boxdd-sys 0.6.0

Low-level FFI bindings for Box2D built from upstream via submodule
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80

// SPDX-FileCopyrightText: 2023 Erin Catto
// SPDX-License-Identifier: MIT

#pragma once

#include "bitset.h"
#include "container.h"
#include "table.h"

#include "box2d/collision.h"
#include "box2d/types.h"

typedef struct b2Shape b2Shape;
typedef struct b2MovePair b2MovePair;
typedef struct b2MoveResult b2MoveResult;
typedef struct b2Stack b2Stack;
typedef struct b2World b2World;

// Store the proxy type in the lower 2 bits of the proxy key. This leaves 30 bits for the id.
#define B2_PROXY_TYPE( KEY ) ( (b2BodyType)( ( KEY ) & 3 ) )
#define B2_PROXY_ID( KEY ) ( ( KEY ) >> 2 )
#define B2_PROXY_KEY( ID, TYPE ) ( ( ( ID ) << 2 ) | ( TYPE ) )

/// The broad-phase is used for computing pairs and performing volume queries and ray casts.
/// This broad-phase does not persist pairs. Instead, this reports potentially new pairs.
/// It is up to the client to consume the new pairs and to track subsequent overlap.
typedef struct b2BroadPhase
{
	b2DynamicTree trees[b2_bodyTypeCount];

	// Per body-type bit sets indexed by proxyId, marking proxies moved this step.
	// Paired with moveArray which preserves deterministic insertion order for pair queries.
	b2BitSet movedProxies[b2_bodyTypeCount];
	b2Array( int ) moveArray;

	// These are the results from the pair query and are used to create new contacts
	// in deterministic order. There is a move result linked list for each moving shape and
	// these follow the dynamic tree query order for determinism.
	b2MoveResult* moveResults;
	b2MovePair* movePairs;
	int movePairCapacity;
	b2AtomicInt movePairIndex;

	// Tracks shape pairs that have a b2Contact
	b2HashSet pairSet;

} b2BroadPhase;

void b2CreateBroadPhase( b2BroadPhase* bp, const b2Capacity* capacity );
void b2DestroyBroadPhase( b2BroadPhase* bp );

int b2BroadPhase_CreateProxy( b2BroadPhase* bp, b2BodyType proxyType, b2AABB aabb, uint64_t categoryBits, int shapeIndex,
							  bool forcePairCreation );
void b2BroadPhase_DestroyProxy( b2BroadPhase* bp, int proxyKey );

void b2BroadPhase_MoveProxy( b2BroadPhase* bp, int proxyKey, b2AABB aabb );
void b2BroadPhase_EnlargeProxy( b2BroadPhase* bp, int proxyKey, b2AABB aabb );

int b2BroadPhase_GetShapeIndex( b2BroadPhase* bp, int proxyKey );

void b2UpdateBroadPhasePairs( b2World* world );
bool b2BroadPhase_TestOverlap( const b2BroadPhase* bp, int proxyKeyA, int proxyKeyB );

void b2ValidateBroadphase( const b2BroadPhase* bp );
void b2ValidateNoEnlarged( const b2BroadPhase* bp );
void b2ValidateMovedProxies( const b2BroadPhase* bp );

// This is what triggers new contact pairs to be created
// Warning: this must be called in deterministic order
static inline void b2BufferMove( b2BroadPhase* bp, int queryProxy )
{
	b2BodyType proxyType = B2_PROXY_TYPE( queryProxy );
	int proxyId = B2_PROXY_ID( queryProxy );
	b2BitSet* set = &bp->movedProxies[proxyType];
	if ( b2GetBit( set, proxyId ) == false )
	{
		b2SetBitGrow( set, proxyId );
		b2Array_Push( bp->moveArray, queryProxy );
	}
}