hexagram/src/anim.c
2024-01-21 21:18:09 -05:00

104 lines
2.6 KiB
C

#include <stdlib.h>
#include <string.h>
#include <hexagram/anim.h>
void hexagram_anim_init(hexagram_anim *anim) {
anim->state = HEXAGRAM_ANIM_PLAYING;
gettimeofday(&anim->start, NULL);
}
static inline double tv_seconds(struct timeval *tv) {
return (double)tv->tv_sec + (double)tv->tv_usec / 1000000.0;
}
static inline double stop_offset(hexagram_anim *anim, size_t index) {
double offset = 0.0;
size_t i;
for (i=0; i<index; i++) {
offset += anim->stops[i].duration;
}
return offset;
}
int hexagram_anim_step(hexagram_anim *anim) {
struct timeval tv;
double offset = 0.0, interval, progress;
size_t i, a;
if (anim->state == HEXAGRAM_ANIM_STOPPED) {
return 0;
}
gettimeofday(&anim->now, NULL);
timersub(&anim->now, &anim->start, &tv);
/* Determine the interval between initialisation and now */
interval = tv_seconds(&tv);
/* Determine current animation stop index and time offset */
for (i=0; i<anim->count; i++) {
double duration = anim->stops[i].duration;
if (duration <= 0) {
continue;
}
if (offset + duration >= interval) {
break;
}
offset += duration;
}
/* Determine progress through current stop */
if (i == anim->count) {
i--;
progress = 1.0;
anim->state = HEXAGRAM_ANIM_STOPPED;
} else if (anim->stops[i].fn) {
progress = anim->stops[i].fn(&anim->stops[i],
(interval - offset) / anim->stops[i].duration);
} else {
progress = (interval - offset) / anim->stops[i].duration;
}
for (a=0; a<anim->stops[i].count; a++) {
hexagram_anim_action *action = &anim->stops[i].actions[a];
if (action->flags & HEXAGRAM_ANIM_MOVE) {
double x = progress * (action->to.x - action->from.x) + action->from.x,
y = progress * (action->to.y - action->from.y) + action->from.y;
hexagram_gauge_move(action->gauge, x, y);
}
if (action->flags & HEXAGRAM_ANIM_ALPHA) {
double alpha = progress * (action->to.alpha - action->from.alpha) + action->from.alpha;
hexagram_gauge_set_alpha(action->gauge, alpha);
}
if (action->flags & HEXAGRAM_ANIM_RADIUS) {
double radius = progress * (action->to.radius - action->from.radius) + action->from.radius;
hexagram_dial_resize(action->dial, radius);
}
}
return 1;
}
double hexagram_anim_duration(hexagram_anim *anim) {
double ret = 0.0;
size_t i;
for (i=0; i<anim->count; i++) {
ret += anim->stops[i].duration;
}
return ret;
}