added the basic requiements for physics with box2d

TSE_Core/include/box2d/id.h

@@ -0,0 +1,157 @@
+// SPDX-FileCopyrightText: 2023 Erin Catto
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "base.h"
+
+#include <stdint.h>
+
+/**
+ * @defgroup id Ids
+ * These ids serve as handles to internal Box2D objects.
+ * These should be considered opaque data and passed by value.
+ * Include this header if you need the id types and not the whole Box2D API.
+ * All ids are considered null if initialized to zero.
+ *
+ * For example in C++:
+ *
+ * @code{.cxx}
+ * b2WorldId worldId = {};
+ * @endcode
+ *
+ * Or in C:
+ *
+ * @code{.c}
+ * b2WorldId worldId = {0};
+ * @endcode
+ *
+ * These are both considered null.
+ *
+ * @warning Do not use the internals of these ids. They are subject to change. Ids should be treated as opaque objects.
+ * @warning You should use ids to access objects in Box2D. Do not access files within the src folder. Such usage is unsupported.
+ * @{
+ */
+
+/// World id references a world instance. This should be treated as an opaque handle.
+typedef struct b2WorldId
+{
+	uint16_t index1;
+	uint16_t generation;
+} b2WorldId;
+
+/// Body id references a body instance. This should be treated as an opaque handle.
+typedef struct b2BodyId
+{
+	int32_t index1;
+	uint16_t world0;
+	uint16_t generation;
+} b2BodyId;
+
+/// Shape id references a shape instance. This should be treated as an opaque handle.
+typedef struct b2ShapeId
+{
+	int32_t index1;
+	uint16_t world0;
+	uint16_t generation;
+} b2ShapeId;
+
+/// Chain id references a chain instances. This should be treated as an opaque handle.
+typedef struct b2ChainId
+{
+	int32_t index1;
+	uint16_t world0;
+	uint16_t generation;
+} b2ChainId;
+
+/// Joint id references a joint instance. This should be treated as an opaque handle.
+typedef struct b2JointId
+{
+	int32_t index1;
+	uint16_t world0;
+	uint16_t generation;
+} b2JointId;
+
+/// Use these to make your identifiers null.
+/// You may also use zero initialization to get null.
+static const b2WorldId b2_nullWorldId = B2_ZERO_INIT;
+static const b2BodyId b2_nullBodyId = B2_ZERO_INIT;
+static const b2ShapeId b2_nullShapeId = B2_ZERO_INIT;
+static const b2ChainId b2_nullChainId = B2_ZERO_INIT;
+static const b2JointId b2_nullJointId = B2_ZERO_INIT;
+
+/// Macro to determine if any id is null.
+#define B2_IS_NULL( id ) ( id.index1 == 0 )
+
+/// Macro to determine if any id is non-null.
+#define B2_IS_NON_NULL( id ) ( id.index1 != 0 )
+
+/// Compare two ids for equality. Doesn't work for b2WorldId.
+#define B2_ID_EQUALS( id1, id2 ) ( id1.index1 == id2.index1 && id1.world0 == id2.world0 && id1.generation == id2.generation )
+
+/// Store a world id into a uint32_t.
+B2_INLINE uint32_t b2StoreWorldId( b2WorldId id )
+{
+	return ( (uint32_t)id.index1 << 16 ) | (uint32_t)id.generation;
+}
+
+/// Load a uint32_t into a world id.
+B2_INLINE b2WorldId b2LoadWorldId( uint32_t x )
+{
+	b2WorldId id = { (uint16_t)( x >> 16 ), (uint16_t)( x ) };
+	return id;
+}
+
+/// Store a body id into a uint64_t.
+B2_INLINE uint64_t b2StoreBodyId( b2BodyId id )
+{
+	return ( (uint64_t)id.index1 << 32 ) | ( (uint64_t)id.world0 ) << 16 | (uint64_t)id.generation;
+}
+
+/// Load a uint64_t into a body id.
+B2_INLINE b2BodyId b2LoadBodyId( uint64_t x )
+{
+	b2BodyId id = { (int32_t)( x >> 32 ), (uint16_t)( x >> 16 ), (uint16_t)( x ) };
+	return id;
+}
+
+/// Store a shape id into a uint64_t.
+B2_INLINE uint64_t b2StoreShapeId( b2ShapeId id )
+{
+	return ( (uint64_t)id.index1 << 32 ) | ( (uint64_t)id.world0 ) << 16 | (uint64_t)id.generation;
+}
+
+/// Load a uint64_t into a shape id.
+B2_INLINE b2ShapeId b2LoadShapeId( uint64_t x )
+{
+	b2ShapeId id = { (int32_t)( x >> 32 ), (uint16_t)( x >> 16 ), (uint16_t)( x ) };
+	return id;
+}
+
+/// Store a chain id into a uint64_t.
+B2_INLINE uint64_t b2StoreChainId( b2ChainId id )
+{
+	return ( (uint64_t)id.index1 << 32 ) | ( (uint64_t)id.world0 ) << 16 | (uint64_t)id.generation;
+}
+
+/// Load a uint64_t into a chain id.
+B2_INLINE b2ChainId b2LoadChainId( uint64_t x )
+{
+	b2ChainId id = { (int32_t)( x >> 32 ), (uint16_t)( x >> 16 ), (uint16_t)( x ) };
+	return id;
+}
+
+/// Store a joint id into a uint64_t.
+B2_INLINE uint64_t b2StoreJointId( b2JointId id )
+{
+	return ( (uint64_t)id.index1 << 32 ) | ( (uint64_t)id.world0 ) << 16 | (uint64_t)id.generation;
+}
+
+/// Load a uint64_t into a joint id.
+B2_INLINE b2JointId b2LoadJointId( uint64_t x )
+{
+	b2JointId id = { (int32_t)( x >> 32 ), (uint16_t)( x >> 16 ), (uint16_t)( x ) };
+	return id;
+}
+
+/**@}*/