X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=dosdemo;a=blobdiff_plain;f=libs%2Fanim%2Fsrc%2Ftrack.c;fp=libs%2Fanim%2Fsrc%2Ftrack.c;h=a144efd4ded610ab35b3f337600b003cba7a47ab;hp=0000000000000000000000000000000000000000;hb=3c8a42c780f4fb7817badbc136f7312aa20dd5ef;hpb=b6c89d9ffbb08c5286448de4773290f0924a420b

diff --git a/libs/anim/src/track.c b/libs/anim/src/track.c
new file mode 100644
index 0000000..a144efd
--- /dev/null
+++ b/libs/anim/src/track.c
@@ -0,0 +1,334 @@
+/*
+libanim - hierarchical keyframe animation library
+Copyright (C) 2012-2015 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/>.
+*/
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include "track.h"
+#include "dynarr.h"
+
+static int keycmp(const void *a, const void *b);
+static int find_prev_key(struct anm_keyframe *arr, int start, int end, anm_time_t tm);
+
+static float interp_step(float v0, float v1, float v2, float v3, float t);
+static float interp_linear(float v0, float v1, float v2, float v3, float t);
+static float interp_cubic(float v0, float v1, float v2, float v3, float t);
+
+static anm_time_t remap_extend(anm_time_t tm, anm_time_t start, anm_time_t end);
+static anm_time_t remap_clamp(anm_time_t tm, anm_time_t start, anm_time_t end);
+static anm_time_t remap_repeat(anm_time_t tm, anm_time_t start, anm_time_t end);
+static anm_time_t remap_pingpong(anm_time_t tm, anm_time_t start, anm_time_t end);
+
+/* XXX keep this in sync with enum anm_interpolator at track.h */
+static float (*interp[])(float, float, float, float, float) = {
+	interp_step,
+	interp_linear,
+	interp_cubic,
+	0
+};
+
+/* XXX keep this in sync with enum anm_extrapolator at track.h */
+static anm_time_t (*remap_time[])(anm_time_t, anm_time_t, anm_time_t) = {
+	remap_extend,
+	remap_clamp,
+	remap_repeat,
+	remap_pingpong,
+	0
+};
+
+int anm_init_track(struct anm_track *track)
+{
+	memset(track, 0, sizeof *track);
+
+	if(!(track->keys = dynarr_alloc(0, sizeof *track->keys))) {
+		return -1;
+	}
+	track->interp = ANM_INTERP_LINEAR;
+	track->extrap = ANM_EXTRAP_CLAMP;
+	return 0;
+}
+
+void anm_destroy_track(struct anm_track *track)
+{
+	dynarr_free(track->keys);
+}
+
+struct anm_track *anm_create_track(void)
+{
+	struct anm_track *track;
+
+	if((track = malloc(sizeof *track))) {
+		if(anm_init_track(track) == -1) {
+			free(track);
+			return 0;
+		}
+	}
+	return track;
+}
+
+void anm_free_track(struct anm_track *track)
+{
+	anm_destroy_track(track);
+	free(track);
+}
+
+void anm_copy_track(struct anm_track *dest, const struct anm_track *src)
+{
+	free(dest->name);
+	if(dest->keys) {
+		dynarr_free(dest->keys);
+	}
+
+	if(src->name) {
+		dest->name = malloc(strlen(src->name) + 1);
+		strcpy(dest->name, src->name);
+	}
+
+	dest->count = src->count;
+	dest->keys = dynarr_alloc(src->count, sizeof *dest->keys);
+	memcpy(dest->keys, src->keys, src->count * sizeof *dest->keys);
+
+	dest->def_val = src->def_val;
+	dest->interp = src->interp;
+	dest->extrap = src->extrap;
+}
+
+int anm_set_track_name(struct anm_track *track, const char *name)
+{
+	char *tmp;
+
+	if(!(tmp = malloc(strlen(name) + 1))) {
+		return -1;
+	}
+	free(track->name);
+	track->name = tmp;
+	return 0;
+}
+
+const char *anm_get_track_name(struct anm_track *track)
+{
+	return track->name;
+}
+
+void anm_set_track_interpolator(struct anm_track *track, enum anm_interpolator in)
+{
+	track->interp = in;
+}
+
+void anm_set_track_extrapolator(struct anm_track *track, enum anm_extrapolator ex)
+{
+	track->extrap = ex;
+}
+
+anm_time_t anm_remap_time(struct anm_track *track, anm_time_t tm, anm_time_t start, anm_time_t end)
+{
+	return remap_time[track->extrap](tm, start, end);
+}
+
+void anm_set_track_default(struct anm_track *track, float def)
+{
+	track->def_val = def;
+}
+
+int anm_set_keyframe(struct anm_track *track, struct anm_keyframe *key)
+{
+	int idx = anm_get_key_interval(track, key->time);
+
+	/* if we got a valid keyframe index, compare them... */
+	if(idx >= 0 && idx < track->count && keycmp(key, track->keys + idx) == 0) {
+		/* ... it's the same key, just update the value */
+		track->keys[idx].val = key->val;
+	} else {
+		/* ... it's a new key, add it and re-sort them */
+		void *tmp;
+		if(!(tmp = dynarr_push(track->keys, key))) {
+			return -1;
+		}
+		track->keys = tmp;
+		/* TODO lazy qsort */
+		qsort(track->keys, ++track->count, sizeof *track->keys, keycmp);
+	}
+	return 0;
+}
+
+static int keycmp(const void *a, const void *b)
+{
+	return ((struct anm_keyframe*)a)->time - ((struct anm_keyframe*)b)->time;
+}
+
+struct anm_keyframe *anm_get_keyframe(struct anm_track *track, int idx)
+{
+	if(idx < 0 || idx >= track->count) {
+		return 0;
+	}
+	return track->keys + idx;
+}
+
+int anm_get_key_interval(struct anm_track *track, anm_time_t tm)
+{
+	int last;
+
+	if(!track->count || tm < track->keys[0].time) {
+		return -1;
+	}
+
+	last = track->count - 1;
+	if(tm > track->keys[last].time) {
+		return last;
+	}
+
+	return find_prev_key(track->keys, 0, last, tm);
+}
+
+static int find_prev_key(struct anm_keyframe *arr, int start, int end, anm_time_t tm)
+{
+	int mid;
+
+	if(end - start <= 1) {
+		return start;
+	}
+
+	mid = (start + end) / 2;
+	if(tm < arr[mid].time) {
+		return find_prev_key(arr, start, mid, tm);
+	}
+	if(tm > arr[mid].time) {
+		return find_prev_key(arr, mid, end, tm);
+	}
+	return mid;
+}
+
+int anm_set_value(struct anm_track *track, anm_time_t tm, float val)
+{
+	struct anm_keyframe key;
+	key.time = tm;
+	key.val = val;
+
+	return anm_set_keyframe(track, &key);
+}
+
+float anm_get_value(struct anm_track *track, anm_time_t tm)
+{
+	int idx0, idx1, last_idx;
+	anm_time_t tstart, tend;
+	float t, dt;
+	float v0, v1, v2, v3;
+
+	if(!track->count) {
+		return track->def_val;
+	}
+
+	last_idx = track->count - 1;
+
+	tstart = track->keys[0].time;
+	tend = track->keys[last_idx].time;
+
+	if(tstart == tend) {
+		return track->keys[0].val;
+	}
+
+	tm = remap_time[track->extrap](tm, tstart, tend);
+
+	idx0 = anm_get_key_interval(track, tm);
+	assert(idx0 >= 0 && idx0 < track->count);
+	idx1 = idx0 + 1;
+
+	if(idx0 == last_idx) {
+		return track->keys[idx0].val;
+	}
+
+	dt = (float)(track->keys[idx1].time - track->keys[idx0].time);
+	t = (float)(tm - track->keys[idx0].time) / dt;
+
+	v1 = track->keys[idx0].val;
+	v2 = track->keys[idx1].val;
+
+	/* get the neigboring values to allow for cubic interpolation */
+	v0 = idx0 > 0 ? track->keys[idx0 - 1].val : v1;
+	v3 = idx1 < last_idx ? track->keys[idx1 + 1].val : v2;
+
+	return interp[track->interp](v0, v1, v2, v3, t);
+}
+
+
+static float interp_step(float v0, float v1, float v2, float v3, float t)
+{
+	return v1;
+}
+
+static float interp_linear(float v0, float v1, float v2, float v3, float t)
+{
+	return v1 + (v2 - v1) * t;
+}
+
+static float interp_cubic(float a, float b, float c, float d, float t)
+{
+	float x, y, z, w;
+	float tsq = t * t;
+
+	x = -a + 3.0 * b - 3.0 * c + d;
+	y = 2.0 * a - 5.0 * b + 4.0 * c - d;
+	z = c - a;
+	w = 2.0 * b;
+
+	return 0.5 * (x * tsq * t + y * tsq + z * t + w);
+}
+
+static anm_time_t remap_extend(anm_time_t tm, anm_time_t start, anm_time_t end)
+{
+	return remap_repeat(tm, start, end);
+}
+
+static anm_time_t remap_clamp(anm_time_t tm, anm_time_t start, anm_time_t end)
+{
+	if(start == end) {
+		return start;
+	}
+	return tm < start ? start : (tm >= end ? end : tm);
+}
+
+static anm_time_t remap_repeat(anm_time_t tm, anm_time_t start, anm_time_t end)
+{
+	anm_time_t x, interv = end - start;
+
+	if(interv == 0) {
+		return start;
+	}
+
+	x = (tm - start) % interv;
+	if(x < 0) {
+		x += interv;
+	}
+	return x + start;
+
+	/*if(tm < start) {
+		while(tm < start) {
+			tm += interv;
+		}
+		return tm;
+	}
+	return (tm - start) % interv + start;*/
+}
+
+static anm_time_t remap_pingpong(anm_time_t tm, anm_time_t start, anm_time_t end)
+{
+	anm_time_t interv = end - start;
+	anm_time_t x = remap_repeat(tm, start, end + interv);
+
+	return x > end ? end + interv - x : x;
+}