source: GTP/trunk/App/Demos/Vis/CHC_revisited/Geometry.cpp @ 2776

#include "Geometry.h"
#include "Triangle3.h"
#include "glInterface.h"
#include "RenderState.h"


namespace CHCDemoEngine 
{

Geometry::Geometry(Vector3 *vertices, 
                                   Vector3 *normals,
                                   float *texcoords,
                                   int numVertices):
mVertices(vertices), 
mNormals(normals), 
mTexCoords(texcoords),
mNumVertices(numVertices), 
mVboId(-1)
{
        Prepare();
}


void Geometry::Prepare()
{
        CalcBoundingBox();

        int dataSize = mNumVertices * 6;

        if (mTexCoords)
                dataSize += mNumVertices * 2;
        
        float *data = new float[dataSize];

        for (int i = 0; i < mNumVertices; ++ i)
        {
                ((Vector3 *)data)[i] = mVertices[i];
                ((Vector3 *)data)[i + mNumVertices] = mNormals[i];
        }

        if (mTexCoords)
        {
                for (int i = 0; i < mNumVertices * 2; ++ i)
                        data[mNumVertices * 6 + i] = mTexCoords[i];
        }

        glGenBuffersARB(1, &mVboId);
        
        glBindBufferARB(GL_ARRAY_BUFFER_ARB, mVboId);

        glVertexPointer(3, GL_FLOAT, 0, (char *)NULL);
        glNormalPointer(GL_FLOAT, 0, (char *)NULL + mNumVertices * sizeof(Vector3));

        if (mTexCoords)
        {
                glTexCoordPointer(2, GL_FLOAT, 0, (char *)NULL + 2 * mNumVertices * sizeof(Vector3));
        }
        glBufferDataARB(GL_ARRAY_BUFFER_ARB, 
                            dataSize * sizeof(float), 
                            (float *)data, 
                                        GL_STATIC_DRAW_ARB);

        glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);

        // data handled by graphics driver from now on
        delete [] data;
}


void Geometry::Render(RenderState *state)
{
        if (state->GetCurrentVboId() != mVboId)
        {
                glBindBufferARB(GL_ARRAY_BUFFER_ARB, mVboId);
                glVertexPointer(3, GL_FLOAT, 0, (char *)NULL);  
                glNormalPointer(GL_FLOAT, 0, (char *)NULL + mNumVertices * sizeof(Vector3));

                if (mTexCoords)
                        glTexCoordPointer(2, GL_FLOAT, 0, (char *)NULL + 2 * mNumVertices * sizeof(Vector3));

                state->SetCurrentVboId(mVboId);
        }

        // don't render first degenerate index
        glDrawArrays(GL_TRIANGLES, 0, mNumVertices);
}


void Geometry::CalcBoundingBox()
{
        mBoundingBox.Initialize();

        for (int i = 0; i < mNumVertices; ++ i)
        {
                mBoundingBox.Include(mVertices[i]);
        }
}


const AxisAlignedBox3& Geometry::GetBoundingBox() const
{
        return mBoundingBox;
}


}