-/* -*- C++ -*- ------------------------------------------------------------
-
-Copyright (c) 2007 Jesse Anders and Demian Nave http://cmldev.net/
-
-The Configurable Math Library (CML) is distributed under the terms of the
-Boost Software License, v1.0 (see cml/LICENSE for details).
-
- *-----------------------------------------------------------------------*/
-/** @file
- * @brief
- */
-
-#ifndef projection_h
-#define projection_h
-
-#include <cml/mathlib/matrix_concat.h>
-#include <cml/mathlib/vector_transform.h>
-
-/* Functions for projection and 'unprojection' of points in 3D. */
-
-namespace cml {
-
-namespace detail {
-
-template < typename E > void
-divide_by_w(vector< E,fixed<4> >& v) {
- v *= E(1) / v[3];
-}
-
-} // namespace detail
-
-/* Project a point to screen space using the given model, view, projection,
- * and viewport matrices. The z value of the returned point is a depth value
- * in the range specified by the viewport matrix.
- */
-
-template <class MatT_1, class MatT_2, class MatT_3, class MatT_4, class VecT>
-vector< typename VecT::value_type, fixed<3> > project_point(
- const MatT_1& model,
- const MatT_2& view,
- const MatT_3& projection,
- const MatT_4& viewport,
- const VecT& p)
-{
- return project_point(
- detail::matrix_concat_transforms_4x4(model,view),
- projection,
- viewport,
- p
- );
-}
-
-/* Project a point to screen space using the given modelview, projection, and
- * viewport matrices. The z value of the returned point is a depth value in
- * the range specified by the viewport matrix.
- */
-
-template < class MatT_1, class MatT_2, class MatT_3, class VecT >
-vector< typename VecT::value_type, fixed<3> > project_point(
- const MatT_1& modelview,
- const MatT_2& projection,
- const MatT_3& viewport,
- const VecT& p)
-{
- typedef vector< typename VecT::value_type, fixed<3> > vector3_type;
- typedef vector< typename VecT::value_type, fixed<4> > vector4_type;
- typedef typename vector3_type::value_type value_type;
-
- detail::CheckVec3(p);
-
- vector4_type result = transform_vector_4D(
- detail::matrix_concat_transforms_4x4(
- modelview,
- detail::matrix_concat_transforms_4x4(
- projection,
- viewport
- )
- ),
- vector4_type(p[0],p[1],p[2],value_type(1))
- );
- detail::divide_by_w(result);
- return vector3_type(result[0],result[1],result[2]);
-}
-
-/* 'Unproject' a point from screen space using the given model, view,
- * projection, and viewport matrices. The z value of the input point is a
- * depth value in the range specified by the viewport matrix.
- */
-
-template <class MatT_1, class MatT_2, class MatT_3, class MatT_4, class VecT>
-vector< typename VecT::value_type, fixed<3> > unproject_point(
- const MatT_1& model,
- const MatT_2& view,
- const MatT_3& projection,
- const MatT_4& viewport,
- const VecT& p)
-{
- return unproject_point(
- detail::matrix_concat_transforms_4x4(model,view),
- projection,
- viewport,
- p
- );
-}
-
-/* 'Unproject' a point from screen space using the given modelview,
- * projection, and viewport matrices. The z value of the input point is a
- * depth value in the range specified by the viewport matrix.
- */
-
-template < class MatT_1, class MatT_2, class MatT_3, class VecT >
-vector< typename VecT::value_type, fixed<3> > unproject_point(
- const MatT_1& modelview,
- const MatT_2& projection,
- const MatT_3& viewport,
- const VecT& p)
-{
- typedef vector< typename VecT::value_type, fixed<3> > vector3_type;
- typedef vector< typename VecT::value_type, fixed<4> > vector4_type;
- typedef typename vector3_type::value_type value_type;
-
- detail::CheckVec3(p);
-
- vector4_type result = transform_vector_4D(
- inverse(
- detail::matrix_concat_transforms_4x4(
- modelview,
- detail::matrix_concat_transforms_4x4(
- projection,
- viewport
- )
- )
- ),
- vector4_type(p[0],p[1],p[2],value_type(1))
- );
- detail::divide_by_w(result);
- return vector3_type(result[0],result[1],result[2]);
-}
-
-} // namespace cml
-
-#endif