nuclear@67: /* An animation track defines the values of a single scalar over time
nuclear@67:  * and supports various interpolation and extrapolation modes.
nuclear@67:  */
nuclear@67: #ifndef LIBANIM_TRACK_H_
nuclear@67: #define LIBANIM_TRACK_H_
nuclear@67: 
nuclear@67: #include <limits.h>
nuclear@67: #include "config.h"
nuclear@67: 
nuclear@67: enum anm_interpolator {
nuclear@67: 	ANM_INTERP_STEP,
nuclear@67: 	ANM_INTERP_LINEAR,
nuclear@67: 	ANM_INTERP_CUBIC
nuclear@67: };
nuclear@67: 
nuclear@67: enum anm_extrapolator {
nuclear@67: 	ANM_EXTRAP_EXTEND,	/* extend to infinity */
nuclear@67: 	ANM_EXTRAP_CLAMP,	/* clamp to last value */
nuclear@67: 	ANM_EXTRAP_REPEAT	/* repeat motion */
nuclear@67: };
nuclear@67: 
nuclear@67: typedef long anm_time_t;
nuclear@67: #define ANM_TIME_INVAL	LONG_MIN
nuclear@67: 
nuclear@67: #define ANM_SEC2TM(x)	((anm_time_t)((x) * 1000))
nuclear@67: #define ANM_MSEC2TM(x)	((anm_time_t)(x))
nuclear@67: #define ANM_TM2SEC(x)	((x) / 1000.0)
nuclear@67: #define ANM_TM2MSEC(x)	(x)
nuclear@67: 
nuclear@67: struct anm_keyframe {
nuclear@67: 	anm_time_t time;
nuclear@67: 	float val;
nuclear@67: };
nuclear@67: 
nuclear@67: struct anm_track {
nuclear@67: 	char *name;
nuclear@67: 	int count;
nuclear@67: 	struct anm_keyframe *keys;
nuclear@67: 
nuclear@67: 	float def_val;
nuclear@67: 
nuclear@67: 	enum anm_interpolator interp;
nuclear@67: 	enum anm_extrapolator extrap;
nuclear@67: };
nuclear@67: 
nuclear@67: /* track constructor and destructor */
nuclear@67: int anm_init_track(struct anm_track *track);
nuclear@67: void anm_destroy_track(struct anm_track *track);
nuclear@67: 
nuclear@67: /* helper functions that use anm_init_track and anm_destroy_track internally */
nuclear@67: struct anm_track *anm_create_track(void);
nuclear@67: void anm_free_track(struct anm_track *track);
nuclear@67: 
nuclear@67: int anm_set_track_name(struct anm_track *track, const char *name);
nuclear@67: const char *anm_get_track_name(struct anm_track *track);
nuclear@67: 
nuclear@67: void anm_set_track_interpolator(struct anm_track *track, enum anm_interpolator in);
nuclear@67: void anm_set_track_extrapolator(struct anm_track *track, enum anm_extrapolator ex);
nuclear@67: 
nuclear@67: anm_time_t anm_remap_time(struct anm_track *track, anm_time_t tm, anm_time_t start, anm_time_t end);
nuclear@67: 
nuclear@67: void anm_set_track_default(struct anm_track *track, float def);
nuclear@67: 
nuclear@67: /* set or update a keyframe */
nuclear@67: int anm_set_keyframe(struct anm_track *track, struct anm_keyframe *key);
nuclear@67: 
nuclear@67: /* get the idx-th keyframe, returns null if it doesn't exist */
nuclear@67: struct anm_keyframe *anm_get_keyframe(struct anm_track *track, int idx);
nuclear@67: 
nuclear@67: /* Finds the 0-based index of the intra-keyframe interval which corresponds
nuclear@67:  * to the specified time. If the time falls exactly onto the N-th keyframe
nuclear@67:  * the function returns N.
nuclear@67:  *
nuclear@67:  * Special cases:
nuclear@67:  * - if the time is before the first keyframe -1 is returned.
nuclear@67:  * - if the time is after the last keyframe, the index of the last keyframe
nuclear@67:  *   is returned.
nuclear@67:  */
nuclear@67: int anm_get_key_interval(struct anm_track *track, anm_time_t tm);
nuclear@67: 
nuclear@67: int anm_set_value(struct anm_track *track, anm_time_t tm, float val);
nuclear@67: 
nuclear@67: /* evaluates and returns the value of the track for a particular time */
nuclear@67: float anm_get_value(struct anm_track *track, anm_time_t tm);
nuclear@67: 
nuclear@67: 
nuclear@67: 
nuclear@67: #endif	/* LIBANIM_TRACK_H_ */