godot/scene/3d/spatial_velocity_tracker.cpp
2017-09-30 16:19:07 +02:00

105 lines
3.1 KiB
C++

#include "spatial_velocity_tracker.h"
#include "engine.h"
void SpatialVelocityTracker::set_track_physics_step(bool p_track_physics_step) {
physics_step = p_track_physics_step;
}
bool SpatialVelocityTracker::is_tracking_physics_step() const {
return physics_step;
}
void SpatialVelocityTracker::update_position(const Vector3 &p_position) {
PositionHistory ph;
ph.position = p_position;
if (physics_step) {
ph.frame = Engine::get_singleton()->get_physics_frames();
} else {
ph.frame = Engine::get_singleton()->get_idle_frame_ticks();
}
if (position_history_len == 0 || position_history[0].frame != ph.frame) { //in same frame, use latest
position_history_len = MIN(position_history.size(), position_history_len + 1);
for (int i = position_history_len - 1; i > 0; i--) {
position_history[i] = position_history[i - 1];
}
}
position_history[0] = ph;
}
Vector3 SpatialVelocityTracker::get_tracked_linear_velocity() const {
Vector3 linear_velocity;
float max_time = 1 / 5.0; //maximum time to interpolate a velocity
Vector3 distance_accum;
float time_accum = 0.0;
float base_time = 0.0;
if (position_history_len) {
if (physics_step) {
uint64_t base = Engine::get_singleton()->get_physics_frames();
base_time = float(base - position_history[0].frame) / Engine::get_singleton()->get_iterations_per_second();
} else {
uint64_t base = Engine::get_singleton()->get_idle_frame_ticks();
base_time = double(base - position_history[0].frame) / 1000000.0;
}
}
for (int i = 0; i < position_history_len - 1; i++) {
float delta = 0.0;
uint64_t diff = position_history[i].frame - position_history[i + 1].frame;
Vector3 distance = position_history[i].position - position_history[i + 1].position;
if (physics_step) {
delta = float(diff) / Engine::get_singleton()->get_iterations_per_second();
} else {
delta = double(diff) / 1000000.0;
}
if (base_time + time_accum + delta > max_time)
break;
distance_accum += distance;
time_accum += delta;
}
if (time_accum) {
linear_velocity = distance_accum / time_accum;
}
return linear_velocity;
}
void SpatialVelocityTracker::reset(const Vector3 &p_new_pos) {
PositionHistory ph;
ph.position = p_new_pos;
if (physics_step) {
ph.frame = Engine::get_singleton()->get_physics_frames();
} else {
ph.frame = Engine::get_singleton()->get_idle_frame_ticks();
}
position_history[0] = ph;
position_history_len = 1;
}
void SpatialVelocityTracker::_bind_methods() {
ClassDB::bind_method(D_METHOD("set_track_physics_step", "enable"), &SpatialVelocityTracker::set_track_physics_step);
ClassDB::bind_method(D_METHOD("is_tracking_physics_step"), &SpatialVelocityTracker::is_tracking_physics_step);
ClassDB::bind_method(D_METHOD("update_position", "position"), &SpatialVelocityTracker::update_position);
ClassDB::bind_method(D_METHOD("get_tracked_linear_velocity"), &SpatialVelocityTracker::get_tracked_linear_velocity);
ClassDB::bind_method(D_METHOD("reset", "position"), &SpatialVelocityTracker::reset);
}
SpatialVelocityTracker::SpatialVelocityTracker() {
position_history.resize(4); // should be configurable
position_history_len = 0;
physics_step = false;
}