/*
 * 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) 2005 by the Blender Foundation.
 * All rights reserved.
 */

/** \file \ingroup modifiers
 */


#include <string.h>

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

#include "BLI_utildefines.h"

#include "BKE_editmesh.h"
#include "BKE_library.h"
#include "BKE_library_query.h"
#include "BKE_mesh.h"
#include "BKE_modifier.h"
#include "BKE_shrinkwrap.h"

#include "DEG_depsgraph_query.h"

#include "MOD_util.h"

static bool dependsOnNormals(ModifierData *md);


static void initData(ModifierData *md)
{
	ShrinkwrapModifierData *smd = (ShrinkwrapModifierData *) md;
	smd->shrinkType = MOD_SHRINKWRAP_NEAREST_SURFACE;
	smd->shrinkOpts = MOD_SHRINKWRAP_PROJECT_ALLOW_POS_DIR;
	smd->keepDist   = 0.0f;

	smd->target     = NULL;
	smd->auxTarget  = NULL;
}

static CustomDataMask requiredDataMask(Object *UNUSED(ob), ModifierData *md)
{
	ShrinkwrapModifierData *smd = (ShrinkwrapModifierData *)md;
	CustomDataMask dataMask = 0;

	/* ask for vertexgroups if we need them */
	if (smd->vgroup_name[0])
		dataMask |= CD_MASK_MDEFORMVERT;

	if ((smd->shrinkType == MOD_SHRINKWRAP_PROJECT) &&
	    (smd->projAxis == MOD_SHRINKWRAP_PROJECT_OVER_NORMAL))
	{
		dataMask |= CD_MASK_MVERT;
	}

	return dataMask;
}

static bool isDisabled(const struct Scene *UNUSED(scene), ModifierData *md, bool UNUSED(useRenderParams))
{
	ShrinkwrapModifierData *smd = (ShrinkwrapModifierData *) md;
	return !smd->target;
}


static void foreachObjectLink(ModifierData *md, Object *ob, ObjectWalkFunc walk, void *userData)
{
	ShrinkwrapModifierData *smd = (ShrinkwrapModifierData *) md;

	walk(userData, ob, &smd->target, IDWALK_CB_NOP);
	walk(userData, ob, &smd->auxTarget, IDWALK_CB_NOP);
}

static void deformVerts(
        ModifierData *md, const ModifierEvalContext *ctx,
        Mesh *mesh,
        float (*vertexCos)[3],
        int numVerts)
{
	ShrinkwrapModifierData *swmd = (ShrinkwrapModifierData *)md;
	struct Scene *scene = DEG_get_evaluated_scene(ctx->depsgraph);
	Mesh *mesh_src = NULL;

	if (ctx->object->type == OB_MESH) {
		/* mesh_src is only needed for vgroups. */
		mesh_src = MOD_deform_mesh_eval_get(ctx->object, NULL, mesh, NULL, numVerts, false, false);
	}

	struct MDeformVert *dvert = NULL;
	int defgrp_index = -1;
	MOD_get_vgroup(ctx->object, mesh_src, swmd->vgroup_name, &dvert, &defgrp_index);

	shrinkwrapModifier_deform(swmd, ctx, scene, ctx->object, mesh_src, dvert, defgrp_index, vertexCos, numVerts);

	if (!ELEM(mesh_src, NULL, mesh)) {
		BKE_id_free(NULL, mesh_src);
	}
}

static void deformVertsEM(
        ModifierData *md, const ModifierEvalContext *ctx,
        struct BMEditMesh *editData, Mesh *mesh,
        float (*vertexCos)[3], int numVerts)
{
	ShrinkwrapModifierData *swmd = (ShrinkwrapModifierData *)md;
	struct Scene *scene = DEG_get_evaluated_scene(ctx->depsgraph);
	Mesh *mesh_src = MOD_deform_mesh_eval_get(ctx->object, editData, mesh, NULL, numVerts, false, false);

	struct MDeformVert *dvert = NULL;
	int defgrp_index = -1;
	MOD_get_vgroup(ctx->object, mesh_src, swmd->vgroup_name, &dvert, &defgrp_index);

	shrinkwrapModifier_deform(swmd, ctx, scene, ctx->object, mesh_src, dvert, defgrp_index, vertexCos, numVerts);

	if (!ELEM(mesh_src, NULL, mesh)) {
		BKE_id_free(NULL, mesh_src);
	}
}

static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
{
	ShrinkwrapModifierData *smd = (ShrinkwrapModifierData *)md;
	CustomDataMask mask = 0;

	if (BKE_shrinkwrap_needs_normals(smd->shrinkType, smd->shrinkMode)) {
		mask |= CD_MASK_NORMAL | CD_MASK_CUSTOMLOOPNORMAL;
	}

	if (smd->target != NULL) {
		DEG_add_object_relation(ctx->node, smd->target, DEG_OB_COMP_TRANSFORM, "Shrinkwrap Modifier");
		DEG_add_object_relation(ctx->node, smd->target, DEG_OB_COMP_GEOMETRY, "Shrinkwrap Modifier");
		DEG_add_customdata_mask(ctx->node, smd->target, mask);
		if (smd->shrinkType == MOD_SHRINKWRAP_TARGET_PROJECT) {
			DEG_add_special_eval_flag(ctx->node, &smd->target->id, DAG_EVAL_NEED_SHRINKWRAP_BOUNDARY);
		}
	}
	if (smd->auxTarget != NULL) {
		DEG_add_object_relation(ctx->node, smd->auxTarget, DEG_OB_COMP_TRANSFORM, "Shrinkwrap Modifier");
		DEG_add_object_relation(ctx->node, smd->auxTarget, DEG_OB_COMP_GEOMETRY, "Shrinkwrap Modifier");
		DEG_add_customdata_mask(ctx->node, smd->auxTarget, mask);
		if (smd->shrinkType == MOD_SHRINKWRAP_TARGET_PROJECT) {
			DEG_add_special_eval_flag(ctx->node, &smd->auxTarget->id, DAG_EVAL_NEED_SHRINKWRAP_BOUNDARY);
		}
	}
	DEG_add_modifier_to_transform_relation(ctx->node, "Shrinkwrap Modifier");
}

static bool dependsOnNormals(ModifierData *md)
{
	ShrinkwrapModifierData *smd = (ShrinkwrapModifierData *)md;

	if (smd->target && smd->shrinkType == MOD_SHRINKWRAP_PROJECT)
		return (smd->projAxis == MOD_SHRINKWRAP_PROJECT_OVER_NORMAL);

	return false;
}

ModifierTypeInfo modifierType_Shrinkwrap = {
	/* name */              "Shrinkwrap",
	/* structName */        "ShrinkwrapModifierData",
	/* structSize */        sizeof(ShrinkwrapModifierData),
	/* type */              eModifierTypeType_OnlyDeform,
	/* flags */             eModifierTypeFlag_AcceptsMesh |
	                        eModifierTypeFlag_AcceptsCVs |
	                        eModifierTypeFlag_AcceptsLattice |
	                        eModifierTypeFlag_SupportsEditmode |
	                        eModifierTypeFlag_EnableInEditmode,

	/* copyData */          modifier_copyData_generic,

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

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

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