godot/core/math/transform_interpolator.h
lawnjelly 522bce1159 Fixed Timestep Interpolation (3D)
Adds fixed timestep interpolation to the visual server.
Switchable on and off with project setting.

This version does not add new API for set_transform etc, when nodes have the interpolated flag set they will always use interpolation.
2022-02-16 09:41:23 +00:00

88 lines
4.6 KiB
C++

/*************************************************************************/
/* transform_interpolator.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
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/* "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. */
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/* 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.*/
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/*************************************************************************/
#ifndef TRANSFORM_INTERPOLATOR_H
#define TRANSFORM_INTERPOLATOR_H
#include "core/math/math_defs.h"
#include "core/math/quat.h"
#include "core/math/transform.h"
#include "core/math/vector3.h"
// Keep all the functions for fixed timestep interpolation together.
// There are two stages involved:
// Finding a method, for determining the interpolation method between two
// keyframes (which are physics ticks).
// And applying that pre-determined method.
// Pre-determining the method makes sense because it is expensive and often
// several frames may occur between each physics tick, which will make it cheaper
// than performing every frame.
class Transform;
class TransformInterpolator {
public:
enum Method {
INTERP_LERP,
INTERP_SLERP,
INTERP_SCALED_SLERP,
};
private:
static real_t _vec3_normalize(Vector3 &p_vec);
static Vector3 _basis_orthonormalize(Basis &r_basis);
static real_t vec3_sum(const Vector3 &p_pt) { return p_pt.x + p_pt.y + p_pt.z; }
static Method _test_basis(Basis p_basis, bool r_needed_normalize, Quat &r_quat);
static Basis _basis_slerp_unchecked(Basis p_from, Basis p_to, real_t p_fraction);
static Quat _quat_slerp_unchecked(const Quat &p_from, const Quat &p_to, real_t p_fraction);
static Quat _basis_to_quat_unchecked(const Basis &p_basis);
static bool _basis_is_orthogonal(const Basis &p_basis, real_t p_epsilon = 0.01f);
static bool _basis_is_orthogonal_any_scale(const Basis &p_basis);
static void interpolate_basis_linear(const Basis &p_prev, const Basis &p_curr, Basis &r_result, real_t p_fraction);
static void interpolate_basis_scaled_slerp(Basis p_prev, Basis p_curr, Basis &r_result, real_t p_fraction);
public:
// Generic functions, use when you don't know what method should be used, e.g. from gdscript.
// These will be slower.
static void interpolate_transform(const Transform &p_prev, const Transform &p_curr, Transform &r_result, real_t p_fraction);
static void interpolate_basis(const Basis &p_prev, const Basis &p_curr, Basis &r_result, real_t p_fraction);
// Optimized function when you know ahead of time the method
static void interpolate_transform_via_method(const Transform &p_prev, const Transform &p_curr, Transform &r_result, real_t p_fraction, Method p_method);
static void interpolate_basis_via_method(const Basis &p_prev, const Basis &p_curr, Basis &r_result, real_t p_fraction, Method p_method);
static real_t checksum_transform(const Transform &p_transform);
static Method find_method(const Basis &p_a, const Basis &p_b);
};
#endif // TRANSFORM_INTERPOLATOR_H