--- /dev/null
+/* -*- 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 matrix_projection_h
+#define matrix_projection_h
+
+#include <cml/mathlib/checking.h>
+#include <cml/mathlib/helper.h>
+
+/* Functions for building matrix transforms other than rotations
+ * (matrix_rotation.h) and viewing projections (matrix_projection.h).
+ *
+ * @todo: Clean up comments and documentation throughout.
+ */
+
+// NOTE: Changed 'near' and 'far' to 'n' and 'f' throughout to work around
+// windows.h 'near' and 'far' macros.
+
+namespace cml {
+
+//////////////////////////////////////////////////////////////////////////////
+// 3D perspective projection from frustum
+//////////////////////////////////////////////////////////////////////////////
+
+/** Build a matrix representing a perspective projection, specified by frustum
+ * bounds in l,r,b,t,n,f form, and with the given handedness and z clipping
+ * range
+ */
+template < typename E, class A, class B, class L > void
+matrix_perspective(matrix<E,A,B,L>& m, E left, E right, E bottom, E top,
+ E n, E f, Handedness handedness,
+ ZClip z_clip)
+{
+ typedef matrix<E,A,B,L> matrix_type;
+ typedef typename matrix_type::value_type value_type;
+
+ /* Checking */
+ detail::CheckMatHomogeneous3D(m);
+
+ identity_transform(m);
+
+ value_type inv_width = value_type(1) / (right - left);
+ value_type inv_height = value_type(1) / (top - bottom);
+ value_type inv_depth = value_type(1) / (f - n);
+ value_type near2 = value_type(2) * n;
+ value_type s = handedness == left_handed ? 1 : -1;
+
+ if (z_clip == z_clip_neg_one) {
+ m.set_basis_element(2,2,s * (f + n) * inv_depth);
+ m.set_basis_element(3,2,value_type(-2) * f * n * inv_depth);
+ } else { // z_clip == z_clip_zero
+ m.set_basis_element(2,2,s * f * inv_depth);
+ m.set_basis_element(3,2,-s * n * m.basis_element(2,2));
+ }
+
+ m.set_basis_element(0,0,near2 * inv_width );
+ m.set_basis_element(1,1,near2 * inv_height );
+ m.set_basis_element(2,0,-s * (right + left) * inv_width );
+ m.set_basis_element(2,1,-s * (top + bottom) * inv_height);
+ m.set_basis_element(2,3,s );
+ m.set_basis_element(3,3,value_type(0) );
+}
+
+/** Build a matrix representing a perspective projection, specified by frustum
+ * bounds in w,h,n,f form, and with the given handedness and z clipping
+ * range
+ */
+template < typename E, class A, class B, class L > void
+matrix_perspective(matrix<E,A,B,L>& m, E width, E height, E n, E f,
+ Handedness handedness, ZClip z_clip)
+{
+ typedef matrix<E,A,B,L> matrix_type;
+ typedef typename matrix_type::value_type value_type;
+
+ value_type half_width = width * value_type(.5);
+ value_type half_height = height * value_type(.5);
+ matrix_perspective(m, -half_width, half_width,
+ -half_height, half_height, n, f, handedness, z_clip);
+}
+
+/** Build a left-handedness frustum perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_LH(matrix<E,A,B,L>& m, E left, E right, E bottom,
+ E top, E n, E f, ZClip z_clip)
+{
+ matrix_perspective(m, left, right, bottom, top, n, f,
+ left_handed, z_clip);
+}
+
+/** Build a right-handedness frustum perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_RH(matrix<E,A,B,L>& m, E left, E right, E bottom,
+ E top, E n, E f, ZClip z_clip)
+{
+ matrix_perspective(m, left, right, bottom, top, n, f,
+ right_handed, z_clip);
+}
+
+/** Build a left-handedness frustum perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_LH(matrix<E,A,B,L>& m, E width, E height, E n,
+ E f, ZClip z_clip)
+{
+ matrix_perspective(m, width, height, n, f, left_handed, z_clip);
+}
+
+/** Build a right-handedness frustum perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_RH(matrix<E,A,B,L>& m, E width, E height, E n,
+ E f, ZClip z_clip)
+{
+ matrix_perspective(m, width, height, n, f, right_handed, z_clip);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// 3D perspective projection from horizontal field of view
+//////////////////////////////////////////////////////////////////////////////
+
+/** Build a perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_xfov(matrix<E,A,B,L>& m, E xfov, E aspect, E n,
+ E f, Handedness handedness, ZClip z_clip)
+{
+ typedef matrix<E,A,B,L> matrix_type;
+ typedef typename matrix_type::value_type value_type;
+
+ value_type width = value_type(2) * std::tan(xfov * value_type(.5)) * n;
+ matrix_perspective(m, width, width / aspect, n, f,
+ handedness, z_clip);
+}
+
+/** Build a left-handedness perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_xfov_LH(matrix<E,A,B,L>& m, E xfov, E aspect, E n,
+ E f, ZClip z_clip)
+{
+ matrix_perspective_xfov(m,xfov,aspect,n,f,left_handed,z_clip);
+}
+
+/** Build a right-handedness perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_xfov_RH(matrix<E,A,B,L>& m, E xfov, E aspect, E n,
+ E f, ZClip z_clip)
+{
+ matrix_perspective_xfov(m,xfov,aspect,n,f,right_handed,z_clip);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// 3D perspective projection from vertical field of view
+//////////////////////////////////////////////////////////////////////////////
+
+/** Build a perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_yfov(matrix<E,A,B,L>& m, E yfov, E aspect, E n,
+ E f, Handedness handedness, ZClip z_clip)
+{
+ typedef matrix<E,A,B,L> matrix_type;
+ typedef typename matrix_type::value_type value_type;
+
+ value_type height = value_type(2) * std::tan(yfov * value_type(.5)) * n;
+ matrix_perspective(m, height * aspect, height, n, f,
+ handedness, z_clip);
+}
+
+/** Build a left-handedness perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_yfov_LH(matrix<E,A,B,L>& m, E yfov, E aspect, E n,
+ E f, ZClip z_clip)
+{
+ matrix_perspective_yfov(m,yfov,aspect,n,f,left_handed,z_clip);
+}
+
+/** Build a right-handedness perspective matrix */
+template < typename E, class A, class B, class L > void
+matrix_perspective_yfov_RH(matrix<E,A,B,L>& m, E yfov, E aspect, E n,
+ E f, ZClip z_clip)
+{
+ matrix_perspective_yfov(m,yfov,aspect,n,f,right_handed,z_clip);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// 3D orthographic projection from frustum
+//////////////////////////////////////////////////////////////////////////////
+
+/** Build a matrix representing an orthographic projection, specified by
+ * frustum bounds in l,r,b,t,n,f form, and with the given handedness and z
+ * clipping range
+ */
+
+template < typename E, class A, class B, class L > void
+matrix_orthographic(matrix<E,A,B,L>& m, E left, E right, E bottom, E top,
+ E n, E f, Handedness handedness,
+ ZClip z_clip)
+{
+ typedef matrix<E,A,B,L> matrix_type;
+ typedef typename matrix_type::value_type value_type;
+
+ /* Checking */
+ detail::CheckMatHomogeneous3D(m);
+
+ identity_transform(m);
+
+ value_type inv_width = value_type(1) / (right - left);
+ value_type inv_height = value_type(1) / (top - bottom);
+ value_type inv_depth = value_type(1) / (f - n);
+ value_type s = handedness == left_handed ? 1 : -1;
+
+ if (z_clip == z_clip_neg_one) {
+ m.set_basis_element(2,2,s * value_type(2) * inv_depth);
+ m.set_basis_element(3,2,-(f + n) * inv_depth);
+ } else { // z_clip.z_clip() == 0
+ m.set_basis_element(2,2,s * inv_depth);
+ m.set_basis_element(3,2,-n * inv_depth);
+ }
+
+ m.set_basis_element(0,0,value_type(2) * inv_width );
+ m.set_basis_element(1,1,value_type(2) * inv_height );
+ m.set_basis_element(3,0,-(right + left) * inv_width );
+ m.set_basis_element(3,1,-(top + bottom) * inv_height);
+}
+
+/** Build an orthographic projection matrix */
+template < typename E, class A, class B, class L > void
+matrix_orthographic(matrix<E,A,B,L>& m, E width, E height, E n, E f,
+ Handedness handedness, ZClip z_clip)
+{
+ typedef matrix<E,A,B,L> matrix_type;
+ typedef typename matrix_type::value_type value_type;
+
+ value_type half_width = width * value_type(.5);
+ value_type half_height = height * value_type(.5);
+ matrix_orthographic(m, -half_width, half_width,
+ -half_height, half_height, n, f, handedness, z_clip);
+}
+
+/** Build a left-handedness orthographic projection matrix */
+template < typename E, class A, class B, class L > void
+matrix_orthographic_LH(matrix<E,A,B,L>& m, E left, E right, E bottom,
+ E top, E n, E f, ZClip z_clip)
+{
+ matrix_orthographic(m, left, right, bottom, top, n, f,
+ left_handed, z_clip);
+}
+
+/** Build a right-handedness orthographic projection matrix */
+template < typename E, class A, class B, class L > void
+matrix_orthographic_RH(matrix<E,A,B,L>& m, E left, E right, E bottom,
+ E top, E n, E f, ZClip z_clip)
+{
+ matrix_orthographic(m, left, right, bottom, top, n, f,
+ right_handed, z_clip);
+}
+
+/** Build a left-handedness orthographic projection matrix */
+template < typename E, class A, class B, class L > void
+matrix_orthographic_LH(matrix<E,A,B,L>& m, E width, E height, E n,
+ E f, ZClip z_clip)
+{
+ matrix_orthographic(m, width, height, n, f, left_handed,
+ z_clip);
+}
+
+/** Build a right-handedness orthographic projection matrix */
+template < typename E, class A, class B, class L > void
+matrix_orthographic_RH(matrix<E,A,B,L>& m, E width, E height, E n,
+ E f, ZClip z_clip)
+{
+ matrix_orthographic(m, width, height, n, f, right_handed,
+ z_clip);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// 3D viewport
+//////////////////////////////////////////////////////////////////////////////
+
+/* Build a viewport matrix
+ *
+ * Note: A viewport matrix is in a sense the opposite of an orthographics
+ * projection matrix, and can be build by constructing and inverting the
+ * latter.
+ *
+ * @todo: Need to look into D3D viewport conventions and see if this needs to
+ * be adapted accordingly.
+ */
+
+template < typename E, class A, class B, class L > void
+matrix_viewport(matrix<E,A,B,L>& m, E left, E right, E bottom,
+ E top, ZClip z_clip, E n = E(0), E f = E(1))
+{
+ matrix_orthographic_LH(m, left, right, bottom, top, n, f, z_clip);
+ /* @todo: invert(m), when available */
+ m = inverse(m);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// 3D picking volume
+//////////////////////////////////////////////////////////////////////////////
+
+/* Build a pick volume matrix
+ *
+ * When post-concatenated with a projection matrix, the pick matrix modifies
+ * the view volume to create a 'picking volume'. This volume corresponds to
+ * a screen rectangle centered at (pick_x, pick_y) and with dimensions
+ * pick_widthXpick_height.
+ *
+ * @todo: Representation of viewport between this function and
+ * matrix_viewport() is inconsistent (position and dimensions vs. bounds).
+ * Should this be addressed?
+ */
+
+template < typename E, class A, class B, class L > void
+matrix_pick(
+ matrix<E,A,B,L>& m, E pick_x, E pick_y, E pick_width, E pick_height,
+ E viewport_x, E viewport_y, E viewport_width, E viewport_height)
+{
+ typedef matrix<E,A,B,L> matrix_type;
+ typedef typename matrix_type::value_type value_type;
+
+ /* Checking */
+ detail::CheckMatHomogeneous3D(m);
+
+ identity_transform(m);
+
+ value_type inv_width = value_type(1) / pick_width;
+ value_type inv_height = value_type(1) / pick_height;
+
+ m.set_basis_element(0,0,viewport_width*inv_width);
+ m.set_basis_element(1,1,viewport_height*inv_height);
+ m.set_basis_element(3,0,
+ (viewport_width+value_type(2)*(viewport_x-pick_x))*inv_width);
+ m.set_basis_element(3,1,
+ (viewport_height+value_type(2)*(viewport_y-pick_y))*inv_height);
+}
+
+} // namespace cml
+
+#endif