Method CreateNode

GTE/Samples/SceneGraphs/BspNodes/BspNodesWindow3.cpp:330–384

}

std::shared_ptr<BspNode> BspNodesWindow3::CreateNode(int32_t i,
    Vector2<float> const& v0, Vector2<float> const& v1,
    Vector4<float> const& color)
{
    // Create the model-space separating plane.
    Vector2<float> dir = v1 - v0;
    Vector3<float> normal{ dir[1], -dir[0], 0.0f };
    Normalize(normal);
    float constant = normal[0] * v0[0] + normal[1] * v0[1];
    Plane3<float> modelPlane(normal, constant);

    // Create the BSP node.
    std::shared_ptr<BspNode> bsp = std::make_shared<BspNode>(modelPlane);

    struct Vertex
    {
        Vector3<float> position;
        Vector4<float> color;
    };
    VertexFormat vformat;
    vformat.Bind(VASemantic::POSITION, DF_R32G32B32_FLOAT, 0);
    vformat.Bind(VASemantic::COLOR, DF_R32G32B32A32_FLOAT, 0);
    MeshFactory mf;
    mf.SetVertexFormat(vformat);

    // Create the rectangle representation of the model plane and set the
    // vertex colors to the specified color.
    float xExtent = 0.5f * Length(dir);
    float yExtent = 0.125f;
    mRectangle[i] = mf.CreateRectangle(2, 2, xExtent, yExtent);
    auto vbuffer = mRectangle[i]->GetVertexBuffer().get();
    Vertex* vertex = vbuffer->Get<Vertex>();
    for (int32_t j = 0; j < 4; ++j)
    {
        vertex[j].color = color;
    }
    mRectangle[i]->SetEffect(mVCEffect[i]);

    // Set the position and orientation for the world-space plane.
    Vector3<float> trn{ 0.5f*(v0[0] + v1[0]), 0.5f*(v0[1] + v1[1]), yExtent + 0.001f };

    Matrix4x4<float> zRotate = Rotation<4, float>(AxisAngle<4, float>(
        Vector4<float>::Unit(2), std::atan2(dir[1], dir[0])));

    Matrix4x4<float> xRotate = Rotation<4, float>(AxisAngle<4, float>(
        Vector4<float>::Unit(0), (float)GTE_C_HALF_PI));

    Matrix4x4<float> rotate = DoTransform(zRotate, xRotate);

    mRectangle[i]->localTransform.SetTranslation(trn);
    mRectangle[i]->localTransform.SetRotation(rotate);

    bsp->AttachCoplanarChild(mRectangle[i]);
    return bsp;
}