/*
 * 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 Nicholas Bishop.
 */

/** \file
 * \ingroup modifiers
 */

#include "MEM_guardedalloc.h"

#include "BLI_utildefines.h"

#include "BLI_math_base.h"

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

#include "MOD_modifiertypes.h"

#include "BKE_mesh.h"
#include "BKE_mesh_runtime.h"

#include <assert.h>
#include <stdlib.h>
#include <string.h>

#ifdef WITH_MOD_REMESH
#  include "BLI_math_vector.h"

#  include "dualcon.h"
#endif

static void initData(ModifierData *md)
{
	RemeshModifierData *rmd = (RemeshModifierData *) md;

	rmd->scale = 0.9;
	rmd->depth = 4;
	rmd->hermite_num = 1;
	rmd->flag = MOD_REMESH_FLOOD_FILL;
	rmd->mode = MOD_REMESH_SHARP_FEATURES;
	rmd->threshold = 1;
}

#ifdef WITH_MOD_REMESH

static void init_dualcon_mesh(DualConInput *input, Mesh *mesh)
{
	memset(input, 0, sizeof(DualConInput));

	input->co = (void *)mesh->mvert;
	input->co_stride = sizeof(MVert);
	input->totco = mesh->totvert;

	input->mloop = (void *)mesh->mloop;
	input->loop_stride = sizeof(MLoop);

	BKE_mesh_runtime_looptri_ensure(mesh);
	input->looptri = (void *)mesh->runtime.looptris.array;
	input->tri_stride = sizeof(MLoopTri);
	input->tottri = mesh->runtime.looptris.len;

	INIT_MINMAX(input->min, input->max);
	BKE_mesh_minmax(mesh, input->min, input->max);
}

/* simple structure to hold the output: a CDDM and two counters to
 * keep track of the current elements */
typedef struct {
	Mesh *mesh;
	int curvert, curface;
} DualConOutput;

/* allocate and initialize a DualConOutput */
static void *dualcon_alloc_output(int totvert, int totquad)
{
	DualConOutput *output;

	if (!(output = MEM_callocN(sizeof(DualConOutput),
	                           "DualConOutput")))
	{
		return NULL;
	}

	output->mesh = BKE_mesh_new_nomain(totvert, 0, 0, 4 * totquad, totquad);
	return output;
}

static void dualcon_add_vert(void *output_v, const float co[3])
{
	DualConOutput *output = output_v;
	Mesh *mesh = output->mesh;

	assert(output->curvert < mesh->totvert);

	copy_v3_v3(mesh->mvert[output->curvert].co, co);
	output->curvert++;
}

static void dualcon_add_quad(void *output_v, const int vert_indices[4])
{
	DualConOutput *output = output_v;
	Mesh *mesh = output->mesh;
	MLoop *mloop;
	MPoly *cur_poly;
	int i;

	assert(output->curface < mesh->totpoly);

	mloop = mesh->mloop;
	cur_poly = &mesh->mpoly[output->curface];

	cur_poly->loopstart = output->curface * 4;
	cur_poly->totloop = 4;
	for (i = 0; i < 4; i++)
		mloop[output->curface * 4 + i].v = vert_indices[i];

	output->curface++;
}

static Mesh *applyModifier(
        ModifierData *md,
        const ModifierEvalContext *UNUSED(ctx),
        Mesh *mesh)
{
	RemeshModifierData *rmd;
	DualConOutput *output;
	DualConInput input;
	Mesh *result;
	DualConFlags flags = 0;
	DualConMode mode = 0;

	rmd = (RemeshModifierData *)md;

	init_dualcon_mesh(&input, mesh);

	if (rmd->flag & MOD_REMESH_FLOOD_FILL)
		flags |= DUALCON_FLOOD_FILL;

	switch (rmd->mode) {
		case MOD_REMESH_CENTROID:
			mode = DUALCON_CENTROID;
			break;
		case MOD_REMESH_MASS_POINT:
			mode = DUALCON_MASS_POINT;
			break;
		case MOD_REMESH_SHARP_FEATURES:
			mode = DUALCON_SHARP_FEATURES;
			break;
	}

	output = dualcon(&input,
	                 dualcon_alloc_output,
	                 dualcon_add_vert,
	                 dualcon_add_quad,
	                 flags,
	                 mode,
	                 rmd->threshold,
	                 rmd->hermite_num,
	                 rmd->scale,
	                 rmd->depth);
	result = output->mesh;
	MEM_freeN(output);

	if (rmd->flag & MOD_REMESH_SMOOTH_SHADING) {
		MPoly *mpoly = result->mpoly;
		int i, totpoly = result->totpoly;

		/* Apply smooth shading to output faces */
		for (i = 0; i < totpoly; i++) {
			mpoly[i].flag |= ME_SMOOTH;
		}
	}

	BKE_mesh_calc_edges(result, true, false);
	result->runtime.cd_dirty_vert |= CD_MASK_NORMAL;
	return result;
}

#else /* !WITH_MOD_REMESH */

static Mesh *applyModifier(
        ModifierData *UNUSED(md),
        const ModifierEvalContext *UNUSED(ctx),
        Mesh *mesh)
{
	return mesh;
}

#endif /* !WITH_MOD_REMESH */

ModifierTypeInfo modifierType_Remesh = {
	/* name */              "Remesh",
	/* structName */        "RemeshModifierData",
	/* structSize */        sizeof(RemeshModifierData),
	/* type */              eModifierTypeType_Nonconstructive,
	/* flags */             eModifierTypeFlag_AcceptsMesh |
	                        eModifierTypeFlag_AcceptsCVs |
	                        eModifierTypeFlag_SupportsEditmode,

	/* copyData */          modifier_copyData_generic,

	/* deformVerts_DM */    NULL,
	/* deformMatrices_DM */ NULL,
	/* deformVertsEM_DM */  NULL,
	/* deformMatricesEM_DM*/NULL,
	/* applyModifier_DM */  NULL,

	/* deformVerts */       NULL,
	/* deformMatrices */    NULL,
	/* deformVertsEM */     NULL,
	/* deformMatricesEM */  NULL,
	/* applyModifier */     applyModifier,

	/* initData */          initData,
	/* requiredDataMask */  NULL,
	/* freeData */          NULL,
	/* isDisabled */        NULL,
	/* updateDepsgraph */   NULL,
	/* dependsOnTime */     NULL,
	/* dependsOnNormals */	NULL,
	/* foreachObjectLink */ NULL,
	/* foreachIDLink */     NULL,
};