/*
 * ***** 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) 2008 Blender Foundation
 *
 * Contributor(s): Joshua Leung
 *
 * ***** END GPL LICENSE BLOCK *****
 */

/** \file blender/editors/animation/keyframes_edit.c
 *  \ingroup edanimation
 */


#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <float.h>

#include "MEM_guardedalloc.h"

#include "BLI_blenlib.h"
#include "BLI_math.h"
#include "BLI_utildefines.h"

#include "DNA_anim_types.h"
#include "DNA_armature_types.h"
#include "DNA_camera_types.h"
#include "DNA_key_types.h"
#include "DNA_lamp_types.h"
#include "DNA_lattice_types.h"
#include "DNA_mesh_types.h"
#include "DNA_material_types.h"
#include "DNA_object_types.h"
#include "DNA_meta_types.h"
#include "DNA_node_types.h"
#include "DNA_particle_types.h"
#include "DNA_scene_types.h"
#include "DNA_space_types.h"
#include "DNA_world_types.h"

#include "BKE_fcurve.h"
#include "BKE_key.h"
#include "BKE_material.h"


#include "ED_anim_api.h"
#include "ED_keyframes_edit.h"
#include "ED_markers.h"

/* This file defines an API and set of callback-operators for non-destructive editing of keyframe data.
 *
 * Two API functions are defined for actually performing the operations on the data:
 *			ANIM_fcurve_keyframes_loop()
 * which take the data they operate on, a few callbacks defining what operations to perform.
 *
 * As operators which work on keyframes usually apply the same operation on all BezTriples in 
 * every channel, the code has been optimized providing a set of functions which will get the 
 * appropriate bezier-modify function to set. These functions (ANIM_editkeyframes_*) will need
 * to be called before getting any channels.
 * 
 * A set of 'validation' callbacks are provided for checking if a BezTriple should be operated on.
 * These should only be used when using a 'general' BezTriple editor (i.e. selection setters which 
 * don't check existing selection status).
 * 
 * - Joshua Leung, Dec 2008
 */

/* ************************************************************************** */
/* Keyframe Editing Loops - Exposed API */

/* --------------------------- Base Functions ------------------------------------ */

/* This function is used to loop over BezTriples in the given F-Curve, applying a given 
 * operation on them, and optionally applies an F-Curve validation function afterwards.
 */
// TODO: make this function work on samples too...
short ANIM_fcurve_keyframes_loop(KeyframeEditData *ked, FCurve *fcu, KeyframeEditFunc key_ok, KeyframeEditFunc key_cb, FcuEditFunc fcu_cb) 
{
	BezTriple *bezt;
	short ok = 0;
	unsigned int i;

	/* sanity check */
	if (ELEM(NULL, fcu, fcu->bezt))
		return 0;

	/* set the F-Curve into the editdata so that it can be accessed */
	if (ked) {
		ked->fcu = fcu;
		ked->curIndex = 0;
		ked->curflags = ok;
	}

	/* if function to apply to bezier curves is set, then loop through executing it on beztriples */
	if (key_cb) {
		/* if there's a validation func, include that check in the loop 
		 * (this is should be more efficient than checking for it in every loop)
		 */
		if (key_ok) {
			for (bezt = fcu->bezt, i = 0; i < fcu->totvert; bezt++, i++) {
				if (ked) {
					/* advance the index, and reset the ok flags (to not influence the result) */
					ked->curIndex = i;
					ked->curflags = 0;
				}
				
				/* Only operate on this BezTriple if it fullfills the criteria of the validation func */
				if ( (ok = key_ok(ked, bezt)) ) {
					if (ked) ked->curflags = ok;
					
					/* Exit with return-code '1' if function returns positive
					 * This is useful if finding if some BezTriple satisfies a condition.
					 */
					if (key_cb(ked, bezt)) return 1;
				}
			}
		}
		else {
			for (bezt = fcu->bezt, i = 0; i < fcu->totvert; bezt++, i++) {
				if (ked) ked->curIndex = i;
				
				/* Exit with return-code '1' if function returns positive
				 * This is useful if finding if some BezTriple satisfies a condition.
				 */
				if (key_cb(ked, bezt)) return 1;
			}
		}
	}
	
	/* unset the F-Curve from the editdata now that it's done */
	if (ked) {
		ked->fcu = NULL;
		ked->curIndex = 0;
		ked->curflags = 0;
	}

	/* if fcu_cb (F-Curve post-editing callback) has been specified then execute it */
	if (fcu_cb)
		fcu_cb(fcu);
	
	/* done */
	return 0;
}

/* -------------------------------- Further Abstracted (Not Exposed Directly) ----------------------------- */

/* This function is used to loop over the keyframe data in an Action Group */
static short agrp_keyframes_loop(KeyframeEditData *ked, bActionGroup *agrp, KeyframeEditFunc key_ok, KeyframeEditFunc key_cb, FcuEditFunc fcu_cb)
{
	FCurve *fcu;
	
	/* sanity check */
	if (agrp == NULL)
		return 0;
	
	/* only iterate over the F-Curves that are in this group */
	for (fcu = agrp->channels.first; fcu && fcu->grp == agrp; fcu = fcu->next) {
		if (ANIM_fcurve_keyframes_loop(ked, fcu, key_ok, key_cb, fcu_cb))
			return 1;
	}
	
	return 0;
}

/* This function is used to loop over the keyframe data in an Action */
static short act_keyframes_loop(KeyframeEditData *ked, bAction *act, KeyframeEditFunc key_ok, KeyframeEditFunc key_cb, FcuEditFunc fcu_cb)
{
	FCurve *fcu;
	
	/* sanity check */
	if (act == NULL)
		return 0;
	
	/* just loop through all F-Curves */
	for (fcu = act->curves.first; fcu; fcu = fcu->next) {
		if (ANIM_fcurve_keyframes_loop(ked, fcu, key_ok, key_cb, fcu_cb))
			return 1;
	}
	
	return 0;
}

/* This function is used to loop over the keyframe data in an Object */
static short ob_keyframes_loop(KeyframeEditData *ked, bDopeSheet *ads, Object *ob, KeyframeEditFunc key_ok, KeyframeEditFunc key_cb, FcuEditFunc fcu_cb)
{
	bAnimContext ac = {NULL};
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	int ret = 0;
	
	bAnimListElem dummychan = {NULL};
	Base dummybase = {NULL};
	
	if (ob == NULL)
		return 0;
	
	/* create a dummy wrapper data to work with */
	dummybase.object = ob;
	
	dummychan.type = ANIMTYPE_OBJECT;
	dummychan.data = &dummybase;
	dummychan.id = &ob->id;
	dummychan.adt = ob->adt;
	
	ac.ads = ads;
	ac.data = &dummychan;
	ac.datatype = ANIMCONT_CHANNEL;
	
	/* get F-Curves to take keyframes from */
	filter = ANIMFILTER_DATA_VISIBLE; // curves only
	ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
	
	/* loop through each F-Curve, applying the operation as required, but stopping on the first one */
	for (ale = anim_data.first; ale; ale = ale->next) {
		if (ANIM_fcurve_keyframes_loop(ked, (FCurve *)ale->data, key_ok, key_cb, fcu_cb)) {
			ret = 1;
			break;
		}
	}
	
	BLI_freelistN(&anim_data);
	
	/* return return code - defaults to zero if nothing happened */
	return ret;
}

/* This function is used to loop over the keyframe data in a Scene */
static short scene_keyframes_loop(KeyframeEditData *ked, bDopeSheet *ads, Scene *sce, KeyframeEditFunc key_ok, KeyframeEditFunc key_cb, FcuEditFunc fcu_cb)
{
	bAnimContext ac = {NULL};
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	int ret = 0;
	
	bAnimListElem dummychan = {NULL};
	
	if (sce == NULL)
		return 0;
	
	/* create a dummy wrapper data to work with */
	dummychan.type = ANIMTYPE_SCENE;
	dummychan.data = sce;
	dummychan.id = &sce->id;
	dummychan.adt = sce->adt;
	
	ac.ads = ads;
	ac.data = &dummychan;
	ac.datatype = ANIMCONT_CHANNEL;
	
	/* get F-Curves to take keyframes from */
	filter = ANIMFILTER_DATA_VISIBLE; // curves only
	ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);
	
	/* loop through each F-Curve, applying the operation as required, but stopping on the first one */
	for (ale = anim_data.first; ale; ale = ale->next) {
		if (ANIM_fcurve_keyframes_loop(ked, (FCurve *)ale->data, key_ok, key_cb, fcu_cb)) {
			ret = 1;
			break;
		}
	}
	
	BLI_freelistN(&anim_data);
	
	/* return return code - defaults to zero if nothing happened */
	return ret;
}

/* This function is used to loop over the keyframe data in a DopeSheet summary */
static short summary_keyframes_loop(KeyframeEditData *ked, bAnimContext *ac, KeyframeEditFunc key_ok, KeyframeEditFunc key_cb, FcuEditFunc fcu_cb)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter, ret_code = 0;
	
	/* sanity check */
	if (ac == NULL)
		return 0;
	
	/* get F-Curves to take keyframes from */
	filter = ANIMFILTER_DATA_VISIBLE;
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* loop through each F-Curve, working on the keyframes until the first curve aborts */
	for (ale = anim_data.first; ale; ale = ale->next) {
		switch (ale->datatype) {
			case ALE_MASKLAY:
			case ALE_GPFRAME:
				break;
			default:
				ret_code = ANIM_fcurve_keyframes_loop(ked, ale->data, key_ok, key_cb, fcu_cb);
				break;
		}
		
		if (ret_code)
			break;
	}
	
	BLI_freelistN(&anim_data);
	
	return ret_code;
}

/* --- */

/* This function is used to apply operation to all keyframes, regardless of the type */
short ANIM_animchannel_keyframes_loop(KeyframeEditData *ked, bDopeSheet *ads, bAnimListElem *ale, KeyframeEditFunc key_ok, KeyframeEditFunc key_cb, FcuEditFunc fcu_cb)
{
	/* sanity checks */
	if (ale == NULL)
		return 0;
	
	/* method to use depends on the type of keyframe data */
	switch (ale->datatype) {
		/* direct keyframe data (these loops are exposed) */
		case ALE_FCURVE: /* F-Curve */
			return ANIM_fcurve_keyframes_loop(ked, ale->key_data, key_ok, key_cb, fcu_cb);
		
		/* indirect 'summaries' (these are not exposed directly) 
		 * NOTE: must keep this code in sync with the drawing code and also the filtering code!
		 */
		case ALE_GROUP: /* action group */
			return agrp_keyframes_loop(ked, (bActionGroup *)ale->data, key_ok, key_cb, fcu_cb);
		case ALE_ACT: /* action */
			return act_keyframes_loop(ked, (bAction *)ale->key_data, key_ok, key_cb, fcu_cb);
			
		case ALE_OB: /* object */
			return ob_keyframes_loop(ked, ads, (Object *)ale->key_data, key_ok, key_cb, fcu_cb);
		case ALE_SCE: /* scene */
			return scene_keyframes_loop(ked, ads, (Scene *)ale->data, key_ok, key_cb, fcu_cb);
		case ALE_ALL: /* 'all' (DopeSheet summary) */
			return summary_keyframes_loop(ked, (bAnimContext *)ale->data, key_ok, key_cb, fcu_cb);
	}
	
	return 0;
}

/* This function is used to apply operation to all keyframes, regardless of the type without needed an AnimListElem wrapper */
short ANIM_animchanneldata_keyframes_loop(KeyframeEditData *ked, bDopeSheet *ads, void *data, int keytype, KeyframeEditFunc key_ok, KeyframeEditFunc key_cb, FcuEditFunc fcu_cb)
{
	/* sanity checks */
	if (data == NULL)
		return 0;
	
	/* method to use depends on the type of keyframe data */
	switch (keytype) {
		/* direct keyframe data (these loops are exposed) */
		case ALE_FCURVE: /* F-Curve */
			return ANIM_fcurve_keyframes_loop(ked, data, key_ok, key_cb, fcu_cb);
		
		/* indirect 'summaries' (these are not exposed directly) 
		 * NOTE: must keep this code in sync with the drawing code and also the filtering code!
		 */
		case ALE_GROUP: /* action group */
			return agrp_keyframes_loop(ked, (bActionGroup *)data, key_ok, key_cb, fcu_cb);
		case ALE_ACT: /* action */
			return act_keyframes_loop(ked, (bAction *)data, key_ok, key_cb, fcu_cb);
			
		case ALE_OB: /* object */
			return ob_keyframes_loop(ked, ads, (Object *)data, key_ok, key_cb, fcu_cb);
		case ALE_SCE: /* scene */
			return scene_keyframes_loop(ked, ads, (Scene *)data, key_ok, key_cb, fcu_cb);
		case ALE_ALL: /* 'all' (DopeSheet summary) */
			return summary_keyframes_loop(ked, (bAnimContext *)data, key_ok, key_cb, fcu_cb);
	}
	
	return 0;
}

/* ************************************************************************** */
/* Keyframe Integrity Tools */

/* Rearrange keyframes if some are out of order */
// used to be recalc_*_ipos() where * was object or action
void ANIM_editkeyframes_refresh(bAnimContext *ac)
{
	ListBase anim_data = {NULL, NULL};
	bAnimListElem *ale;
	int filter;
	/* when not in graph view, don't use handles */
	SpaceIpo *sipo = (ac->spacetype == SPACE_IPO) ? (SpaceIpo *)ac->sl : NULL;
	const short use_handle = sipo ? !(sipo->flag & SIPO_NOHANDLES) : FALSE;
	
	/* filter animation data */
	filter = ANIMFILTER_DATA_VISIBLE;
	ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);
	
	/* loop over F-Curves that are likely to have been edited, and check them */
	for (ale = anim_data.first; ale; ale = ale->next) {
		FCurve *fcu = ale->key_data;
		
		/* make sure keyframes in F-Curve are all in order, and handles are in valid positions */
		sort_time_fcurve(fcu);
		testhandles_fcurve(fcu, use_handle);
	}
	
	/* free temp data */
	BLI_freelistN(&anim_data);
}

/* ************************************************************************** */
/* BezTriple Validation Callbacks */

/* ------------------------ */
/* Some macros to make this easier... */

/* run the given check on the 3 handles 
 *	- check should be a macro, which takes the handle index as its single arg, which it substitutes later
 *	- requires that a var, of type short, is named 'ok', and has been initialized to 0
 */
#define KEYFRAME_OK_CHECKS(check) \
	{ \
		if (check(1)) \
			ok |= KEYFRAME_OK_KEY; \
		 \
		if (ked && (ked->iterflags & KEYFRAME_ITER_INCL_HANDLES)) { \
			if (check(0)) \
				ok |= KEYFRAME_OK_H1; \
			if (check(2)) \
				ok |= KEYFRAME_OK_H2; \
		} \
	} (void)0
 
/* ------------------------ */
 
static short ok_bezier_frame(KeyframeEditData *ked, BezTriple *bezt)
{
	short ok = 0;
	
	/* frame is stored in f1 property (this float accuracy check may need to be dropped?) */
	#define KEY_CHECK_OK(_index) IS_EQF(bezt->vec[_index][0], ked->f1)
	KEYFRAME_OK_CHECKS(KEY_CHECK_OK);
	#undef KEY_CHECK_OK
	
	/* return ok flags */
	return ok;
}

static short ok_bezier_framerange(KeyframeEditData *ked, BezTriple *bezt)
{
	short ok = 0;
	
	/* frame range is stored in float properties */
	#define KEY_CHECK_OK(_index) ((bezt->vec[_index][0] > ked->f1) && (bezt->vec[_index][0] < ked->f2))
	KEYFRAME_OK_CHECKS(KEY_CHECK_OK);
	#undef KEY_CHECK_OK
	
	/* return ok flags */
	return ok;
}

static short ok_bezier_selected(KeyframeEditData *UNUSED(ked), BezTriple *bezt)
{
	/* this macro checks all beztriple handles for selection... 
	 * only one of the verts has to be selected for this to be ok...
	 */
	if (BEZSELECTED(bezt))
		return KEYFRAME_OK_ALL;
	else
		return 0;
}

static short ok_bezier_value(KeyframeEditData *ked, BezTriple *bezt)
{	
	short ok = 0;
	
	/* value is stored in f1 property 
	 *	- this float accuracy check may need to be dropped?
	 *	- should value be stored in f2 instead so that we won't have conflicts when using f1 for frames too?
	 */
	#define KEY_CHECK_OK(_index) IS_EQF(bezt->vec[_index][1], ked->f1)
	KEYFRAME_OK_CHECKS(KEY_CHECK_OK);
	#undef KEY_CHECK_OK
	
	/* return ok flags */
	return ok;
}

static short ok_bezier_valuerange(KeyframeEditData *ked, BezTriple *bezt)
{
	short ok = 0;
	
	/* value range is stored in float properties */
	#define KEY_CHECK_OK(_index) ((bezt->vec[_index][1] > ked->f1) && (bezt->vec[_index][1] < ked->f2))
	KEYFRAME_OK_CHECKS(KEY_CHECK_OK);
	#undef KEY_CHECK_OK
	
	/* return ok flags */
	return ok;
}

static short ok_bezier_region(KeyframeEditData *ked, BezTriple *bezt)
{
	/* rect is stored in data property (it's of type rectf, but may not be set) */
	if (ked->data) {
		short ok = 0;
		
		#define KEY_CHECK_OK(_index) BLI_rctf_isect_pt_v(ked->data, bezt->vec[_index])
		KEYFRAME_OK_CHECKS(KEY_CHECK_OK);
		#undef KEY_CHECK_OK
		
		/* return ok flags */
		return ok;
	}
	else 
		return 0;
}


KeyframeEditFunc ANIM_editkeyframes_ok(short mode)
{
	/* eEditKeyframes_Validate */
	switch (mode) {
		case BEZT_OK_FRAME: /* only if bezt falls on the right frame (float) */
			return ok_bezier_frame;
		case BEZT_OK_FRAMERANGE: /* only if bezt falls within the specified frame range (floats) */
			return ok_bezier_framerange;
		case BEZT_OK_SELECTED:  /* only if bezt is selected (self) */
			return ok_bezier_selected;
		case BEZT_OK_VALUE: /* only if bezt value matches (float) */
			return ok_bezier_value;
		case BEZT_OK_VALUERANGE: /* only if bezier falls within the specified value range (floats) */
			return ok_bezier_valuerange;
		case BEZT_OK_REGION: /* only if bezier falls within the specified rect (data -> rectf) */
			return ok_bezier_region;
		default: /* nothing was ok */
			return NULL;
	}
}

/* ******************************************* */
/* Assorted Utility Functions */

/* helper callback for <animeditor>_cfrasnap_exec() -> used to help get the average time of all selected beztriples */
short bezt_calc_average(KeyframeEditData *ked, BezTriple *bezt)
{
	/* only if selected */
	if (bezt->f2 & SELECT) {
		/* store average time in float 1 (only do rounding at last step) */
		ked->f1 += bezt->vec[1][0];
		
		/* store average value in float 2 (only do rounding at last step) 
		 *	- this isn't always needed, but some operators may also require this
		 */
		ked->f2 += bezt->vec[1][1];
		
		/* increment number of items */
		ked->i1++;
	}
	
	return 0;
}

/* helper callback for columnselect_<animeditor>_keys() -> populate list CfraElems with frame numbers from selected beztriples */
short bezt_to_cfraelem(KeyframeEditData *ked, BezTriple *bezt)
{
	/* only if selected */
	if (bezt->f2 & SELECT) {
		CfraElem *ce = MEM_callocN(sizeof(CfraElem), "cfraElem");
		BLI_addtail(&ked->list, ce);
		
		ce->cfra = bezt->vec[1][0];
	}
	
	return 0;
}

/* used to remap times from one range to another
 * requires:  ked->data = KeyframeEditCD_Remap	
 */
void bezt_remap_times(KeyframeEditData *ked, BezTriple *bezt)
{
	KeyframeEditCD_Remap *rmap = (KeyframeEditCD_Remap *)ked->data;
	const float scale = (rmap->newMax - rmap->newMin) / (rmap->oldMax - rmap->oldMin);
	
	/* perform transform on all three handles unless indicated otherwise */
	// TODO: need to include some checks for that
	
	bezt->vec[0][0] = scale * (bezt->vec[0][0] - rmap->oldMin) + rmap->newMin;
	bezt->vec[1][0] = scale * (bezt->vec[1][0] - rmap->oldMin) + rmap->newMin;
	bezt->vec[2][0] = scale * (bezt->vec[2][0] - rmap->oldMin) + rmap->newMin;
}

/* ******************************************* */
/* Transform */

/* snaps the keyframe to the nearest frame */
static short snap_bezier_nearest(KeyframeEditData *UNUSED(ked), BezTriple *bezt)
{
	if (bezt->f2 & SELECT)
		bezt->vec[1][0] = (float)(floorf(bezt->vec[1][0] + 0.5f));
	return 0;
}

/* snaps the keyframe to the neares second */
static short snap_bezier_nearestsec(KeyframeEditData *ked, BezTriple *bezt)
{
	const Scene *scene = ked->scene;
	const float secf = (float)FPS;
	
	if (bezt->f2 & SELECT)
		bezt->vec[1][0] = ((float)floor(bezt->vec[1][0] / secf + 0.5f) * secf);
	return 0;
}

/* snaps the keyframe to the current frame */
static short snap_bezier_cframe(KeyframeEditData *ked, BezTriple *bezt)
{
	const Scene *scene = ked->scene;
	if (bezt->f2 & SELECT)
		bezt->vec[1][0] = (float)CFRA;
	return 0;
}

/* snaps the keyframe time to the nearest marker's frame */
static short snap_bezier_nearmarker(KeyframeEditData *ked, BezTriple *bezt)
{
	if (bezt->f2 & SELECT)
		bezt->vec[1][0] = (float)ED_markers_find_nearest_marker_time(&ked->list, bezt->vec[1][0]);
	return 0;
}

/* make the handles have the same value as the key */
static short snap_bezier_horizontal(KeyframeEditData *UNUSED(ked), BezTriple *bezt)
{
	if (bezt->f2 & SELECT) {
		bezt->vec[0][1] = bezt->vec[2][1] = bezt->vec[1][1];
		
		if (ELEM3(bezt->h1, HD_AUTO, HD_AUTO_ANIM, HD_VECT)) bezt->h1 = HD_ALIGN;
		if (ELEM3(bezt->h2, HD_AUTO, HD_AUTO_ANIM, HD_VECT)) bezt->h2 = HD_ALIGN;
	}
	return 0;
}

/* value to snap to is stored in the custom data -> first float value slot */
static short snap_bezier_value(KeyframeEditData *ked, BezTriple *bezt)
{
	if (bezt->f2 & SELECT)
		bezt->vec[1][1] = ked->f1;
	return 0;
}

KeyframeEditFunc ANIM_editkeyframes_snap(short type)
{
	/* eEditKeyframes_Snap */
	switch (type) {
		case SNAP_KEYS_NEARFRAME: /* snap to nearest frame */
			return snap_bezier_nearest;
		case SNAP_KEYS_CURFRAME: /* snap to current frame */
			return snap_bezier_cframe;
		case SNAP_KEYS_NEARMARKER: /* snap to nearest marker */
			return snap_bezier_nearmarker;
		case SNAP_KEYS_NEARSEC: /* snap to nearest second */
			return snap_bezier_nearestsec;
		case SNAP_KEYS_HORIZONTAL: /* snap handles to same value */
			return snap_bezier_horizontal;
		case SNAP_KEYS_VALUE: /* snap to given value */
			return snap_bezier_value;
		default: /* just in case */
			return snap_bezier_nearest;
	}
}

/* --------- */

static short mirror_bezier_cframe(KeyframeEditData *ked, BezTriple *bezt)
{
	const Scene *scene = ked->scene;
	float diff;
	
	if (bezt->f2 & SELECT) {
		diff = ((float)CFRA - bezt->vec[1][0]);
		bezt->vec[1][0] = ((float)CFRA + diff);
	}
	
	return 0;
}

static short mirror_bezier_yaxis(KeyframeEditData *UNUSED(ked), BezTriple *bezt)
{
	float diff;
	
	if (bezt->f2 & SELECT) {
		diff = (0.0f - bezt->vec[1][0]);
		bezt->vec[1][0] = (0.0f + diff);
	}
	
	return 0;
}

static short mirror_bezier_xaxis(KeyframeEditData *UNUSED(ked), BezTriple *bezt)
{
	float diff;
	
	if (bezt->f2 & SELECT) {
		diff = (0.0f - bezt->vec[1][1]);
		bezt->vec[1][1] = (0.0f + diff);
	}
	
	return 0;
}

static short mirror_bezier_marker(KeyframeEditData *ked, BezTriple *bezt)
{
	/* mirroring time stored in f1 */
	if (bezt->f2 & SELECT) {
		const float diff = (ked->f1 - bezt->vec[1][0]);
		bezt->vec[1][0] = (ked->f1 + diff);
	}
	
	return 0;
}

static short mirror_bezier_value(KeyframeEditData *ked, BezTriple *bezt)
{
	float diff;
	
	/* value to mirror over is stored in the custom data -> first float value slot */
	if (bezt->f2 & SELECT) {
		diff = (ked->f1 - bezt->vec[1][1]);
		bezt->vec[1][1] = (ked->f1 + diff);
	}
	
	return 0;
}

/* Note: for markers and 'value', the values to use must be supplied as the first float value */
// calchandles_fcurve
KeyframeEditFunc ANIM_editkeyframes_mirror(short type)
{
	switch (type) {
		case MIRROR_KEYS_CURFRAME: /* mirror over current frame */
			return mirror_bezier_cframe;
		case MIRROR_KEYS_YAXIS: /* mirror over frame 0 */
			return mirror_bezier_yaxis;
		case MIRROR_KEYS_XAXIS: /* mirror over value 0 */
			return mirror_bezier_xaxis;
		case MIRROR_KEYS_MARKER: /* mirror over marker */
			return mirror_bezier_marker; 
		case MIRROR_KEYS_VALUE: /* mirror over given value */
			return mirror_bezier_value;
		default: /* just in case */
			return mirror_bezier_yaxis;
	}
}

/* ******************************************* */
/* Settings */

/* standard validation step for a few of these (implemented as macro for inlining without fn-call overhead):
 *	"if the handles are not of the same type, set them to type free"
 */
#define ENSURE_HANDLES_MATCH(bezt)                                            \
	if (bezt->h1 != bezt->h2) {                                               \
		if (ELEM3(bezt->h1, HD_ALIGN, HD_AUTO, HD_AUTO_ANIM))                 \
			bezt->h1 = HD_FREE;                                               \
		if (ELEM3(bezt->h2, HD_ALIGN, HD_AUTO, HD_AUTO_ANIM))                 \
			bezt->h2 = HD_FREE;                                               \
	} (void)0

/* Sets the selected bezier handles to type 'auto' */
static short set_bezier_auto(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if ((bezt->f1 & SELECT) || (bezt->f3 & SELECT)) {
		if (bezt->f1 & SELECT) bezt->h1 = HD_AUTO;
		if (bezt->f3 & SELECT) bezt->h2 = HD_AUTO;
		
		ENSURE_HANDLES_MATCH(bezt);
	}
	return 0;
}

/* Sets the selected bezier handles to type 'auto-clamped'
 * NOTE: this is like auto above, but they're handled a bit different
 */
static short set_bezier_auto_clamped(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if ((bezt->f1 & SELECT) || (bezt->f3 & SELECT)) {
		if (bezt->f1 & SELECT) bezt->h1 = HD_AUTO_ANIM;
		if (bezt->f3 & SELECT) bezt->h2 = HD_AUTO_ANIM;
		
		ENSURE_HANDLES_MATCH(bezt);
	}
	return 0;
}

/* Sets the selected bezier handles to type 'vector'  */
static short set_bezier_vector(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if (bezt->f1 & SELECT) bezt->h1 = HD_VECT;
	if (bezt->f3 & SELECT) bezt->h2 = HD_VECT;
	return 0;
}

/* Queries if the handle should be set to 'free' or 'align' */
// NOTE: this was used for the 'toggle free/align' option
//		currently this isn't used, but may be restored later
static short bezier_isfree(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if ((bezt->f1 & SELECT) && (bezt->h1)) return 1;
	if ((bezt->f3 & SELECT) && (bezt->h2)) return 1;
	return 0;
}

/* Sets selected bezier handles to type 'align' */
static short set_bezier_align(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{	
	if (bezt->f1 & SELECT) bezt->h1 = HD_ALIGN;
	if (bezt->f3 & SELECT) bezt->h2 = HD_ALIGN;
	return 0;
}

/* Sets selected bezier handles to type 'free'  */
static short set_bezier_free(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if (bezt->f1 & SELECT) bezt->h1 = HD_FREE;
	if (bezt->f3 & SELECT) bezt->h2 = HD_FREE;
	return 0;
}

/* Set all selected Bezier Handles to a single type */
// calchandles_fcurve
KeyframeEditFunc ANIM_editkeyframes_handles(short code)
{
	switch (code) {
		case HD_AUTO: /* auto */
			return set_bezier_auto;
		case HD_AUTO_ANIM: /* auto clamped */
			return set_bezier_auto_clamped;
			
		case HD_VECT: /* vector */
			return set_bezier_vector;
		case HD_FREE: /* free */
			return set_bezier_free;
		case HD_ALIGN: /* align */
			return set_bezier_align;
		
		default: /* check for toggle free or align? */
			return bezier_isfree;
	}
}

/* ------- */

static short set_bezt_constant(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if (bezt->f2 & SELECT) 
		bezt->ipo = BEZT_IPO_CONST;
	return 0;
}

static short set_bezt_linear(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if (bezt->f2 & SELECT) 
		bezt->ipo = BEZT_IPO_LIN;
	return 0;
}

static short set_bezt_bezier(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if (bezt->f2 & SELECT) 
		bezt->ipo = BEZT_IPO_BEZ;
	return 0;
}

/* Set the interpolation type of the selected BezTriples in each F-Curve to the specified one */
// ANIM_editkeyframes_ipocurve_ipotype() !
KeyframeEditFunc ANIM_editkeyframes_ipo(short code)
{
	switch (code) {
		case BEZT_IPO_CONST: /* constant */
			return set_bezt_constant;
		case BEZT_IPO_LIN: /* linear */
			return set_bezt_linear;
		default: /* bezier */
			return set_bezt_bezier;
	}
}

/* ------- */

static short set_keytype_keyframe(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if (bezt->f2 & SELECT) 
		BEZKEYTYPE(bezt) = BEZT_KEYTYPE_KEYFRAME;
	return 0;
}

static short set_keytype_breakdown(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if (bezt->f2 & SELECT) 
		BEZKEYTYPE(bezt) = BEZT_KEYTYPE_BREAKDOWN;
	return 0;
}

static short set_keytype_extreme(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if (bezt->f2 & SELECT) 
		BEZKEYTYPE(bezt) = BEZT_KEYTYPE_EXTREME;
	return 0;
}

static short set_keytype_jitter(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	if (bezt->f2 & SELECT) 
		BEZKEYTYPE(bezt) = BEZT_KEYTYPE_JITTER;
	return 0;
}

/* Set the interpolation type of the selected BezTriples in each F-Curve to the specified one */
KeyframeEditFunc ANIM_editkeyframes_keytype(short code)
{
	switch (code) {
		case BEZT_KEYTYPE_BREAKDOWN: /* breakdown */
			return set_keytype_breakdown;
			
		case BEZT_KEYTYPE_EXTREME: /* extreme keyframe */
			return set_keytype_extreme;
			
		case BEZT_KEYTYPE_JITTER: /* jitter keyframe */
			return set_keytype_jitter;
			
		case BEZT_KEYTYPE_KEYFRAME: /* proper keyframe */
		default:
			return set_keytype_keyframe;
	}
}

/* ******************************************* */
/* Selection */

static short select_bezier_add(KeyframeEditData *ked, BezTriple *bezt) 
{
	/* if we've got info on what to select, use it, otherwise select all */
	if ((ked) && (ked->iterflags & KEYFRAME_ITER_INCL_HANDLES)) {
		if (ked->curflags & KEYFRAME_OK_KEY)
			bezt->f2 |= SELECT;
		if (ked->curflags & KEYFRAME_OK_H1)
			bezt->f1 |= SELECT;
		if (ked->curflags & KEYFRAME_OK_H2)
			bezt->f3 |= SELECT;
	}
	else {
		BEZ_SEL(bezt);
	}
	
	return 0;
}

static short select_bezier_subtract(KeyframeEditData *ked, BezTriple *bezt) 
{
	/* if we've got info on what to deselect, use it, otherwise deselect all */
	if ((ked) && (ked->iterflags & KEYFRAME_ITER_INCL_HANDLES)) {
		if (ked->curflags & KEYFRAME_OK_KEY)
			bezt->f2 &= ~SELECT;
		if (ked->curflags & KEYFRAME_OK_H1)
			bezt->f1 &= ~SELECT;
		if (ked->curflags & KEYFRAME_OK_H2)
			bezt->f3 &= ~SELECT;
	}
	else {
		BEZ_DESEL(bezt);
	}
	
	return 0;
}

static short select_bezier_invert(KeyframeEditData *UNUSED(ked), BezTriple *bezt) 
{
	/* Invert the selection for the whole bezier triple */
	bezt->f2 ^= SELECT;
	if (bezt->f2 & SELECT) {
		bezt->f1 |= SELECT;
		bezt->f3 |= SELECT;
	}
	else {
		bezt->f1 &= ~SELECT;
		bezt->f3 &= ~SELECT;
	}
	return 0;
}

KeyframeEditFunc ANIM_editkeyframes_select(short selectmode)
{
	switch (selectmode) {
		case SELECT_ADD: /* add */
			return select_bezier_add;
		case SELECT_SUBTRACT: /* subtract */
			return select_bezier_subtract;
		case SELECT_INVERT: /* invert */
			return select_bezier_invert;
		default: /* replace (need to clear all, then add) */
			return select_bezier_add;
	}
}

/* ******************************************* */
/* Selection Maps */

/* Selection maps are simply fancy names for char arrays that store on/off
 * info for whether the selection status. The main purpose for these is to
 * allow extra info to be tagged to the keyframes without influencing their
 * values or having to be removed later.
 */

/* ----------- */

static short selmap_build_bezier_more(KeyframeEditData *ked, BezTriple *bezt)
{
	FCurve *fcu = ked->fcu;
	char *map = ked->data;
	int i = ked->curIndex;
	
	/* if current is selected, just make sure it stays this way */
	if (BEZSELECTED(bezt)) {
		map[i] = 1;
		return 0;
	}
	
	/* if previous is selected, that means that selection should extend across */
	if (i > 0) {
		BezTriple *prev = bezt - 1;
		
		if (BEZSELECTED(prev)) {
			map[i] = 1;
			return 0;
		}
	}
	
	/* if next is selected, that means that selection should extend across */
	if (i < (fcu->totvert - 1)) {
		BezTriple *next = bezt + 1;
		
		if (BEZSELECTED(next)) {
			map[i] = 1;
			return 0;
		}
	}
	
	return 0;
}

static short selmap_build_bezier_less(KeyframeEditData *ked, BezTriple *bezt)
{
	FCurve *fcu = ked->fcu;
	char *map = ked->data;
	int i = ked->curIndex;
	
	/* if current is selected, check the left/right keyframes
	 * since it might need to be deselected (but otherwise no)
	 */
	if (BEZSELECTED(bezt)) {
		/* if previous is not selected, we're on the tip of an iceberg */
		if (i > 0) {
			BezTriple *prev = bezt - 1;
			
			if (BEZSELECTED(prev) == 0)
				return 0;
		}
		else if (i == 0) {
			/* current keyframe is selected at an endpoint, so should get deselected */
			return 0;
		}
		
		/* if next is not selected, we're on the tip of an iceberg */
		if (i < (fcu->totvert - 1)) {
			BezTriple *next = bezt + 1;
			
			if (BEZSELECTED(next) == 0)
				return 0;
		}
		else if (i == (fcu->totvert - 1)) {
			/* current keyframe is selected at an endpoint, so should get deselected */
			return 0;
		}
		
		/* if we're still here, that means that keyframe should remain untouched */
		map[i] = 1;
	}
	
	return 0;
}

/* Get callback for building selection map */
KeyframeEditFunc ANIM_editkeyframes_buildselmap(short mode)
{
	switch (mode) {
		case SELMAP_LESS: /* less */
			return selmap_build_bezier_less;
		
		case SELMAP_MORE: /* more */
		default:
			return selmap_build_bezier_more;
	}
}

/* ----------- */

/* flush selection map values to the given beztriple */
short bezt_selmap_flush(KeyframeEditData *ked, BezTriple *bezt)
{
	char *map = ked->data;
	short on = map[ked->curIndex];
	
	/* select or deselect based on whether the map allows it or not */
	if (on) {
		BEZ_SEL(bezt);
	}
	else {
		BEZ_DESEL(bezt);
	}
	
	return 0;
}

