1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/track.c	Sun Jan 08 05:13:13 2012 +0200
     1.3 @@ -0,0 +1,272 @@
     1.4 +#include <stdlib.h>
     1.5 +#include <string.h>
     1.6 +#include <assert.h>
     1.7 +#include "track.h"
     1.8 +#include "dynarr.h"
     1.9 +
    1.10 +static int keycmp(const void *a, const void *b);
    1.11 +static int find_prev_key(struct anm_keyframe *arr, int start, int end, anm_time_t tm);
    1.12 +
    1.13 +static float interp_step(float v0, float v1, float v2, float v3, float t);
    1.14 +static float interp_linear(float v0, float v1, float v2, float v3, float t);
    1.15 +static float interp_cubic(float v0, float v1, float v2, float v3, float t);
    1.16 +
    1.17 +static anm_time_t remap_extend(anm_time_t tm, anm_time_t start, anm_time_t end);
    1.18 +static anm_time_t remap_clamp(anm_time_t tm, anm_time_t start, anm_time_t end);
    1.19 +static anm_time_t remap_repeat(anm_time_t tm, anm_time_t start, anm_time_t end);
    1.20 +
    1.21 +/* XXX keep this in sync with enum anm_interpolator at track.h */
    1.22 +static float (*interp[])(float, float, float, float, float) = {
    1.23 +	interp_step,
    1.24 +	interp_linear,
    1.25 +	interp_cubic,
    1.26 +	0
    1.27 +};
    1.28 +
    1.29 +/* XXX keep this in sync with enum anm_extrapolator at track.h */
    1.30 +static anm_time_t (*remap_time[])(anm_time_t, anm_time_t, anm_time_t) = {
    1.31 +	remap_extend,
    1.32 +	remap_clamp,
    1.33 +	remap_repeat,
    1.34 +	0
    1.35 +};
    1.36 +
    1.37 +int anm_init_track(struct anm_track *track)
    1.38 +{
    1.39 +	memset(track, 0, sizeof *track);
    1.40 +
    1.41 +	if(!(track->keys = dynarr_alloc(0, sizeof *track->keys))) {
    1.42 +		return -1;
    1.43 +	}
    1.44 +	track->interp = ANM_INTERP_LINEAR;
    1.45 +	track->extrap = ANM_EXTRAP_CLAMP;
    1.46 +	return 0;
    1.47 +}
    1.48 +
    1.49 +void anm_destroy_track(struct anm_track *track)
    1.50 +{
    1.51 +	dynarr_free(track->keys);
    1.52 +}
    1.53 +
    1.54 +struct anm_track *anm_create_track(void)
    1.55 +{
    1.56 +	struct anm_track *track;
    1.57 +
    1.58 +	if((track = malloc(sizeof *track))) {
    1.59 +		if(anm_init_track(track) == -1) {
    1.60 +			free(track);
    1.61 +			return 0;
    1.62 +		}
    1.63 +	}
    1.64 +	return track;
    1.65 +}
    1.66 +
    1.67 +void anm_free_track(struct anm_track *track)
    1.68 +{
    1.69 +	anm_destroy_track(track);
    1.70 +	free(track);
    1.71 +}
    1.72 +
    1.73 +int anm_set_track_name(struct anm_track *track, const char *name)
    1.74 +{
    1.75 +	char *tmp;
    1.76 +
    1.77 +	if(!(tmp = malloc(strlen(name) + 1))) {
    1.78 +		return -1;
    1.79 +	}
    1.80 +	free(track->name);
    1.81 +	track->name = tmp;
    1.82 +	return 0;
    1.83 +}
    1.84 +
    1.85 +const char *anm_get_track_name(struct anm_track *track)
    1.86 +{
    1.87 +	return track->name;
    1.88 +}
    1.89 +
    1.90 +void anm_set_track_interpolator(struct anm_track *track, enum anm_interpolator in)
    1.91 +{
    1.92 +	track->interp = in;
    1.93 +}
    1.94 +
    1.95 +void anm_set_track_extrapolator(struct anm_track *track, enum anm_extrapolator ex)
    1.96 +{
    1.97 +	track->extrap = ex;
    1.98 +}
    1.99 +
   1.100 +anm_time_t anm_remap_time(struct anm_track *track, anm_time_t tm, anm_time_t start, anm_time_t end)
   1.101 +{
   1.102 +	return remap_time[track->extrap](tm, start, end);
   1.103 +}
   1.104 +
   1.105 +void anm_set_track_default(struct anm_track *track, float def)
   1.106 +{
   1.107 +	track->def_val = def;
   1.108 +}
   1.109 +
   1.110 +int anm_set_keyframe(struct anm_track *track, struct anm_keyframe *key)
   1.111 +{
   1.112 +	int idx = anm_get_key_interval(track, key->time);
   1.113 +
   1.114 +	/* if we got a valid keyframe index, compare them... */
   1.115 +	if(idx >= 0 && idx < track->count && keycmp(key, track->keys + idx) == 0) {
   1.116 +		/* ... it's the same key, just update the value */
   1.117 +		track->keys[idx].val = key->val;
   1.118 +	} else {
   1.119 +		/* ... it's a new key, add it and re-sort them */
   1.120 +		void *tmp;
   1.121 +		if(!(tmp = dynarr_push(track->keys, key))) {
   1.122 +			return -1;
   1.123 +		}
   1.124 +		track->keys = tmp;
   1.125 +		/* TODO lazy qsort */
   1.126 +		qsort(track->keys, ++track->count, sizeof *track->keys, keycmp);
   1.127 +	}
   1.128 +	return 0;
   1.129 +}
   1.130 +
   1.131 +static int keycmp(const void *a, const void *b)
   1.132 +{
   1.133 +	return ((struct anm_keyframe*)a)->time - ((struct anm_keyframe*)b)->time;
   1.134 +}
   1.135 +
   1.136 +struct anm_keyframe *anm_get_keyframe(struct anm_track *track, int idx)
   1.137 +{
   1.138 +	if(idx < 0 || idx >= track->count) {
   1.139 +		return 0;
   1.140 +	}
   1.141 +	return track->keys + idx;
   1.142 +}
   1.143 +
   1.144 +int anm_get_key_interval(struct anm_track *track, anm_time_t tm)
   1.145 +{
   1.146 +	int last;
   1.147 +
   1.148 +	if(!track->count || tm < track->keys[0].time) {
   1.149 +		return -1;
   1.150 +	}
   1.151 +
   1.152 +	last = track->count - 1;
   1.153 +	if(tm > track->keys[last].time) {
   1.154 +		return last;
   1.155 +	}
   1.156 +
   1.157 +	return find_prev_key(track->keys, 0, last, tm);
   1.158 +}
   1.159 +
   1.160 +static int find_prev_key(struct anm_keyframe *arr, int start, int end, anm_time_t tm)
   1.161 +{
   1.162 +	int mid;
   1.163 +
   1.164 +	if(end - start <= 1) {
   1.165 +		return start;
   1.166 +	}
   1.167 +
   1.168 +	mid = (start + end) / 2;
   1.169 +	if(tm < arr[mid].time) {
   1.170 +		return find_prev_key(arr, start, mid, tm);
   1.171 +	}
   1.172 +	if(tm > arr[mid].time) {
   1.173 +		return find_prev_key(arr, mid, end, tm);
   1.174 +	}
   1.175 +	return mid;
   1.176 +}
   1.177 +
   1.178 +int anm_set_value(struct anm_track *track, anm_time_t tm, float val)
   1.179 +{
   1.180 +	struct anm_keyframe key;
   1.181 +	key.time = tm;
   1.182 +	key.val = val;
   1.183 +
   1.184 +	return anm_set_keyframe(track, &key);
   1.185 +}
   1.186 +
   1.187 +float anm_get_value(struct anm_track *track, anm_time_t tm)
   1.188 +{
   1.189 +	int idx0, idx1, last_idx;
   1.190 +	anm_time_t tstart, tend;
   1.191 +	float t, dt;
   1.192 +	float v0, v1, v2, v3;
   1.193 +
   1.194 +	if(!track->count) {
   1.195 +		return track->def_val;
   1.196 +	}
   1.197 +
   1.198 +	last_idx = track->count - 1;
   1.199 +
   1.200 +	tstart = track->keys[0].time;
   1.201 +	tend = track->keys[last_idx].time;
   1.202 +
   1.203 +	if(tstart == tend) {
   1.204 +		return track->keys[0].val;
   1.205 +	}
   1.206 +
   1.207 +	tm = remap_time[track->extrap](tm, tstart, tend);
   1.208 +
   1.209 +	idx0 = anm_get_key_interval(track, tm);
   1.210 +	assert(idx0 >= 0 && idx0 < track->count);
   1.211 +	idx1 = idx0 + 1;
   1.212 +
   1.213 +	if(idx0 == last_idx) {
   1.214 +		return track->keys[idx0].val;
   1.215 +	}
   1.216 +
   1.217 +	dt = (float)(track->keys[idx1].time - track->keys[idx0].time);
   1.218 +	t = (float)(tm - track->keys[idx0].time) / dt;
   1.219 +
   1.220 +	v1 = track->keys[idx0].val;
   1.221 +	v2 = track->keys[idx1].val;
   1.222 +
   1.223 +	/* get the neigboring values to allow for cubic interpolation */
   1.224 +	v0 = idx0 > 0 ? track->keys[idx0 - 1].val : v1;
   1.225 +	v3 = idx1 < last_idx ? track->keys[idx1 + 1].val : v2;
   1.226 +
   1.227 +	return interp[track->interp](v0, v1, v2, v3, t);
   1.228 +}
   1.229 +
   1.230 +
   1.231 +static float interp_step(float v0, float v1, float v2, float v3, float t)
   1.232 +{
   1.233 +	return v1;
   1.234 +}
   1.235 +
   1.236 +static float interp_linear(float v0, float v1, float v2, float v3, float t)
   1.237 +{
   1.238 +	return v1 + (v2 - v1) * t;
   1.239 +}
   1.240 +
   1.241 +static float interp_cubic(float a, float b, float c, float d, float t)
   1.242 +{
   1.243 +	float x, y, z, w;
   1.244 +	float tsq = t * t;
   1.245 +
   1.246 +	x = -a + 3.0 * b - 3.0 * c + d;
   1.247 +	y = 2.0 * a - 5.0 * b + 4.0 * c - d;
   1.248 +	z = c - a;
   1.249 +	w = 2.0 * b;
   1.250 +
   1.251 +	return 0.5 * (x * tsq * t + y * tsq + z * t + w);
   1.252 +}
   1.253 +
   1.254 +static anm_time_t remap_extend(anm_time_t tm, anm_time_t start, anm_time_t end)
   1.255 +{
   1.256 +	return remap_repeat(tm, start, end);
   1.257 +}
   1.258 +
   1.259 +static anm_time_t remap_clamp(anm_time_t tm, anm_time_t start, anm_time_t end)
   1.260 +{
   1.261 +	return tm < start ? start : (tm >= end ? end - 1 : tm);
   1.262 +}
   1.263 +
   1.264 +static anm_time_t remap_repeat(anm_time_t tm, anm_time_t start, anm_time_t end)
   1.265 +{
   1.266 +	anm_time_t interv = end - start;
   1.267 +
   1.268 +	if(tm < start) {
   1.269 +		while(tm < start) {
   1.270 +			tm += interv;
   1.271 +		}
   1.272 +		return tm;
   1.273 +	}
   1.274 +	return (tm - start) % interv + start;
   1.275 +}