RENDERING - User Interface Programming for Games - page 79

vector3 Project(vector3 worldPosition, matrix world, matrix view, matrix projection)
{
matrix wvp = world * view * projection;
vector4 result = vector4::Transform(worldPosition, wvp);
result.z() = result.z() * (m_maxDepth - m_minDepth);
result /= result.w();
vector3 finalResult = result;
finalResult.x() = m_left + (1.f + finalResult.x()) * Width()/2;
finalResult.y() = m_top + (1.f - finalResult.y()) * Height()/2;
finalResult.z() = finalResult.z() + m_minDepth;
return finalResult;
}