Help with GetMeshInformation

Hello there! I'm trying to adapt the following function to ODN:


void getMeshInformation( const Ogre::Mesh* const mesh, size_t &vertex_count,
Ogre::Vector3* &vertices,
size_t &index_count, unsigned long* &indices,
const Ogre::Vector3 &position,
const Ogre::Quaternion &orient,
const Ogre::Vector3 &scale)
{
bool added_shared = false;
size_t current_offset = 0;
size_t shared_offset = 0;
size_t next_offset = 0;
size_t index_offset = 0;


vertex_count = index_count = 0;

// Calculate how many vertices and indices we're going to need
for ( unsigned short i = 0; i < mesh->getNumSubMeshes(); ++i)
{
Ogre::SubMesh* submesh = mesh->getSubMesh( i );

// We only need to add the shared vertices once
if(submesh->useSharedVertices)
{
if( !added_shared )
{
vertex_count += mesh->sharedVertexData->vertexCount;
added_shared = true;
}
}
else
{
vertex_count += submesh->vertexData->vertexCount;
}

// Add the indices
index_count += submesh->indexData->indexCount;
}


// Allocate space for the vertices and indices
vertices = new Ogre::Vector3[vertex_count];
indices = new unsigned long[index_count];

added_shared = false;

// Run through the submeshes again, adding the data into the arrays
for ( unsigned short i = 0; i < mesh->getNumSubMeshes(); ++i)
{
Ogre::SubMesh* submesh = mesh->getSubMesh(i);

Ogre::VertexData* vertex_data = submesh->useSharedVertices ? mesh->sharedVertexData : submesh->vertexData;

if((!submesh->useSharedVertices)||(submesh->useSharedVertices && !added_shared))
{
if(submesh->useSharedVertices)
{
added_shared = true;
shared_offset = current_offset;
}

const Ogre::VertexElement* posElem =
vertex_data->vertexDeclaration->findElementBySemantic(Ogre::VES_POSITION);

Ogre::HardwareVertexBufferSharedPtr vbuf =
vertex_data->vertexBufferBinding->getBuffer(posElem->getSource());

unsigned char* vertex =
static_cast<unsigned char*>(vbuf->lock(Ogre::HardwareBuffer::HBL_READ_ONLY));

// There is _no_ baseVertexPointerToElement() which takes an Ogre::Real or a double
// as second argument. So make it float, to avoid trouble when Ogre::Real will
// be comiled/typedefed as double:
// Ogre::Real* pReal;
float* pReal;

for( size_t j = 0; j < vertex_data->vertexCount; ++j, vertex += vbuf->getVertexSize())
{
posElem->baseVertexPointerToElement(vertex, &pReal);

Ogre::Vector3 pt(pReal[0], pReal[1], pReal[2]);

vertices[current_offset + j] = (orient * (pt * scale)) + position;
}

vbuf->unlock();
next_offset += vertex_data->vertexCount;
}


Ogre::IndexData* index_data = submesh->indexData;
size_t numTris = index_data->indexCount / 3;
Ogre::HardwareIndexBufferSharedPtr ibuf = index_data->indexBuffer;

bool use32bitindexes = (ibuf->getType() == Ogre::HardwareIndexBuffer::IT_32BIT);

unsigned long* pLong = static_cast<unsigned long*>(ibuf->lock(Ogre::HardwareBuffer::HBL_READ_ONLY));
unsigned short* pShort = reinterpret_cast<unsigned short*>(pLong);


size_t offset = (submesh->useSharedVertices)? shared_offset : current_offset;

if ( use32bitindexes )
{
for ( size_t k = 0; k < numTris*3; ++k)
{
indices[index_offset++] = pLong[k] + static_cast<unsigned long>(offset);
}
}
else
{
for ( size_t k = 0; k < numTris*3; ++k)
{
indices[index_offset++] = static_cast<unsigned long>(pShort[k]) +
static_cast<unsigned long>(offset);
}
}

ibuf->unlock();
current_offset = next_offset;
}
}


However, there is one function missing (posElem->baseVertexPointerToElement) can anyone help me? Is there another way to get the vertex data?

Actually, let me be a little more specific: I'm doing a point'n'click adventure game, using a standard mesh as the "level". However, as you all know, Ray Scene Queries only work on the bounding box with meshes, so there's no way to determine where I clicked on the floor for example. Someone suggested using the previous function as the basis for a brute force method that would check every triangle for an intersection point. I didn't want to use a full-blown physics library only to perform such basic collision detection. Do I have any other choice with ODN? Can OpCode be used?

thank you for your code,it's great~