Minor fixes

.gitignore

@@ -7,3 +7,4 @@ settings.ini
 .DS_Store
 CMakeUserPresets.json
 .cache/
+.idea/

CMakeLists.txt

@@ -10,6 +10,7 @@ project(box2d
 )
 
 # stuff to help debug cmake
+# message(STATUS "cmake tool chain: ${CMAKE_TOOLCHAIN_FILE}")
 # message(STATUS "cmake source dir: ${CMAKE_SOURCE_DIR}")
 # message(STATUS "library postfix: ${CMAKE_DEBUG_POSTFIX}")
 message(STATUS "CMake C compiler: ${CMAKE_C_COMPILER_ID}")
@@ -66,7 +67,7 @@ endif()
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_COMPILE_WARNING_AS_ERROR ON)
 
-# set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 set(CMAKE_VERBOSE_MAKEFILE ON)
 

docs/collision.md

@@ -54,7 +54,7 @@ semicircles that are connected by a rectangle.
 ```c
 b2Capsule capsule;
 capsule.center1 = (b2Vec2){1.0f, 1.0f};
-capsule.center1 = (b2Vec2){2.0f, 3.0f};
+capsule.center2 = (b2Vec2){2.0f, 3.0f};
 capsule.radius = 0.25f;
 ```
 

include/box2d/base.h

@@ -115,7 +115,7 @@ typedef struct b2Timer
 {
 #if defined( _WIN32 )
 	int64_t start;
-#elif defined( __linux__ ) || defined( __APPLE__ )
+#elif defined( __linux__ ) || defined( __APPLE__ ) || defined( __EMSCRIPTEN__ )
 	unsigned long long start_sec;
 	unsigned long long start_usec;
 #else

include/box2d/box2d.h

@@ -542,15 +542,17 @@ B2_API b2Filter b2Shape_GetFilter( b2ShapeId shapeId );
 /// @see b2ShapeDef::filter
 B2_API void b2Shape_SetFilter( b2ShapeId shapeId, b2Filter filter );
 
-/// Enable sensor events for this shape. Only applies to kinematic and dynamic bodies. Ignored for sensors.
+/// Enable sensor events for this shape. Only applies to kinematic and dynamic bodies.
 /// @see b2ShapeDef::isSensor
+/// @warning changing this at run-time may lead to lost begin/end events
 B2_API void b2Shape_EnableSensorEvents( b2ShapeId shapeId, bool flag );
 
 /// Returns true if sensor events are enabled
 B2_API bool b2Shape_AreSensorEventsEnabled( b2ShapeId shapeId );
 
 /// Enable contact events for this shape. Only applies to kinematic and dynamic bodies. Ignored for sensors.
 /// @see b2ShapeDef::enableContactEvents
+/// @warning changing this at run-time may lead to lost begin/end events
 B2_API void b2Shape_EnableContactEvents( b2ShapeId shapeId, bool flag );
 
 /// Returns true if contact events are enabled

include/box2d/collision.h

@@ -8,13 +8,7 @@
 
 #include <stdbool.h>
 
-typedef struct b2Circle b2Circle;
-typedef struct b2Capsule b2Capsule;
 typedef struct b2DistanceCache b2DistanceCache;
-typedef struct b2Polygon b2Polygon;
-typedef struct b2Segment b2Segment;
-typedef struct b2ChainSegment b2ChainSegment;
-
 typedef struct b2Hull b2Hull;
 
 /**

include/box2d/math_functions.h

@@ -24,7 +24,7 @@ typedef struct b2Vec2
 } b2Vec2;
 
 /// Cosine and sine pair
-/// This uses a custom implementation designed for cross platform determinism
+/// This uses a custom implementation designed for cross-platform determinism
 typedef struct b2CosSin
 {
 	/// cosine and sine
@@ -69,67 +69,71 @@ typedef struct b2AABB
  */
 
 /// https://en.wikipedia.org/wiki/Pi
-#define b2_pi 3.14159265359f
+#define B2_PI 3.14159265359f
 
 static const b2Vec2 b2Vec2_zero = { 0.0f, 0.0f };
 static const b2Rot b2Rot_identity = { 1.0f, 0.0f };
 static const b2Transform b2Transform_identity = { { 0.0f, 0.0f }, { 1.0f, 0.0f } };
 static const b2Mat22 b2Mat22_zero = { { 0.0f, 0.0f }, { 0.0f, 0.0f } };
 
-/// Compute an approximate arctangent in the range [-pi, pi]
-/// This is hand coded for cross platform determinism. The atan2f
-/// function in the standard library is not cross platform deterministic.
-///	Accurate to around 0.0023 degrees
-B2_API float b2Atan2( float y, float x );
-
-/// @return the minimum of two floats
-B2_INLINE float b2MinFloat( float a, float b )
+/// @return the minimum of two integers
+B2_INLINE int b2MinInt( int a, int b )
 {
 	return a < b ? a : b;
 }
 
-/// @return the maximum of two floats
-B2_INLINE float b2MaxFloat( float a, float b )
+/// @return the maximum of two integers
+B2_INLINE int b2MaxInt( int a, int b )
 {
 	return a > b ? a : b;
 }
 
-/// @return the absolute value of a float
-B2_INLINE float b2AbsFloat( float a )
+/// @return the absolute value of an integer
+B2_INLINE int b2AbsInt( int a )
 {
 	return a < 0 ? -a : a;
 }
 
-/// @return a float clamped between a lower and upper bound
-B2_INLINE float b2ClampFloat( float a, float lower, float upper )
+/// @return an integer clamped between a lower and upper bound
+B2_INLINE int b2ClampInt( int a, int lower, int upper )
 {
 	return a < lower ? lower : ( a > upper ? upper : a );
 }
 
-/// @return the minimum of two integers
-B2_INLINE int b2MinInt( int a, int b )
+/// @return the minimum of two floats
+B2_INLINE float b2MinFloat( float a, float b )
 {
 	return a < b ? a : b;
 }
 
-/// @return the maximum of two integers
-B2_INLINE int b2MaxInt( int a, int b )
+/// @return the maximum of two floats
+B2_INLINE float b2MaxFloat( float a, float b )
 {
 	return a > b ? a : b;
 }
 
-/// @return the absolute value of an integer
-B2_INLINE int b2AbsInt( int a )
+/// @return the absolute value of a float
+B2_INLINE float b2AbsFloat( float a )
 {
 	return a < 0 ? -a : a;
 }
 
-/// @return an integer clamped between a lower and upper bound
-B2_INLINE int b2ClampInt( int a, int lower, int upper )
+/// @return a float clamped between a lower and upper bound
+B2_INLINE float b2ClampFloat( float a, float lower, float upper )
 {
 	return a < lower ? lower : ( a > upper ? upper : a );
 }
 
+/// Compute an approximate arctangent in the range [-pi, pi]
+/// This is hand coded for cross-platform determinism. The atan2f
+/// function in the standard library is not cross-platform deterministic.
+///	Accurate to around 0.0023 degrees
+B2_API float b2Atan2( float y, float x );
+
+/// Compute the cosine and sine of an angle in radians. Implemented
+/// for cross-platform determinism.
+B2_API b2CosSin b2ComputeCosSin( float radians );
+
 /// Vector dot product
 B2_INLINE float b2Dot( b2Vec2 a, b2Vec2 b )
 {
@@ -191,11 +195,11 @@ B2_INLINE b2Vec2 b2Lerp( b2Vec2 a, b2Vec2 b, float t )
 	return B2_LITERAL( b2Vec2 ){ ( 1.0f - t ) * a.x + t * b.x, ( 1.0f - t ) * a.y + t * b.y };
 }
 
-///// Component-wise multiplication
-//B2_INLINE b2Vec2 b2Mul( b2Vec2 a, b2Vec2 b )
-//{
-//	return B2_LITERAL( b2Vec2 ){ a.x * b.x, a.y * b.y };
-//}
+/// Component-wise multiplication
+B2_INLINE b2Vec2 b2Mul( b2Vec2 a, b2Vec2 b )
+{
+	return B2_LITERAL( b2Vec2 ){ a.x * b.x, a.y * b.y };
+}
 
 /// Multiply a scalar and vector
 B2_INLINE b2Vec2 b2MulSV( float s, b2Vec2 v )
@@ -333,12 +337,9 @@ B2_INLINE float b2DistanceSquared( b2Vec2 a, b2Vec2 b )
 }
 
 /// Make a rotation using an angle in radians
-B2_API b2CosSin b2ComputeCosSin( float angle );
-
-/// Make a rotation using an angle in radians
-B2_INLINE b2Rot b2MakeRot( float angle )
+B2_INLINE b2Rot b2MakeRot( float radians )
 {
-	b2CosSin cs = b2ComputeCosSin( angle );
+	b2CosSin cs = b2ComputeCosSin( radians );
 	return B2_LITERAL( b2Rot ){ cs.cosine, cs.sine };
 }
 
@@ -444,34 +445,34 @@ B2_INLINE float b2RelativeAngle( b2Rot b, b2Rot a )
 }
 
 /// Convert an angle in the range [-2*pi, 2*pi] into the range [-pi, pi]
-B2_INLINE float b2UnwindAngle( float angle )
+B2_INLINE float b2UnwindAngle( float radians )
 {
-	if ( angle < -b2_pi )
+	if ( radians < -B2_PI )
 	{
-		return angle + 2.0f * b2_pi;
+		return radians + 2.0f * B2_PI;
 	}
-	else if ( angle > b2_pi )
+	else if ( radians > B2_PI )
 	{
-		return angle - 2.0f * b2_pi;
+		return radians - 2.0f * B2_PI;
 	}
 
-	return angle;
+	return radians;
 }
 
 /// Convert any into the range [-pi, pi] (slow)
-B2_INLINE float b2UnwindLargeAngle( float angle )
+B2_INLINE float b2UnwindLargeAngle( float radians )
 {
-	while ( angle > b2_pi )
+	while ( radians > B2_PI )
 	{
-		angle -= 2.0f * b2_pi;
+		radians -= 2.0f * B2_PI;
 	}
 
-	while ( angle < -b2_pi )
+	while ( radians < -B2_PI )
 	{
-		angle += 2.0f * b2_pi;
+		radians += 2.0f * B2_PI;
 	}
 
-	return angle;
+	return radians;
 }
 
 /// Rotate a vector
@@ -619,6 +620,16 @@ B2_API bool b2IsValidAABB( b2AABB aabb );
 /// Box2D bases all length units on meters, but you may need different units for your game.
 /// You can set this value to use different units. This should be done at application startup
 /// and only modified once. Default value is 1.
+/// For example, if your game uses pixels for units you can use pixels for all length values
+/// sent to Box2D. There should be no extra cost. However, Box2D has some internal tolerances
+/// and thresholds that have been tuned for meters. By calling this function, Box2D is able
+/// to adjust those tolerances and thresholds to improve accuracy.
+/// A good rule of thumb is to pass the height of your player character to this function. So
+/// if your player character is 32 pixels high, then pass 32 to this function. Then you may
+/// confidently use pixels for all the length values sent to Box2D. All length values returned
+/// from Box2D will also be pixels because Box2D does not do any scaling internally.
+/// However, you are now on the hook for coming up with good values for gravity, density, and
+/// forces.
 /// @warning This must be modified before any calls to Box2D
 B2_API void b2SetLengthUnitsPerMeter( float lengthUnits );