libanim

annotate src/track.h @ 0:fad4701f484e

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libanim mercurial repo
author John Tsiombikas <nuclear@mutantstargoat.com>
date Sun, 08 Jan 2012 05:13:13 +0200
parents
children f561282b13e8
rev   line source
nuclear@0 1 /* An animation track defines the values of a single scalar over time
nuclear@0 2 * and supports various interpolation and extrapolation modes.
nuclear@0 3 */
nuclear@0 4 #ifndef LIBANIM_TRACK_H_
nuclear@0 5 #define LIBANIM_TRACK_H_
nuclear@0 6
nuclear@0 7 #include <limits.h>
nuclear@0 8 #include "config.h"
nuclear@0 9
nuclear@0 10 enum anm_interpolator {
nuclear@0 11 ANM_INTERP_STEP,
nuclear@0 12 ANM_INTERP_LINEAR,
nuclear@0 13 ANM_INTERP_CUBIC
nuclear@0 14 };
nuclear@0 15
nuclear@0 16 enum anm_extrapolator {
nuclear@0 17 ANM_EXTRAP_EXTEND, /* extend to infinity */
nuclear@0 18 ANM_EXTRAP_CLAMP, /* clamp to last value */
nuclear@0 19 ANM_EXTRAP_REPEAT /* repeat motion */
nuclear@0 20 };
nuclear@0 21
nuclear@0 22 typedef long anm_time_t;
nuclear@0 23 #define ANM_TIME_INVAL LONG_MIN
nuclear@0 24
nuclear@0 25 #define ANM_SEC2TM(x) ((anm_time_t)((x) * 1000))
nuclear@0 26 #define ANM_MSEC2TM(x) ((anm_time_t)(x))
nuclear@0 27 #define ANM_TM2SEC(x) ((x) / 1000.0)
nuclear@0 28 #define ANM_TM2MSEC(x) (x)
nuclear@0 29
nuclear@0 30 struct anm_keyframe {
nuclear@0 31 anm_time_t time;
nuclear@0 32 float val;
nuclear@0 33 };
nuclear@0 34
nuclear@0 35 struct anm_track {
nuclear@0 36 char *name;
nuclear@0 37 int count;
nuclear@0 38 struct anm_keyframe *keys;
nuclear@0 39
nuclear@0 40 float def_val;
nuclear@0 41
nuclear@0 42 enum anm_interpolator interp;
nuclear@0 43 enum anm_extrapolator extrap;
nuclear@0 44 };
nuclear@0 45
nuclear@0 46 #ifdef __cplusplus
nuclear@0 47 extern "C" {
nuclear@0 48 #endif
nuclear@0 49
nuclear@0 50 /* track constructor and destructor */
nuclear@0 51 int anm_init_track(struct anm_track *track);
nuclear@0 52 void anm_destroy_track(struct anm_track *track);
nuclear@0 53
nuclear@0 54 /* helper functions that use anm_init_track and anm_destroy_track internally */
nuclear@0 55 struct anm_track *anm_create_track(void);
nuclear@0 56 void anm_free_track(struct anm_track *track);
nuclear@0 57
nuclear@0 58 int anm_set_track_name(struct anm_track *track, const char *name);
nuclear@0 59 const char *anm_get_track_name(struct anm_track *track);
nuclear@0 60
nuclear@0 61 void anm_set_track_interpolator(struct anm_track *track, enum anm_interpolator in);
nuclear@0 62 void anm_set_track_extrapolator(struct anm_track *track, enum anm_extrapolator ex);
nuclear@0 63
nuclear@0 64 anm_time_t anm_remap_time(struct anm_track *track, anm_time_t tm, anm_time_t start, anm_time_t end);
nuclear@0 65
nuclear@0 66 void anm_set_track_default(struct anm_track *track, float def);
nuclear@0 67
nuclear@0 68 /* set or update a keyframe */
nuclear@0 69 int anm_set_keyframe(struct anm_track *track, struct anm_keyframe *key);
nuclear@0 70
nuclear@0 71 /* get the idx-th keyframe, returns null if it doesn't exist */
nuclear@0 72 struct anm_keyframe *anm_get_keyframe(struct anm_track *track, int idx);
nuclear@0 73
nuclear@0 74 /* Finds the 0-based index of the intra-keyframe interval which corresponds
nuclear@0 75 * to the specified time. If the time falls exactly onto the N-th keyframe
nuclear@0 76 * the function returns N.
nuclear@0 77 *
nuclear@0 78 * Special cases:
nuclear@0 79 * - if the time is before the first keyframe -1 is returned.
nuclear@0 80 * - if the time is after the last keyframe, the index of the last keyframe
nuclear@0 81 * is returned.
nuclear@0 82 */
nuclear@0 83 int anm_get_key_interval(struct anm_track *track, anm_time_t tm);
nuclear@0 84
nuclear@0 85 int anm_set_value(struct anm_track *track, anm_time_t tm, float val);
nuclear@0 86
nuclear@0 87 /* evaluates and returns the value of the track for a particular time */
nuclear@0 88 float anm_get_value(struct anm_track *track, anm_time_t tm);
nuclear@0 89
nuclear@0 90 #ifdef __cplusplus
nuclear@0 91 }
nuclear@0 92 #endif
nuclear@0 93
nuclear@0 94
nuclear@0 95 #endif /* LIBANIM_TRACK_H_ */