From 399c2a8dea31f0980d604c9ab2bbbe988f5e063e Mon Sep 17 00:00:00 2001 From: Yaohua Xiong Date: Fri, 5 Aug 2022 17:03:00 +0800 Subject: [PATCH] Move rotation sampling from Path2D to Curve2D The rotation sampling code is moved from Path2D to a new method `sample_baked_with_rotation` on Curve2D. --- doc/classes/Curve2D.xml | 16 ++++++++++++++ scene/2d/path_2d.cpp | 45 ++++++--------------------------------- scene/resources/curve.cpp | 41 +++++++++++++++++++++++++++++++++++ scene/resources/curve.h | 1 + 4 files changed, 64 insertions(+), 39 deletions(-) diff --git a/doc/classes/Curve2D.xml b/doc/classes/Curve2D.xml index cc4124d0841..ccdf0853191 100644 --- a/doc/classes/Curve2D.xml +++ b/doc/classes/Curve2D.xml @@ -102,6 +102,22 @@ Cubic interpolation tends to follow the curves better, but linear is faster (and often, precise enough). + + + + + + + + Similar to [method sample_baked], but returns [Transform2D] that includes a rotation along the curve. Returns empty transform if length of the curve is [code]0[/code]. + Use [param loop] to smooth the tangent at the end of the curve. [param lookahead] defines the distance to a nearby point for calculating the tangent vector. + [codeblock] + var transform = curve.sample_baked_with_rotation(offset) + position = transform.get_origin() + rotation = transform.get_rotation() + [/codeblock] + + diff --git a/scene/2d/path_2d.cpp b/scene/2d/path_2d.cpp index c1044fdf5bd..b5945a45628 100644 --- a/scene/2d/path_2d.cpp +++ b/scene/2d/path_2d.cpp @@ -175,51 +175,18 @@ void PathFollow2D::_update_transform() { if (path_length == 0) { return; } - Vector2 pos = c->sample_baked(progress, cubic); if (rotates) { - real_t ahead = progress + lookahead; - - if (loop && ahead >= path_length) { - // If our lookahead will loop, we need to check if the path is closed. - int point_count = c->get_point_count(); - if (point_count > 0) { - Vector2 start_point = c->get_point_position(0); - Vector2 end_point = c->get_point_position(point_count - 1); - if (start_point == end_point) { - // Since the path is closed we want to 'smooth off' - // the corner at the start/end. - // So we wrap the lookahead back round. - ahead = Math::fmod(ahead, path_length); - } - } - } - - Vector2 ahead_pos = c->sample_baked(ahead, cubic); - - Vector2 tangent_to_curve; - if (ahead_pos == pos) { - // This will happen at the end of non-looping or non-closed paths. - // We'll try a look behind instead, in order to get a meaningful angle. - tangent_to_curve = - (pos - c->sample_baked(progress - lookahead, cubic)).normalized(); - } else { - tangent_to_curve = (ahead_pos - pos).normalized(); - } - - Vector2 normal_of_curve = -tangent_to_curve.orthogonal(); - - pos += tangent_to_curve * h_offset; - pos += normal_of_curve * v_offset; - - set_rotation(tangent_to_curve.angle()); - + Transform2D xform = c->sample_baked_with_rotation(progress, cubic, loop, lookahead); + xform.translate_local(v_offset, h_offset); + set_rotation(xform[1].angle()); + set_position(xform[2]); } else { + Vector2 pos = c->sample_baked(progress, cubic); pos.x += h_offset; pos.y += v_offset; + set_position(pos); } - - set_position(pos); } void PathFollow2D::_notification(int p_what) { diff --git a/scene/resources/curve.cpp b/scene/resources/curve.cpp index 49b78a091db..eda9af9dde8 100644 --- a/scene/resources/curve.cpp +++ b/scene/resources/curve.cpp @@ -936,6 +936,46 @@ Vector2 Curve2D::sample_baked(real_t p_offset, bool p_cubic) const { } } +Transform2D Curve2D::sample_baked_with_rotation(real_t p_offset, bool p_cubic, bool p_loop, real_t p_lookahead) const { + real_t path_length = get_baked_length(); // Ensure baked. + ERR_FAIL_COND_V_MSG(path_length == 0, Transform2D(), "Length of Curve2D is 0."); + + Vector2 pos = sample_baked(p_offset, p_cubic); + + real_t ahead = p_offset + p_lookahead; + + if (p_loop && ahead >= path_length) { + // If our lookahead will loop, we need to check if the path is closed. + int point_count = get_point_count(); + if (point_count > 0) { + Vector2 start_point = get_point_position(0); + Vector2 end_point = get_point_position(point_count - 1); + if (start_point == end_point) { + // Since the path is closed we want to 'smooth off' + // the corner at the start/end. + // So we wrap the lookahead back round. + ahead = Math::fmod(ahead, path_length); + } + } + } + + Vector2 ahead_pos = sample_baked(ahead, p_cubic); + + Vector2 tangent_to_curve; + if (ahead_pos == pos) { + // This will happen at the end of non-looping or non-closed paths. + // We'll try a look behind instead, in order to get a meaningful angle. + tangent_to_curve = + (pos - sample_baked(p_offset - p_lookahead, p_cubic)).normalized(); + } else { + tangent_to_curve = (ahead_pos - pos).normalized(); + } + + Vector2 normal_of_curve = -tangent_to_curve.orthogonal(); + + return Transform2D(normal_of_curve, tangent_to_curve, pos); +} + PackedVector2Array Curve2D::get_baked_points() const { if (baked_cache_dirty) { _bake(); @@ -1184,6 +1224,7 @@ void Curve2D::_bind_methods() { ClassDB::bind_method(D_METHOD("get_baked_length"), &Curve2D::get_baked_length); ClassDB::bind_method(D_METHOD("sample_baked", "offset", "cubic"), &Curve2D::sample_baked, DEFVAL(false)); + ClassDB::bind_method(D_METHOD("sample_baked_with_rotation", "offset", "cubic", "loop", "lookahead"), &Curve2D::sample_baked_with_rotation, DEFVAL(false), DEFVAL(true), DEFVAL(4.0)); ClassDB::bind_method(D_METHOD("get_baked_points"), &Curve2D::get_baked_points); ClassDB::bind_method(D_METHOD("get_closest_point", "to_point"), &Curve2D::get_closest_point); ClassDB::bind_method(D_METHOD("get_closest_offset", "to_point"), &Curve2D::get_closest_offset); diff --git a/scene/resources/curve.h b/scene/resources/curve.h index 88b6dda0968..fa1d35aab1f 100644 --- a/scene/resources/curve.h +++ b/scene/resources/curve.h @@ -216,6 +216,7 @@ public: real_t get_baked_length() const; Vector2 sample_baked(real_t p_offset, bool p_cubic = false) const; + Transform2D sample_baked_with_rotation(real_t p_offset, bool p_cubic = false, bool p_loop = true, real_t p_lookahead = 4.0) const; PackedVector2Array get_baked_points() const; //useful for going through Vector2 get_closest_point(const Vector2 &p_to_point) const; real_t get_closest_offset(const Vector2 &p_to_point) const;