pandemonium_engine/servers/physics_2d/collision_solver_2d_sw.cpp

250 lines
9.5 KiB
C++

/*************************************************************************/
/* collision_solver_2d_sw.cpp */
/*************************************************************************/
/* This file is part of: */
/* PANDEMONIUM ENGINE */
/* https://github.com/Relintai/pandemonium_engine */
/*************************************************************************/
/* Copyright (c) 2022-present Péter Magyar. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* */
/* 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 "collision_solver_2d_sw.h"
#include "collision_solver_2d_sat.h"
#define collision_solver sat_2d_calculate_penetration
//#define collision_solver gjk_epa_calculate_penetration
bool CollisionSolver2DSW::solve_static_line(const Shape2DSW *p_shape_A, const Transform2D &p_transform_A, const Shape2DSW *p_shape_B, const Transform2D &p_transform_B, CallbackResult p_result_callback, void *p_userdata, bool p_swap_result) {
const LineShape2DSW *line = static_cast<const LineShape2DSW *>(p_shape_A);
if (p_shape_B->get_type() == Physics2DServer::SHAPE_LINE) {
return false;
}
Vector2 n = p_transform_A.basis_xform(line->get_normal()).normalized();
Vector2 p = p_transform_A.xform(line->get_normal() * line->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 CollisionSolver2DSW::solve_raycast(const Shape2DSW *p_shape_A, const Vector2 &p_motion_A, const Transform2D &p_transform_A, const Shape2DSW *p_shape_B, const Transform2D &p_transform_B, CallbackResult p_result_callback, void *p_userdata, bool p_swap_result, Vector2 *sep_axis, real_t p_margin) {
const RayShape2DSW *ray = static_cast<const RayShape2DSW *>(p_shape_A);
if (p_shape_B->get_type() == Physics2DServer::SHAPE_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 (sep_axis) {
*sep_axis = p_transform_A[1].normalized();
}
return false;
}
Vector2 support_B = p_transform_B.xform(p);
if (ray->get_slips_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;
const Shape2DSW *shape_A;
const Transform2D *transform_B;
Vector2 motion_A;
Vector2 motion_B;
real_t margin_A;
real_t margin_B;
CollisionSolver2DSW::CallbackResult result_callback;
void *userdata;
bool swap_result;
bool collided;
int aabb_tests;
int collisions;
Vector2 *sep_axis;
};
bool CollisionSolver2DSW::concave_callback(void *p_userdata, Shape2DSW *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 CollisionSolver2DSW::solve_concave(const Shape2DSW *p_shape_A, const Transform2D &p_transform_A, const Vector2 &p_motion_A, const Shape2DSW *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 *sep_axis, real_t p_margin_A, real_t p_margin_B) {
const ConcaveShape2DSW *concave_B = static_cast<const ConcaveShape2DSW *>(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 = 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.columns[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.columns[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 CollisionSolver2DSW::solve(const Shape2DSW *p_shape_A, const Transform2D &p_transform_A, const Vector2 &p_motion_A, const Shape2DSW *p_shape_B, const Transform2D &p_transform_B, const Vector2 &p_motion_B, CallbackResult p_result_callback, void *p_userdata, Vector2 *sep_axis, real_t p_margin_A, real_t p_margin_B) {
Physics2DServer::ShapeType type_A = p_shape_A->get_type();
Physics2DServer::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 == Physics2DServer::SHAPE_LINE) {
if (type_B == Physics2DServer::SHAPE_LINE || type_B == Physics2DServer::SHAPE_RAY) {
return false;
}
if (swap) {
return solve_static_line(p_shape_B, p_transform_B, p_shape_A, p_transform_A, p_result_callback, p_userdata, true);
} else {
return solve_static_line(p_shape_A, p_transform_A, p_shape_B, p_transform_B, p_result_callback, p_userdata, false);
}
} else if (type_A == Physics2DServer::SHAPE_RAY) {
if (type_B == Physics2DServer::SHAPE_RAY) {
return false; //no ray-ray
}
if (swap) {
return solve_raycast(p_shape_B, p_motion_B, p_transform_B, p_shape_A, p_transform_A, p_result_callback, p_userdata, true, sep_axis, p_margin_B);
} else {
return solve_raycast(p_shape_A, p_motion_A, p_transform_A, p_shape_B, p_transform_B, p_result_callback, p_userdata, false, 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, 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, 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, sep_axis, margin_A, margin_B);
}
}