BKE_fcurve.h

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/*
 * ***** 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) 2009 Blender Foundation, Joshua Leung
 * All rights reserved.
 *
 * Contributor(s): Joshua Leung (full recode)
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#ifndef BKE_FCURVE_H
#define BKE_FCURVE_H

#ifdef __cplusplus
extern "C" {
#endif

struct FCurve;
struct FModifier;
struct ChannelDriver;
struct DriverVar;
struct DriverTarget;

struct bAction;
struct BezTriple;
struct StructRNA;
struct PointerRNA;
struct PropertyRNA;

#include "DNA_curve_types.h"

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

typedef struct CfraElem {
    struct CfraElem *next, *prev;
    float cfra;
    int sel;
} CfraElem;

void bezt_add_to_cfra_elem(ListBase *lb, struct BezTriple *bezt);

/* ************** F-Curve Drivers ***************** */

/* With these iterators for convenience, the variables "tarIndex" and "dtar" can be 
 * accessed directly from the code using them, but it is not recommended that their
 * values be changed to point at other slots...
 */

/* convenience looper over ALL driver targets for a given variable (even the unused ones) */
#define DRIVER_TARGETS_LOOPER(dvar) \
    { \
        DriverTarget *dtar= &dvar->targets[0]; \
        int tarIndex= 0; \
        for (; tarIndex < MAX_DRIVER_TARGETS; tarIndex++, dtar++)
         
/* convenience looper over USED driver targets only */
#define DRIVER_TARGETS_USED_LOOPER(dvar) \
    { \
        DriverTarget *dtar= &dvar->targets[0]; \
        int tarIndex= 0; \
        for (; tarIndex < dvar->num_targets; tarIndex++, dtar++)
        
/* tidy up for driver targets loopers */
#define DRIVER_TARGETS_LOOPER_END \
    }

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

void fcurve_free_driver(struct FCurve *fcu);
struct ChannelDriver *fcurve_copy_driver(struct ChannelDriver *driver);

void driver_free_variable(struct ChannelDriver *driver, struct DriverVar *dvar);
void driver_change_variable_type(struct DriverVar *dvar, int type);
struct DriverVar *driver_add_new_variable(struct ChannelDriver *driver);

float driver_get_variable_value (struct ChannelDriver *driver, struct DriverVar *dvar);

/* ************** F-Curve Modifiers *************** */

/* F-Curve Modifier Type-Info (fmi):
 *  This struct provides function pointers for runtime, so that functions can be
 *  written more generally (with fewer/no special exceptions for various modifiers).
 *
 *  Callers of these functions must check that they actually point to something useful,
 *  as some constraints don't define some of these.
 *
 *  Warning: it is not too advisable to reorder order of members of this struct,
 *          as you'll have to edit quite a few ($FMODIFIER_NUM_TYPES) of these
 *          structs.
 */
typedef struct FModifierTypeInfo {
    /* admin/ident */
    short type;             /* FMODIFIER_TYPE_### */
    short size;             /* size in bytes of the struct */
    short acttype;          /* eFMI_Action_Types */
    short requires;         /* eFMI_Requirement_Flags */
    char name[64];          /* name of modifier in interface */
    char structName[64];    /* name of struct for SDNA */
    
    /* data management function pointers - special handling */
        /* free any data that is allocated separately (optional) */
    void (*free_data)(struct FModifier *fcm);
        /* copy any special data that is allocated separately (optional) */
    void (*copy_data)(struct FModifier *fcm, struct FModifier *src);
        /* set settings for data that will be used for FCuModifier.data (memory already allocated using MEM_callocN) */
    void (*new_data)(void *mdata);
        /* verifies that the modifier settings are valid */
    void (*verify_data)(struct FModifier *fcm);
    
    /* evaluation */
        /* evaluate time that the modifier requires the F-Curve to be evaluated at */
    float (*evaluate_modifier_time)(struct FCurve *fcu, struct FModifier *fcm, float cvalue, float evaltime);
        /* evaluate the modifier for the given time and 'accumulated' value */
    void (*evaluate_modifier)(struct FCurve *fcu, struct FModifier *fcm, float *cvalue, float evaltime);
} FModifierTypeInfo;

/* Values which describe the behaviour of a FModifier Type */
typedef enum eFMI_Action_Types {
        /* modifier only modifies values outside of data range */
    FMI_TYPE_EXTRAPOLATION = 0,
        /* modifier leaves data-points alone, but adjusts the interpolation between and around them */
    FMI_TYPE_INTERPOLATION,
        /* modifier only modifies the values of points (but times stay the same) */
    FMI_TYPE_REPLACE_VALUES,
        /* modifier generates a curve regardless of what came before */
    FMI_TYPE_GENERATE_CURVE
} eFMI_Action_Types;

/* Flags for the requirements of a FModifier Type */
typedef enum eFMI_Requirement_Flags {
        /* modifier requires original data-points (kindof beats the purpose of a modifier stack?) */
    FMI_REQUIRES_ORIGINAL_DATA      = (1<<0),
        /* modifier doesn't require on any preceding data (i.e. it will generate a curve). 
         * Use in conjunction with FMI_TYPE_GENRATE_CURVE 
         */
    FMI_REQUIRES_NOTHING            = (1<<1),
        /* refer to modifier instance */
    FMI_REQUIRES_RUNTIME_CHECK      = (1<<2)
} eFMI_Requirement_Flags;

/* Function Prototypes for FModifierTypeInfo's */
FModifierTypeInfo *fmodifier_get_typeinfo(struct FModifier *fcm);
FModifierTypeInfo *get_fmodifier_typeinfo(int type);

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

struct FModifier *add_fmodifier(ListBase *modifiers, int type);
struct FModifier *copy_fmodifier(struct FModifier *src);
void copy_fmodifiers(ListBase *dst, ListBase *src);
int remove_fmodifier(ListBase *modifiers, struct FModifier *fcm);
void free_fmodifiers(ListBase *modifiers);

struct FModifier *find_active_fmodifier(ListBase *modifiers);
void set_active_fmodifier(ListBase *modifiers, struct FModifier *fcm);

short list_has_suitable_fmodifier(ListBase *modifiers, int mtype, short acttype);

float evaluate_time_fmodifiers(ListBase *modifiers, struct FCurve *fcu, float cvalue, float evaltime);
void evaluate_value_fmodifiers(ListBase *modifiers, struct FCurve *fcu, float *cvalue, float evaltime);

void fcurve_bake_modifiers(struct FCurve *fcu, int start, int end);

/* ************** F-Curves API ******************** */

/* -------- Data Managemnt  --------  */

void free_fcurve(struct FCurve *fcu);
struct FCurve *copy_fcurve(struct FCurve *fcu);

void free_fcurves(ListBase *list);
void copy_fcurves(ListBase *dst, ListBase *src);

/* find matching F-Curve in the given list of F-Curves */
struct FCurve *list_find_fcurve(ListBase *list, const char rna_path[], const int array_index);

struct FCurve *iter_step_fcurve (struct FCurve *fcu_iter, const char rna_path[]);

/* high level function to get an fcurve from C without having the rna */
struct FCurve *id_data_find_fcurve(ID *id, void *data, struct StructRNA *type, const char *prop_name, int index, char *driven);

/* Get list of LinkData's containing pointers to the F-Curves which control the types of data indicated 
 *  e.g.  numMatches = list_find_data_fcurves(matches, &act->curves, "pose.bones[", "MyFancyBone");
 */
int list_find_data_fcurves(ListBase *dst, ListBase *src, const char *dataPrefix, const char *dataName);

/* find an f-curve based on an rna property */
struct FCurve *rna_get_fcurve(struct PointerRNA *ptr, struct PropertyRNA *prop, int rnaindex, struct bAction **action, int *driven);

/* Binary search algorithm for finding where to 'insert' BezTriple with given frame number.
 * Returns the index to insert at (data already at that index will be offset if replace is 0)
 */
int binarysearch_bezt_index(struct BezTriple array[], float frame, int arraylen, short *replace);

/* get the time extents for F-Curve */
void calc_fcurve_range(struct FCurve *fcu, float *min, float *max,
                       const short do_sel_only, const short do_min_length);

/* get the bounding-box extents for F-Curve */
void calc_fcurve_bounds(struct FCurve *fcu, float *xmin, float *xmax, float *ymin, float *ymax,
                        const short do_sel_only);

/* .............. */

/* Are keyframes on F-Curve of any use (to final result, and to show in editors)? */
short fcurve_are_keyframes_usable(struct FCurve *fcu);

/* Can keyframes be added to F-Curve? */
short fcurve_is_keyframable(struct FCurve *fcu);

/* -------- Curve Sanity --------  */

void calchandles_fcurve(struct FCurve *fcu);
void testhandles_fcurve(struct FCurve *fcu, const short use_handle);
void sort_time_fcurve(struct FCurve *fcu);
short test_time_fcurve(struct FCurve *fcu);

void correct_bezpart(float *v1, float *v2, float *v3, float *v4);

/* -------- Evaluation --------  */

/* evaluate fcurve */
float evaluate_fcurve(struct FCurve *fcu, float evaltime);
/* evaluate fcurve and store value */
void calculate_fcurve(struct FCurve *fcu, float ctime);

/* ************* F-Curve Samples API ******************** */

/* -------- Defines --------  */

/* Basic signature for F-Curve sample-creation function 
 *  - fcu: the F-Curve being operated on
 *  - data: pointer to some specific data that may be used by one of the callbacks
 */
typedef float (*FcuSampleFunc)(struct FCurve *fcu, void *data, float evaltime);

/* ----- Sampling Callbacks ------  */

/* Basic sampling callback which acts as a wrapper for evaluate_fcurve() */
float fcurve_samplingcb_evalcurve(struct FCurve *fcu, void *data, float evaltime);

/* -------- Main Methods --------  */

/* Main API function for creating a set of sampled curve data, given some callback function 
 * used to retrieve the values to store.
 */
void fcurve_store_samples(struct FCurve *fcu, void *data, int start, int end, FcuSampleFunc sample_cb);

#ifdef __cplusplus
}
#endif

#endif /* BKE_FCURVE_H*/