[ODE] patch: AABBs for TriMeshes

[Aras Pranckevicius]

Hi,

Modifications to enable AABBs on trimeshes:

collision_trimesh_internal.h: add to struct dxTriMeshData:
    /* aabb in model space */
    dVector3 AABBCenter;
    dVector3 AABBExtents;

collision_trimesh.cpp: add at end of dxTriMeshData::Build:
    // compute model space AABB
    dVector3 AABBMax, AABBMin;
    AABBMax[0] = AABBMax[1] = AABBMax[2] = -dInfinity;
    AABBMin[0] = AABBMin[1] = AABBMin[2] = dInfinity;
    if( Single ) {
        const char* verts = (const char*)Vertices;
        for( int i = 0; i < VertexCount; ++i ) {
            const float* v = (const float*)verts;
            if( v[0] > AABBMax[0] ) AABBMax[0] = v[0];
            if( v[1] > AABBMax[1] ) AABBMax[1] = v[1];
            if( v[2] > AABBMax[2] ) AABBMax[2] = v[2];
            if( v[0] < AABBMin[0] ) AABBMin[0] = v[0];
            if( v[1] < AABBMin[1] ) AABBMin[1] = v[1];
            if( v[2] < AABBMin[2] ) AABBMin[2] = v[2];
            verts += VertexStide;
        }
    } else {
        const char* verts = (const char*)Vertices;
        for( int i = 0; i < VertexCount; ++i ) {
            const double* v = (const double*)verts;
            if( v[0] > AABBMax[0] ) AABBMax[0] = v[0];
            if( v[1] > AABBMax[1] ) AABBMax[1] = v[1];
            if( v[2] > AABBMax[2] ) AABBMax[2] = v[2];
            if( v[0] < AABBMin[0] ) AABBMin[0] = v[0];
            if( v[1] < AABBMin[1] ) AABBMin[1] = v[1];
            if( v[2] < AABBMin[2] ) AABBMin[2] = v[2];
            verts += VertexStide;
        }
    }
    AABBCenter[0] = (AABBMin[0] + AABBMax[0]) * REAL(0.5);
    AABBCenter[1] = (AABBMin[1] + AABBMax[1]) * REAL(0.5);
    AABBCenter[2] = (AABBMin[2] + AABBMax[2]) * REAL(0.5);
    AABBExtents[0] = AABBMax[0] - AABBCenter[0];
    AABBExtents[1] = AABBMax[1] - AABBCenter[1];
    AABBExtents[2] = AABBMax[2] - AABBCenter[2];

collision_trimesh.cpp: change dxTriMesh::computeAABB() to:
    void dxTriMesh::computeAABB() {
        const dxTriMeshData* d = Data;
        dVector3 c;
        dMULTIPLY0_331( c, R, d->AABBCenter );
        dReal xrange = dFabs(R[0] * Data->AABBExtents[0]) +
                dFabs(R[1] * Data->AABBExtents[1]) + dFabs(R[2] *
Data->AABBExtents[2]);
        dReal yrange = dFabs(R[4] * Data->AABBExtents[0]) +
                dFabs(R[5] * Data->AABBExtents[1]) + dFabs(R[6] *
Data->AABBExtents[2]);
        dReal zrange = dFabs(R[8] * Data->AABBExtents[0]) +
                dFabs(R[9] * Data->AABBExtents[1]) + dFabs(R[10] *
Data->AABBExtents[2]);
        aabb[0] = c[0] + pos[0] - xrange;
        aabb[1] = c[0] + pos[0] + xrange;
        aabb[2] = c[1] + pos[1] - yrange;
        aabb[3] = c[1] + pos[1] + yrange;
        aabb[4] = c[2] + pos[2] - zrange;
        aabb[5] = c[2] + pos[2] + zrange;
    }


Aras Pranckevicius aka NeARAZ
http://www.gim.ktu.lt/nesnausk/nearaz/