144 lines
4.5 KiB
C
144 lines
4.5 KiB
C
/*
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Copyright (C) 1996-1997 Id Software, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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See file, 'COPYING', for details.
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*/
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#ifndef __QF_winding_h
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#define __QF_winding_h
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#include "QF/mathlib.h"
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/** \defgroup winding Winding Manipulation
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*/
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///@{
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struct plane_s;
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#define ON_EPSILON 0.05
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typedef struct winding_s {
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int numpoints; ///< The number of points in the winding
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vec3_t points[4]; ///< variable sized, never less than 3
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} winding_t;
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/** Create a very large four-point winding with all point on the plane.
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The winding will be a box with aligned with the axes of the plane. The
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order of yhe points is clockwise when viewed from the front side of
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the plane.
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In terms of s and t, the axes of the plane will be such that t (up) is
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the projection of either the z-axis or the x-axis (whichever is
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"closer"), and s is to the right (n = s cross t).
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\param p The plane on which to create the winding.
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\return The new winding.
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\note It is the caller's responsibiltiy to free the new winding.
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*/
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winding_t *BaseWindingForPlane (const struct plane_s *p);
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/** Create a new, empty winding with space for the specified number of points.
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\param points The number of points for which to leave space.
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\return The new winding.
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\note It is the caller's responsibiltiy to free the new winding.
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*/
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winding_t *NewWinding (int points);
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/** Free the winding.
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\param w The winding to be freed.
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*/
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void FreeWinding (winding_t *w);
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/** Create a new winding with the same points as the given winding.
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\param w The winding to copy.
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\return The new winding.
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\note It is the caller's responsibiltiy to free the new winding.
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*/
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winding_t *CopyWinding (const winding_t *w);
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/** Create a new winding with the reverse points of the given winding.
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This is useful when a winding for the back side of a plane is required.
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\param w The winding to copy.
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\return The new winding.
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\note It is the caller's responsibiltiy to free the new winding.
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*/
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winding_t *CopyWindingReverse (const winding_t *w);
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/** Create a new "winding" that holds the unit vectors of the edges of the
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given winding.
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\param w The winding to convert.
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\param unit If true, normalize the vectors.
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\return The "winding" holding the (unit) vectors.
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\note It is the caller's responsibiltiy to free the new winding.
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*/
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winding_t *WindingVectors (const winding_t *w, int unit);
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/** Clip the winding to the plain.
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The new winding will be the part of the input winding that is on the
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front side of the plane.
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The direction of the winding is preserved.
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\note It is the caller's responsibiltiy to free the new winding.
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\note The input winding will be freed.
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\param in The winding to be clipped.
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\param split The plane by which the winding will be clipped.
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\param keepon If true, an exactly on-plane winding will be saved,
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otherwise it will be clipped away.
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\return The new winding representing the part of the input winding
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on the font side of the plane, or NULL if the winding has
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been clipped away.
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*/
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winding_t *ClipWinding (winding_t *in, struct plane_s *split, qboolean keepon);
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/** Divide a winding by a plane, producing one or two windings.
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\note The original winding is not damaged or freed.
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\note If one of \a front or \a back is NULL, the other will point to
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the input winding.
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\note If neither \a front nor \a back are NULL, then both will be new
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windings and the caller will be responsible for freeing them.
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\param in The winding to be divided.
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\param split The plane by which the winding will be divided.
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\param front Set to the part of the input winding that is in front of
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the plane, or NULL if no part of the winding is in front
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of the plane.
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\param back Set to the part of the input winding that is behind the
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plane, or NULL if no part of the winding is behind the
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plane.
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*/
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void DivideWinding (winding_t *in, struct plane_s *split,
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winding_t **front, winding_t **back);
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///@}
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#endif//__QF_winding_h
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