/*
 * ***** 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) 2012 Blender Foundation.
 * All rights reserved.
 *
 *
 * Contributor(s): Blender Foundation,
 *                 Sergey Sharybin
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/editors/mask/mask_ops.c
 *  \ingroup edmask
 */

#include "MEM_guardedalloc.h"

#include "BLI_listbase.h"
#include "BLI_math.h"

#include "BKE_context.h"
#include "BKE_depsgraph.h"
#include "BKE_main.h"
#include "BKE_mask.h"

#include "DNA_scene_types.h"
#include "DNA_mask_types.h"
#include "DNA_object_types.h"  /* SELECT */

#include "WM_api.h"
#include "WM_types.h"

#include "ED_clip.h"
#include "ED_image.h"
#include "ED_keyframing.h"
#include "ED_mask.h"
#include "ED_screen.h"

#include "RNA_access.h"
#include "RNA_define.h"

#include "mask_intern.h"  /* own include */

/******************** utility functions *********************/

static void mask_point_scaled_handle(/*const*/ MaskSplinePoint *point, /*const*/ eMaskWhichHandle which_handle,
                                     const float scalex, const float scaley, float handle[2])
{
	BKE_mask_point_handle(point, which_handle, handle);
	handle[0] *= scalex;
	handle[1] *= scaley;
}

MaskSplinePoint *ED_mask_point_find_nearest(const bContext *C, Mask *mask, const float normal_co[2], const float threshold,
                                            MaskLayer **masklay_r, MaskSpline **spline_r,
                                            eMaskWhichHandle *which_handle_r, float *score)
{
	ScrArea *sa = CTX_wm_area(C);
	ARegion *ar = CTX_wm_region(C);

	MaskLayer *masklay;
	MaskLayer *point_masklay = NULL;
	MaskSpline *point_spline = NULL;
	MaskSplinePoint *point = NULL;
	float co[2];
	const float threshold_sq = threshold * threshold;
	float len_sq = FLT_MAX, scalex, scaley;
	eMaskWhichHandle which_handle = MASK_WHICH_HANDLE_NONE;
	int width, height;

	ED_mask_get_size(sa, &width, &height);
	ED_mask_pixelspace_factor(sa, ar, &scalex, &scaley);

	co[0] = normal_co[0] * scalex;
	co[1] = normal_co[1] * scaley;

	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
		MaskSpline *spline;

		if (masklay->restrictflag & (MASK_RESTRICT_VIEW | MASK_RESTRICT_SELECT)) {
			continue;
		}

		for (spline = masklay->splines.first; spline; spline = spline->next) {
			MaskSplinePoint *points_array = BKE_mask_spline_point_array(spline);

			int i;

			for (i = 0; i < spline->tot_point; i++) {
				MaskSplinePoint *cur_point = &spline->points[i];
				MaskSplinePoint *cur_point_deform = &points_array[i];
				eMaskWhichHandle cur_which_handle = MASK_WHICH_HANDLE_NONE;
				BezTriple *bezt = &cur_point_deform->bezt;
				float cur_len_sq, vec[2];

				vec[0] = bezt->vec[1][0] * scalex;
				vec[1] = bezt->vec[1][1] * scaley;

				cur_len_sq = len_squared_v2v2(co, vec);

				if (cur_len_sq < len_sq) {
					point_spline = spline;
					point_masklay = masklay;
					point = cur_point;
					len_sq = cur_len_sq;
					which_handle = MASK_WHICH_HANDLE_NONE;
				}

				if (BKE_mask_point_handles_mode_get(cur_point_deform) == MASK_HANDLE_MODE_STICK) {
					float handle[2];
					mask_point_scaled_handle(cur_point_deform, MASK_WHICH_HANDLE_STICK, scalex, scaley, handle);
					cur_len_sq = len_squared_v2v2(co, handle);
					cur_which_handle = MASK_WHICH_HANDLE_STICK;
				}
				else {
					float handle_left[2], handle_right[2];
					float len_left_sq, len_right_sq;
					mask_point_scaled_handle(cur_point_deform, MASK_WHICH_HANDLE_LEFT, scalex, scaley, handle_left);
					mask_point_scaled_handle(cur_point_deform, MASK_WHICH_HANDLE_RIGHT, scalex, scaley, handle_right);

					len_left_sq = len_squared_v2v2(co, handle_left);
					len_right_sq = len_squared_v2v2(co, handle_right);
					if (i == 0) {
						if (len_left_sq <= len_right_sq) {
							if (bezt->h1 != HD_VECT) {
								cur_which_handle = MASK_WHICH_HANDLE_LEFT;
								cur_len_sq = len_left_sq;
							}
						}
						else if (bezt->h2 != HD_VECT) {
							cur_which_handle = MASK_WHICH_HANDLE_RIGHT;
							cur_len_sq = len_right_sq;
						}
					}
					else {
						if (len_right_sq <= len_left_sq) {
							if (bezt->h2 != HD_VECT) {
								cur_which_handle = MASK_WHICH_HANDLE_RIGHT;
								cur_len_sq = len_right_sq;
							}
						}
						else if (bezt->h1 != HD_VECT) {
							cur_which_handle = MASK_WHICH_HANDLE_LEFT;
							cur_len_sq = len_left_sq;
						}
					}
				}

				if (cur_len_sq <= len_sq && cur_which_handle != MASK_WHICH_HANDLE_NONE) {
					point_masklay = masklay;
					point_spline = spline;
					point = cur_point;
					len_sq = cur_len_sq;
					which_handle = cur_which_handle;
				}
			}
		}
	}

	if (len_sq < threshold_sq) {
		if (masklay_r)
			*masklay_r = point_masklay;

		if (spline_r)
			*spline_r = point_spline;

		if (which_handle_r)
			*which_handle_r = which_handle;

		if (score)
			*score = sqrtf(len_sq);

		return point;
	}

	if (masklay_r)
		*masklay_r = NULL;

	if (spline_r)
		*spline_r = NULL;

	if (which_handle_r)
		*which_handle_r = MASK_WHICH_HANDLE_NONE;

	return NULL;
}

bool ED_mask_feather_find_nearest(const bContext *C, Mask *mask, const float normal_co[2], const float threshold,
                                  MaskLayer **masklay_r, MaskSpline **spline_r, MaskSplinePoint **point_r,
                                  MaskSplinePointUW **uw_r, float *score)
{
	ScrArea *sa = CTX_wm_area(C);
	ARegion *ar = CTX_wm_region(C);

	MaskLayer *masklay, *point_masklay = NULL;
	MaskSpline *point_spline = NULL;
	MaskSplinePoint *point = NULL;
	MaskSplinePointUW *uw = NULL;
	const float threshold_sq = threshold * threshold;
	float len = FLT_MAX, co[2];
	float scalex, scaley;
	int width, height;

	ED_mask_get_size(sa, &width, &height);
	ED_mask_pixelspace_factor(sa, ar, &scalex, &scaley);

	co[0] = normal_co[0] * scalex;
	co[1] = normal_co[1] * scaley;

	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
		MaskSpline *spline;

		for (spline = masklay->splines.first; spline; spline = spline->next) {
			//MaskSplinePoint *points_array = BKE_mask_spline_point_array(spline);

			int i, tot_feather_point;
			float (*feather_points)[2], (*fp)[2];

			if (masklay->restrictflag & (MASK_RESTRICT_VIEW | MASK_RESTRICT_SELECT)) {
				continue;
			}

			feather_points = fp = BKE_mask_spline_feather_points(spline, &tot_feather_point);

			for (i = 0; i < spline->tot_point; i++) {
				int j;
				MaskSplinePoint *cur_point = &spline->points[i];

				for (j = 0; j <= cur_point->tot_uw; j++) {
					float cur_len_sq, vec[2];

					vec[0] = (*fp)[0] * scalex;
					vec[1] = (*fp)[1] * scaley;

					cur_len_sq = len_squared_v2v2(vec, co);

					if (point == NULL || cur_len_sq < len) {
						if (j == 0)
							uw = NULL;
						else
							uw = &cur_point->uw[j - 1];

						point_masklay = masklay;
						point_spline = spline;
						point = cur_point;
						len = cur_len_sq;
					}

					fp++;
				}
			}

			MEM_freeN(feather_points);
		}
	}

	if (len < threshold_sq) {
		if (masklay_r)
			*masklay_r = point_masklay;

		if (spline_r)
			*spline_r = point_spline;

		if (point_r)
			*point_r = point;

		if (uw_r)
			*uw_r = uw;

		if (score)
			*score = sqrtf(len);

		return true;
	}

	if (masklay_r)
		*masklay_r = NULL;

	if (spline_r)
		*spline_r = NULL;

	if (point_r)
		*point_r = NULL;

	return false;
}


/******************** create new mask *********************/

Mask *ED_mask_new(bContext *C, const char *name)
{
	ScrArea *sa = CTX_wm_area(C);
	Main *bmain = CTX_data_main(C);
	Mask *mask;

	mask = BKE_mask_new(bmain, name);

	if (sa && sa->spacedata.first) {
		switch (sa->spacetype) {
			case SPACE_CLIP:
			{
				SpaceClip *sc = sa->spacedata.first;
				ED_space_clip_set_mask(C, sc, mask);
				break;
			}
			case SPACE_SEQ:
			{
				/* do nothing */
				break;
			}
			case SPACE_IMAGE:
			{
				SpaceImage *sima = sa->spacedata.first;
				ED_space_image_set_mask(C, sima, mask);
				break;
			}
		}
	}

	return mask;
}

/* Get ative layer. Will create mask/layer to be sure there's an active layer.  */
MaskLayer *ED_mask_layer_ensure(bContext *C)
{
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *mask_layer;

	if (mask == NULL) {
		/* If there's no active mask, create one. */
		mask = ED_mask_new(C, NULL);
	}

	mask_layer = BKE_mask_layer_active(mask);
	if (mask_layer == NULL) {
		/* If there's no active mask layer, create one. */
		mask_layer = BKE_mask_layer_new(mask, "");
	}

	return mask_layer;
}

static int mask_new_exec(bContext *C, wmOperator *op)
{
	char name[MAX_ID_NAME - 2];

	RNA_string_get(op->ptr, "name", name);

	ED_mask_new(C, name);

	return OPERATOR_FINISHED;
}

void MASK_OT_new(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "New Mask";
	ot->description = "Create new mask";
	ot->idname = "MASK_OT_new";

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* api callbacks */
	ot->exec = mask_new_exec;
	ot->poll = ED_operator_mask;

	/* properties */
	RNA_def_string(ot->srna, "name", NULL, MAX_ID_NAME - 2, "Name", "Name of new mask");
}

/******************** create new masklay *********************/

static int masklay_new_exec(bContext *C, wmOperator *op)
{
	Mask *mask = CTX_data_edit_mask(C);
	char name[MAX_ID_NAME - 2];

	RNA_string_get(op->ptr, "name", name);

	BKE_mask_layer_new(mask, name);
	mask->masklay_act = mask->masklay_tot - 1;

	WM_event_add_notifier(C, NC_MASK | NA_EDITED, mask);

	return OPERATOR_FINISHED;
}

void MASK_OT_layer_new(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Add Mask Layer";
	ot->description = "Add new mask layer for masking";
	ot->idname = "MASK_OT_layer_new";

	/* api callbacks */
	ot->exec = masklay_new_exec;
	ot->poll = ED_maskedit_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* properties */
	RNA_def_string(ot->srna, "name", NULL, MAX_ID_NAME - 2, "Name", "Name of new mask layer");
}

/******************** remove mask layer *********************/

static int masklay_remove_exec(bContext *C, wmOperator *UNUSED(op))
{
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *masklay = BKE_mask_layer_active(mask);

	if (masklay) {
		BKE_mask_layer_remove(mask, masklay);

		WM_event_add_notifier(C, NC_MASK | NA_EDITED, mask);
	}

	return OPERATOR_FINISHED;
}

void MASK_OT_layer_remove(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Remove Mask Layer";
	ot->description = "Remove mask layer";
	ot->idname = "MASK_OT_layer_remove";

	/* api callbacks */
	ot->exec = masklay_remove_exec;
	ot->poll = ED_maskedit_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/******************** slide *********************/

enum {
	SLIDE_ACTION_NONE    = 0,
	SLIDE_ACTION_POINT   = 1,
	SLIDE_ACTION_HANDLE  = 2,
	SLIDE_ACTION_FEATHER = 3,
	SLIDE_ACTION_SPLINE  = 4
};

typedef struct SlidePointData {
	/* Generic fields. */
	short event_invoke_type;
	int action;
	Mask *mask;
	MaskLayer *masklay;
	MaskSpline *spline, *orig_spline;
	MaskSplinePoint *point;
	MaskSplinePointUW *uw;
	eMaskWhichHandle which_handle;
	int width, height;

	float prev_mouse_coord[2];
	float no[2];

	bool is_curvature_only,
	     is_accurate,
	     is_initial_feather,
	     is_overall_feather;

	bool is_sliding_new_point;

	/* Data needed to restre the state. */
	float vec[3][3];
	char old_h1, old_h2;

	/* Point sliding. */

	/* Handle sliding. */
	float orig_handle_coord[2], prev_handle_coord[2];

	/* Feather sliding. */
	float prev_feather_coord[2];
	float weight, weight_scalar;
} SlidePointData;

static void mask_point_undistort_pos(SpaceClip *sc, float r_co[2], const float co[2])
{
	BKE_mask_coord_to_movieclip(sc->clip, &sc->user, r_co, co);
	ED_clip_point_undistorted_pos(sc, r_co, r_co);
	BKE_mask_coord_from_movieclip(sc->clip, &sc->user, r_co, r_co);
}

static bool spline_under_mouse_get(const bContext *C,
                                   Mask *mask, const float co[2],
                                   MaskLayer **mask_layer_r,
                                   MaskSpline **mask_spline_r)
{
	ScrArea *sa = CTX_wm_area(C);
	SpaceClip *sc = CTX_wm_space_clip(C);
	MaskLayer *mask_layer;
	int width, height;
	float pixel_co[2];
	float closest_dist_squared;
	MaskLayer *closest_layer = NULL;
	MaskSpline *closest_spline = NULL;
	bool undistort = false;
	*mask_layer_r = NULL;
	*mask_spline_r = NULL;
	ED_mask_get_size(sa, &width, &height);
	pixel_co[0] = co[0] * width;
	pixel_co[1] = co[1] * height;
	if (sc != NULL) {
		undistort = (sc->clip != NULL) &&
		            (sc->user.render_flag & MCLIP_PROXY_RENDER_UNDISTORT) != 0;
	}
	for (mask_layer = mask->masklayers.first;
	     mask_layer != NULL;
	     mask_layer = mask_layer->next)
	{
		MaskSpline *spline;
		if (mask_layer->restrictflag & MASK_RESTRICT_SELECT) {
			continue;
		}

		for (spline = mask_layer->splines.first;
		     spline != NULL;
		     spline = spline->next)
		{
			MaskSplinePoint *points_array;
			float min[2], max[2], center[2];
			float dist_squared;
			int i;
			float max_bb_side;
			if ((spline->flag & SELECT) == 0) {
				continue;
			}

			points_array = BKE_mask_spline_point_array(spline);
			INIT_MINMAX2(min, max);
			for (i = 0; i < spline->tot_point; i++) {
				MaskSplinePoint *point_deform = &points_array[i];
				BezTriple *bezt = &point_deform->bezt;

				float vert[2];

				copy_v2_v2(vert, bezt->vec[1]);

				if (undistort) {
					mask_point_undistort_pos(sc, vert, vert);
				}

				minmax_v2v2_v2(min, max, vert);
			}

			center[0] = (min[0] + max[0]) / 2.0f * width;
			center[1] = (min[1] + max[1]) / 2.0f * height;
			dist_squared = len_squared_v2v2(pixel_co, center);
			max_bb_side = min_ff((max[0] - min[0]) * width, (max[1] - min[1]) * height);
			if (dist_squared <= max_bb_side * max_bb_side * 0.5f &&
			    (closest_spline == NULL || dist_squared < closest_dist_squared))
			{
				closest_layer = mask_layer;
				closest_spline = spline;
				closest_dist_squared = dist_squared;
			}
		}
	}
	/* TODO(sergey): Chech whether tesellated spline point is closer
	 * to the mouse than the spline center.
	 */
	if (closest_dist_squared < 32.0f * 32.0f && closest_spline != NULL) {
		*mask_layer_r = closest_layer;
		*mask_spline_r = closest_spline;
		return true;
	}
	return false;
}

static bool slide_point_check_initial_feather(MaskSpline *spline)
{
	int i;

	for (i = 0; i < spline->tot_point; i++) {
		MaskSplinePoint *point = &spline->points[i];

		if (point->bezt.weight != 0.0f) {
			return false;
		}
	}

	return true;
}

static void select_sliding_point(Mask *mask, MaskLayer *mask_layer, MaskSpline *spline,
                                 MaskSplinePoint *point, eMaskWhichHandle which_handle)
{
	ED_mask_select_toggle_all(mask, SEL_DESELECT);

	switch (which_handle) {
		case MASK_WHICH_HANDLE_NONE:
			BKE_mask_point_select_set(point, true);
			break;
		case MASK_WHICH_HANDLE_LEFT:
			point->bezt.f1 |= SELECT;
			break;
		case MASK_WHICH_HANDLE_RIGHT:
			point->bezt.f3 |= SELECT;
			break;
		case MASK_WHICH_HANDLE_STICK:
			point->bezt.f1 |= SELECT;
			point->bezt.f3 |= SELECT;
			break;
		default:
			BLI_assert(!"Unexpected situation in select_sliding_point()");
	}

	mask_layer->act_spline = spline;
	mask_layer->act_point = point;
	ED_mask_select_flush_all(mask);
}

static void check_sliding_handle_type(MaskSplinePoint *point, eMaskWhichHandle which_handle)
{
	BezTriple *bezt = &point->bezt;

	if (which_handle == MASK_WHICH_HANDLE_LEFT) {
		if (bezt->h1 == HD_VECT) {
			bezt->h1 = HD_FREE;
		}
		else if (bezt->h1 == HD_AUTO) {
			bezt->h1 = HD_ALIGN_DOUBLESIDE;
			bezt->h2 = HD_ALIGN_DOUBLESIDE;
		}
	}
	else if (which_handle == MASK_WHICH_HANDLE_RIGHT) {
		if (bezt->h2 == HD_VECT) {
			bezt->h2 = HD_FREE;
		}
		else if (bezt->h2 == HD_AUTO) {
			bezt->h1 = HD_ALIGN_DOUBLESIDE;
			bezt->h2 = HD_ALIGN_DOUBLESIDE;
		}
	}
}

static void *slide_point_customdata(bContext *C, wmOperator *op, const wmEvent *event)
{
	ScrArea *sa = CTX_wm_area(C);
	ARegion *ar = CTX_wm_region(C);

	Mask *mask = CTX_data_edit_mask(C);
	SlidePointData *customdata = NULL;
	MaskLayer *masklay, *cv_masklay, *feather_masklay;
	MaskSpline *spline, *cv_spline, *feather_spline;
	MaskSplinePoint *point, *cv_point, *feather_point;
	MaskSplinePointUW *uw = NULL;
	int width, height, action = SLIDE_ACTION_NONE;
	const bool slide_feather = RNA_boolean_get(op->ptr, "slide_feather");
	float co[2], cv_score, feather_score;
	const float threshold = 19;
	eMaskWhichHandle which_handle;

	ED_mask_mouse_pos(sa, ar, event->mval, co);
	ED_mask_get_size(sa, &width, &height);

	cv_point = ED_mask_point_find_nearest(C, mask, co, threshold, &cv_masklay, &cv_spline, &which_handle, &cv_score);

	if (ED_mask_feather_find_nearest(C, mask, co, threshold, &feather_masklay, &feather_spline, &feather_point, &uw, &feather_score)) {
		if (slide_feather || !cv_point || feather_score < cv_score) {
			action = SLIDE_ACTION_FEATHER;

			masklay = feather_masklay;
			spline = feather_spline;
			point = feather_point;
		}
	}

	if (cv_point && action == SLIDE_ACTION_NONE) {
		if (which_handle != MASK_WHICH_HANDLE_NONE)
			action = SLIDE_ACTION_HANDLE;
		else
			action = SLIDE_ACTION_POINT;

		masklay = cv_masklay;
		spline = cv_spline;
		point = cv_point;
	}

	if (action == SLIDE_ACTION_NONE) {
		if (spline_under_mouse_get(C, mask, co, &masklay, &spline)) {
			action = SLIDE_ACTION_SPLINE;
			point = NULL;
		}
	}

	if (action != SLIDE_ACTION_NONE) {
		customdata = MEM_callocN(sizeof(SlidePointData), "mask slide point data");
		customdata->event_invoke_type = event->type;
		customdata->mask = mask;
		customdata->masklay = masklay;
		customdata->spline = spline;
		customdata->point = point;
		customdata->width = width;
		customdata->height = height;
		customdata->action = action;
		customdata->uw = uw;

		customdata->is_sliding_new_point = RNA_boolean_get(op->ptr, "is_new_point");

		if (customdata->action != SLIDE_ACTION_SPLINE) {
			customdata->old_h1 = point->bezt.h1;
			customdata->old_h2 = point->bezt.h2;
			select_sliding_point(mask, masklay, spline, point, which_handle);
			check_sliding_handle_type(point, which_handle);
		}

		if (uw) {
			float co_uw[2];
			float weight_scalar = BKE_mask_point_weight_scalar(spline, point, uw->u);

			customdata->weight = uw->w;
			customdata->weight_scalar = weight_scalar;
			BKE_mask_point_segment_co(spline, point, uw->u, co_uw);
			BKE_mask_point_normal(spline, point, uw->u, customdata->no);

			madd_v2_v2v2fl(customdata->prev_feather_coord, co_uw, customdata->no, uw->w * weight_scalar);
		}
		else if (customdata->action != SLIDE_ACTION_SPLINE) {
			BezTriple *bezt = &point->bezt;

			customdata->weight = bezt->weight;
			customdata->weight_scalar = 1.0f;
			BKE_mask_point_normal(spline, point, 0.0f, customdata->no);

			madd_v2_v2v2fl(customdata->prev_feather_coord, bezt->vec[1], customdata->no, bezt->weight);
		}

		if (customdata->action == SLIDE_ACTION_FEATHER) {
			customdata->is_initial_feather = slide_point_check_initial_feather(spline);
		}

		if (customdata->action != SLIDE_ACTION_SPLINE) {
			copy_m3_m3(customdata->vec, point->bezt.vec);
			if (which_handle != MASK_WHICH_HANDLE_NONE) {
				BKE_mask_point_handle(point, which_handle, customdata->orig_handle_coord);
				copy_v2_v2(customdata->prev_handle_coord, customdata->orig_handle_coord);
			}
		}
		customdata->which_handle = which_handle;

		ED_mask_mouse_pos(sa, ar, event->mval, customdata->prev_mouse_coord);
	}

	return customdata;
}

static int slide_point_invoke(bContext *C, wmOperator *op, const wmEvent *event)
{
	Mask *mask = CTX_data_edit_mask(C);
	SlidePointData *slidedata;

	if (mask == NULL) {
		return OPERATOR_CANCELLED;
	}

	slidedata = slide_point_customdata(C, op, event);

	if (slidedata) {
		op->customdata = slidedata;

		WM_event_add_modal_handler(C, op);

		slidedata->masklay->act_spline = slidedata->spline;
		slidedata->masklay->act_point = slidedata->point;

		WM_event_add_notifier(C, NC_MASK | ND_SELECT, mask);

		return OPERATOR_RUNNING_MODAL;
	}

	return OPERATOR_PASS_THROUGH;
}

static void slide_point_delta_all_feather(SlidePointData *data, float delta)
{
	int i;

	for (i = 0; i < data->spline->tot_point; i++) {
		MaskSplinePoint *point = &data->spline->points[i];
		MaskSplinePoint *orig_point = &data->orig_spline->points[i];

		point->bezt.weight = orig_point->bezt.weight + delta;
		if (point->bezt.weight < 0.0f) {
			point->bezt.weight = 0.0f;
		}
	}
}

static void slide_point_restore_spline(SlidePointData *data)
{
	int i;

	for (i = 0; i < data->spline->tot_point; i++) {
		MaskSplinePoint *point = &data->spline->points[i];
		MaskSplinePoint *orig_point = &data->orig_spline->points[i];
		int j;

		point->bezt = orig_point->bezt;

		for (j = 0; j < point->tot_uw; j++)
			point->uw[j] = orig_point->uw[j];
	}
}

static void cancel_slide_point(SlidePointData *data)
{
	/* cancel sliding */

	if (data->orig_spline) {
		slide_point_restore_spline(data);
	}
	else {
		if (data->action == SLIDE_ACTION_FEATHER) {
			if (data->uw)
				data->uw->w = data->weight;
			else
				data->point->bezt.weight = data->weight;
		}
		else if (data->action != SLIDE_ACTION_SPLINE) {
			copy_m3_m3(data->point->bezt.vec, data->vec);
			data->point->bezt.h1 = data->old_h1;
			data->point->bezt.h2 = data->old_h2;
		}
	}
}

static void free_slide_point_data(SlidePointData *data)
{
	if (data->orig_spline)
		BKE_mask_spline_free(data->orig_spline);

	MEM_freeN(data);
}

static int slide_point_modal(bContext *C, wmOperator *op, const wmEvent *event)
{
	SlidePointData *data = (SlidePointData *)op->customdata;
	BezTriple *bezt = &data->point->bezt;
	float co[2];

	switch (event->type) {
		case LEFTALTKEY:
		case RIGHTALTKEY:
		case LEFTSHIFTKEY:
		case RIGHTSHIFTKEY:
			if (ELEM(event->type, LEFTALTKEY, RIGHTALTKEY)) {
				if (data->action == SLIDE_ACTION_FEATHER) {
					data->is_overall_feather = (event->val == KM_PRESS);
				}
				else {
					data->is_curvature_only = (event->val == KM_PRESS);
				}
			}

			if (ELEM(event->type, LEFTSHIFTKEY, RIGHTSHIFTKEY))
				data->is_accurate = (event->val == KM_PRESS);

			/* fall-through */  /* update CV position */
		case MOUSEMOVE:
		{
			ScrArea *sa = CTX_wm_area(C);
			ARegion *ar = CTX_wm_region(C);
			float delta[2];

			ED_mask_mouse_pos(sa, ar, event->mval, co);
			sub_v2_v2v2(delta, co, data->prev_mouse_coord);
			if (data->is_accurate) {
				mul_v2_fl(delta, 0.2f);
			}
			copy_v2_v2(data->prev_mouse_coord, co);

			if (data->action == SLIDE_ACTION_HANDLE) {
				float new_handle[2];

				if (data->is_sliding_new_point && data->which_handle == MASK_WHICH_HANDLE_STICK) {
					if (ELEM(data->point, &data->spline->points[0],
					                      &data->spline->points[data->spline->tot_point - 1]))
					{
						SWAP(float, delta[0], delta[1]);
						delta[1] *= -1;

						/* flip last point */
						if (data->point != &data->spline->points[0]) {
							negate_v2(delta);
						}
					}
				}

				add_v2_v2v2(new_handle, data->prev_handle_coord, delta);

				BKE_mask_point_set_handle(data->point, data->which_handle,
				                          new_handle, data->is_curvature_only,
				                          data->orig_handle_coord, data->vec);
				BKE_mask_point_handle(data->point, data->which_handle, data->prev_handle_coord);

				if (data->is_sliding_new_point) {
					if (ELEM(data->which_handle, MASK_WHICH_HANDLE_LEFT, MASK_WHICH_HANDLE_RIGHT)) {
						BezTriple *bezt = &data->point->bezt;
						float vec[2];
						short self_handle = (data->which_handle == MASK_WHICH_HANDLE_LEFT) ? 0 : 2;
						short other_handle = (data->which_handle == MASK_WHICH_HANDLE_LEFT) ? 2 : 0;

						sub_v2_v2v2(vec, bezt->vec[1], bezt->vec[self_handle]);
						add_v2_v2v2(bezt->vec[other_handle], bezt->vec[1], vec);
					}
				}
			}
			else if (data->action == SLIDE_ACTION_POINT) {
				add_v2_v2(bezt->vec[0], delta);
				add_v2_v2(bezt->vec[1], delta);
				add_v2_v2(bezt->vec[2], delta);
			}
			else if (data->action == SLIDE_ACTION_FEATHER) {
				float vec[2], no[2], p[2], c[2], w, offco[2];
				float *weight = NULL;
				float weight_scalar = 1.0f;
				bool is_overall_feather = data->is_overall_feather || data->is_initial_feather;

				add_v2_v2v2(offco, data->prev_feather_coord, delta);

				if (data->uw) {
					/* project on both sides and find the closest one,
					 * prevents flickering when projecting onto both sides can happen */
					const float u_pos = BKE_mask_spline_project_co(data->spline, data->point,
					                                               data->uw->u, offco, MASK_PROJ_NEG);
					const float u_neg = BKE_mask_spline_project_co(data->spline, data->point,
					                                               data->uw->u, offco, MASK_PROJ_POS);
					float dist_pos = FLT_MAX;
					float dist_neg = FLT_MAX;
					float co_pos[2];
					float co_neg[2];
					float u;

					if (u_pos > 0.0f && u_pos < 1.0f) {
						BKE_mask_point_segment_co(data->spline, data->point, u_pos, co_pos);
						dist_pos = len_squared_v2v2(offco, co_pos);
					}

					if (u_neg > 0.0f && u_neg < 1.0f) {
						BKE_mask_point_segment_co(data->spline, data->point, u_neg, co_neg);
						dist_neg = len_squared_v2v2(offco, co_neg);
					}

					u = dist_pos < dist_neg ? u_pos : u_neg;

					if (u > 0.0f && u < 1.0f) {
						data->uw->u = u;

						data->uw = BKE_mask_point_sort_uw(data->point, data->uw);
						weight = &data->uw->w;
						weight_scalar = BKE_mask_point_weight_scalar(data->spline, data->point, u);
						if (weight_scalar != 0.0f) {
							weight_scalar = 1.0f / weight_scalar;
						}

						BKE_mask_point_normal(data->spline, data->point, data->uw->u, no);
						BKE_mask_point_segment_co(data->spline, data->point, data->uw->u, p);
					}
				}
				else {
					weight = &bezt->weight;
					/* weight_scalar = 1.0f; keep as is */
					copy_v2_v2(no, data->no);
					copy_v2_v2(p, bezt->vec[1]);
				}

				if (weight) {
					sub_v2_v2v2(c, offco, p);
					project_v2_v2v2(vec, c, no);

					w = len_v2(vec);

					if (is_overall_feather) {
						float delta;

						if (dot_v2v2(no, vec) <= 0.0f)
							w = -w;

						delta = w - data->weight * data->weight_scalar;

						if (data->orig_spline == NULL) {
							/* restore weight for currently sliding point, so orig_spline would be created
							 * with original weights used
							 */
							*weight = data->weight;

							data->orig_spline = BKE_mask_spline_copy(data->spline);
						}

						if (data->is_initial_feather) {
							*weight = w * weight_scalar;
						}

						slide_point_delta_all_feather(data, delta);
					}
					else {
						if (dot_v2v2(no, vec) <= 0.0f)
							w = 0.0f;

						if (data->orig_spline) {
							/* restore possible overall feather changes */
							slide_point_restore_spline(data);

							BKE_mask_spline_free(data->orig_spline);
							data->orig_spline = NULL;
						}

						if (weight_scalar != 0.0f) {
							*weight = w * weight_scalar;
						}
					}

					copy_v2_v2(data->prev_feather_coord, offco);
				}
			}
			else if (data->action == SLIDE_ACTION_SPLINE) {
				int i;

				if (data->orig_spline == NULL) {
					data->orig_spline = BKE_mask_spline_copy(data->spline);
				}

				for (i = 0; i < data->spline->tot_point; i++) {
					MaskSplinePoint *point = &data->spline->points[i];
					add_v2_v2(point->bezt.vec[0], delta);
					add_v2_v2(point->bezt.vec[1], delta);
					add_v2_v2(point->bezt.vec[2], delta);
				}
			}

			WM_event_add_notifier(C, NC_MASK | NA_EDITED, data->mask);
			DAG_id_tag_update(&data->mask->id, 0);

			break;
		}

		case LEFTMOUSE:
		case RIGHTMOUSE:
			if (event->type == data->event_invoke_type && event->val == KM_RELEASE) {
				Scene *scene = CTX_data_scene(C);

				/* dont key sliding feather uw's */
				if ((data->action == SLIDE_ACTION_FEATHER && data->uw) == false) {
					if (IS_AUTOKEY_ON(scene)) {
						ED_mask_layer_shape_auto_key(data->masklay, CFRA);
					}
				}

				if (data->is_sliding_new_point) {
					BezTriple *bezt = &data->point->bezt;
					if (len_squared_v2v2(bezt->vec[0], bezt->vec[1]) < FLT_EPSILON) {
						bezt->h1 = HD_VECT;
					}
					if (len_squared_v2v2(bezt->vec[2], bezt->vec[1]) < FLT_EPSILON) {
						bezt->h2 = HD_VECT;
					}
				}

				WM_event_add_notifier(C, NC_MASK | NA_EDITED, data->mask);
				DAG_id_tag_update(&data->mask->id, 0);

				free_slide_point_data(op->customdata); /* keep this last! */
				return OPERATOR_FINISHED;
			}
			else if (event->type != data->event_invoke_type && event->val == KM_PRESS) {
				/* pass to ESCKEY */
			}
			else {
				break;
			}

		case ESCKEY:
			cancel_slide_point(op->customdata);

			WM_event_add_notifier(C, NC_MASK | NA_EDITED, data->mask);
			DAG_id_tag_update(&data->mask->id, 0);

			free_slide_point_data(op->customdata); /* keep this last! */
			return OPERATOR_CANCELLED;
	}

	return OPERATOR_RUNNING_MODAL;
}

void MASK_OT_slide_point(wmOperatorType *ot)
{
	PropertyRNA *prop;

	/* identifiers */
	ot->name = "Slide Point";
	ot->description = "Slide control points";
	ot->idname = "MASK_OT_slide_point";

	/* api callbacks */
	ot->invoke = slide_point_invoke;
	ot->modal = slide_point_modal;
	ot->poll = ED_operator_mask;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	RNA_def_boolean(ot->srna, "slide_feather", 0, "Slide Feather", "First try to slide feather instead of vertex");

	prop = RNA_def_boolean(ot->srna, "is_new_point", 0, "Slide New Point", "Newly created vertex is being slid");
	RNA_def_property_flag(prop, PROP_SKIP_SAVE);
}

/******************** slide spline curvature *********************/

typedef struct SlideSplineCurvatureData {
	short event_invoke_type;

	Mask *mask;
	MaskLayer *mask_layer;
	MaskSpline *spline;
	MaskSplinePoint *point;
	float u;
	bool accurate;

	BezTriple *adjust_bezt, *other_bezt;
	BezTriple bezt_backup, other_bezt_backup;

	float prev_mouse_coord[2];
	float prev_spline_coord[2];

	float P0[2], P1[2], P2[2], P3[3];
} SlideSplineCurvatureData;

static void cancel_slide_spline_curvature(SlideSplineCurvatureData *slide_data)
{
	*slide_data->adjust_bezt = slide_data->bezt_backup;
	*slide_data->other_bezt = slide_data->other_bezt_backup;
}


static void free_slide_spline_curvature_data(SlideSplineCurvatureData *slide_data)
{
	MEM_freeN(slide_data);
}

static bool slide_spline_curvature_check(bContext *C, const wmEvent *event)
{
	Mask *mask = CTX_data_edit_mask(C);
	float co[2];
	const float threshold = 19;

	ED_mask_mouse_pos(CTX_wm_area(C), CTX_wm_region(C), event->mval, co);

	if (ED_mask_point_find_nearest(C, mask, co, threshold, NULL, NULL, NULL, NULL)) {
		return false;
	}

	if (ED_mask_feather_find_nearest(C, mask, co, threshold, NULL, NULL, NULL, NULL, NULL)) {
		return false;
	}

	return true;
}

static SlideSplineCurvatureData *slide_spline_curvature_customdata(
	bContext *C, const wmEvent *event)
{
	const float threshold = 19;

	Mask *mask = CTX_data_edit_mask(C);
	SlideSplineCurvatureData *slide_data;
	MaskLayer *mask_layer;
	MaskSpline *spline;
	MaskSplinePoint *point;
	float u, co[2];
	BezTriple *next_bezt;

	ED_mask_mouse_pos(CTX_wm_area(C), CTX_wm_region(C), event->mval, co);

	if (!ED_mask_find_nearest_diff_point(C, mask, co, threshold, false,
	                                     &mask_layer, &spline, &point, &u,
	                                     NULL, true, false))
	{
		return NULL;
	}

	next_bezt = BKE_mask_spline_point_next_bezt(spline, spline->points, point);
	if (next_bezt == NULL) {
		return NULL;
	}

	slide_data = MEM_callocN(sizeof(SlideSplineCurvatureData), "slide curvature slide");
	slide_data->event_invoke_type = event->type;
	slide_data->mask = mask;
	slide_data->mask_layer = mask_layer;
	slide_data->spline = spline;
	slide_data->point = point;
	slide_data->u = u;

	copy_v2_v2(slide_data->prev_mouse_coord, co);
	BKE_mask_point_segment_co(spline, point, u, slide_data->prev_spline_coord);

	copy_v2_v2(slide_data->P0, point->bezt.vec[1]);
	copy_v2_v2(slide_data->P1, point->bezt.vec[2]);
	copy_v2_v2(slide_data->P2, next_bezt->vec[0]);
	copy_v2_v2(slide_data->P3, next_bezt->vec[1]);

	/* Depending to which end we're closer to adjust either left or right side of the spline. */
	if (u <= 0.5f) {
		slide_data->adjust_bezt = &point->bezt;
		slide_data->other_bezt = next_bezt;
	}
	else {
		slide_data->adjust_bezt = next_bezt;
		slide_data->other_bezt = &point->bezt;
	}

	/* Data needed for restoring state. */
	slide_data->bezt_backup = *slide_data->adjust_bezt;
	slide_data->other_bezt_backup = *slide_data->other_bezt;

	/* Let's dont touch other side of the point for now, so set handle to FREE. */
	if (u < 0.5f) {
		if (slide_data->adjust_bezt->h2 <= HD_VECT) {
			slide_data->adjust_bezt->h2 = HD_FREE;
		}
	}
	else {
		if (slide_data->adjust_bezt->h1 <= HD_VECT) {
			slide_data->adjust_bezt->h1 = HD_FREE;
		}
	}

	/* Change selection */
	ED_mask_select_toggle_all(mask, SEL_DESELECT);
	slide_data->adjust_bezt->f2 |= SELECT;
	slide_data->other_bezt->f2 |= SELECT;
	if (u < 0.5f) {
		slide_data->adjust_bezt->f3 |= SELECT;
		slide_data->other_bezt->f1 |= SELECT;
	}
	else {
		slide_data->adjust_bezt->f1 |= SELECT;
		slide_data->other_bezt->f3 |= SELECT;
	}
	mask_layer->act_spline = spline;
	mask_layer->act_point = point;
	ED_mask_select_flush_all(mask);

	return slide_data;
}

static int slide_spline_curvature_invoke(bContext *C, wmOperator *op, const wmEvent *event)
{
	Mask *mask = CTX_data_edit_mask(C);
	SlideSplineCurvatureData *slide_data;

	if (mask == NULL) {
		return OPERATOR_CANCELLED;
	}

	/* Be sure we don't conflict with point slide here. */
	if (!slide_spline_curvature_check(C, event)) {
		return OPERATOR_PASS_THROUGH;
	}

	slide_data = slide_spline_curvature_customdata(C, event);
	if (slide_data != NULL) {
		op->customdata = slide_data;
		WM_event_add_modal_handler(C, op);
		WM_event_add_notifier(C, NC_MASK | ND_SELECT, mask);
		return OPERATOR_RUNNING_MODAL;
	}

	return OPERATOR_PASS_THROUGH;
}

static void slide_spline_solve_P1(const float u,
                                  const float B[2],
                                  const float P0[2],
                                  const float P2[2],
                                  const float P3[2],
                                  float solution[2])
{
	const float u2 = u * u, u3 = u * u * u;
	const float v = 1.0f - u;
	const float v2 = v * v, v3 = v * v * v;
	const float inv_divider = 1.0f / (3.0f * v2 * u);
	const float t = 3.0f * v * u2;
	solution[0] = -(v3 * P0[0] + t * P2[0] + u3 * P3[0] - B[0]) * inv_divider;
	solution[1] = -(v3 * P0[1] + t * P2[1] + u3 * P3[1] - B[1]) * inv_divider;
}

static void slide_spline_solve_P2(const float u,
                                  const float B[2],
                                  const float P0[2],
                                  const float P1[2],
                                  const float P3[2],
                                  float solution[2])
{
	const float u2 = u * u, u3 = u * u * u;
	const float v = 1.0f - u;
	const float v2 = v * v, v3 = v * v * v;
	const float inv_divider = 1.0f / (3.0f * v * u2);
	const float t = 3.0f * v2 * u;
	solution[0] = -(v3 * P0[0] + t * P1[0] + u3 * P3[0] - B[0]) * inv_divider;
	solution[1] = -(v3 * P0[1] + t * P1[1] + u3 * P3[1] - B[1]) * inv_divider;
}

static int slide_spline_curvature_modal(bContext *C, wmOperator *op, const wmEvent *event)
{
	Scene *scene = CTX_data_scene(C);
	const float margin = 0.2f;
	SlideSplineCurvatureData *slide_data = (SlideSplineCurvatureData *) op->customdata;
	float u = slide_data->u;

	switch (event->type) {
		case LEFTSHIFTKEY:
		case RIGHTSHIFTKEY:
		case LEFTCTRLKEY:
		case RIGHTCTRLKEY:
			if (ELEM(event->type, LEFTSHIFTKEY, RIGHTSHIFTKEY)) {
				slide_data->accurate = (event->val == KM_PRESS);
			}

			if (ELEM(event->type, LEFTCTRLKEY, RIGHTCTRLKEY)) {
				if (event->val == KM_PRESS) {
					slide_data->adjust_bezt->h1 = slide_data->adjust_bezt->h2 = HD_FREE;
					if ((u > margin && u < 0.5f) || (u >= 0.5f && u < 1.0f - margin)) {
						slide_data->other_bezt->h1 = slide_data->other_bezt->h2 = HD_FREE;
					}
				}
				else if (event->val == KM_RELEASE) {
					slide_data->adjust_bezt->h1 = slide_data->bezt_backup.h1;
					slide_data->adjust_bezt->h2 = slide_data->bezt_backup.h2;
					slide_data->other_bezt->h1 = slide_data->other_bezt_backup.h1;
					slide_data->other_bezt->h2 = slide_data->other_bezt_backup.h2;
				}

				if (u < 0.5f) {
					copy_v2_v2(slide_data->adjust_bezt->vec[0], slide_data->bezt_backup.vec[0]);
					copy_v2_v2(slide_data->other_bezt->vec[2], slide_data->other_bezt_backup.vec[2]);
				}
				else {
					copy_v2_v2(slide_data->adjust_bezt->vec[2], slide_data->bezt_backup.vec[2]);
					copy_v2_v2(slide_data->other_bezt->vec[0], slide_data->other_bezt_backup.vec[0]);
				}

			}

			/* fall-through */  /* update CV position */
		case MOUSEMOVE:
		{
			float B[2], mouse_coord[2], delta[2];

			/* Get coordinate spline is expected to go through. */
			ED_mask_mouse_pos(CTX_wm_area(C), CTX_wm_region(C), event->mval, mouse_coord);
			sub_v2_v2v2(delta, mouse_coord, slide_data->prev_mouse_coord);
			if (slide_data->accurate) {
				mul_v2_fl(delta, 0.2f);
			}
			add_v2_v2v2(B, slide_data->prev_spline_coord, delta);
			copy_v2_v2(slide_data->prev_spline_coord, B);
			copy_v2_v2(slide_data->prev_mouse_coord, mouse_coord);

			if (u < 0.5f) {
				float oldP2[2];
				bool need_restore_P2 = false;

				if (u > margin) {
					float solution[2];
					float x = (u - margin) * 0.5f / (0.5f - margin);
					float weight =  (3 * x * x - 2 * x * x * x);

					slide_spline_solve_P2(u, B,
					                      slide_data->P0,
					                      slide_data->P1,
					                      slide_data->P3,
					                      solution);

					copy_v2_v2(oldP2, slide_data->P2);
					interp_v2_v2v2(slide_data->P2, slide_data->P2, solution, weight);
					copy_v2_v2(slide_data->other_bezt->vec[0], slide_data->P2);
					need_restore_P2 = true;

					/* Tweak handle type in order to be able to apply the delta. */
					if (weight > 0.0f) {
						if (slide_data->other_bezt->h1 <= HD_VECT) {
							slide_data->other_bezt->h1 = HD_FREE;
						}
					}
				}

				slide_spline_solve_P1(u, B,
				                      slide_data->P0,
				                      slide_data->P2,
				                      slide_data->P3,
				                      slide_data->adjust_bezt->vec[2]);

				if (need_restore_P2) {
					copy_v2_v2(slide_data->P2, oldP2);
				}
			}
			else {
				float oldP1[2];
				bool need_restore_P1 = false;

				if (u < 1.0f - margin) {
					float solution[2];
					float x = ((1.0f - u) - margin) * 0.5f / (0.5f - margin);
					float weight = 3 * x * x - 2 * x * x * x;

					slide_spline_solve_P1(u, B,
					                      slide_data->P0,
					                      slide_data->P2,
					                      slide_data->P3,
					                      solution);

					copy_v2_v2(oldP1, slide_data->P1);
					interp_v2_v2v2(slide_data->P1, slide_data->P1, solution, weight);
					copy_v2_v2(slide_data->other_bezt->vec[2], slide_data->P1);
					need_restore_P1 = true;

					/* Tweak handle type in order to be able to apply the delta. */
					if (weight > 0.0f) {
						if (slide_data->other_bezt->h2 <= HD_VECT) {
							slide_data->other_bezt->h2 = HD_FREE;
						}
					}
				}

				slide_spline_solve_P2(u, B,
				                      slide_data->P0,
				                      slide_data->P1,
				                      slide_data->P3,
				                      slide_data->adjust_bezt->vec[0]);

				if (need_restore_P1) {
					copy_v2_v2(slide_data->P1, oldP1);
				}
			}

			WM_event_add_notifier(C, NC_MASK | NA_EDITED, slide_data->mask);
			DAG_id_tag_update(&slide_data->mask->id, 0);

			break;
		}

		case LEFTMOUSE:
		case RIGHTMOUSE:
			if (event->type == slide_data->event_invoke_type && event->val == KM_RELEASE) {
				/* dont key sliding feather uw's */
				if (IS_AUTOKEY_ON(scene)) {
					ED_mask_layer_shape_auto_key(slide_data->mask_layer, CFRA);
				}

				WM_event_add_notifier(C, NC_MASK | NA_EDITED, slide_data->mask);
				DAG_id_tag_update(&slide_data->mask->id, 0);

				free_slide_spline_curvature_data(slide_data); /* keep this last! */
				return OPERATOR_FINISHED;
			}

			break;

		case ESCKEY:
			cancel_slide_spline_curvature(slide_data);

			WM_event_add_notifier(C, NC_MASK | NA_EDITED, slide_data->mask);
			DAG_id_tag_update(&slide_data->mask->id, 0);

			free_slide_spline_curvature_data(op->customdata); /* keep this last! */
			return OPERATOR_CANCELLED;
	}

	return OPERATOR_RUNNING_MODAL;
}

void MASK_OT_slide_spline_curvature(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Slide Spline Curvature";
	ot->description = "Slide a point on the spline to define it's curvature";
	ot->idname = "MASK_OT_slide_spline_curvature";

	/* api callbacks */
	ot->invoke = slide_spline_curvature_invoke;
	ot->modal = slide_spline_curvature_modal;
	ot->poll = ED_operator_mask;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/******************** toggle cyclic *********************/

static int cyclic_toggle_exec(bContext *C, wmOperator *UNUSED(op))
{
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *masklay;

	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
		MaskSpline *spline;

		if (masklay->restrictflag & (MASK_RESTRICT_VIEW | MASK_RESTRICT_SELECT)) {
			continue;
		}

		for (spline = masklay->splines.first; spline; spline = spline->next) {
			if (ED_mask_spline_select_check(spline)) {
				spline->flag ^= MASK_SPLINE_CYCLIC;
			}
		}
	}

	DAG_id_tag_update(&mask->id, 0);
	WM_event_add_notifier(C, NC_MASK | NA_EDITED, mask);

	return OPERATOR_FINISHED;
}

void MASK_OT_cyclic_toggle(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Toggle Cyclic";
	ot->description = "Toggle cyclic for selected splines";
	ot->idname = "MASK_OT_cyclic_toggle";

	/* api callbacks */
	ot->exec = cyclic_toggle_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/******************** delete *********************/

static void delete_feather_points(MaskSplinePoint *point)
{
	int i, count = 0;

	if (!point->tot_uw)
		return;

	for (i = 0; i < point->tot_uw; i++) {
		if ((point->uw[i].flag & SELECT) == 0)
			count++;
	}

	if (count == 0) {
		MEM_freeN(point->uw);
		point->uw = NULL;
		point->tot_uw = 0;
	}
	else {
		MaskSplinePointUW *new_uw;
		int j = 0;

		new_uw = MEM_callocN(count * sizeof(MaskSplinePointUW), "new mask uw points");

		for (i = 0; i < point->tot_uw; i++) {
			if ((point->uw[i].flag & SELECT) == 0) {
				new_uw[j++] = point->uw[i];
			}
		}

		MEM_freeN(point->uw);

		point->uw = new_uw;
		point->tot_uw = count;
	}
}

static int delete_exec(bContext *C, wmOperator *UNUSED(op))
{
	Scene *scene = CTX_data_scene(C);
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *masklay;
	bool changed = false;

	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
		MaskSpline *spline;
		int mask_layer_shape_ofs = 0;

		if (masklay->restrictflag & (MASK_RESTRICT_VIEW | MASK_RESTRICT_SELECT)) {
			continue;
		}

		spline = masklay->splines.first;

		while (spline) {
			const int tot_point_orig = spline->tot_point;
			int i, count = 0;
			MaskSpline *next_spline = spline->next;

			/* count unselected points */
			for (i = 0; i < spline->tot_point; i++) {
				MaskSplinePoint *point = &spline->points[i];

				if (!MASKPOINT_ISSEL_ANY(point))
					count++;
			}

			if (count == 0) {
				/* delete the whole spline */
				BLI_remlink(&masklay->splines, spline);
				BKE_mask_spline_free(spline);

				if (spline == masklay->act_spline) {
					masklay->act_spline = NULL;
					masklay->act_point = NULL;
				}

				BKE_mask_layer_shape_changed_remove(masklay, mask_layer_shape_ofs, tot_point_orig);
			}
			else {
				MaskSplinePoint *new_points;
				int j;

				new_points = MEM_callocN(count * sizeof(MaskSplinePoint), "deleteMaskPoints");

				for (i = 0, j = 0; i < tot_point_orig; i++) {
					MaskSplinePoint *point = &spline->points[i];

					if (!MASKPOINT_ISSEL_ANY(point)) {
						if (point == masklay->act_point)
							masklay->act_point = &new_points[j];

						delete_feather_points(point);

						new_points[j] = *point;
						j++;
					}
					else {
						if (point == masklay->act_point)
							masklay->act_point = NULL;

						BKE_mask_point_free(point);
						spline->tot_point--;

						BKE_mask_layer_shape_changed_remove(masklay, mask_layer_shape_ofs + j, 1);
					}
				}

				mask_layer_shape_ofs += spline->tot_point;

				MEM_freeN(spline->points);
				spline->points = new_points;

				ED_mask_select_flush_all(mask);
			}

			changed = true;
			spline = next_spline;
		}

		/* not essential but confuses users when there are keys with no data!
		 * assume if they delete all data from the layer they also dont care about keys */
		if (BLI_listbase_is_empty(&masklay->splines)) {
			BKE_mask_layer_free_shapes(masklay);
		}
	}

	if (!changed) {
		return OPERATOR_CANCELLED;
	}

	/* TODO: only update edited splines */
	BKE_mask_update_display(mask, CFRA);

	WM_event_add_notifier(C, NC_MASK | NA_EDITED, mask);

	return OPERATOR_FINISHED;
}

void MASK_OT_delete(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Delete";
	ot->description = "Delete selected control points or splines";
	ot->idname = "MASK_OT_delete";

	/* api callbacks */
	ot->invoke = WM_operator_confirm;
	ot->exec = delete_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* *** switch direction *** */
static int mask_switch_direction_exec(bContext *C, wmOperator *UNUSED(op))
{
	Scene *scene = CTX_data_scene(C);
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *masklay;

	bool changed = false;

	/* do actual selection */
	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
		MaskSpline *spline;
		bool changed_layer = false;

		if (masklay->restrictflag & (MASK_RESTRICT_VIEW | MASK_RESTRICT_SELECT)) {
			continue;
		}

		for (spline = masklay->splines.first; spline; spline = spline->next) {
			if (ED_mask_spline_select_check(spline)) {
				BKE_mask_spline_direction_switch(masklay, spline);
				changed = true;
				changed_layer = true;
			}
		}

		if (changed_layer) {
			if (IS_AUTOKEY_ON(scene)) {
				ED_mask_layer_shape_auto_key(masklay, CFRA);
			}
		}
	}

	if (changed) {
		/* TODO: only update this spline */
		BKE_mask_update_display(mask, CFRA);

		WM_event_add_notifier(C, NC_MASK | ND_SELECT, mask);
		WM_event_add_notifier(C, NC_MASK | NA_EDITED, mask);

		return OPERATOR_FINISHED;
	}

	return OPERATOR_CANCELLED;
}

void MASK_OT_switch_direction(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Switch Direction";
	ot->description = "Switch direction of selected splines";
	ot->idname = "MASK_OT_switch_direction";

	/* api callbacks */
	ot->exec = mask_switch_direction_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}


/* *** recalc normals *** */
static int mask_normals_make_consistent_exec(bContext *C, wmOperator *UNUSED(op))
{
	Scene *scene = CTX_data_scene(C);
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *masklay;
	int i;

	bool changed = false;

	/* do actual selection */
	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
		MaskSpline *spline;
		bool changed_layer = false;

		if (masklay->restrictflag & (MASK_RESTRICT_VIEW | MASK_RESTRICT_SELECT)) {
			continue;
		}

		for (spline = masklay->splines.first; spline; spline = spline->next) {
			for (i = 0; i < spline->tot_point; i++) {
				MaskSplinePoint *point = &spline->points[i];

				if (MASKPOINT_ISSEL_ANY(point)) {
					BKE_mask_calc_handle_point_auto(spline, point, false);
					changed = true;
					changed_layer = true;
				}
			}
		}

		if (changed_layer) {
			if (IS_AUTOKEY_ON(scene)) {
				ED_mask_layer_shape_auto_key(masklay, CFRA);
			}
		}
	}

	if (changed) {
		/* TODO: only update this spline */
		BKE_mask_update_display(mask, CFRA);

		WM_event_add_notifier(C, NC_MASK | ND_SELECT, mask);
		WM_event_add_notifier(C, NC_MASK | NA_EDITED, mask);

		return OPERATOR_FINISHED;
	}

	return OPERATOR_CANCELLED;
}

/* named to match mesh recalc normals */
void MASK_OT_normals_make_consistent(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Recalc Normals";
	ot->description = "Re-calculate the direction of selected handles";
	ot->idname = "MASK_OT_normals_make_consistent";

	/* api callbacks */
	ot->exec = mask_normals_make_consistent_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}


/******************** set handle type *********************/

static int set_handle_type_exec(bContext *C, wmOperator *op)
{
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *masklay;
	int handle_type = RNA_enum_get(op->ptr, "type");

	bool changed = false;

	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
		MaskSpline *spline;
		int i;

		if (masklay->restrictflag & (MASK_RESTRICT_VIEW | MASK_RESTRICT_SELECT)) {
			continue;
		}

		for (spline = masklay->splines.first; spline; spline = spline->next) {
			for (i = 0; i < spline->tot_point; i++) {
				MaskSplinePoint *point = &spline->points[i];

				if (MASKPOINT_ISSEL_ANY(point)) {
					BezTriple *bezt = &point->bezt;

					if (bezt->f2 & SELECT) {
						bezt->h1 = handle_type;
						bezt->h2 = handle_type;
					}
					else {
						if (bezt->f1 & SELECT) {
							bezt->h1 = handle_type;
						}
						if (bezt->f3 & SELECT) {
							bezt->h2 = handle_type;
						}
					}

					if (handle_type == HD_ALIGN) {
						float vec[3];
						sub_v3_v3v3(vec, bezt->vec[0], bezt->vec[1]);
						add_v3_v3v3(bezt->vec[2], bezt->vec[1], vec);
					}

					changed = true;
				}
			}
		}
	}

	if (changed) {
		WM_event_add_notifier(C, NC_MASK | ND_DATA, mask);
		DAG_id_tag_update(&mask->id, 0);

		return OPERATOR_FINISHED;
	}
	return OPERATOR_CANCELLED;
}

void MASK_OT_handle_type_set(wmOperatorType *ot)
{
	static EnumPropertyItem editcurve_handle_type_items[] = {
		{HD_AUTO, "AUTO", 0, "Auto", ""},
		{HD_VECT, "VECTOR", 0, "Vector", ""},
		{HD_ALIGN, "ALIGNED", 0, "Aligned Single", ""},
		{HD_ALIGN_DOUBLESIDE, "ALIGNED_DOUBLESIDE", 0, "Aligned", ""},
		{HD_FREE, "FREE", 0, "Free", ""},
		{0, NULL, 0, NULL, NULL}
	};

	/* identifiers */
	ot->name = "Set Handle Type";
	ot->description = "Set type of handles for selected control points";
	ot->idname = "MASK_OT_handle_type_set";

	/* api callbacks */
	ot->invoke = WM_menu_invoke;
	ot->exec = set_handle_type_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* properties */
	ot->prop = RNA_def_enum(ot->srna, "type", editcurve_handle_type_items, 1, "Type", "Spline type");
}


/* ********* clear/set restrict view *********/
static int mask_hide_view_clear_exec(bContext *C, wmOperator *UNUSED(op))
{
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *masklay;
	bool changed = false;

	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {

		if (masklay->restrictflag & OB_RESTRICT_VIEW) {
			ED_mask_layer_select_set(masklay, true);
			masklay->restrictflag &= ~OB_RESTRICT_VIEW;
			changed = true;
		}
	}

	if (changed) {
		WM_event_add_notifier(C, NC_MASK | ND_DRAW, mask);
		DAG_id_tag_update(&mask->id, 0);

		return OPERATOR_FINISHED;
	}
	else {
		return OPERATOR_CANCELLED;
	}
}

void MASK_OT_hide_view_clear(wmOperatorType *ot)
{

	/* identifiers */
	ot->name = "Clear Restrict View";
	ot->description = "Reveal the layer by setting the hide flag";
	ot->idname = "MASK_OT_hide_view_clear";

	/* api callbacks */
	ot->exec = mask_hide_view_clear_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

static int mask_hide_view_set_exec(bContext *C, wmOperator *op)
{
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *masklay;
	const bool unselected = RNA_boolean_get(op->ptr, "unselected");
	bool changed = false;

	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {

		if (masklay->restrictflag & MASK_RESTRICT_SELECT) {
			continue;
		}

		if (!unselected) {
			if (ED_mask_layer_select_check(masklay)) {
				ED_mask_layer_select_set(masklay, false);

				masklay->restrictflag |= OB_RESTRICT_VIEW;
				changed = true;
				if (masklay == BKE_mask_layer_active(mask)) {
					BKE_mask_layer_active_set(mask, NULL);
				}
			}
		}
		else {
			if (!ED_mask_layer_select_check(masklay)) {
				masklay->restrictflag |= OB_RESTRICT_VIEW;
				changed = true;
				if (masklay == BKE_mask_layer_active(mask)) {
					BKE_mask_layer_active_set(mask, NULL);
				}
			}
		}
	}

	if (changed) {
		WM_event_add_notifier(C, NC_MASK | ND_DRAW, mask);
		DAG_id_tag_update(&mask->id, 0);

		return OPERATOR_FINISHED;
	}
	else {
		return OPERATOR_CANCELLED;
	}
}

void MASK_OT_hide_view_set(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Set Restrict View";
	ot->description = "Hide the layer by setting the hide flag";
	ot->idname = "MASK_OT_hide_view_set";

	/* api callbacks */
	ot->exec = mask_hide_view_set_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	RNA_def_boolean(ot->srna, "unselected", 0, "Unselected", "Hide unselected rather than selected layers");
}


static int mask_feather_weight_clear_exec(bContext *C, wmOperator *UNUSED(op))
{
	Scene *scene = CTX_data_scene(C);
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *masklay;
	bool changed = false;
	int i;

	for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
		MaskSpline *spline;

		if (masklay->restrictflag & (MASK_RESTRICT_SELECT | MASK_RESTRICT_VIEW)) {
			continue;
		}

		for (spline = masklay->splines.first; spline; spline = spline->next) {
			for (i = 0; i < spline->tot_point; i++) {
				MaskSplinePoint *point = &spline->points[i];

				if (MASKPOINT_ISSEL_ANY(point)) {
					BezTriple *bezt = &point->bezt;
					bezt->weight = 0.0f;
					changed = true;
				}
			}
		}
	}

	if (changed) {
		/* TODO: only update edited splines */
		BKE_mask_update_display(mask, CFRA);

		WM_event_add_notifier(C, NC_MASK | ND_DRAW, mask);
		DAG_id_tag_update(&mask->id, 0);

		return OPERATOR_FINISHED;
	}
	else {
		return OPERATOR_CANCELLED;
	}
}

void MASK_OT_feather_weight_clear(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Clear Feather Weight";
	ot->description = "Reset the feather weight to zero";
	ot->idname = "MASK_OT_feather_weight_clear";

	/* api callbacks */
	ot->exec = mask_feather_weight_clear_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/******************** move mask layer operator *********************/

static int mask_layer_move_poll(bContext *C)
{
	if (ED_maskedit_mask_poll(C)) {
		Mask *mask = CTX_data_edit_mask(C);

		return mask->masklay_tot > 0;
	}

	return false;
}

static int mask_layer_move_exec(bContext *C, wmOperator *op)
{
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *mask_layer = BLI_findlink(&mask->masklayers, mask->masklay_act);
	MaskLayer *mask_layer_other;
	int direction = RNA_enum_get(op->ptr, "direction");

	if (!mask_layer)
		return OPERATOR_CANCELLED;

	if (direction == -1) {
		mask_layer_other = mask_layer->prev;

		if (!mask_layer_other)
			return OPERATOR_CANCELLED;

		BLI_remlink(&mask->masklayers, mask_layer);
		BLI_insertlinkbefore(&mask->masklayers, mask_layer_other, mask_layer);
		mask->masklay_act--;
	}
	else if (direction == 1) {
		mask_layer_other = mask_layer->next;

		if (!mask_layer_other)
			return OPERATOR_CANCELLED;

		BLI_remlink(&mask->masklayers, mask_layer);
		BLI_insertlinkafter(&mask->masklayers, mask_layer_other, mask_layer);
		mask->masklay_act++;
	}

	WM_event_add_notifier(C, NC_MASK | NA_EDITED, mask);

	return OPERATOR_FINISHED;
}

void MASK_OT_layer_move(wmOperatorType *ot)
{
	static EnumPropertyItem direction_items[] = {
		{-1, "UP", 0, "Up", ""},
		{1, "DOWN", 0, "Down", ""},
		{0, NULL, 0, NULL, NULL}
	};

	/* identifiers */
	ot->name = "Move Layer";
	ot->description = "Move the active layer up/down in the list";
	ot->idname = "MASK_OT_layer_move";

	/* api callbacks */
	ot->exec = mask_layer_move_exec;
	ot->poll = mask_layer_move_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

	/* properties */
	RNA_def_enum(ot->srna, "direction", direction_items, 0, "Direction", "Direction to move the active layer");
}

/******************** duplicate *********************/

static int mask_duplicate_exec(bContext *C, wmOperator *UNUSED(op))
{
	Scene *scene = CTX_data_scene(C);
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *mask_layer;

	for (mask_layer = mask->masklayers.first;
	     mask_layer;
	     mask_layer = mask_layer->next)
	{
		MaskSpline *spline;

		for (spline = mask_layer->splines.last;
		     spline;
		     spline = spline->prev)
		{
			MaskSplinePoint *point = spline->points;
			int i = 0;
			while (i < spline->tot_point) {
				int start = i, end = -1;
				/* Find next selected segment. */
				while (MASKPOINT_ISSEL_ANY(point)) {
					BKE_mask_point_select_set(point, false);
					end = i;
					if (i >= spline->tot_point - 1) {
						break;
					}
					i++;
					point++;
				}
				if (end >= start) {
					int tot_point;
					int tot_point_shape_start;
					MaskSpline *new_spline = BKE_mask_spline_add(mask_layer);
					MaskSplinePoint *new_point;
					int b;

					/* BKE_mask_spline_add might allocate the points, need to free them in this case. */
					if (new_spline->points) {
						MEM_freeN(new_spline->points);
					}

					/* Copy options from old spline. */
					new_spline->flag = spline->flag;
					new_spline->offset_mode = spline->offset_mode;
					new_spline->weight_interp = spline->weight_interp;
					new_spline->parent = spline->parent;

					/* Allocate new points and copy them from old spline. */
					new_spline->tot_point = end - start + 1;
					new_spline->points = MEM_mallocN(sizeof(MaskSplinePoint) * new_spline->tot_point,
					                                 "duplicated mask points");

					memcpy(new_spline->points, spline->points + start,
					       new_spline->tot_point * sizeof(MaskSplinePoint));

					tot_point = new_spline->tot_point;

					/* animation requires points added one by one */
					if (mask_layer->splines_shapes.first) {
						new_spline->tot_point = 0;
						tot_point_shape_start = BKE_mask_layer_shape_spline_to_index(mask_layer, new_spline);
					}

					/* Select points and duplicate their UWs (if needed). */
					for (b = 0, new_point = new_spline->points;
					     b < tot_point;
					     b++, new_point++)
					{
						if (new_point->uw) {
							new_point->uw = MEM_dupallocN(new_point->uw);
						}
						BKE_mask_point_select_set(new_point, true);


						if (mask_layer->splines_shapes.first) {
							new_spline->tot_point++;
							BKE_mask_layer_shape_changed_add(mask_layer, tot_point_shape_start + b, true, false);
						}
					}

					/* Clear cyclic flag if we didn't copy the whole spline. */
					if (new_spline->flag & MASK_SPLINE_CYCLIC) {
						if (start != 0 || end != spline->tot_point - 1) {
							new_spline->flag &= ~MASK_SPLINE_CYCLIC;
						}
					}

					/* Flush selection to splines. */
					new_spline->flag |= SELECT;
					spline->flag &= ~SELECT;

					mask_layer->act_spline = new_spline;
				}
				i++;
				point++;
			}
		}
	}

	/* TODO: only update edited splines */
	BKE_mask_update_display(mask, CFRA);

	WM_event_add_notifier(C, NC_MASK | NA_EDITED, mask);

	return OPERATOR_FINISHED;
}

void MASK_OT_duplicate(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Duplicate Mask";
	ot->description = "Duplicate selected control points and segments between them";
	ot->idname = "MASK_OT_duplicate";

	/* api callbacks */
	ot->exec = mask_duplicate_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/********************** copy splines to clipboard operator *********************/

static int copy_splines_exec(bContext *C, wmOperator *UNUSED(op))
{
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *mask_layer = BKE_mask_layer_active(mask);

	if (mask_layer == NULL) {
		return OPERATOR_CANCELLED;
	}

	BKE_mask_clipboard_copy_from_layer(mask_layer);

	return OPERATOR_FINISHED;
}

void MASK_OT_copy_splines(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Copy Splines";
	ot->description = "Copy selected splines to clipboard";
	ot->idname = "MASK_OT_copy_splines";

	/* api callbacks */
	ot->exec = copy_splines_exec;
	ot->poll = ED_maskedit_mask_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER;
}

/********************** paste tracks from clipboard operator *********************/

static int paste_splines_poll(bContext *C)
{
	if (ED_maskedit_mask_poll(C)) {
		return BKE_mask_clipboard_is_empty() == false;
	}

	return 0;
}

static int paste_splines_exec(bContext *C, wmOperator *UNUSED(op))
{
	Scene *scene = CTX_data_scene(C);
	Mask *mask = CTX_data_edit_mask(C);
	MaskLayer *mask_layer = BKE_mask_layer_active(mask);

	if (mask_layer == NULL) {
		mask_layer = BKE_mask_layer_new(mask, "");
	}

	BKE_mask_clipboard_paste_to_layer(CTX_data_main(C), mask_layer);

	/* TODO: only update edited splines */
	BKE_mask_update_display(mask, CFRA);

	WM_event_add_notifier(C, NC_MASK | NA_EDITED, mask);

	return OPERATOR_FINISHED;
}

void MASK_OT_paste_splines(wmOperatorType *ot)
{
	/* identifiers */
	ot->name = "Paste Splines";
	ot->description = "Paste splines from clipboard";
	ot->idname = "MASK_OT_paste_splines";

	/* api callbacks */
	ot->exec = paste_splines_exec;
	ot->poll = paste_splines_poll;

	/* flags */
	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}