eco2d/code/game/src/prediction.c

115 lines
3.2 KiB
C

#include "zpl.h"
#include "prediction.h"
#include "platform.h"
#include "world/world.h"
#include "game.h"
#define PREDICT_SMOOTH_FACTOR_LO 0.10
#define PREDICT_SMOOTH_FACTOR_HI 0.01
static inline float map_factor(float x) {
x = 1.0f - zpl_clamp01(x);
return 1.0f - x*x*x*x*x*x*x*x;
}
static inline float base_angle(float x) {
while (x > ZPL_TAU) x -= ZPL_TAU;
while (x < 0.0f) x += ZPL_TAU;
return x;
}
static inline float spherical_lerp(float a, float b, float t) {
a = base_angle(a);
b = base_angle(b);
float d = b - a;
if (d < -ZPL_PI) {
b += ZPL_TAU;
} else if (d > ZPL_PI) {
b -= ZPL_TAU;
}
return base_angle(zpl_lerp(a, b, t));
}
float smooth_val(float cur, float tgt, uint64_t dt) {
float factor = zpl_clamp01(map_factor(zpl_unlerp(dt, WORLD_TRACKER_UPDATE_FAST_MS, WORLD_TRACKER_UPDATE_SLOW_MS)));
#if 0
dt = 200;
factor = map_factor(zpl_unlerp(dt, WORLD_TRACKER_UPDATE_FAST_MS, WORLD_TRACKER_UPDATE_SLOW_MS));
zpl_printf("lerp factor: %f\n", factor);
zpl_exit(0);
#endif
return zpl_lerp(cur, tgt, zpl_lerp(PREDICT_SMOOTH_FACTOR_LO, PREDICT_SMOOTH_FACTOR_HI, factor));
}
float smooth_val_spherical(float cur, float tgt, uint64_t dt) {
float factor = zpl_clamp01(map_factor(zpl_unlerp(dt, WORLD_TRACKER_UPDATE_FAST_MS, WORLD_TRACKER_UPDATE_SLOW_MS)));
return spherical_lerp(cur, tgt, zpl_lerp(PREDICT_SMOOTH_FACTOR_LO, PREDICT_SMOOTH_FACTOR_HI, factor));
}
void predict_receive_update(entity_view *d, entity_view *data) {
if (d && data->flag & EFLAG_INTERP) {
// NOTE(zaklaus): store target pos but keep x,y unchanged
float tx = data->x;
float ty = data->y;
float theading = data->heading;
data->x = d->x;
data->y = d->y;
data->heading = d->heading;
data->tx = tx;
data->ty = ty;
data->theading = theading;
}
data->tran_effect = d->tran_effect;
data->tran_time = d->tran_time;
}
void lerp_entity_positions(uint64_t key, entity_view *data) {
(void)key;
world_view *view = game_world_view_get_active();
if (data->flag == EFLAG_INTERP) {
#if 1
data->x = smooth_val(data->x, data->tx, view->delta_time[data->layer_id]);
data->y = smooth_val(data->y, data->ty, view->delta_time[data->layer_id]);
data->heading = smooth_val_spherical(data->heading, data->theading, view->delta_time[data->layer_id]);
#else
data->x = data->tx;
data->y = data->ty;
data->heading = data->theading;
#endif
}
}
void do_entity_fadeinout(uint64_t key, entity_view * data) {
(void)key;
switch (data->tran_effect) {
case ETRAN_FADEIN: {
data->tran_time += platform_frametime();
if (data->tran_time > 1.0f) {
data->tran_effect = ETRAN_NONE;
data->tran_time = 1.0f;
}
}break;
case ETRAN_FADEOUT: {
data->tran_time -= platform_frametime();
if (data->tran_time < 0.0f) {
data->tran_effect = ETRAN_REMOVE;
data->tran_time = 0.0f;
}
}break;
default: break;
}
}