godot/scene/3d/velocity_tracker_3d.cpp

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/*************************************************************************/
/* velocity_tracker_3d.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "velocity_tracker_3d.h"
#include "core/config/engine.h"
void VelocityTracker3D::set_track_physics_step(bool p_track_physics_step) {
physics_step = p_track_physics_step;
}
bool VelocityTracker3D::is_tracking_physics_step() const {
return physics_step;
}
void VelocityTracker3D::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_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.write[i] = position_history[i - 1];
}
}
position_history.write[0] = ph;
}
Vector3 VelocityTracker3D::get_tracked_linear_velocity() const {
Vector3 linear_velocity;
double max_time = 1 / 5.0; //maximum time to interpolate a velocity
Vector3 distance_accum;
double time_accum = 0.0;
double base_time = 0.0;
if (position_history_len) {
if (physics_step) {
uint64_t base = Engine::get_singleton()->get_physics_frames();
base_time = double(base - position_history[0].frame) / Engine::get_singleton()->get_physics_ticks_per_second();
} else {
uint64_t base = Engine::get_singleton()->get_frame_ticks();
base_time = double(base - position_history[0].frame) / 1000000.0;
}
}
for (int i = 0; i < position_history_len - 1; i++) {
double 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 = double(diff) / Engine::get_singleton()->get_physics_ticks_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 VelocityTracker3D::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_frame_ticks();
}
position_history.write[0] = ph;
position_history_len = 1;
}
void VelocityTracker3D::_bind_methods() {
ClassDB::bind_method(D_METHOD("set_track_physics_step", "enable"), &VelocityTracker3D::set_track_physics_step);
ClassDB::bind_method(D_METHOD("is_tracking_physics_step"), &VelocityTracker3D::is_tracking_physics_step);
ClassDB::bind_method(D_METHOD("update_position", "position"), &VelocityTracker3D::update_position);
ClassDB::bind_method(D_METHOD("get_tracked_linear_velocity"), &VelocityTracker3D::get_tracked_linear_velocity);
ClassDB::bind_method(D_METHOD("reset", "position"), &VelocityTracker3D::reset);
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "track_physics_step"), "set_track_physics_step", "is_tracking_physics_step");
}
VelocityTracker3D::VelocityTracker3D() {
position_history.resize(4); // should be configurable
}