/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software  Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2011 by Bastien Montagne.
 * All rights reserved.
 *
 * Contributor(s): None yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 *
 */

/** \file blender/modifiers/intern/MOD_weightvg_util.h
 *  \ingroup modifiers
 */

#ifndef __MOD_WEIGHTVG_UTIL_H__
#define __MOD_WEIGHTVG_UTIL_H__

struct CurveMapping;
struct DerivedMesh;
struct Object;
struct Tex;
struct Scene;
struct RNG;

/*
 * XXX I'd like to make modified weights visible in WeightPaint mode,
 *     but couldn't figure a way to do this...
 *     Maybe this will need changes in mesh_calc_modifiers (DerivedMesh.c)?
 *     Or the WeightPaint mode code itself?
 */

/**************************************
 * Util functions.                    *
 **************************************/

/* We cannot divide by zero (what a surprise...).
 * So if -MOD_WEIGHTVGROUP_DIVMODE_ZEROFLOOR < weightf < MOD_WEIGHTVGROUP_DIVMODE_ZEROFLOOR,
 * we clamp weightf to this value (or its negative version).
 * Also used to avoid null power factor.
 */
#define MOD_WVG_ZEROFLOOR		1.0e-32f

/* Maps new_w weights in place, using either one of the predefined functions, or a custom curve.
 * Return values are in new_w.
 * If indices is not NULL, it must be a table of same length as org_w and new_w, mapping to the real
 * vertex index (in case the weight tables do not cover the whole vertices...).
 * cmap might be NULL, in which case curve mapping mode will return unmodified data.
 */
void weightvg_do_map(int num, float *new_w, short mode, struct CurveMapping *cmap, struct RNG *rng);

/* Applies new_w weights to org_w ones, using either a texture, vgroup or constant value as factor.
 * Return values are in org_w.
 * If indices is not NULL, it must be a table of same length as org_w and new_w, mapping to the real
 * vertex index (in case the weight tables do not cover the whole vertices...).
 * XXX The standard "factor" value is assumed in [0.0, 1.0] range. Else, weird results might appear.
 */
void weightvg_do_mask(int num, const int *indices, float *org_w, const float *new_w, Object *ob,
                      DerivedMesh *dm, float fact, const char defgrp_name[MAX_VGROUP_NAME],
                      struct Scene *scene, Tex *texture, int tex_use_channel, int tex_mapping,
                      Object *tex_map_object, const char *tex_uvlayer_name);

/* Applies weights to given vgroup (defgroup), and optionally add/remove vertices from the group.
 * If indices is not NULL, it must be a table of same length as weights, mapping to the real
 * vertex index (in case the weight table does not cover the whole vertices...).
 */
void weightvg_update_vg(MDeformVert *dvert, int defgrp_idx, MDeformWeight **dws, int num,
                        const int *indices, const float *weights, const bool do_add,
                        const float add_thresh, const bool do_rem, const float rem_thresh);

#endif /* __MOD_WEIGHTVG_UTIL_H__ */