743 lines
19 KiB
C++
743 lines
19 KiB
C++
/*************************************************************************/
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/* broad_phase_2d_hash_grid.cpp */
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/*************************************************************************/
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/* This file is part of: */
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/* GODOT ENGINE */
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/* http://www.godotengine.org */
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/*************************************************************************/
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/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
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/* */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the */
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/* "Software"), to deal in the Software without restriction, including */
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/* without limitation the rights to use, copy, modify, merge, publish, */
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/* distribute, sublicense, and/or sell copies of the Software, and to */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions: */
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/* */
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/* The above copyright notice and this permission notice shall be */
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/* included in all copies or substantial portions of the Software. */
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/* */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/*************************************************************************/
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#include "broad_phase_2d_hash_grid.h"
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#include "globals.h"
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#define LARGE_ELEMENT_FI 1.01239812
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void BroadPhase2DHashGrid::_pair_attempt(Element *p_elem, Element *p_with) {
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Map<Element *, PairData *>::Element *E = p_elem->paired.find(p_with);
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ERR_FAIL_COND(p_elem->_static && p_with->_static);
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if (!E) {
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PairData *pd = memnew(PairData);
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p_elem->paired[p_with] = pd;
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p_with->paired[p_elem] = pd;
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} else {
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E->get()->rc++;
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}
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}
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void BroadPhase2DHashGrid::_unpair_attempt(Element *p_elem, Element *p_with) {
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Map<Element *, PairData *>::Element *E = p_elem->paired.find(p_with);
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ERR_FAIL_COND(!E); //this should really be paired..
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E->get()->rc--;
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if (E->get()->rc == 0) {
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if (E->get()->colliding) {
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//uncollide
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if (unpair_callback) {
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unpair_callback(p_elem->owner, p_elem->subindex, p_with->owner, p_with->subindex, E->get()->ud, unpair_userdata);
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}
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}
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memdelete(E->get());
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p_elem->paired.erase(E);
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p_with->paired.erase(p_elem);
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}
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}
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void BroadPhase2DHashGrid::_check_motion(Element *p_elem) {
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for (Map<Element *, PairData *>::Element *E = p_elem->paired.front(); E; E = E->next()) {
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bool pairing = p_elem->aabb.intersects(E->key()->aabb);
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if (pairing != E->get()->colliding) {
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if (pairing) {
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if (pair_callback) {
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E->get()->ud = pair_callback(p_elem->owner, p_elem->subindex, E->key()->owner, E->key()->subindex, pair_userdata);
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}
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} else {
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if (unpair_callback) {
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unpair_callback(p_elem->owner, p_elem->subindex, E->key()->owner, E->key()->subindex, E->get()->ud, unpair_userdata);
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}
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}
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E->get()->colliding = pairing;
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}
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}
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}
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void BroadPhase2DHashGrid::_enter_grid(Element *p_elem, const Rect2 &p_rect, bool p_static) {
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Vector2 sz = (p_rect.size / cell_size * LARGE_ELEMENT_FI); //use magic number to avoid floating point issues
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if (sz.width * sz.height > large_object_min_surface) {
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//large object, do not use grid, must check against all elements
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for (Map<ID, Element>::Element *E = element_map.front(); E; E = E->next()) {
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if (E->key() == p_elem->self)
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continue; // do not pair against itself
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if (E->get().owner == p_elem->owner)
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continue;
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if (E->get()._static && p_static)
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continue;
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_pair_attempt(p_elem, &E->get());
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}
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large_elements[p_elem].inc();
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return;
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}
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Point2i from = (p_rect.pos / cell_size).floor();
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Point2i to = ((p_rect.pos + p_rect.size) / cell_size).floor();
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for (int i = from.x; i <= to.x; i++) {
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for (int j = from.y; j <= to.y; j++) {
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PosKey pk;
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pk.x = i;
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pk.y = j;
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uint32_t idx = pk.hash() % hash_table_size;
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PosBin *pb = hash_table[idx];
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while (pb) {
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if (pb->key == pk) {
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break;
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}
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pb = pb->next;
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}
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bool entered = false;
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if (!pb) {
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//does not exist, create!
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pb = memnew(PosBin);
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pb->key = pk;
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pb->next = hash_table[idx];
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hash_table[idx] = pb;
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}
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if (p_static) {
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if (pb->static_object_set[p_elem].inc() == 1) {
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entered = true;
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}
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} else {
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if (pb->object_set[p_elem].inc() == 1) {
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entered = true;
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}
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}
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if (entered) {
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for (Map<Element *, RC>::Element *E = pb->object_set.front(); E; E = E->next()) {
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if (E->key()->owner == p_elem->owner)
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continue;
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_pair_attempt(p_elem, E->key());
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}
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if (!p_static) {
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for (Map<Element *, RC>::Element *E = pb->static_object_set.front(); E; E = E->next()) {
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if (E->key()->owner == p_elem->owner)
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continue;
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_pair_attempt(p_elem, E->key());
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}
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}
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}
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}
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}
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//pair separatedly with large elements
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for (Map<Element *, RC>::Element *E = large_elements.front(); E; E = E->next()) {
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if (E->key() == p_elem)
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continue; // do not pair against itself
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if (E->key()->owner == p_elem->owner)
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continue;
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if (E->key()->_static && p_static)
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continue;
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_pair_attempt(E->key(), p_elem);
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}
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}
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void BroadPhase2DHashGrid::_exit_grid(Element *p_elem, const Rect2 &p_rect, bool p_static) {
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Vector2 sz = (p_rect.size / cell_size * LARGE_ELEMENT_FI);
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if (sz.width * sz.height > large_object_min_surface) {
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//unpair all elements, instead of checking all, just check what is already paired, so we at least save from checking static vs static
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for (Map<Element *, PairData *>::Element *E = p_elem->paired.front(); E; E = E->next()) {
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_unpair_attempt(p_elem, E->key());
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}
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if (large_elements[p_elem].dec() == 0) {
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large_elements.erase(p_elem);
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}
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return;
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}
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Point2i from = (p_rect.pos / cell_size).floor();
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Point2i to = ((p_rect.pos + p_rect.size) / cell_size).floor();
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for (int i = from.x; i <= to.x; i++) {
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for (int j = from.y; j <= to.y; j++) {
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PosKey pk;
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pk.x = i;
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pk.y = j;
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uint32_t idx = pk.hash() % hash_table_size;
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PosBin *pb = hash_table[idx];
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while (pb) {
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if (pb->key == pk) {
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break;
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}
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pb = pb->next;
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}
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ERR_CONTINUE(!pb); //should exist!!
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bool exited = false;
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if (p_static) {
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if (pb->static_object_set[p_elem].dec() == 0) {
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pb->static_object_set.erase(p_elem);
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exited = true;
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}
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} else {
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if (pb->object_set[p_elem].dec() == 0) {
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pb->object_set.erase(p_elem);
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exited = true;
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}
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}
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if (exited) {
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for (Map<Element *, RC>::Element *E = pb->object_set.front(); E; E = E->next()) {
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if (E->key()->owner == p_elem->owner)
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continue;
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_unpair_attempt(p_elem, E->key());
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}
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if (!p_static) {
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for (Map<Element *, RC>::Element *E = pb->static_object_set.front(); E; E = E->next()) {
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if (E->key()->owner == p_elem->owner)
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continue;
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_unpair_attempt(p_elem, E->key());
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}
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}
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}
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if (pb->object_set.empty() && pb->static_object_set.empty()) {
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if (hash_table[idx] == pb) {
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hash_table[idx] = pb->next;
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} else {
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PosBin *px = hash_table[idx];
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while (px) {
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if (px->next == pb) {
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px->next = pb->next;
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break;
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}
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px = px->next;
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}
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ERR_CONTINUE(!px);
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}
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memdelete(pb);
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}
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}
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}
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for (Map<Element *, RC>::Element *E = large_elements.front(); E; E = E->next()) {
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if (E->key() == p_elem)
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continue; // do not pair against itself
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if (E->key()->owner == p_elem->owner)
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continue;
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if (E->key()->_static && p_static)
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continue;
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//unpair from large elements
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_unpair_attempt(p_elem, E->key());
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}
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}
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BroadPhase2DHashGrid::ID BroadPhase2DHashGrid::create(CollisionObject2DSW *p_object, int p_subindex) {
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current++;
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Element e;
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e.owner = p_object;
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e._static = false;
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e.subindex = p_subindex;
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e.self = current;
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e.pass = 0;
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element_map[current] = e;
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return current;
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}
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void BroadPhase2DHashGrid::move(ID p_id, const Rect2 &p_aabb) {
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Map<ID, Element>::Element *E = element_map.find(p_id);
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ERR_FAIL_COND(!E);
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Element &e = E->get();
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if (p_aabb == e.aabb)
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return;
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if (p_aabb != Rect2()) {
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_enter_grid(&e, p_aabb, e._static);
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}
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if (e.aabb != Rect2()) {
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_exit_grid(&e, e.aabb, e._static);
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}
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e.aabb = p_aabb;
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_check_motion(&e);
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e.aabb = p_aabb;
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}
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void BroadPhase2DHashGrid::set_static(ID p_id, bool p_static) {
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Map<ID, Element>::Element *E = element_map.find(p_id);
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ERR_FAIL_COND(!E);
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Element &e = E->get();
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if (e._static == p_static)
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return;
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if (e.aabb != Rect2())
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_exit_grid(&e, e.aabb, e._static);
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e._static = p_static;
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if (e.aabb != Rect2()) {
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_enter_grid(&e, e.aabb, e._static);
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_check_motion(&e);
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}
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}
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void BroadPhase2DHashGrid::remove(ID p_id) {
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Map<ID, Element>::Element *E = element_map.find(p_id);
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ERR_FAIL_COND(!E);
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Element &e = E->get();
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if (e.aabb != Rect2())
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_exit_grid(&e, e.aabb, e._static);
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element_map.erase(p_id);
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}
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CollisionObject2DSW *BroadPhase2DHashGrid::get_object(ID p_id) const {
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const Map<ID, Element>::Element *E = element_map.find(p_id);
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ERR_FAIL_COND_V(!E, NULL);
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return E->get().owner;
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}
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bool BroadPhase2DHashGrid::is_static(ID p_id) const {
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const Map<ID, Element>::Element *E = element_map.find(p_id);
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ERR_FAIL_COND_V(!E, false);
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return E->get()._static;
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}
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int BroadPhase2DHashGrid::get_subindex(ID p_id) const {
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const Map<ID, Element>::Element *E = element_map.find(p_id);
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ERR_FAIL_COND_V(!E, -1);
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return E->get().subindex;
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}
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template <bool use_aabb, bool use_segment>
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void BroadPhase2DHashGrid::_cull(const Point2i p_cell, const Rect2 &p_aabb, const Point2 &p_from, const Point2 &p_to, CollisionObject2DSW **p_results, int p_max_results, int *p_result_indices, int &index) {
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PosKey pk;
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pk.x = p_cell.x;
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pk.y = p_cell.y;
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uint32_t idx = pk.hash() % hash_table_size;
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PosBin *pb = hash_table[idx];
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while (pb) {
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if (pb->key == pk) {
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break;
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}
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pb = pb->next;
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}
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if (!pb)
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return;
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for (Map<Element *, RC>::Element *E = pb->object_set.front(); E; E = E->next()) {
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if (index >= p_max_results)
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break;
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if (E->key()->pass == pass)
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continue;
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E->key()->pass = pass;
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if (use_aabb && !p_aabb.intersects(E->key()->aabb))
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continue;
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if (use_segment && !E->key()->aabb.intersects_segment(p_from, p_to))
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continue;
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p_results[index] = E->key()->owner;
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p_result_indices[index] = E->key()->subindex;
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index++;
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}
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for (Map<Element *, RC>::Element *E = pb->static_object_set.front(); E; E = E->next()) {
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if (index >= p_max_results)
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break;
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if (E->key()->pass == pass)
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continue;
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if (use_aabb && !p_aabb.intersects(E->key()->aabb)) {
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continue;
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}
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if (use_segment && !E->key()->aabb.intersects_segment(p_from, p_to))
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continue;
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E->key()->pass = pass;
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p_results[index] = E->key()->owner;
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p_result_indices[index] = E->key()->subindex;
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index++;
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}
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}
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int BroadPhase2DHashGrid::cull_segment(const Vector2 &p_from, const Vector2 &p_to, CollisionObject2DSW **p_results, int p_max_results, int *p_result_indices) {
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pass++;
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Vector2 dir = (p_to - p_from);
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if (dir == Vector2())
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return 0;
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//avoid divisions by zero
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dir.normalize();
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if (dir.x == 0.0)
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dir.x = 0.000001;
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if (dir.y == 0.0)
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dir.y = 0.000001;
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Vector2 delta = dir.abs();
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delta.x = cell_size / delta.x;
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delta.y = cell_size / delta.y;
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Point2i pos = (p_from / cell_size).floor();
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Point2i end = (p_to / cell_size).floor();
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Point2i step = Vector2(SGN(dir.x), SGN(dir.y));
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Vector2 max;
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if (dir.x < 0)
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max.x = (Math::floor(pos.x) * cell_size - p_from.x) / dir.x;
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else
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max.x = (Math::floor(pos.x + 1) * cell_size - p_from.x) / dir.x;
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if (dir.y < 0)
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max.y = (Math::floor(pos.y) * cell_size - p_from.y) / dir.y;
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else
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max.y = (Math::floor(pos.y + 1) * cell_size - p_from.y) / dir.y;
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int cullcount = 0;
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_cull<false, true>(pos, Rect2(), p_from, p_to, p_results, p_max_results, p_result_indices, cullcount);
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bool reached_x = false;
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bool reached_y = false;
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while (true) {
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if (max.x < max.y) {
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max.x += delta.x;
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pos.x += step.x;
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} else {
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max.y += delta.y;
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pos.y += step.y;
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}
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if (step.x > 0) {
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if (pos.x >= end.x)
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reached_x = true;
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} else if (pos.x <= end.x) {
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reached_x = true;
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}
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if (step.y > 0) {
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if (pos.y >= end.y)
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reached_y = true;
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} else if (pos.y <= end.y) {
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reached_y = true;
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}
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_cull<false, true>(pos, Rect2(), p_from, p_to, p_results, p_max_results, p_result_indices, cullcount);
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|
|
if (reached_x && reached_y)
|
|
break;
|
|
}
|
|
|
|
for (Map<Element *, RC>::Element *E = large_elements.front(); E; E = E->next()) {
|
|
|
|
if (cullcount >= p_max_results)
|
|
break;
|
|
if (E->key()->pass == pass)
|
|
continue;
|
|
|
|
E->key()->pass = pass;
|
|
|
|
// if (use_aabb && !p_aabb.intersects(E->key()->aabb))
|
|
// continue;
|
|
|
|
if (!E->key()->aabb.intersects_segment(p_from, p_to))
|
|
continue;
|
|
|
|
p_results[cullcount] = E->key()->owner;
|
|
p_result_indices[cullcount] = E->key()->subindex;
|
|
cullcount++;
|
|
}
|
|
|
|
return cullcount;
|
|
}
|
|
|
|
int BroadPhase2DHashGrid::cull_aabb(const Rect2 &p_aabb, CollisionObject2DSW **p_results, int p_max_results, int *p_result_indices) {
|
|
|
|
pass++;
|
|
|
|
Point2i from = (p_aabb.pos / cell_size).floor();
|
|
Point2i to = ((p_aabb.pos + p_aabb.size) / cell_size).floor();
|
|
int cullcount = 0;
|
|
|
|
for (int i = from.x; i <= to.x; i++) {
|
|
|
|
for (int j = from.y; j <= to.y; j++) {
|
|
|
|
_cull<true, false>(Point2i(i, j), p_aabb, Point2(), Point2(), p_results, p_max_results, p_result_indices, cullcount);
|
|
}
|
|
}
|
|
|
|
for (Map<Element *, RC>::Element *E = large_elements.front(); E; E = E->next()) {
|
|
|
|
if (cullcount >= p_max_results)
|
|
break;
|
|
if (E->key()->pass == pass)
|
|
continue;
|
|
|
|
E->key()->pass = pass;
|
|
|
|
if (!p_aabb.intersects(E->key()->aabb))
|
|
continue;
|
|
|
|
// if (!E->key()->aabb.intersects_segment(p_from,p_to))
|
|
// continue;
|
|
|
|
p_results[cullcount] = E->key()->owner;
|
|
p_result_indices[cullcount] = E->key()->subindex;
|
|
cullcount++;
|
|
}
|
|
return cullcount;
|
|
}
|
|
|
|
void BroadPhase2DHashGrid::set_pair_callback(PairCallback p_pair_callback, void *p_userdata) {
|
|
|
|
pair_callback = p_pair_callback;
|
|
pair_userdata = p_userdata;
|
|
}
|
|
void BroadPhase2DHashGrid::set_unpair_callback(UnpairCallback p_unpair_callback, void *p_userdata) {
|
|
|
|
unpair_callback = p_unpair_callback;
|
|
unpair_userdata = p_userdata;
|
|
}
|
|
|
|
void BroadPhase2DHashGrid::update() {
|
|
}
|
|
|
|
BroadPhase2DSW *BroadPhase2DHashGrid::_create() {
|
|
|
|
return memnew(BroadPhase2DHashGrid);
|
|
}
|
|
|
|
BroadPhase2DHashGrid::BroadPhase2DHashGrid() {
|
|
|
|
hash_table_size = GLOBAL_DEF("physics_2d/bp_hash_table_size", 4096);
|
|
hash_table_size = Math::larger_prime(hash_table_size);
|
|
hash_table = memnew_arr(PosBin *, hash_table_size);
|
|
|
|
cell_size = GLOBAL_DEF("physics_2d/cell_size", 128);
|
|
large_object_min_surface = GLOBAL_DEF("physics_2d/large_object_surface_treshold_in_cells", 512);
|
|
|
|
for (int i = 0; i < hash_table_size; i++)
|
|
hash_table[i] = NULL;
|
|
pass = 1;
|
|
|
|
current = 0;
|
|
}
|
|
|
|
BroadPhase2DHashGrid::~BroadPhase2DHashGrid() {
|
|
|
|
for (int i = 0; i < hash_table_size; i++) {
|
|
while (hash_table[i]) {
|
|
PosBin *pb = hash_table[i];
|
|
hash_table[i] = pb->next;
|
|
memdelete(pb);
|
|
}
|
|
}
|
|
|
|
memdelete_arr(hash_table);
|
|
}
|
|
|
|
/* 3D version of voxel traversal:
|
|
|
|
public IEnumerable<Point3D> GetCellsOnRay(Ray ray, int maxDepth)
|
|
{
|
|
// Implementation is based on:
|
|
// "A Fast Voxel Traversal Algorithm for Ray Tracing"
|
|
// John Amanatides, Andrew Woo
|
|
// http://www.cse.yorku.ca/~amana/research/grid.pdf
|
|
// http://www.devmaster.net/articles/raytracing_series/A%20faster%20voxel%20traversal%20algorithm%20for%20ray%20tracing.pdf
|
|
|
|
// NOTES:
|
|
// * This code assumes that the ray's position and direction are in 'cell coordinates', which means
|
|
// that one unit equals one cell in all directions.
|
|
// * When the ray doesn't start within the voxel grid, calculate the first position at which the
|
|
// ray could enter the grid. If it never enters the grid, there is nothing more to do here.
|
|
// * Also, it is important to test when the ray exits the voxel grid when the grid isn't infinite.
|
|
// * The Point3D structure is a simple structure having three integer fields (X, Y and Z).
|
|
|
|
// The cell in which the ray starts.
|
|
Point3D start = GetCellAt(ray.Position); // Rounds the position's X, Y and Z down to the nearest integer values.
|
|
int x = start.X;
|
|
int y = start.Y;
|
|
int z = start.Z;
|
|
|
|
// Determine which way we go.
|
|
int stepX = Math.Sign(ray.Direction.X);
|
|
int stepY = Math.Sign(ray.Direction.Y);
|
|
int stepZ = Math.Sign(ray.Direction.Z);
|
|
|
|
// Calculate cell boundaries. When the step (i.e. direction sign) is positive,
|
|
// the next boundary is AFTER our current position, meaning that we have to add 1.
|
|
// Otherwise, it is BEFORE our current position, in which case we add nothing.
|
|
Point3D cellBoundary = new Point3D(
|
|
x + (stepX > 0 ? 1 : 0),
|
|
y + (stepY > 0 ? 1 : 0),
|
|
z + (stepZ > 0 ? 1 : 0));
|
|
|
|
// NOTE: For the following calculations, the result will be Single.PositiveInfinity
|
|
// when ray.Direction.X, Y or Z equals zero, which is OK. However, when the left-hand
|
|
// value of the division also equals zero, the result is Single.NaN, which is not OK.
|
|
|
|
// Determine how far we can travel along the ray before we hit a voxel boundary.
|
|
Vector3 tMax = new Vector3(
|
|
(cellBoundary.X - ray.Position.X) / ray.Direction.X, // Boundary is a plane on the YZ axis.
|
|
(cellBoundary.Y - ray.Position.Y) / ray.Direction.Y, // Boundary is a plane on the XZ axis.
|
|
(cellBoundary.Z - ray.Position.Z) / ray.Direction.Z); // Boundary is a plane on the XY axis.
|
|
if (Single.IsNaN(tMax.X)) tMax.X = Single.PositiveInfinity;
|
|
if (Single.IsNaN(tMax.Y)) tMax.Y = Single.PositiveInfinity;
|
|
if (Single.IsNaN(tMax.Z)) tMax.Z = Single.PositiveInfinity;
|
|
|
|
// Determine how far we must travel along the ray before we have crossed a gridcell.
|
|
Vector3 tDelta = new Vector3(
|
|
stepX / ray.Direction.X, // Crossing the width of a cell.
|
|
stepY / ray.Direction.Y, // Crossing the height of a cell.
|
|
stepZ / ray.Direction.Z); // Crossing the depth of a cell.
|
|
if (Single.IsNaN(tDelta.X)) tDelta.X = Single.PositiveInfinity;
|
|
if (Single.IsNaN(tDelta.Y)) tDelta.Y = Single.PositiveInfinity;
|
|
if (Single.IsNaN(tDelta.Z)) tDelta.Z = Single.PositiveInfinity;
|
|
|
|
// For each step, determine which distance to the next voxel boundary is lowest (i.e.
|
|
// which voxel boundary is nearest) and walk that way.
|
|
for (int i = 0; i < maxDepth; i++)
|
|
{
|
|
// Return it.
|
|
yield return new Point3D(x, y, z);
|
|
|
|
// Do the next step.
|
|
if (tMax.X < tMax.Y && tMax.X < tMax.Z)
|
|
{
|
|
// tMax.X is the lowest, an YZ cell boundary plane is nearest.
|
|
x += stepX;
|
|
tMax.X += tDelta.X;
|
|
}
|
|
else if (tMax.Y < tMax.Z)
|
|
{
|
|
// tMax.Y is the lowest, an XZ cell boundary plane is nearest.
|
|
y += stepY;
|
|
tMax.Y += tDelta.Y;
|
|
}
|
|
else
|
|
{
|
|
// tMax.Z is the lowest, an XY cell boundary plane is nearest.
|
|
z += stepZ;
|
|
tMax.Z += tDelta.Z;
|
|
}
|
|
}
|
|
|
|
*/
|