Kinematic bodies

include/box2d/box2d.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include "box2d/api.h"
+#include "box2d/geometry.h"
 #include "box2d/id.h"
 #include "box2d/joint_types.h"
 #include "box2d/timer.h"
@@ -41,16 +42,51 @@ BOX2D_API void b2World_DestroyBody(b2BodyId bodyId);
 
 BOX2D_API b2Vec2 b2Body_GetPosition(b2BodyId bodyId);
 BOX2D_API float b2Body_GetAngle(b2BodyId bodyId);
+BOX2D_API void b2Body_SetTransform(b2BodyId bodyId, b2Vec2 position, float angle);
+
 BOX2D_API b2Vec2 b2Body_GetLocalPoint(b2BodyId bodyId, b2Vec2 globalPoint);
+BOX2D_API b2Vec2 b2Body_GetWorldPoint(b2BodyId bodyId, b2Vec2 localPoint);
 
-BOX2D_API void b2Body_SetTransform(b2BodyId bodyId, b2Vec2 position, float angle);
+BOX2D_API b2Vec2 b2Body_GetLinearVelocity(b2BodyId bodyId);
+BOX2D_API float  b2Body_GetAngularVelocity(b2BodyId bodyId);
 BOX2D_API void b2Body_SetLinearVelocity(b2BodyId bodyId, b2Vec2 linearVelocity);
 BOX2D_API void b2Body_SetAngularVelocity(b2BodyId bodyId, float angularVelocity);
 
 BOX2D_API b2BodyType b2Body_GetType(b2BodyId bodyId);
+BOX2D_API void b2Body_SetType(b2BodyId bodyId, b2BodyType type);
+
+/// Get the mass of the body (kilograms)
 BOX2D_API float b2Body_GetMass(b2BodyId bodyId);
+
+/// Get the inertia tensor of the body. In 2D this is a single number. (kilograms * meters^2)
+BOX2D_API float b2Body_GetInertiaTensor(b2BodyId bodyId);
+
+/// Get the center of mass position of the body in local space.
+BOX2D_API b2Vec2 b2Body_GetLocalCenterOfMass(b2BodyId bodyId);
+
+/// Get the center of mass position of the body in world space.
+BOX2D_API b2Vec2 b2Body_GetWorldCenterOfMass(b2BodyId bodyId);
+
+/// Override the body's mass properties. Normally this is computed automatically using the
+///	shape geometry and density. This information is lost if a shape is added or removed or if the
+///	body type changes.
+BOX2D_API void b2Body_SetMassData(b2MassData massData);
+
+/// Is this body awake?
+BOX2D_API void b2Body_IsAwake(b2BodyId bodyId);
+
+/// Wake a body from sleep. This wakes the entire island the body is touching.
 BOX2D_API void b2Body_Wake(b2BodyId bodyId);
 
+/// Is this body enabled?
+BOX2D_API bool b2Body_IsEnabled(b2BodyId bodyId);
+
+/// Disable a body by removing it completely from the simulation
+BOX2D_API void b2Body_Disable(b2BodyId bodyId);
+
+/// Enable a body by adding it to the simulation
+BOX2D_API void b2Body_Enable(b2BodyId bodyId);
+
 /// Create a shape and attach it to a body. Contacts are not created until the next time step.
 /// @warning This function is locked during callbacks.
 BOX2D_API b2ShapeId b2Body_CreateCircle(b2BodyId bodyId, const b2ShapeDef* def, const b2Circle* circle);
@@ -62,6 +98,7 @@ BOX2D_API b2BodyId b2Shape_GetBody(b2ShapeId shapeId);
 BOX2D_API bool b2Shape_TestPoint(b2ShapeId shapeId, b2Vec2 point);
 
 BOX2D_API b2JointId b2World_CreateMouseJoint(b2WorldId worldId, const b2MouseJointDef* def);
+BOX2D_API b2JointId b2World_CreatePrismaticJoint(b2WorldId worldId, const b2PrismaticJointDef* def);
 BOX2D_API b2JointId b2World_CreateRevoluteJoint(b2WorldId worldId, const b2RevoluteJointDef* def);
 BOX2D_API b2JointId b2World_CreateWeldJoint(b2WorldId worldId, const b2WeldJointDef* def);
 BOX2D_API void b2World_DestroyJoint(b2JointId jointId);
@@ -78,7 +115,7 @@ BOX2D_API float b2RevoluteJoint_GetMotorTorque(b2JointId jointId, float inverseT
 BOX2D_API void b2RevoluteJoint_SetMaxMotorTorque(b2JointId jointId, float torque);
 BOX2D_API b2Vec2 b2RevoluteJoint_GetConstraintForce(b2JointId jointId);
 
-	/// This function receives shapes found in the AABB query.
+/// This function receives shapes found in the AABB query.
 /// @return true if the query should continue
 typedef bool b2QueryCallbackFcn(b2ShapeId shapeId, void* context);
 
@@ -87,7 +124,6 @@ typedef bool b2QueryCallbackFcn(b2ShapeId shapeId, void* context);
 /// @param aabb the query box.
 BOX2D_API void b2World_QueryAABB(b2WorldId worldId, b2AABB aabb, b2QueryCallbackFcn* fcn, void* context);
 
-
 /// Advanced API for testing and special cases
 
 /// Enable/disable sleep.

include/box2d/geometry.h

@@ -23,6 +23,8 @@ typedef struct b2MassData
 	/// The rotational inertia of the shape about the local origin.
 	float I;
 
+	/// TODO_ERIN remove geometry info from this
+
 	/// Distance from shape centroid to closest point on perimeter.
 	float minExtent;
 

include/box2d/joint_types.h

@@ -35,7 +35,7 @@ typedef struct b2MouseJointDef
 	float damping;
 } b2MouseJointDef;
 
-static inline struct b2MouseJointDef b2DefaultMouseJointDef(void)
+static inline b2MouseJointDef b2DefaultMouseJointDef(void)
 {
 	b2MouseJointDef def = {0};
 	def.bodyIdA = b2_nullBodyId;
@@ -47,6 +47,73 @@ static inline struct b2MouseJointDef b2DefaultMouseJointDef(void)
 	return def;
 }
 
+/// Prismatic joint definition. This requires defining a line of
+/// motion using an axis and an anchor point. The definition uses local
+/// anchor points and a local axis so that the initial configuration
+/// can violate the constraint slightly. The joint translation is zero
+/// when the local anchor points coincide in world space.
+typedef struct b2PrismaticJointDef
+{
+	/// The first attached body.
+	b2BodyId bodyIdA;
+
+	/// The second attached body.
+	b2BodyId bodyIdB;
+
+	/// The local anchor point relative to bodyA's origin.
+	b2Vec2 localAnchorA;
+
+	/// The local anchor point relative to bodyB's origin.
+	b2Vec2 localAnchorB;
+
+	/// The local translation unit axis in bodyA.
+	b2Vec2 localAxisA;
+
+	/// The constrained angle between the bodies: bodyB_angle - bodyA_angle.
+	float referenceAngle;
+
+	/// Enable/disable the joint limit.
+	bool enableLimit;
+
+	/// The lower translation limit, usually in meters.
+	float lowerTranslation;
+
+	/// The upper translation limit, usually in meters.
+	float upperTranslation;
+
+	/// Enable/disable the joint motor.
+	bool enableMotor;
+
+	/// The maximum motor torque, usually in N-m.
+	float maxMotorForce;
+
+	/// The desired motor speed in radians per second.
+	float motorSpeed;
+
+	/// Set this flag to true if the attached bodies should collide.
+	bool collideConnected;
+} b2PrismaticJointDef;
+
+/// Use this to initialize your joint definition
+static inline b2PrismaticJointDef b2DefaultPrismaticJointDef(void)
+{
+	b2PrismaticJointDef def = {0};
+	def.bodyIdA = b2_nullBodyId;
+	def.bodyIdB = b2_nullBodyId;
+	def.localAnchorA = B2_LITERAL(b2Vec2){0.0f, 0.0f};
+	def.localAnchorB = B2_LITERAL(b2Vec2){0.0f, 0.0f};
+	def.localAxisA = B2_LITERAL(b2Vec2){1.0f, 0.0f};
+	def.referenceAngle = 0.0f;
+	def.enableLimit = false;
+	def.lowerTranslation = 0.0f;
+	def.upperTranslation = 0.0f;
+	def.enableMotor = false;
+	def.maxMotorForce = 0.0f;
+	def.motorSpeed = 0.0f;
+	def.collideConnected = false;
+	return def;
+}
+
 /// Revolute joint definition. This requires defining an anchor point where the
 /// bodies are joined. The definition uses local anchor points so that the
 /// initial configuration can violate the constraint slightly. You also need to
@@ -98,7 +165,8 @@ typedef struct b2RevoluteJointDef
 	bool collideConnected;
 } b2RevoluteJointDef;
 
-static inline struct b2RevoluteJointDef b2DefaultRevoluteJointDef(void)
+/// Use this to initialize your joint definition
+static inline b2RevoluteJointDef b2DefaultRevoluteJointDef(void)
 {
 	b2RevoluteJointDef def = {0};
 	def.bodyIdA = b2_nullBodyId;
@@ -146,7 +214,8 @@ typedef struct b2WeldJointDef
 	bool collideConnected;
 } b2WeldJointDef;
 
-static inline struct b2WeldJointDef b2DefaultWeldJointDef(void)
+/// Use this to initialize your joint definition
+static inline b2WeldJointDef b2DefaultWeldJointDef(void)
 {
 	b2WeldJointDef def = {0};
 	def.bodyIdA = b2_nullBodyId;

include/box2d/math.h

@@ -72,7 +72,13 @@ static inline b2Vec2 b2CrossSV(float s, b2Vec2 v)
 	return B2_LITERAL(b2Vec2){-s * v.y, s * v.x};
 }
 
-/// Get a right pointing perpendicular vector. Equivalent to b2CrossVS(v, 1.0f).
+/// Get a left pointing perpendicular vector. Equivalent to b2CrossSV(1.0f, v)
+static inline b2Vec2 b2LeftPerp(b2Vec2 v)
+{
+	return B2_LITERAL(b2Vec2){-v.y, v.x};
+}
+
+/// Get a right pointing perpendicular vector. Equivalent to b2CrossVS(v, 1.0f)
 static inline b2Vec2 b2RightPerp(b2Vec2 v)
 {
 	return B2_LITERAL(b2Vec2){v.y, -v.x};

samples/CMakeLists.txt

@@ -69,8 +69,9 @@ set(BOX2D_SAMPLES
 	collection/benchmark_many_tumblers.cpp
 	collection/benchmark_pyramid.cpp
 	collection/benchmark_tumbler.cpp
-	collection/behavior.cpp
-	collection/sample_continuous1.cpp
+	collection/sample_robustness.cpp
+	collection/sample_bodies.cpp
+	collection/sample_continuous.cpp
 	collection/sample_distance.cpp
 	collection/sample_dynamic_tree.cpp
 	collection/sample_hull.cpp