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Diffstat (limited to 'servers/physics_2d/godot_collision_solver_2d.cpp')
| -rw-r--r-- | servers/physics_2d/godot_collision_solver_2d.cpp | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/servers/physics_2d/godot_collision_solver_2d.cpp b/servers/physics_2d/godot_collision_solver_2d.cpp new file mode 100644 index 0000000000..25371b9885 --- /dev/null +++ b/servers/physics_2d/godot_collision_solver_2d.cpp @@ -0,0 +1,264 @@ +/*************************************************************************/ +/* godot_collision_solver_2d.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 "godot_collision_solver_2d.h" +#include "godot_collision_solver_2d_sat.h" + +#define collision_solver sat_2d_calculate_penetration +//#define collision_solver gjk_epa_calculate_penetration + +bool GodotCollisionSolver2D::solve_static_world_boundary(const GodotShape2D *p_shape_A, const Transform2D &p_transform_A, const GodotShape2D *p_shape_B, const Transform2D &p_transform_B, CallbackResult p_result_callback, void *p_userdata, bool p_swap_result) { + const GodotWorldBoundaryShape2D *world_boundary = static_cast<const GodotWorldBoundaryShape2D *>(p_shape_A); + if (p_shape_B->get_type() == PhysicsServer2D::SHAPE_WORLD_BOUNDARY) { + return false; + } + + Vector2 n = p_transform_A.basis_xform(world_boundary->get_normal()).normalized(); + Vector2 p = p_transform_A.xform(world_boundary->get_normal() * world_boundary->get_d()); + real_t d = n.dot(p); + + Vector2 supports[2]; + int support_count; + + p_shape_B->get_supports(p_transform_B.affine_inverse().basis_xform(-n).normalized(), supports, support_count); + + bool found = false; + + for (int i = 0; i < support_count; i++) { + supports[i] = p_transform_B.xform(supports[i]); + real_t pd = n.dot(supports[i]); + if (pd >= d) { + continue; + } + found = true; + + Vector2 support_A = supports[i] - n * (pd - d); + + if (p_result_callback) { + if (p_swap_result) { + p_result_callback(supports[i], support_A, p_userdata); + } else { + p_result_callback(support_A, supports[i], p_userdata); + } + } + } + + return found; +} + +bool GodotCollisionSolver2D::solve_separation_ray(const GodotShape2D *p_shape_A, const Vector2 &p_motion_A, const Transform2D &p_transform_A, const GodotShape2D *p_shape_B, const Transform2D &p_transform_B, CallbackResult p_result_callback, void *p_userdata, bool p_swap_result, Vector2 *r_sep_axis, real_t p_margin) { + const GodotSeparationRayShape2D *ray = static_cast<const GodotSeparationRayShape2D *>(p_shape_A); + if (p_shape_B->get_type() == PhysicsServer2D::SHAPE_SEPARATION_RAY) { + return false; + } + + Vector2 from = p_transform_A.get_origin(); + Vector2 to = from + p_transform_A[1] * (ray->get_length() + p_margin); + if (p_motion_A != Vector2()) { + //not the best but should be enough + Vector2 normal = (to - from).normalized(); + to += normal * MAX(0.0, normal.dot(p_motion_A)); + } + Vector2 support_A = to; + + Transform2D invb = p_transform_B.affine_inverse(); + from = invb.xform(from); + to = invb.xform(to); + + Vector2 p, n; + if (!p_shape_B->intersect_segment(from, to, p, n)) { + if (r_sep_axis) { + *r_sep_axis = p_transform_A[1].normalized(); + } + return false; + } + + // Discard contacts when the ray is fully contained inside the shape. + if (n == Vector2()) { + if (r_sep_axis) { + *r_sep_axis = p_transform_A[1].normalized(); + } + return false; + } + + // Discard contacts in the wrong direction. + if (n.dot(from - to) < CMP_EPSILON) { + if (r_sep_axis) { + *r_sep_axis = p_transform_A[1].normalized(); + } + return false; + } + + Vector2 support_B = p_transform_B.xform(p); + if (ray->get_slide_on_slope()) { + Vector2 global_n = invb.basis_xform_inv(n).normalized(); + support_B = support_A + (support_B - support_A).length() * global_n; + } + + if (p_result_callback) { + if (p_swap_result) { + p_result_callback(support_B, support_A, p_userdata); + } else { + p_result_callback(support_A, support_B, p_userdata); + } + } + return true; +} + +struct _ConcaveCollisionInfo2D { + const Transform2D *transform_A = nullptr; + const GodotShape2D *shape_A = nullptr; + const Transform2D *transform_B = nullptr; + Vector2 motion_A; + Vector2 motion_B; + real_t margin_A = 0.0; + real_t margin_B = 0.0; + GodotCollisionSolver2D::CallbackResult result_callback; + void *userdata = nullptr; + bool swap_result = false; + bool collided = false; + int aabb_tests = 0; + int collisions = 0; + Vector2 *sep_axis = nullptr; +}; + +bool GodotCollisionSolver2D::concave_callback(void *p_userdata, GodotShape2D *p_convex) { + _ConcaveCollisionInfo2D &cinfo = *(_ConcaveCollisionInfo2D *)(p_userdata); + cinfo.aabb_tests++; + + bool collided = collision_solver(cinfo.shape_A, *cinfo.transform_A, cinfo.motion_A, p_convex, *cinfo.transform_B, cinfo.motion_B, cinfo.result_callback, cinfo.userdata, cinfo.swap_result, cinfo.sep_axis, cinfo.margin_A, cinfo.margin_B); + if (!collided) { + return false; + } + + cinfo.collided = true; + cinfo.collisions++; + + // Stop at first collision if contacts are not needed. + return !cinfo.result_callback; +} + +bool GodotCollisionSolver2D::solve_concave(const GodotShape2D *p_shape_A, const Transform2D &p_transform_A, const Vector2 &p_motion_A, const GodotShape2D *p_shape_B, const Transform2D &p_transform_B, const Vector2 &p_motion_B, CallbackResult p_result_callback, void *p_userdata, bool p_swap_result, Vector2 *r_sep_axis, real_t p_margin_A, real_t p_margin_B) { + const GodotConcaveShape2D *concave_B = static_cast<const GodotConcaveShape2D *>(p_shape_B); + + _ConcaveCollisionInfo2D cinfo; + cinfo.transform_A = &p_transform_A; + cinfo.shape_A = p_shape_A; + cinfo.transform_B = &p_transform_B; + cinfo.motion_A = p_motion_A; + cinfo.result_callback = p_result_callback; + cinfo.userdata = p_userdata; + cinfo.swap_result = p_swap_result; + cinfo.collided = false; + cinfo.collisions = 0; + cinfo.sep_axis = r_sep_axis; + cinfo.margin_A = p_margin_A; + cinfo.margin_B = p_margin_B; + + cinfo.aabb_tests = 0; + + Transform2D rel_transform = p_transform_A; + rel_transform.elements[2] -= p_transform_B.get_origin(); + + //quickly compute a local Rect2 + + Rect2 local_aabb; + for (int i = 0; i < 2; i++) { + Vector2 axis(p_transform_B.elements[i]); + real_t axis_scale = 1.0 / axis.length(); + axis *= axis_scale; + + real_t smin, smax; + p_shape_A->project_rangev(axis, rel_transform, smin, smax); + smin *= axis_scale; + smax *= axis_scale; + + local_aabb.position[i] = smin; + local_aabb.size[i] = smax - smin; + } + + concave_B->cull(local_aabb, concave_callback, &cinfo); + + return cinfo.collided; +} + +bool GodotCollisionSolver2D::solve(const GodotShape2D *p_shape_A, const Transform2D &p_transform_A, const Vector2 &p_motion_A, const GodotShape2D *p_shape_B, const Transform2D &p_transform_B, const Vector2 &p_motion_B, CallbackResult p_result_callback, void *p_userdata, Vector2 *r_sep_axis, real_t p_margin_A, real_t p_margin_B) { + PhysicsServer2D::ShapeType type_A = p_shape_A->get_type(); + PhysicsServer2D::ShapeType type_B = p_shape_B->get_type(); + bool concave_A = p_shape_A->is_concave(); + bool concave_B = p_shape_B->is_concave(); + real_t margin_A = p_margin_A, margin_B = p_margin_B; + + bool swap = false; + + if (type_A > type_B) { + SWAP(type_A, type_B); + SWAP(concave_A, concave_B); + SWAP(margin_A, margin_B); + swap = true; + } + + if (type_A == PhysicsServer2D::SHAPE_WORLD_BOUNDARY) { + if (type_B == PhysicsServer2D::SHAPE_WORLD_BOUNDARY) { + return false; + } + + if (swap) { + return solve_static_world_boundary(p_shape_B, p_transform_B, p_shape_A, p_transform_A, p_result_callback, p_userdata, true); + } else { + return solve_static_world_boundary(p_shape_A, p_transform_A, p_shape_B, p_transform_B, p_result_callback, p_userdata, false); + } + + } else if (type_A == PhysicsServer2D::SHAPE_SEPARATION_RAY) { + if (type_B == PhysicsServer2D::SHAPE_SEPARATION_RAY) { + return false; //no ray-ray + } + + if (swap) { + return solve_separation_ray(p_shape_B, p_motion_B, p_transform_B, p_shape_A, p_transform_A, p_result_callback, p_userdata, true, r_sep_axis, p_margin_B); + } else { + return solve_separation_ray(p_shape_A, p_motion_A, p_transform_A, p_shape_B, p_transform_B, p_result_callback, p_userdata, false, r_sep_axis, p_margin_A); + } + + } else if (concave_B) { + if (concave_A) { + return false; + } + + if (!swap) { + return solve_concave(p_shape_A, p_transform_A, p_motion_A, p_shape_B, p_transform_B, p_motion_B, p_result_callback, p_userdata, false, r_sep_axis, margin_A, margin_B); + } else { + return solve_concave(p_shape_B, p_transform_B, p_motion_B, p_shape_A, p_transform_A, p_motion_A, p_result_callback, p_userdata, true, r_sep_axis, margin_A, margin_B); + } + + } else { + return collision_solver(p_shape_A, p_transform_A, p_motion_A, p_shape_B, p_transform_B, p_motion_B, p_result_callback, p_userdata, false, r_sep_axis, margin_A, margin_B); + } +} |