RainManualHardwareBillboardMeshLoader.h

//
//              Realistic rain real-time simulation program
//
//              Pierre Rousseau
//
//
//              Definition of the mesh for the particles
//


#ifndef __HARDWARE_BILLBOARD_LOADER__
#define __HARDWARE_BILLBOARD_LOADER__


#include <OgreResource.h>



class ManualHardwareBillboardMeshLoader : public ManualResourceLoader
{
private :
    String mMaterialName;

public :

    ManualHardwareBillboardMeshLoader(String materialName)
    {
        mMaterialName = materialName;
    }


    void loadResource(Resource *res)
    {
        Mesh* msh = static_cast<Mesh*>(res);
        SubMesh* sm = msh->createSubMesh();
        sm->useSharedVertices = false;
        sm->vertexData = new VertexData();
        sm->vertexData->vertexStart = 0;
        sm->vertexData->vertexCount = 4;
        VertexDeclaration* dcl = sm->vertexData->vertexDeclaration;
        size_t offset = 0;
        dcl->addElement(0, offset, VET_FLOAT3, VES_POSITION);
        offset += VertexElement::getTypeSize(VET_FLOAT3);
        dcl->addElement(0, offset, VET_FLOAT4, VES_TEXTURE_COORDINATES); // xy will serve as regular texCoords, zw, for positionning in the texture
        offset += VertexElement::getTypeSize(VET_FLOAT4);

        HardwareVertexBufferSharedPtr vbuf = HardwareBufferManager::getSingleton().createVertexBuffer(offset, 4, HardwareBuffer::HBU_STATIC_WRITE_ONLY);
        float* pReal = static_cast<float*>(vbuf->lock(HardwareBuffer::HBL_DISCARD));


        // vertex 0
        // position
        *pReal++ = 0;
        *pReal++ = 0;
        *pReal++ = 0;
        // uv
        *pReal++ = 1;
        *pReal++ = 0;
        // position texture coordinates
        *pReal++ = 0;
        *pReal++ = 0;

        // vertex 1
        // position
        *pReal++ = 0;
        *pReal++ = 0;
        *pReal++ = 0;
        // uv
        *pReal++ = 0;
        *pReal++ = 0;
        // position texture coordinates
        *pReal++ = 0;
        *pReal++ = 0;

        // vertex 2
        // position
        *pReal++ = 0;
        *pReal++ = 0;
        *pReal++ = 0;
        // uv
        *pReal++ = 0;
        *pReal++ = 1;
        // position texture coordinates
        *pReal++ = 0;
        *pReal++ = 0;

        // vertex 3
        // position
        *pReal++ = 0;
        *pReal++ = 0;
        *pReal++ = 0;
        // uv
        *pReal++ = 1;
        *pReal++ = 1;
        // position texture coordinates
        *pReal++ = 0;
        *pReal++ = 0;


        vbuf->unlock();

        sm->vertexData->vertexBufferBinding->setBinding(0, vbuf);
        sm->indexData->indexCount = 6;
        sm->indexData->indexBuffer = HardwareBufferManager::getSingleton()
                                     .createIndexBuffer(HardwareIndexBuffer::IT_16BIT, 6,
                                                        HardwareBuffer::HBU_STATIC_WRITE_ONLY);
        uint16* pI = static_cast<uint16*>(
                         sm->indexData->indexBuffer->lock(HardwareBuffer::HBL_DISCARD))
                     ;

        // we link vertices 0, 1, and 2
        *pI++ = 0;
        *pI++ = 1;
        *pI++ = 2;

        // second triangle : we link vertices 0, 2, and 3
        *pI++ = 0;
        *pI++ = 2;
        *pI++ = 3;

        sm->indexData->indexBuffer->unlock();

        sm->setMaterialName(mMaterialName);


        msh->_setBounds(AxisAlignedBox(0,0,0,0,0,0), true);
        msh->_setBoundingSphereRadius(1);
    }
};


#endif //__HARDWARE_BILLBOARD_LOADER__

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