/*
 * ***** 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 Blender Foundation.
 * All rights reserved.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/blenkernel/intern/mesh_validate.c
 *  \ingroup bke
 */


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>

#include "DNA_mesh_types.h"
#include "DNA_meshdata_types.h"
#include "DNA_object_types.h"

#include "BLO_sys_types.h"

#include "BLI_edgehash.h"
#include "BLI_math_base.h"
#include "BLI_utildefines.h"

#include "BKE_deform.h"
#include "BKE_depsgraph.h"
#include "BKE_DerivedMesh.h"
#include "BKE_mesh.h"

#include "MEM_guardedalloc.h"

#define SELECT 1

typedef union {
	uint32_t verts[2];
	int64_t edval;
} EdgeUUID;

typedef struct SortFace {
	EdgeUUID		es[4];
	unsigned int	index;
} SortFace;

/* Used to detect polys (faces) using exactly the same vertices. */
/* Used to detect loops used by no (disjoint) or more than one (intersect) polys. */
typedef struct SortPoly {
	int *verts;
	int numverts;
	int loopstart;
	unsigned int index;
	int invalid; /* Poly index. */
} SortPoly;

static void edge_store_assign(uint32_t verts[2],  const uint32_t v1, const uint32_t v2)
{
	if (v1 < v2) {
		verts[0] = v1;
		verts[1] = v2;
	}
	else {
		verts[0] = v2;
		verts[1] = v1;
	}
}

static void edge_store_from_mface_quad(EdgeUUID es[4], MFace *mf)
{
	edge_store_assign(es[0].verts, mf->v1, mf->v2);
	edge_store_assign(es[1].verts, mf->v2, mf->v3);
	edge_store_assign(es[2].verts, mf->v3, mf->v4);
	edge_store_assign(es[3].verts, mf->v4, mf->v1);
}

static void edge_store_from_mface_tri(EdgeUUID es[4], MFace *mf)
{
	edge_store_assign(es[0].verts, mf->v1, mf->v2);
	edge_store_assign(es[1].verts, mf->v2, mf->v3);
	edge_store_assign(es[2].verts, mf->v3, mf->v1);
	es[3].verts[0] = es[3].verts[1] = UINT_MAX;
}

static int int64_cmp(const void *v1, const void *v2)
{
	const int64_t x1 = *(const int64_t *)v1;
	const int64_t x2 = *(const int64_t *)v2;

	if (x1 > x2) {
		return 1;
	}
	else if (x1 < x2) {
		return -1;
	}

	return 0;
}

static int search_face_cmp(const void *v1, const void *v2)
{
	const SortFace *sfa = v1, *sfb = v2;

	if (sfa->es[0].edval > sfb->es[0].edval) {
		return 1;
	}
	else if	(sfa->es[0].edval < sfb->es[0].edval) {
		return -1;
	}

	else if	(sfa->es[1].edval > sfb->es[1].edval) {
		return 1;
	}
	else if	(sfa->es[1].edval < sfb->es[1].edval) {
		return -1;
	}

	else if	(sfa->es[2].edval > sfb->es[2].edval) {
		return 1;
	}
	else if	(sfa->es[2].edval < sfb->es[2].edval) {
		return -1;
	}

	else if	(sfa->es[3].edval > sfb->es[3].edval) {
		return 1;
	}
	else if	(sfa->es[3].edval < sfb->es[3].edval) {
		return -1;
	}

	return 0;
}

/* TODO check there is not some standard define of this somewhere! */
static int int_cmp(const void *v1, const void *v2)
{
	return *(int *)v1 > *(int *)v2 ? 1 : *(int *)v1 < *(int *)v2 ? -1 : 0;
}

static int search_poly_cmp(const void *v1, const void *v2)
{
	const SortPoly *sp1 = v1, *sp2 = v2;
	const int max_idx = sp1->numverts > sp2->numverts ? sp2->numverts : sp1->numverts;
	int idx = 0;

	/* Reject all invalid polys at end of list! */
	if (sp1->invalid || sp2->invalid)
		return sp1->invalid && sp2->invalid ? 0 : sp1->invalid ? 1 : -1;
	/* Else, sort on first non-egal verts (remember verts of valid polys are sorted). */
	while (idx < max_idx && sp1->verts[idx] == sp2->verts[idx])
		idx++;
	return sp1->verts[idx] > sp2->verts[idx] ? 1 : sp1->verts[idx] < sp2->verts[idx] ? -1 :
	       sp1->numverts > sp2->numverts ? 1 : sp1->numverts < sp2->numverts ? -1 : 0;
}

static int search_polyloop_cmp(const void *v1, const void *v2)
{
	const SortPoly *sp1 = v1, *sp2 = v2;

	/* Reject all invalid polys at end of list! */
	if (sp1->invalid || sp2->invalid)
		return sp1->invalid && sp2->invalid ? 0 : sp1->invalid ? 1 : -1;
	/* Else, sort on loopstart. */
	return sp1->loopstart > sp2->loopstart ? 1 : sp1->loopstart < sp2->loopstart ? -1 : 0;
}

#define PRINT if (do_verbose) printf

int BKE_mesh_validate_arrays(Mesh *mesh,
                             MVert *mverts, unsigned int totvert,
                             MEdge *medges, unsigned int totedge,
                             MFace *mfaces, unsigned int totface,
                             MLoop *mloops, unsigned int totloop,
                             MPoly *mpolys, unsigned int totpoly,
                             MDeformVert *dverts, /* assume totvert length */
                             const short do_verbose, const short do_fixes)
{
#   define REMOVE_EDGE_TAG(_me) { _me->v2 = _me->v1; do_edge_free = TRUE; } (void)0
#   define IS_REMOVED_EDGE(_me) (_me->v2 == _me->v1)

#   define REMOVE_LOOP_TAG(_ml) { _ml->e = INVALID_LOOP_EDGE_MARKER; do_polyloop_free = TRUE; } (void)0
#   define REMOVE_POLY_TAG(_mp) { _mp->totloop *= -1; do_polyloop_free = TRUE; } (void)0

	MVert *mv = mverts;
	MEdge *me;
	MLoop *ml;
	MPoly *mp;
	unsigned int i, j;
	int *v;

	short do_edge_free = FALSE;
	short do_face_free = FALSE;
	short do_polyloop_free = FALSE; /* This regroups loops and polys! */

	short verts_fixed = FALSE;
	short vert_weights_fixed = FALSE;
	int msel_fixed = FALSE;

	int do_edge_recalc = FALSE;

	EdgeHash *edge_hash = BLI_edgehash_new();

	BLI_assert(!(do_fixes && mesh == NULL));

	PRINT("%s: verts(%u), edges(%u), loops(%u), polygons(%u)\n",
	      __func__, totvert, totedge, totloop, totpoly);

	if (totedge == 0 && totpoly != 0) {
		PRINT("\tLogical error, %u polygons and 0 edges\n", totpoly);
		do_edge_recalc = do_fixes;
	}

	for (i = 1; i < totvert; i++, mv++) {
		int fix_normal = TRUE;

		for (j = 0; j < 3; j++) {
			if (!finite(mv->co[j])) {
				PRINT("\tVertex %u: has invalid coordinate\n", i);

				if (do_fixes) {
					zero_v3(mv->co);

					verts_fixed = TRUE;
				}
			}

			if (mv->no[j] != 0)
				fix_normal = FALSE;
		}

		if (fix_normal) {
			PRINT("\tVertex %u: has zero normal, assuming Z-up normal\n", i);
			if (do_fixes) {
				mv->no[2] = SHRT_MAX;
				verts_fixed = TRUE;
			}
		}
	}

	for (i = 0, me = medges; i < totedge; i++, me++) {
		int remove = FALSE;
		if (me->v1 == me->v2) {
			PRINT("\tEdge %u: has matching verts, both %u\n", i, me->v1);
			remove = do_fixes;
		}
		if (me->v1 >= totvert) {
			PRINT("\tEdge %u: v1 index out of range, %u\n", i, me->v1);
			remove = do_fixes;
		}
		if (me->v2 >= totvert) {
			PRINT("\tEdge %u: v2 index out of range, %u\n", i, me->v2);
			remove = do_fixes;
		}

		if (BLI_edgehash_haskey(edge_hash, me->v1, me->v2)) {
			PRINT("\tEdge %u: is a duplicate of %d\n", i,
			      GET_INT_FROM_POINTER(BLI_edgehash_lookup(edge_hash, me->v1, me->v2)));
			remove = do_fixes;
		}

		if (remove == FALSE) {
			BLI_edgehash_insert(edge_hash, me->v1, me->v2, SET_INT_IN_POINTER(i));
		}
		else {
			REMOVE_EDGE_TAG(me);
		}
	}

	if (mfaces && !mpolys) {
#		define REMOVE_FACE_TAG(_mf) { _mf->v3 = 0; do_face_free = TRUE; } (void)0
#		define CHECK_FACE_VERT_INDEX(a, b) \
					if (mf->a == mf->b) { \
						PRINT("    face %u: verts invalid, " STRINGIFY(a) "/" STRINGIFY(b) " both %u\n", i, mf->a); \
						remove = do_fixes; \
					} (void)0
#		define CHECK_FACE_EDGE(a, b) \
					if (!BLI_edgehash_haskey(edge_hash, mf->a, mf->b)) { \
						PRINT("    face %u: edge " STRINGIFY(a) "/" STRINGIFY(b) \
						      " (%u,%u) is missing egde data\n", i, mf->a, mf->b); \
						do_edge_recalc = TRUE; \
					} (void)0

		MFace *mf;
		MFace *mf_prev;

		SortFace *sort_faces = MEM_callocN(sizeof(SortFace) * totface, "search faces");
		SortFace *sf;
		SortFace *sf_prev;
		unsigned int totsortface = 0;

		PRINT("No Polys, only tesselated Faces\n");

		for (i = 0, mf = mfaces, sf = sort_faces; i < totface; i++, mf++) {
			int remove = FALSE;
			int fidx;
			unsigned int fv[4];

			fidx = mf->v4 ? 3 : 2;
			do {
				fv[fidx] = *(&(mf->v1) + fidx);
				if (fv[fidx] >= totvert) {
					PRINT("\tFace %u: 'v%d' index out of range, %u\n", i, fidx + 1, fv[fidx]);
					remove = do_fixes;
				}
			} while (fidx--);

			if (remove == FALSE) {
				if (mf->v4) {
					CHECK_FACE_VERT_INDEX(v1, v2);
					CHECK_FACE_VERT_INDEX(v1, v3);
					CHECK_FACE_VERT_INDEX(v1, v4);

					CHECK_FACE_VERT_INDEX(v2, v3);
					CHECK_FACE_VERT_INDEX(v2, v4);

					CHECK_FACE_VERT_INDEX(v3, v4);
				}
				else {
					CHECK_FACE_VERT_INDEX(v1, v2);
					CHECK_FACE_VERT_INDEX(v1, v3);

					CHECK_FACE_VERT_INDEX(v2, v3);
				}

				if (remove == FALSE) {
					if (totedge) {
						if (mf->v4) {
							CHECK_FACE_EDGE(v1, v2);
							CHECK_FACE_EDGE(v2, v3);
							CHECK_FACE_EDGE(v3, v4);
							CHECK_FACE_EDGE(v4, v1);
						}
						else {
							CHECK_FACE_EDGE(v1, v2);
							CHECK_FACE_EDGE(v2, v3);
							CHECK_FACE_EDGE(v3, v1);
						}
					}

					sf->index = i;

					if (mf->v4) {
						edge_store_from_mface_quad(sf->es, mf);

						qsort(sf->es, 4, sizeof(int64_t), int64_cmp);
					}
					else {
						edge_store_from_mface_tri(sf->es, mf);
						qsort(sf->es, 3, sizeof(int64_t), int64_cmp);
					}

					totsortface++;
					sf++;
				}
			}

			if (remove) {
				REMOVE_FACE_TAG(mf);
			}
		}

		qsort(sort_faces, totsortface, sizeof(SortFace), search_face_cmp);

		sf = sort_faces;
		sf_prev = sf;
		sf++;

		for (i = 1; i < totsortface; i++, sf++) {
			int remove = FALSE;

			/* on a valid mesh, code below will never run */
			if (memcmp(sf->es, sf_prev->es, sizeof(sf_prev->es)) == 0) {
				mf = mfaces + sf->index;

				if (do_verbose) {
					mf_prev = mfaces + sf_prev->index;

					if (mf->v4) {
						PRINT("\tFace %u & %u: are duplicates (%u,%u,%u,%u) (%u,%u,%u,%u)\n",
						      sf->index, sf_prev->index, mf->v1, mf->v2, mf->v3, mf->v4,
						      mf_prev->v1, mf_prev->v2, mf_prev->v3, mf_prev->v4);
					}
					else {
						PRINT("\tFace %u & %u: are duplicates (%u,%u,%u) (%u,%u,%u)\n",
						      sf->index, sf_prev->index, mf->v1, mf->v2, mf->v3,
						      mf_prev->v1, mf_prev->v2, mf_prev->v3);
					}
				}

				remove = do_fixes;
			}
			else {
				sf_prev = sf;
			}

			if (remove) {
				REMOVE_FACE_TAG(mf);
			}
		}

		MEM_freeN(sort_faces);

#		undef REMOVE_FACE_TAG
#		undef CHECK_FACE_VERT_INDEX
#		undef CHECK_FACE_EDGE
	}

	/* Checking loops and polys is a bit tricky, as they are quite intricated...
	 *
	 * Polys must have:
	 * - a valid loopstart value.
	 * - a valid totloop value (>= 3 and loopstart+totloop < me.totloop).
	 *
	 * Loops must have:
	 * - a valid v value.
	 * - a valid e value (corresponding to the edge it defines with the next loop in poly).
	 *
	 * Also, loops not used by polys can be discarded.
	 * And "intersecting" loops (i.e. loops used by more than one poly) are invalid,
	 * so be sure to leave at most one poly per loop!
	 */
	{
		SortPoly *sort_polys = MEM_callocN(sizeof(SortPoly) * totpoly, "mesh validate's sort_polys");
		SortPoly *prev_sp, *sp = sort_polys;
		int prev_end;
		for (i = 0, mp = mpolys; i < totpoly; i++, mp++, sp++) {
			sp->index = i;

			if (mp->loopstart < 0 || mp->totloop < 3) {
				/* Invalid loop data. */
				PRINT("\tPoly %u is invalid (loopstart: %u, totloop: %u)\n", sp->index, mp->loopstart, mp->totloop);
				sp->invalid = TRUE;
			}
			else if (mp->loopstart + mp->totloop > totloop) {
				/* Invalid loop data. */
				PRINT("\tPoly %u uses loops out of range (loopstart: %u, loopend: %u, max nbr of loops: %u)\n",
				      sp->index, mp->loopstart, mp->loopstart + mp->totloop - 1, totloop - 1);
				sp->invalid = TRUE;
			}
			else {
				/* Poly itself is valid, for now. */
				int v1, v2; /* v1 is prev loop vert idx, v2 is current loop one. */
				sp->invalid = FALSE;
				sp->verts = v = MEM_mallocN(sizeof(int) * mp->totloop, "Vert idx of SortPoly");
				sp->numverts = mp->totloop;
				sp->loopstart = mp->loopstart;

				/* Test all poly's loops' vert idx. */
				for (j = 0, ml = &mloops[sp->loopstart]; j < mp->totloop; j++, ml++, v++) {
					if (ml->v >= totvert) {
						/* Invalid vert idx. */
						PRINT("\tLoop %u has invalid vert reference (%u)\n", sp->loopstart + j, ml->v);
						sp->invalid = TRUE;
					}

					mverts[ml->v].flag |= ME_VERT_TMP_TAG;
					*v = ml->v;
				}

				/* is the same vertex used more then once */
				if (!sp->invalid) {
					v = sp->verts;
					for (j = 0; j < mp->totloop; j++, v++) {
						if ((mverts[*v].flag & ME_VERT_TMP_TAG) == 0) {
							PRINT("\tPoly %u has duplicate vert reference at corner (%u)\n", i, j);
							sp->invalid = TRUE;
						}
						mverts[*v].flag &= ~ME_VERT_TMP_TAG;
					}
				}

				if (sp->invalid)
					continue;

				/* Test all poly's loops. */
				for (j = 0, ml = &mloops[sp->loopstart]; j < mp->totloop; j++, ml++) {
					v1 = ml->v;
					v2 = mloops[sp->loopstart + (j + 1) % mp->totloop].v;
					if (!BLI_edgehash_haskey(edge_hash, v1, v2)) {
						/* Edge not existing. */
						PRINT("\tPoly %u needs missing edge (%u, %u)\n", sp->index, v1, v2);
						if (do_fixes)
							do_edge_recalc = TRUE;
						else
							sp->invalid = TRUE;
					}
					else if (ml->e >= totedge) {
						/* Invalid edge idx.
						 * We already know from previous text that a valid edge exists, use it (if allowed)! */
						if (do_fixes) {
							int prev_e = ml->e;
							ml->e = GET_INT_FROM_POINTER(BLI_edgehash_lookup(edge_hash, v1, v2));
							PRINT("\tLoop %u has invalid edge reference (%u), fixed using edge %u\n",
							      sp->loopstart + j, prev_e, ml->e);
						}
						else {
							PRINT("\tLoop %u has invalid edge reference (%u)\n", sp->loopstart + j, ml->e);
							sp->invalid = TRUE;
						}
					}
					else {
						me = &medges[ml->e];
						if (IS_REMOVED_EDGE(me) || !((me->v1 == v1 && me->v2 == v2) || (me->v1 == v2 && me->v2 == v1))) {
							/* The pointed edge is invalid (tagged as removed, or vert idx mismatch),
							 * and we already know from previous test that a valid one exists, use it (if allowed)! */
							if (do_fixes) {
								int prev_e = ml->e;
								ml->e = GET_INT_FROM_POINTER(BLI_edgehash_lookup(edge_hash, v1, v2));
								PRINT("\tPoly %u has invalid edge reference (%u), fixed using edge %u\n",
								      sp->index, prev_e, ml->e);
							}
							else {
								PRINT("\tPoly %u has invalid edge reference (%u)\n", sp->index, ml->e);
								sp->invalid = TRUE;
							}
						}
					}
				}

				/* Now check that that poly does not use a same vertex more than once! */
				if (!sp->invalid) {
					int *prev_v = v = sp->verts;
					j = sp->numverts;

					qsort(sp->verts, j, sizeof(int), int_cmp);

					for (j--, v++; j; j--, v++) {
						if (*v != *prev_v) {
							int dlt = v - prev_v;
							if (dlt > 1) {
								PRINT("\tPoly %u is invalid, it multi-uses vertex %u (%u times)\n",
								      sp->index, *prev_v, dlt);
								sp->invalid = TRUE;
							}
							prev_v = v;
						}
					}
					if (v - prev_v > 1) { /* Don't forget final verts! */
						PRINT("\tPoly %u is invalid, it multi-uses vertex %u (%u times)\n",
						      sp->index, *prev_v, (int)(v - prev_v));
						sp->invalid = TRUE;
					}
				}
			
			}
		}

		/* Second check pass, testing polys using the same verts. */
		qsort(sort_polys, totpoly, sizeof(SortPoly), search_poly_cmp);
		sp = prev_sp = sort_polys;
		sp++;

		for (i = 1; i < totpoly; i++, sp++) {
			int p1_nv = sp->numverts, p2_nv = prev_sp->numverts;
			int *p1_v = sp->verts, *p2_v = prev_sp->verts;
			short p1_sub = TRUE, p2_sub = TRUE;
			if (sp->invalid)
				break;
			/* Test same polys. */
#if 0
			/* NOTE: This performs a sub-set test. */
			/* XXX This (and the sort of verts list) is better than systematic
			 *     search of all verts of one list into the other if lists have
			 *     a fair amount of elements.
			 *     Not sure however it's worth it in this case?
			 *     But as we also need sorted vert list to check verts multi-used
			 *     (in first pass of checks)... */
			/* XXX If we consider only "equal" polys (i.e. using exactly same set of verts)
			 *     as invalid, better to replace this by a simple memory cmp... */
			while ((p1_nv && p2_nv) && (p1_sub || p2_sub)) {
				if (*p1_v < *p2_v) {
					if (p1_sub)
						p1_sub = FALSE;
					p1_nv--;
					p1_v++;
				}
				else if (*p2_v < *p1_v) {
					if (p2_sub)
						p2_sub = FALSE;
					p2_nv--;
					p2_v++;
				}
				else {
					/* Equality, both next verts. */
					p1_nv--;
					p2_nv--;
					p1_v++;
					p2_v++;
				}
			}
			if (p1_nv && p1_sub)
				p1_sub = FALSE;
			else if (p2_nv && p2_sub)
				p2_sub = FALSE;

			if (p1_sub && p2_sub) {
				PRINT("\tPolys %u and %u use same vertices, considering poly %u as invalid.\n",
				      prev_sp->index, sp->index, sp->index);
				sp->invalid = TRUE;
			}
			/* XXX In fact, these might be valid? :/ */
			else if (p1_sub) {
				PRINT("\t%u is a sub-poly of %u, considering it as invalid.\n", sp->index, prev_sp->index);
				sp->invalid = TRUE;
			}
			else if (p2_sub) {
				PRINT("\t%u is a sub-poly of %u, considering it as invalid.\n", prev_sp->index, sp->index);
				prev_sp->invalid = TRUE;
				prev_sp = sp; /* sp is new reference poly. */
			}
#else
			if (0) {
				p1_sub += 0;
				p2_sub += 0;
			}
			if ((p1_nv == p2_nv) && (memcmp(p1_v, p2_v, p1_nv * sizeof(*p1_v)) == 0)) {
				if (do_verbose) {
					PRINT("\tPolys %u and %u use same vertices (%u",
					      prev_sp->index, sp->index, *p1_v);
					for (j = 1; j < p1_nv; j++)
						PRINT(", %u", p1_v[j]);
					PRINT("), considering poly %u as invalid.\n", sp->index);
				}
				sp->invalid = TRUE;
			}
#endif
			else {
				prev_sp = sp;
			}
		}

		/* Third check pass, testing loops used by none or more than one poly. */
		qsort(sort_polys, totpoly, sizeof(SortPoly), search_polyloop_cmp);
		sp = sort_polys;
		prev_sp = NULL;
		prev_end = 0;
		for (i = 0; i < totpoly; i++, sp++) {
			/* Free this now, we don't need it anymore, and avoid us another loop! */
			if (sp->verts)
				MEM_freeN(sp->verts);

			/* Note above prev_sp: in following code, we make sure it is always valid poly (or NULL). */
			if (sp->invalid) {
				if (do_fixes) {
					REMOVE_POLY_TAG((&mpolys[sp->index]));
					/* DO NOT REMOVE ITS LOOPS!!!
					 * As already invalid polys are at the end of the SortPoly list, the loops they
					 * were the only users have already been tagged as "to remove" during previous
					 * iterations, and we don't want to remove some loops that may be used by
					 * another valid poly! */
				}
			}
			/* Test loops users. */
			else {
				/* Unused loops. */
				if (prev_end < sp->loopstart) {
					for (j = prev_end, ml = &mloops[prev_end]; j < sp->loopstart; j++, ml++) {
						PRINT("\tLoop %u is unused.\n", j);
						if (do_fixes)
							REMOVE_LOOP_TAG(ml);
					}
					prev_end = sp->loopstart + sp->numverts;
					prev_sp = sp;
				}
				/* Multi-used loops. */
				else if (prev_end > sp->loopstart) {
					PRINT("\tPolys %u and %u share loops from %u to %u, considering poly %u as invalid.\n",
					      prev_sp->index, sp->index, sp->loopstart, prev_end, sp->index);
					if (do_fixes) {
						REMOVE_POLY_TAG((&mpolys[sp->index]));
						/* DO NOT REMOVE ITS LOOPS!!!
						 * They might be used by some next, valid poly!
						 * Just not updating prev_end/prev_sp vars is enough to ensure the loops
						 * effectively no more needed will be marked as "to be removed"! */
					}
				}
				else {
					prev_end = sp->loopstart + sp->numverts;
					prev_sp = sp;
				}
			}
		}
		/* We may have some remaining unused loops to get rid of! */
		if (prev_end < totloop) {
			for (j = prev_end, ml = &mloops[prev_end]; j < totloop; j++, ml++) {
				PRINT("\tLoop %u is unused.\n", j);
				if (do_fixes)
					REMOVE_LOOP_TAG(ml);
			}
		}

		MEM_freeN(sort_polys);
	}

	BLI_edgehash_free(edge_hash, NULL);

	/* fix deform verts */
	if (dverts) {
		MDeformVert *dv;
		for (i = 0, dv = dverts; i < totvert; i++, dv++) {
			MDeformWeight *dw;

			for (j = 0, dw = dv->dw; j < dv->totweight; j++, dw++) {
				/* note, greater then max defgroups is accounted for in our code, but not < 0 */
				if (!finite(dw->weight)) {
					PRINT("\tVertex deform %u, group %d has weight: %f\n", i, dw->def_nr, dw->weight);
					if (do_fixes) {
						dw->weight = 0.0f;
						vert_weights_fixed = TRUE;
					}
				}
				else if (dw->weight < 0.0f || dw->weight > 1.0f) {
					PRINT("\tVertex deform %u, group %d has weight: %f\n", i, dw->def_nr, dw->weight);
					if (do_fixes) {
						CLAMP(dw->weight, 0.0f, 1.0f);
						vert_weights_fixed = TRUE;
					}
				}

				if (dw->def_nr < 0) {
					PRINT("\tVertex deform %u, has invalid group %d\n", i, dw->def_nr);
					if (do_fixes) {
						defvert_remove_group(dv, dw);
						if (dv->dw) {
							/* re-allocated, the new values compensate for stepping
							 * within the for loop and may not be valid */
							j--;
							dw = dv->dw + j;

							vert_weights_fixed = TRUE;
						}
						else { /* all freed */
							break;
						}
					}
				}
			}
		}
	}

#   undef REMOVE_EDGE_TAG
#   undef IS_REMOVED_EDGE
#   undef REMOVE_LOOP_TAG
#   undef REMOVE_POLY_TAG

	if (mesh) {
		if (do_face_free) {
			BKE_mesh_strip_loose_faces(mesh);
		}

		if (do_polyloop_free) {
			BKE_mesh_strip_loose_polysloops(mesh);
		}

		if (do_edge_free) {
			BKE_mesh_strip_loose_edges(mesh);
		}

		if (do_edge_recalc) {
			BKE_mesh_calc_edges(mesh, TRUE);
		}
	}

	if (mesh && mesh->mselect) {
		MSelect *msel;
		int free_msel = FALSE;

		for (i = 0, msel = mesh->mselect; i < mesh->totselect; i++, msel++) {
			int tot_elem = 0;

			if (msel->index < 0) {
				PRINT("\tMesh select element %d type %d index is negative, "
				      "resetting selection stack.\n", i, msel->type);
				free_msel = TRUE;
				break;
			}

			switch (msel->type) {
				case ME_VSEL:
					tot_elem = mesh->totvert;
					break;
				case ME_ESEL:
					tot_elem = mesh->totedge;
					break;
				case ME_FSEL:
					tot_elem = mesh->totface;
					break;
			}

			if (msel->index > tot_elem) {
				PRINT("\tMesh select element %d type %d index %d is larger than data array size %d, "
				      "resetting selection stack.\n", i, msel->type, msel->index, tot_elem);

				free_msel = TRUE;
				break;
			}
		}

		if (free_msel) {
			MEM_freeN(mesh->mselect);
			mesh->mselect = NULL;
			mesh->totselect = 0;
		}
	}

	PRINT("%s: finished\n\n", __func__);

	return (verts_fixed || vert_weights_fixed || do_polyloop_free || do_edge_free || do_edge_recalc || msel_fixed);
}

static int mesh_validate_customdata(CustomData *data, short do_verbose, const short do_fixes)
{
	int i = 0, has_fixes = 0;

	PRINT("%s: Checking %d CD layers...\n", __func__, data->totlayer);

	while (i < data->totlayer) {
		CustomDataLayer *layer = &data->layers[i];
		CustomDataMask mask = CD_TYPE_AS_MASK(layer->type);
		int ok = 1;

		if ((mask & CD_MASK_MESH) == 0) {
			PRINT("\tCustomDataLayer type %d which isn't in CD_MASK_MESH is stored in Mesh structure\n", layer->type);

			if (do_fixes) {
				CustomData_free_layer(data, layer->type, 0, i);
				ok = 0;
				has_fixes = 1;
			}
		}

		if (ok)
			i++;
	}

	PRINT("%s: Finished\n\n", __func__);

	return has_fixes;
}

#undef PRINT

static int BKE_mesh_validate_all_customdata(CustomData *vdata, CustomData *edata,
                                            CustomData *ldata, CustomData *pdata,
                                            short do_verbose, const short do_fixes)
{
	int vfixed = 0, efixed = 0, lfixed = 0, pfixed = 0;

	vfixed = mesh_validate_customdata(vdata, do_verbose, do_fixes);
	efixed = mesh_validate_customdata(edata, do_verbose, do_fixes);
	lfixed = mesh_validate_customdata(ldata, do_verbose, do_fixes);
	pfixed = mesh_validate_customdata(pdata, do_verbose, do_fixes);

	return vfixed || efixed || lfixed || pfixed;
}

int BKE_mesh_validate(Mesh *me, int do_verbose)
{
	int layers_fixed = 0, arrays_fixed = 0;

	if (do_verbose) {
		printf("MESH: %s\n", me->id.name + 2);
	}

	layers_fixed = BKE_mesh_validate_all_customdata(&me->vdata, &me->edata, &me->ldata, &me->pdata, do_verbose, TRUE);
	arrays_fixed = BKE_mesh_validate_arrays(me,
	                                        me->mvert, me->totvert,
	                                        me->medge, me->totedge,
	                                        me->mface, me->totface,
	                                        me->mloop, me->totloop,
	                                        me->mpoly, me->totpoly,
	                                        me->dvert,
	                                        do_verbose, TRUE);

	if (layers_fixed || arrays_fixed) {
		DAG_id_tag_update(&me->id, OB_RECALC_DATA);
		return TRUE;
	}
	return FALSE;
}

int BKE_mesh_validate_dm(DerivedMesh *dm)
{
	return BKE_mesh_validate_arrays(NULL,
	                                dm->getVertArray(dm), dm->getNumVerts(dm),
	                                dm->getEdgeArray(dm), dm->getNumEdges(dm),
	                                dm->getTessFaceArray(dm), dm->getNumTessFaces(dm),
	                                dm->getLoopArray(dm), dm->getNumLoops(dm),
	                                dm->getPolyArray(dm), dm->getNumPolys(dm),
	                                dm->getVertDataArray(dm, CD_MDEFORMVERT),
	                                TRUE, FALSE);
}

void BKE_mesh_calc_edges(Mesh *mesh, int update)
{
	CustomData edata;
	EdgeHashIterator *ehi;
	MPoly *mp;
	MEdge *med, *med_orig;
	EdgeHash *eh = BLI_edgehash_new();
	int i, totedge, totpoly = mesh->totpoly;
	int med_index;

	if (mesh->totedge == 0)
		update = FALSE;

	if (update) {
		/* assume existing edges are valid
		 * useful when adding more faces and generating edges from them */
		med = mesh->medge;
		for (i = 0; i < mesh->totedge; i++, med++)
			BLI_edgehash_insert(eh, med->v1, med->v2, med);
	}

	/* mesh loops (bmesh only) */
	for (mp = mesh->mpoly, i = 0; i < totpoly; mp++, i++) {
		MLoop *l = &mesh->mloop[mp->loopstart];
		int j, l_prev = (l + (mp->totloop - 1))->v;
		for (j = 0; j < mp->totloop; j++, l++) {
			if (!BLI_edgehash_haskey(eh, l_prev, l->v)) {
				BLI_edgehash_insert(eh, l_prev, l->v, NULL);
			}
			l_prev = l->v;
		}
	}

	totedge = BLI_edgehash_size(eh);

	/* write new edges into a temporary CustomData */
	CustomData_reset(&edata);
	CustomData_add_layer(&edata, CD_MEDGE, CD_CALLOC, NULL, totedge);

	med = CustomData_get_layer(&edata, CD_MEDGE);
	for (ehi = BLI_edgehashIterator_new(eh), i = 0;
	     BLI_edgehashIterator_isDone(ehi) == FALSE;
	     BLI_edgehashIterator_step(ehi), ++i, ++med)
	{
		if (update && (med_orig = BLI_edgehashIterator_getValue(ehi))) {
			*med = *med_orig; /* copy from the original */
		}
		else {
			BLI_edgehashIterator_getKey(ehi, &med->v1, &med->v2);
			med->flag = ME_EDGEDRAW | ME_EDGERENDER | SELECT; /* select for newly created meshes which are selected [#25595] */
		}

		/* store the new edge index in the hash value */
		BLI_edgehashIterator_setValue(ehi, SET_INT_IN_POINTER(i));
	}
	BLI_edgehashIterator_free(ehi);

	if (mesh->totpoly) {
		/* second pass, iterate through all loops again and assign
		 * the newly created edges to them. */
		for (mp = mesh->mpoly, i = 0; i < mesh->totpoly; mp++, i++) {
			MLoop *l = &mesh->mloop[mp->loopstart];
			MLoop *l_prev = (l + (mp->totloop - 1));
			int j;
			for (j = 0; j < mp->totloop; j++, l++) {
				/* lookup hashed edge index */
				med_index = GET_INT_FROM_POINTER(BLI_edgehash_lookup(eh, l_prev->v, l->v));
				l_prev->e = med_index;
				l_prev = l;
			}
		}
	}

	/* free old CustomData and assign new one */
	CustomData_free(&mesh->edata, mesh->totedge);
	mesh->edata = edata;
	mesh->totedge = totedge;

	mesh->medge = CustomData_get_layer(&mesh->edata, CD_MEDGE);

	BLI_edgehash_free(eh, NULL);
}