added libanim, and moved gph-cmath into libs/cgmath

[dosdemo] / libs / anim / src / track.h

diff --git a/libs/anim/src/track.h b/libs/anim/src/track.h
new file mode 100644 (file)
index 0000000..89749dd
--- /dev/null
+++ b/libs/anim/src/track.h
@@ -0,0 +1,119 @@
+/*
+libanim - hierarchical keyframe animation library
+Copyright (C) 2012-2014 John Tsiombikas <nuclear@member.fsf.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published
+by the Free Software Foundation, either version 3 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* An animation track defines the values of a single scalar over time
+ * and supports various interpolation and extrapolation modes.
+ */
+#ifndef LIBANIM_TRACK_H_
+#define LIBANIM_TRACK_H_
+
+#include <limits.h>
+#include "config.h"
+
+enum anm_interpolator {
+       ANM_INTERP_STEP,
+       ANM_INTERP_LINEAR,
+       ANM_INTERP_CUBIC
+};
+
+enum anm_extrapolator {
+       ANM_EXTRAP_EXTEND,      /* extend to infinity */
+       ANM_EXTRAP_CLAMP,       /* clamp to last value */
+       ANM_EXTRAP_REPEAT,      /* repeat motion */
+       ANM_EXTRAP_PINGPONG     /* repeat with mirroring */
+};
+
+typedef long anm_time_t;
+#define ANM_TIME_INVAL LONG_MIN
+
+#define ANM_SEC2TM(x)  ((anm_time_t)((x) * 1000))
+#define ANM_MSEC2TM(x) ((anm_time_t)(x))
+#define ANM_TM2SEC(x)  ((x) / 1000.0)
+#define ANM_TM2MSEC(x) (x)
+
+struct anm_keyframe {
+       anm_time_t time;
+       float val;
+};
+
+struct anm_track {
+       char *name;
+       int count;
+       struct anm_keyframe *keys;
+
+       float def_val;
+
+       enum anm_interpolator interp;
+       enum anm_extrapolator extrap;
+};
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* track constructor and destructor */
+int anm_init_track(struct anm_track *track);
+void anm_destroy_track(struct anm_track *track);
+
+/* helper functions that use anm_init_track and anm_destroy_track internally */
+struct anm_track *anm_create_track(void);
+void anm_free_track(struct anm_track *track);
+
+/* copies track src to dest
+ * XXX: dest must have been initialized first
+ */
+void anm_copy_track(struct anm_track *dest, const struct anm_track *src);
+
+int anm_set_track_name(struct anm_track *track, const char *name);
+const char *anm_get_track_name(struct anm_track *track);
+
+void anm_set_track_interpolator(struct anm_track *track, enum anm_interpolator in);
+void anm_set_track_extrapolator(struct anm_track *track, enum anm_extrapolator ex);
+
+anm_time_t anm_remap_time(struct anm_track *track, anm_time_t tm, anm_time_t start, anm_time_t end);
+
+void anm_set_track_default(struct anm_track *track, float def);
+
+/* set or update a keyframe */
+int anm_set_keyframe(struct anm_track *track, struct anm_keyframe *key);
+
+/* get the idx-th keyframe, returns null if it doesn't exist */
+struct anm_keyframe *anm_get_keyframe(struct anm_track *track, int idx);
+
+/* Finds the 0-based index of the intra-keyframe interval which corresponds
+ * to the specified time. If the time falls exactly onto the N-th keyframe
+ * the function returns N.
+ *
+ * Special cases:
+ * - if the time is before the first keyframe -1 is returned.
+ * - if the time is after the last keyframe, the index of the last keyframe
+ *   is returned.
+ */
+int anm_get_key_interval(struct anm_track *track, anm_time_t tm);
+
+int anm_set_value(struct anm_track *track, anm_time_t tm, float val);
+
+/* evaluates and returns the value of the track for a particular time */
+float anm_get_value(struct anm_track *track, anm_time_t tm);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* LIBANIM_TRACK_H_ */