prosperon/source/engine/thirdparty/Chipmunk2D/src/cpSpaceComponent.c
2022-01-25 15:22:03 +00:00

350 lines
12 KiB
C
Executable file

/* Copyright (c) 2007 Scott Lembcke
*
* 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 <string.h>
#include "chipmunk/chipmunk_private.h"
//MARK: Sleeping Functions
void
cpSpaceActivateBody(cpSpace *space, cpBody *body)
{
cpAssertHard(cpBodyGetType(body) == CP_BODY_TYPE_DYNAMIC, "Internal error: Attempting to activate a non-dynamic body.");
if(space->locked){
// cpSpaceActivateBody() is called again once the space is unlocked
if(!cpArrayContains(space->rousedBodies, body)) cpArrayPush(space->rousedBodies, body);
} else {
cpAssertSoft(body->sleeping.root == NULL && body->sleeping.next == NULL, "Internal error: Activating body non-NULL node pointers.");
cpArrayPush(space->dynamicBodies, body);
CP_BODY_FOREACH_SHAPE(body, shape){
cpSpatialIndexRemove(space->staticShapes, shape, shape->hashid);
cpSpatialIndexInsert(space->dynamicShapes, shape, shape->hashid);
}
CP_BODY_FOREACH_ARBITER(body, arb){
cpBody *bodyA = arb->body_a;
// Arbiters are shared between two bodies that are always woken up together.
// You only want to restore the arbiter once, so bodyA is arbitrarily chosen to own the arbiter.
// The edge case is when static bodies are involved as the static bodies never actually sleep.
// If the static body is bodyB then all is good. If the static body is bodyA, that can easily be checked.
if(body == bodyA || cpBodyGetType(bodyA) == CP_BODY_TYPE_STATIC){
int numContacts = arb->count;
struct cpContact *contacts = arb->contacts;
// Restore contact values back to the space's contact buffer memory
arb->contacts = cpContactBufferGetArray(space);
memcpy(arb->contacts, contacts, numContacts*sizeof(struct cpContact));
cpSpacePushContacts(space, numContacts);
// Reinsert the arbiter into the arbiter cache
const cpShape *a = arb->a, *b = arb->b;
const cpShape *shape_pair[] = {a, b};
cpHashValue arbHashID = CP_HASH_PAIR((cpHashValue)a, (cpHashValue)b);
cpHashSetInsert(space->cachedArbiters, arbHashID, shape_pair, NULL, arb);
// Update the arbiter's state
arb->stamp = space->stamp;
cpArrayPush(space->arbiters, arb);
cpfree(contacts);
}
}
CP_BODY_FOREACH_CONSTRAINT(body, constraint){
cpBody *bodyA = constraint->a;
if(body == bodyA || cpBodyGetType(bodyA) == CP_BODY_TYPE_STATIC) cpArrayPush(space->constraints, constraint);
}
}
}
static void
cpSpaceDeactivateBody(cpSpace *space, cpBody *body)
{
cpAssertHard(cpBodyGetType(body) == CP_BODY_TYPE_DYNAMIC, "Internal error: Attempting to deactivate a non-dynamic body.");
cpArrayDeleteObj(space->dynamicBodies, body);
CP_BODY_FOREACH_SHAPE(body, shape){
cpSpatialIndexRemove(space->dynamicShapes, shape, shape->hashid);
cpSpatialIndexInsert(space->staticShapes, shape, shape->hashid);
}
CP_BODY_FOREACH_ARBITER(body, arb){
cpBody *bodyA = arb->body_a;
if(body == bodyA || cpBodyGetType(bodyA) == CP_BODY_TYPE_STATIC){
cpSpaceUncacheArbiter(space, arb);
// Save contact values to a new block of memory so they won't time out
size_t bytes = arb->count*sizeof(struct cpContact);
struct cpContact *contacts = (struct cpContact *)cpcalloc(1, bytes);
memcpy(contacts, arb->contacts, bytes);
arb->contacts = contacts;
}
}
CP_BODY_FOREACH_CONSTRAINT(body, constraint){
cpBody *bodyA = constraint->a;
if(body == bodyA || cpBodyGetType(bodyA) == CP_BODY_TYPE_STATIC) cpArrayDeleteObj(space->constraints, constraint);
}
}
static inline cpBody *
ComponentRoot(cpBody *body)
{
return (body ? body->sleeping.root : NULL);
}
void
cpBodyActivate(cpBody *body)
{
if(body != NULL && cpBodyGetType(body) == CP_BODY_TYPE_DYNAMIC){
body->sleeping.idleTime = 0.0f;
cpBody *root = ComponentRoot(body);
if(root && cpBodyIsSleeping(root)){
// TODO should cpBodyIsSleeping(root) be an assertion?
cpAssertSoft(cpBodyGetType(root) == CP_BODY_TYPE_DYNAMIC, "Internal Error: Non-dynamic body component root detected.");
cpSpace *space = root->space;
cpBody *body = root;
while(body){
cpBody *next = body->sleeping.next;
body->sleeping.idleTime = 0.0f;
body->sleeping.root = NULL;
body->sleeping.next = NULL;
cpSpaceActivateBody(space, body);
body = next;
}
cpArrayDeleteObj(space->sleepingComponents, root);
}
CP_BODY_FOREACH_ARBITER(body, arb){
// Reset the idle timer of things the body is touching as well.
// That way things don't get left hanging in the air.
cpBody *other = (arb->body_a == body ? arb->body_b : arb->body_a);
if(cpBodyGetType(other) != CP_BODY_TYPE_STATIC) other->sleeping.idleTime = 0.0f;
}
}
}
void
cpBodyActivateStatic(cpBody *body, cpShape *filter)
{
cpAssertHard(cpBodyGetType(body) == CP_BODY_TYPE_STATIC, "cpBodyActivateStatic() called on a non-static body.");
CP_BODY_FOREACH_ARBITER(body, arb){
if(!filter || filter == arb->a || filter == arb->b){
cpBodyActivate(arb->body_a == body ? arb->body_b : arb->body_a);
}
}
// TODO: should also activate joints?
}
static inline void
cpBodyPushArbiter(cpBody *body, cpArbiter *arb)
{
cpAssertSoft(cpArbiterThreadForBody(arb, body)->next == NULL, "Internal Error: Dangling contact graph pointers detected. (A)");
cpAssertSoft(cpArbiterThreadForBody(arb, body)->prev == NULL, "Internal Error: Dangling contact graph pointers detected. (B)");
cpArbiter *next = body->arbiterList;
cpAssertSoft(next == NULL || cpArbiterThreadForBody(next, body)->prev == NULL, "Internal Error: Dangling contact graph pointers detected. (C)");
cpArbiterThreadForBody(arb, body)->next = next;
if(next) cpArbiterThreadForBody(next, body)->prev = arb;
body->arbiterList = arb;
}
static inline void
ComponentAdd(cpBody *root, cpBody *body){
body->sleeping.root = root;
if(body != root){
body->sleeping.next = root->sleeping.next;
root->sleeping.next = body;
}
}
static inline void
FloodFillComponent(cpBody *root, cpBody *body)
{
// Kinematic bodies cannot be put to sleep and prevent bodies they are touching from sleeping.
// Static bodies are effectively sleeping all the time.
if(cpBodyGetType(body) == CP_BODY_TYPE_DYNAMIC){
cpBody *other_root = ComponentRoot(body);
if(other_root == NULL){
ComponentAdd(root, body);
CP_BODY_FOREACH_ARBITER(body, arb) FloodFillComponent(root, (body == arb->body_a ? arb->body_b : arb->body_a));
CP_BODY_FOREACH_CONSTRAINT(body, constraint) FloodFillComponent(root, (body == constraint->a ? constraint->b : constraint->a));
} else {
cpAssertSoft(other_root == root, "Internal Error: Inconsistency dectected in the contact graph.");
}
}
}
static inline cpBool
ComponentActive(cpBody *root, cpFloat threshold)
{
CP_BODY_FOREACH_COMPONENT(root, body){
if(body->sleeping.idleTime < threshold) return cpTrue;
}
return cpFalse;
}
void
cpSpaceProcessComponents(cpSpace *space, cpFloat dt)
{
cpBool sleep = (space->sleepTimeThreshold != INFINITY);
cpArray *bodies = space->dynamicBodies;
#ifndef NDEBUG
for(int i=0; i<bodies->num; i++){
cpBody *body = (cpBody*)bodies->arr[i];
cpAssertSoft(body->sleeping.next == NULL, "Internal Error: Dangling next pointer detected in contact graph.");
cpAssertSoft(body->sleeping.root == NULL, "Internal Error: Dangling root pointer detected in contact graph.");
}
#endif
// Calculate the kinetic energy of all the bodies.
if(sleep){
cpFloat dv = space->idleSpeedThreshold;
cpFloat dvsq = (dv ? dv*dv : cpvlengthsq(space->gravity)*dt*dt);
// update idling and reset component nodes
for(int i=0; i<bodies->num; i++){
cpBody *body = (cpBody*)bodies->arr[i];
// TODO should make a separate array for kinematic bodies.
if(cpBodyGetType(body) != CP_BODY_TYPE_DYNAMIC) continue;
// Need to deal with infinite mass objects
cpFloat keThreshold = (dvsq ? body->m*dvsq : 0.0f);
body->sleeping.idleTime = (cpBodyKineticEnergy(body) > keThreshold ? 0.0f : body->sleeping.idleTime + dt);
}
}
// Awaken any sleeping bodies found and then push arbiters to the bodies' lists.
cpArray *arbiters = space->arbiters;
for(int i=0, count=arbiters->num; i<count; i++){
cpArbiter *arb = (cpArbiter*)arbiters->arr[i];
cpBody *a = arb->body_a, *b = arb->body_b;
if(sleep){
// TODO checking cpBodyIsSleepin() redundant?
if(cpBodyGetType(b) == CP_BODY_TYPE_KINEMATIC || cpBodyIsSleeping(a)) cpBodyActivate(a);
if(cpBodyGetType(a) == CP_BODY_TYPE_KINEMATIC || cpBodyIsSleeping(b)) cpBodyActivate(b);
}
cpBodyPushArbiter(a, arb);
cpBodyPushArbiter(b, arb);
}
if(sleep){
// Bodies should be held active if connected by a joint to a kinematic.
cpArray *constraints = space->constraints;
for(int i=0; i<constraints->num; i++){
cpConstraint *constraint = (cpConstraint *)constraints->arr[i];
cpBody *a = constraint->a, *b = constraint->b;
if(cpBodyGetType(b) == CP_BODY_TYPE_KINEMATIC) cpBodyActivate(a);
if(cpBodyGetType(a) == CP_BODY_TYPE_KINEMATIC) cpBodyActivate(b);
}
// Generate components and deactivate sleeping ones
for(int i=0; i<bodies->num;){
cpBody *body = (cpBody*)bodies->arr[i];
if(ComponentRoot(body) == NULL){
// Body not in a component yet. Perform a DFS to flood fill mark
// the component in the contact graph using this body as the root.
FloodFillComponent(body, body);
// Check if the component should be put to sleep.
if(!ComponentActive(body, space->sleepTimeThreshold)){
cpArrayPush(space->sleepingComponents, body);
CP_BODY_FOREACH_COMPONENT(body, other) cpSpaceDeactivateBody(space, other);
// cpSpaceDeactivateBody() removed the current body from the list.
// Skip incrementing the index counter.
continue;
}
}
i++;
// Only sleeping bodies retain their component node pointers.
body->sleeping.root = NULL;
body->sleeping.next = NULL;
}
}
}
void
cpBodySleep(cpBody *body)
{
cpBodySleepWithGroup(body, NULL);
}
void
cpBodySleepWithGroup(cpBody *body, cpBody *group){
cpAssertHard(cpBodyGetType(body) == CP_BODY_TYPE_DYNAMIC, "Non-dynamic bodies cannot be put to sleep.");
cpSpace *space = body->space;
cpAssertHard(!cpSpaceIsLocked(space), "Bodies cannot be put to sleep during a query or a call to cpSpaceStep(). Put these calls into a post-step callback.");
cpAssertHard(cpSpaceGetSleepTimeThreshold(space) < INFINITY, "Sleeping is not enabled on the space. You cannot sleep a body without setting a sleep time threshold on the space.");
cpAssertHard(group == NULL || cpBodyIsSleeping(group), "Cannot use a non-sleeping body as a group identifier.");
if(cpBodyIsSleeping(body)){
cpAssertHard(ComponentRoot(body) == ComponentRoot(group), "The body is already sleeping and it's group cannot be reassigned.");
return;
}
CP_BODY_FOREACH_SHAPE(body, shape) cpShapeCacheBB(shape);
cpSpaceDeactivateBody(space, body);
if(group){
cpBody *root = ComponentRoot(group);
body->sleeping.root = root;
body->sleeping.next = root->sleeping.next;
body->sleeping.idleTime = 0.0f;
root->sleeping.next = body;
} else {
body->sleeping.root = body;
body->sleeping.next = NULL;
body->sleeping.idleTime = 0.0f;
cpArrayPush(space->sleepingComponents, body);
}
cpArrayDeleteObj(space->dynamicBodies, body);
}