From 1808c5113a89b30261864786087ef857b96ff9e3 Mon Sep 17 00:00:00 2001 From: "yakun.zhang" Date: Mon, 20 May 2019 12:19:14 +0800 Subject: [PATCH] Fix some shape2d get_moment_of_inertia error --- servers/physics_2d/shape_2d_sw.cpp | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/servers/physics_2d/shape_2d_sw.cpp b/servers/physics_2d/shape_2d_sw.cpp index 66d2dcd417e..0043b948b0b 100644 --- a/servers/physics_2d/shape_2d_sw.cpp +++ b/servers/physics_2d/shape_2d_sw.cpp @@ -240,12 +240,7 @@ bool SegmentShape2DSW::intersect_segment(const Vector2 &p_begin, const Vector2 & real_t SegmentShape2DSW::get_moment_of_inertia(real_t p_mass, const Size2 &p_scale) const { - Vector2 s[2] = { a * p_scale, b * p_scale }; - - real_t l = s[1].distance_to(s[0]); - Vector2 ofs = (s[0] + s[1]) * 0.5; - - return p_mass * (l * l / 12.0 + ofs.length_squared()); + return p_mass * ((a * p_scale).distance_squared_to(b * p_scale)) / 12; } void SegmentShape2DSW::set_data(const Variant &p_data) { @@ -318,7 +313,9 @@ bool CircleShape2DSW::intersect_segment(const Vector2 &p_begin, const Vector2 &p real_t CircleShape2DSW::get_moment_of_inertia(real_t p_mass, const Size2 &p_scale) const { - return (radius * radius) * (p_scale.x * 0.5 + p_scale.y * 0.5); + real_t a = radius * p_scale.x; + real_t b = radius * p_scale.y; + return p_mass * (a * a + b * b) / 4; } void CircleShape2DSW::set_data(const Variant &p_data) { @@ -637,7 +634,7 @@ real_t ConvexPolygonShape2DSW::get_moment_of_inertia(real_t p_mass, const Size2 aabb.expand_to(points[i].pos * p_scale); } - return p_mass * aabb.size.dot(aabb.size) / 12.0 + p_mass * (aabb.position + aabb.size * 0.5).length_squared(); + return p_mass * aabb.size.dot(aabb.size) / 12.0; } void ConvexPolygonShape2DSW::set_data(const Variant &p_data) {