OgreTechnique.h>
#include <OgreLogManager.h>

namespace Ogre {

#define POSITION_BINDING 0
//-----------------------------------------------------------------------
SolidBoundingBox::SolidBoundingBox()
{
         mRenderOp.vertexData = new VertexData();
         mRenderOp.indexData = new IndexData();

         mRenderOp.indexData->indexStart = 0;
         mRenderOp.vertexData->vertexStart = 0;

         mRenderOp.vertexData->vertexCount = 8;
         mRenderOp.indexData->indexCount  = 36;

         mRenderOp.operationType = RenderOperation::OT_TRIANGLE_LIST; 
         mRenderOp.useIndexes = true; 

     VertexDeclaration* decl = mRenderOp.vertexData->vertexDeclaration;
     VertexBufferBinding* bind = mRenderOp.vertexData->vertexBufferBinding;

     decl->addElement(POSITION_BINDING, 0, VET_FLOAT3, VES_POSITION);
         //decl->addElement(INDEX_BINDING, 0, VET_, VES_POSITION);

         // create the vertex buffer
     HardwareVertexBufferSharedPtr vbuf = 
            HardwareBufferManager::getSingleton().createVertexBuffer(
                decl->getVertexSize(POSITION_BINDING),
                mRenderOp.vertexData->vertexCount,
                HardwareBuffer::HBU_STATIC_WRITE_ONLY);

     // Bind buffer
     bind->setBinding(POSITION_BINDING, vbuf);

         //-- index buffer
         unsigned short faces[36] = 
         {
        0,2,3,
        0,1,2,
        1,6,2,
        1,5,6,
        4,6,5,
        4,7,6,
        0,7,4,
        0,3,7,
        0,5,1,
        0,4,5,
        2,7,3,
        2,6,7
         };

         /// Allocate index buffer of the requested number of vertices 
     HardwareIndexBufferSharedPtr ibuf = HardwareBufferManager::getSingleton().
         createIndexBuffer(
             HardwareIndexBuffer::IT_16BIT, 
             mRenderOp.indexData->indexCount, 
             HardwareBuffer::HBU_STATIC_WRITE_ONLY);

         /// Upload the index data to the card
         ibuf->writeData(0, ibuf->getSizeInBytes(), faces, true);
         mRenderOp.indexData->indexBuffer = ibuf;
         // set material with no lighting, no color, no depth write
         SetOcclusionQueryMaterial();
}
//-----------------------------------------------------------------------
SolidBoundingBox::~SolidBoundingBox() 
{
        delete mRenderOp.vertexData;
        delete mRenderOp.indexData;
}
//-----------------------------------------------------------------------
void SolidBoundingBox::SetupBoundingBoxVertices(const AxisAlignedBox& aab) 
{
        const Vector3& min = aab.getMinimum();
    const Vector3& max = aab.getMaximum();

        // fill the vertex buffer: 12 lines with 2 endpoints each make up a box
    HardwareVertexBufferSharedPtr vbuf =
        mRenderOp.vertexData->vertexBufferBinding->getBuffer(POSITION_BINDING);     

    float* pPos = static_cast<float*>(vbuf->lock(HardwareBuffer::HBL_DISCARD));

        *pPos++ = min.x; *pPos++ = max.y; *pPos++ = min.z; 
        *pPos++ = max.x; *pPos++ = max.y; *pPos++ = min.z; 
        *pPos++ = max.x; *pPos++ = min.y; *pPos++ = min.z; 
        *pPos++ = min.x; *pPos++ = min.y; *pPos++ = min.z; 
                
        *pPos++ = min.x; *pPos++ = max.y; *pPos++ = max.z; 
        *pPos++ = max.x; *pPos++ = max.y; *pPos++ = max.z; 
        *pPos++ = max.x; *pPos++ = min.y; *pPos++ = max.z; 
        *pPos++ = min.x; *pPos++ = min.y; *pPos++ = max.z;

    vbuf->unlock();
}
//-----------------------------------------------------------------------
void SolidBoundingBox::SetupBoundingBox(const AxisAlignedBox& aab)
{
        // init the vertices to the aabb
        SetupBoundingBoxVertices(aab);

        Real sqLen = std::max(aab.getMaximum().squaredLength(), 
                                                  aab.getMinimum().squaredLength());
    mRadius = Math::Sqrt(sqLen);

    // setup the bounding box of this SimpleRenderable
        setBoundingBox(aab);
}
//-----------------------------------------------------------------------
void SolidBoundingBox::SetOcclusionQueryMaterial()
{
        m_pMaterial = MaterialManager::getSingleton().getByName("Visibility/QueryMaterial");

        if (m_pMaterial.isNull())
        {
                m_pMaterial = MaterialManager::getSingleton().
                        create("Visibility/QueryMaterial", ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);

                Pass *queryPass = m_pMaterial->getTechnique(0)->getPass(0);
                queryPass->setColourWriteEnabled(false);
                queryPass->setDepthWriteEnabled(false);
                queryPass->setLightingEnabled(false);
        }

        setMaterial("Visibility/QueryMaterial");
}

// Override this method to prevent parent transforms (rotation,translation,scale)
void SolidBoundingBox::getWorldTransforms(Matrix4* xform) const
{
        // return identity matrix to prevent parent transforms
    *xform = Matrix4::IDENTITY;
}
//-----------------------------------------------------------------------
const Quaternion& SolidBoundingBox::getWorldOrientation() const
{
        return Quaternion::IDENTITY;
}
//-----------------------------------------------------------------------
const Vector3& SolidBoundingBox::getWorldPosition() const
{
        return Vector3::ZERO;
}

Real SolidBoundingBox::getSquaredViewDepth(const Camera* cam) const
{
        const Vector3 &min = mBox.getMinimum();
        const Vector3 &max = mBox.getMaximum();
        const Vector3 &mid = ((min - max) * 0.5) + min;
        const Vector3 &dist = cam->getDerivedPosition() - mid;

        return dist.squaredLength();
}

} // namespace Ogre