godot/servers/physics_2d/collision_solver_2d_sw.cpp
Rémi Verschelde a7f49ac9a1 Update copyright statements to 2020
Happy new year to the wonderful Godot community!

We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.

Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
2020-01-01 11:16:22 +01:00

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/*************************************************************************/
/* collision_solver_2d_sw.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2020 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 "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_A.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) {
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();
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;
};
void CollisionSolver2DSW::concave_callback(void *p_userdata, Shape2DSW *p_convex) {
_ConcaveCollisionInfo2D &cinfo = *(_ConcaveCollisionInfo2D *)(p_userdata);
cinfo.aabb_tests++;
if (!cinfo.result_callback && cinfo.collided)
return; //already collided and no contacts requested, don't test anymore
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;
cinfo.collided = true;
cinfo.collisions++;
}
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.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 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);
} 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);
}
} 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);
}
}