# 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.
#

const Lib = "libchipmunk.so.6.1.1"

when defined(MoreNim):
  {.hint: "MoreNim defined; some Chipmunk functions replaced in Nim".}
{.deadCodeElim: on.}
from math import sqrt, sin, cos, arctan2
when defined(CpUseFloat):
  {.hint: "CpUseFloat defined; using float32 as float".}
  type CpFloat* = cfloat
else:
  type CpFloat* = cdouble
const
  CP_BUFFER_BYTES* = (32 * 1024)
  CP_MAX_CONTACTS_PER_ARBITER* = 4
  CpInfinity*: CpFloat = 1.0/0
{.pragma: pf, pure, final.}
type
  Bool32* = cint  #replace one day with cint-compatible bool
  CpDataPointer* = pointer
  TVector* {.final, pure.} = object
    x*, y*: CpFloat
  TTimestamp* = cuint
  TBodyVelocityFunc* = proc(body: PBody, gravity: TVector,
                            damping: CpFloat; dt: CpFloat){.cdecl.}
  TBodyPositionFunc* = proc(body: PBody; dt: CpFloat){.cdecl.}
  TComponentNode*{.pf.} = object
    root*: PBody
    next*: PBody
    idleTime*: CpFloat

  THashValue = cuint  # uintptr_t
  TCollisionType* = cuint #uintptr_t
  TGroup * = cuint #uintptr_t
  TLayers* = cuint
  PArray = ptr TArray
  TArray{.pure,final.} = object
  PHashSet = ptr THashSet
  THashSet{.pf.} = object
  PContact* = ptr TContact
  TContact*{.pure,final.} = object
  PArbiter* = ptr TArbiter
  TArbiter*{.pf.} = object
    e*: CpFloat
    u*: CpFloat
    surface_vr*: TVector
    a*: PShape
    b*: PShape
    body_a*: PBody
    body_b*: PBody
    thread_a*: TArbiterThread
    thread_b*: TArbiterThread
    numContacts*: cint
    contacts*: PContact
    stamp*: TTimestamp
    handler*: PCollisionHandler
    swappedColl*: Bool32
    state*: TArbiterState
  PCollisionHandler* = ptr TCollisionHandler
  TCollisionHandler*{.pf.} = object
    a*: TCollisionType
    b*: TCollisionType
    begin*: TCollisionBeginFunc
    preSolve*: TCollisionPreSolveFunc
    postSolve*: TCollisionPostSolveFunc
    separate*: TCollisionSeparateFunc
    data*: pointer
  TArbiterState*{.size: sizeof(cint).} = enum
    ArbiterStateFirstColl,    # Arbiter is active and its not the first collision.
    ArbiterStateNormal,       # Collision has been explicitly ignored.
                              # Either by returning false from a begin collision handler or calling cpArbiterIgnore().
    ArbiterStateIgnore,       # Collison is no longer active. A space will cache an arbiter for up to cpSpace.collisionPersistence more steps.
    ArbiterStateCached
  TArbiterThread*{.pf.} = object
    next*: PArbiter        # Links to next and previous arbiters in the contact graph.
    prev*: PArbiter

  TContactPoint*{.pf.} = object
    point*: TVector    #/ The position of the contact point.
    normal*: TVector   #/ The normal of the contact point.
    dist*: CpFloat     #/ The depth of the contact point.
  #/ A struct that wraps up the important collision data for an arbiter.
  PContactPointSet* = ptr TContactPointSet
  TContactPointSet*{.pf.} = object
    count*: cint              #/ The number of contact points in the set.
    points*: array[0..CP_MAX_CONTACTS_PER_ARBITER - 1, TContactPoint] #/ The array of contact points.

  #/ Collision begin event function callback type.
  #/ Returning false from a begin callback causes the collision to be ignored until
  #/ the the separate callback is called when the objects stop colliding.
  TCollisionBeginFunc* = proc (arb: PArbiter; space: PSpace; data: pointer): bool{.
      cdecl.}
  #/ Collision pre-solve event function callback type.
  #/ Returning false from a pre-step callback causes the collision to be ignored until the next step.
  TCollisionPreSolveFunc* = proc (arb: PArbiter; space: PSpace;
                                  data: pointer): bool {.cdecl.}
  #/ Collision post-solve event function callback type.
  TCollisionPostSolveFunc* = proc (arb: PArbiter; space: PSpace;
                                   data: pointer){.cdecl.}
  #/ Collision separate event function callback type.
  TCollisionSeparateFunc* = proc (arb: PArbiter; space: PSpace;
                                  data: pointer){.cdecl.}

  #/ Chipmunk's axis-aligned 2D bounding box type. (left, bottom, right, top)
  PBB* = ptr TBB
  TBB* {.pf.} = object
    l*, b*, r*, t*: CpFloat

  #/ Spatial index bounding box callback function type.
  #/ The spatial index calls this function and passes you a pointer to an object you added
  #/ when it needs to get the bounding box associated with that object.
  TSpatialIndexBBFunc* = proc (obj: pointer): TBB{.cdecl.}
  #/ Spatial index/object iterator callback function type.
  TSpatialIndexIteratorFunc* = proc (obj: pointer; data: pointer){.cdecl.}
  #/ Spatial query callback function type.
  TSpatialIndexQueryFunc* = proc (obj1: pointer; obj2: pointer; data: pointer){.
      cdecl.}
  #/ Spatial segment query callback function type.
  TSpatialIndexSegmentQueryFunc* = proc (obj1: pointer; obj2: pointer;
      data: pointer): CpFloat {.cdecl.}
  #/ private
  PSpatialIndex = ptr TSpatialIndex
  TSpatialIndex{.pf.} = object
    klass: PSpatialIndexClass
    bbfun: TSpatialIndexBBFunc
    staticIndex: PSpatialIndex
    dynamicIndex: PSpatialIndex

  TSpatialIndexDestroyImpl* = proc (index: PSpatialIndex){.cdecl.}
  TSpatialIndexCountImpl* = proc (index: PSpatialIndex): cint{.cdecl.}
  TSpatialIndexEachImpl* = proc (index: PSpatialIndex;
                                 fun: TSpatialIndexIteratorFunc; data: pointer){.
      cdecl.}
  TSpatialIndexContainsImpl* = proc (index: PSpatialIndex; obj: pointer;
                                     hashid: THashValue): Bool32 {.cdecl.}
  TSpatialIndexInsertImpl* = proc (index: PSpatialIndex; obj: pointer;
                                   hashid: THashValue){.cdecl.}
  TSpatialIndexRemoveImpl* = proc (index: PSpatialIndex; obj: pointer;
                                   hashid: THashValue){.cdecl.}
  TSpatialIndexReindexImpl* = proc (index: PSpatialIndex){.cdecl.}
  TSpatialIndexReindexObjectImpl* = proc (index: PSpatialIndex;
      obj: pointer; hashid: THashValue){.cdecl.}
  TSpatialIndexReindexQueryImpl* = proc (index: PSpatialIndex;
      fun: TSpatialIndexQueryFunc; data: pointer){.cdecl.}
  TSpatialIndexPointQueryImpl* = proc (index: PSpatialIndex; point: TVector;
                                       fun: TSpatialIndexQueryFunc;
                                       data: pointer){.cdecl.}
  TSpatialIndexSegmentQueryImpl* = proc (index: PSpatialIndex; obj: pointer;
      a: TVector; b: TVector; t_exit: CpFloat; fun: TSpatialIndexSegmentQueryFunc;
      data: pointer){.cdecl.}
  TSpatialIndexQueryImpl* = proc (index: PSpatialIndex; obj: pointer;
                                  bb: TBB; fun: TSpatialIndexQueryFunc;
                                  data: pointer){.cdecl.}
  PSpatialIndexClass* = ptr TSpatialIndexClass
  TSpatialIndexClass*{.pf.} = object
    destroy*: TSpatialIndexDestroyImpl
    count*: TSpatialIndexCountImpl
    each*: TSpatialIndexEachImpl
    contains*: TSpatialIndexContainsImpl
    insert*: TSpatialIndexInsertImpl
    remove*: TSpatialIndexRemoveImpl
    reindex*: TSpatialIndexReindexImpl
    reindexObject*: TSpatialIndexReindexObjectImpl
    reindexQuery*: TSpatialIndexReindexQueryImpl
    pointQuery*: TSpatialIndexPointQueryImpl
    segmentQuery*: TSpatialIndexSegmentQueryImpl
    query*: TSpatialIndexQueryImpl

  PSpaceHash* = ptr TSpaceHash
  TSpaceHash* {.pf.} = object
  PBBTree* = ptr TBBTree
  TBBTree* {.pf.} = object
  PSweep1D* = ptr TSweep1D
  TSweep1D* {.pf.} = object

  #/ Bounding box tree velocity callback function.
  #/ This function should return an estimate for the object's velocity.
  TBBTreeVelocityFunc* = proc (obj: pointer): TVector {.cdecl.}

  PContactBufferHeader* = ptr TContentBufferHeader
  TContentBufferHeader* {.pf.} = object
  TSpaceArbiterApplyImpulseFunc* = proc (arb: PArbiter){.cdecl.}

  PSpace* = ptr TSpace
  TSpace* {.pf.} = object
    iterations*: cint
    gravity*: TVector
    damping*: CpFloat
    idleSpeedThreshold*: CpFloat
    sleepTimeThreshold*: CpFloat
    collisionSlop*: CpFloat
    collisionBias*: CpFloat
    collisionPersistence*: TTimestamp
    enableContactGraph*: cint ##BOOL
    data*: pointer
    staticBody*: PBody
    stamp: TTimestamp
    currDT: CpFloat
    bodies: PArray
    rousedBodies: PArray
    sleepingComponents: PArray
    staticShapes: PSpatialIndex
    activeShapes: PSpatialIndex
    arbiters: PArray
    contactBuffersHead: PContactBufferHeader
    cachedArbiters: PHashSet
    pooledArbiters: PArray
    constraints: PArray
    allocatedBuffers: PArray
    locked: cint
    collisionHandlers: PHashSet
    defaultHandler: TCollisionHandler
    postStepCallbacks: PHashSet
    arbiterApplyImpulse: TSpaceArbiterApplyImpulseFunc
    staticBody2: TBody  #_staticBody
  PBody* = ptr TBody
  TBody*{.pf.} = object
    velocityFunc*: TBodyVelocityFunc
    positionFunc*: TBodyPositionFunc
    m*: CpFloat
    mInv*: CpFloat
    i*: CpFloat
    iInv*: CpFloat
    p*: TVector
    v*: TVector
    f*: TVector
    a*: CpFloat
    w*: CpFloat
    t*: CpFloat
    rot*: TVector
    data*: pointer
    vLimit*: CpFloat
    wLimit*: CpFloat
    vBias*: TVector
    wBias*: CpFloat
    space*: PSpace
    shapeList*: PShape
    arbiterList*: PArbiter
    constraintList*: PConstraint
    node*: TComponentNode
  #/ Body/shape iterator callback function type.
  TBodyShapeIteratorFunc* = proc (body: PBody; shape: PShape;
                                   data: pointer) {.cdecl.}
  #/ Body/constraint iterator callback function type.
  TBodyConstraintIteratorFunc* = proc (body: PBody;
                                        constraint: PConstraint;
                                        data: pointer) {.cdecl.}
  #/ Body/arbiter iterator callback function type.
  TBodyArbiterIteratorFunc* = proc (body: PBody; arbiter: PArbiter;
                                     data: pointer) {.cdecl.}

  PNearestPointQueryInfo* = ptr TNearestPointQueryInfo
  #/ Nearest point query info struct.
  TNearestPointQueryInfo*{.pf.} = object
    shape: PShape  #/ The nearest shape, NULL if no shape was within range.
    p: TVector     #/ The closest point on the shape's surface. (in world space coordinates)
    d: CpFloat      #/ The distance to the point. The distance is negative if the point is inside the shape.

  PSegmentQueryInfo* = ptr TSegmentQueryInfo
  #/ Segment query info struct.
  TSegmentQueryInfo*{.pf.} = object
    shape*: PShape         #/ The shape that was hit, NULL if no collision occurred.
    t*: CpFloat            #/ The normalized distance along the query segment in the range [0, 1].
    n*: TVector            #/ The normal of the surface hit.
  TShapeType*{.size: sizeof(cint).} = enum
    CP_CIRCLE_SHAPE, CP_SEGMENT_SHAPE, CP_POLY_SHAPE, CP_NUM_SHAPES
  TShapeCacheDataImpl* = proc (shape: PShape; p: TVector; rot: TVector): TBB{.cdecl.}
  TShapeDestroyImpl* = proc (shape: PShape){.cdecl.}
  TShapePointQueryImpl* = proc (shape: PShape; p: TVector): Bool32 {.cdecl.}
  TShapeSegmentQueryImpl* = proc (shape: PShape; a: TVector; b: TVector;
                                  info: PSegmentQueryInfo){.cdecl.}
  PShapeClass* = ptr TShapeClass
  TShapeClass*{.pf.} = object
    kind*: TShapeType
    cacheData*: TShapeCacheDataImpl
    destroy*: TShapeDestroyImpl
    pointQuery*: TShapePointQueryImpl
    segmentQuery*: TShapeSegmentQueryImpl
  PShape* = ptr TShape
  TShape*{.pf.} = object
    klass: PShapeClass   #/ PRIVATE
    body*: PBody           #/ The rigid body this collision shape is attached to.
    bb*: TBB               #/ The current bounding box of the shape.
    sensor*: Bool32        #/ Sensor flag.
                           #/ Sensor shapes call collision callbacks but don't produce collisions.
    e*: CpFloat            #/ Coefficient of restitution. (elasticity)
    u*: CpFloat            #/ Coefficient of friction.
    surface_v*: TVector    #/ Surface velocity used when solving for friction.
    data*: pointer        #/ User definable data pointer. Generally this points to your the game object class so you can access it when given a cpShape reference in a callback.
    collision_type*: TCollisionType #/ Collision type of this shape used when picking collision handlers.
    group*: TGroup      #/ Group of this shape. Shapes in the same group don't collide.
    layers*: TLayers   #/ Layer bitmask for this shape. Shapes only collide if the bitwise and of their layers is non-zero.
    space: PSpace        #PRIVATE
    next: PShape         #PRIVATE
    prev: PShape         #PRIVATE
    hashid: THashValue  #PRIVATE
  PCircleShape* = ptr TCircleShape
  TCircleShape*{.pf.} = object
    shape: PShape
    c, tc: TVector
    r: CpFloat
  PPolyShape* = ptr TPolyShape
  TPolyShape*{.pf.} = object
    shape: PShape
    numVerts: cint
    verts, tVerts: TVector
    planes, tPlanes: PSplittingPlane
  PSegmentShape* = ptr TSegmentShape
  TSegmentShape*{.pf.} = object
    shape: PShape
    a, b, n: TVector
    ta, tb, tn: TVector
    r: CpFloat
    aTangent, bTangent: TVector
  PSplittingPlane* = ptr TSplittingPlane
  TSplittingPlane*{.pf.} = object
    n: TVector
    d: CpFloat

  #/ Post Step callback function type.
  TPostStepFunc* = proc (space: PSpace; obj: pointer; data: pointer){.cdecl.}
  #/ Point query callback function type.
  TSpacePointQueryFunc* = proc (shape: PShape; data: pointer){.cdecl.}
  #/ Segment query callback function type.
  TSpaceSegmentQueryFunc* = proc (shape: PShape; t: CpFloat; n: TVector;
                                  data: pointer){.cdecl.}
  #/ Rectangle Query callback function type.
  TSpaceBBQueryFunc* = proc (shape: PShape; data: pointer){.cdecl.}
  #/ Shape query callback function type.
  TSpaceShapeQueryFunc* = proc (shape: PShape; points: PContactPointSet;
                                data: pointer){.cdecl.}
  #/ Space/body iterator callback function type.
  TSpaceBodyIteratorFunc* = proc (body: PBody; data: pointer){.cdecl.}
  #/ Space/body iterator callback function type.
  TSpaceShapeIteratorFunc* = proc (shape: PShape; data: pointer){.cdecl.}
  #/ Space/constraint iterator callback function type.
  TSpaceConstraintIteratorFunc* = proc (constraint: PConstraint;
                                        data: pointer){.cdecl.}
  #/ Opaque cpConstraint struct.
  PConstraint* = ptr TConstraint
  TConstraint*{.pf.} = object
    klass: PConstraintClass #/PRIVATE
    a*: PBody            #/ The first body connected to this constraint.
    b*: PBody              #/ The second body connected to this constraint.
    space: PSpace         #/PRIVATE
    next_a: PConstraint  #/PRIVATE
    next_b: PConstraint #/PRIVATE
    maxForce*: CpFloat  #/ The maximum force that this constraint is allowed to use. Defaults to infinity.
    errorBias*: CpFloat #/ The rate at which joint error is corrected. Defaults to pow(1.0 - 0.1, 60.0) meaning that it will correct 10% of the error every 1/60th of a second.
    maxBias*: CpFloat    #/ The maximum rate at which joint error is corrected. Defaults to infinity.
    preSolve*: TConstraintPreSolveFunc  #/ Function called before the solver runs. Animate your joint anchors, update your motor torque, etc.
    postSolve*: TConstraintPostSolveFunc #/ Function called after the solver runs. Use the applied impulse to perform effects like breakable joints.
    data*: CpDataPointer  # User definable data pointer. Generally this points to your the game object class so you can access it when given a cpConstraint reference in a callback.
  TConstraintPreStepImpl = proc (constraint: PConstraint; dt: CpFloat){.cdecl.}
  TConstraintApplyCachedImpulseImpl = proc (constraint: PConstraint; dt_coef: CpFloat){.cdecl.}
  TConstraintApplyImpulseImpl = proc (constraint: PConstraint){.cdecl.}
  TConstraintGetImpulseImpl = proc (constraint: PConstraint): CpFloat{.cdecl.}
  PConstraintClass = ptr TConstraintClass
  TConstraintClass{.pf.} = object
    preStep*: TConstraintPreStepImpl
    applyCachedImpulse*: TConstraintApplyCachedImpulseImpl
    applyImpulse*: TConstraintApplyImpulseImpl
    getImpulse*: TConstraintGetImpulseImpl
  #/ Callback function type that gets called before solving a joint.
  TConstraintPreSolveFunc* = proc (constraint: PConstraint; space: PSpace){.
    cdecl.}
  #/ Callback function type that gets called after solving a joint.
  TConstraintPostSolveFunc* = proc (constraint: PConstraint; space: PSpace){.
    cdecl.}

##cp property emulators
template defGetter(otype: typedesc, memberType: typedesc, memberName: expr, procName: expr): stmt {.immediate.} =
  proc `get procName`*(obj: otype): memberType {.cdecl.} =
    return obj.memberName
template defSetter(otype: typedesc, memberType: typedesc, memberName: expr, procName: expr): stmt {.immediate.} =
  proc `set procName`*(obj: otype, value: memberType) {.cdecl.} =
    obj.memberName = value
template defProp(otype: typedesc, memberType: typedesc, memberName: expr, procName: expr): stmt {.immediate.} =
  defGetter(otype, memberType, memberName, procName)
  defSetter(otype, memberType, memberName, procName)


##cpspace.h
proc allocSpace*(): PSpace {.
  importc: "cpSpaceAlloc", dynlib: Lib.}
proc Init*(space: PSpace): PSpace {.
  importc: "cpSpaceInit", dynlib: Lib.}
proc newSpace*(): PSpace {.
  importc: "cpSpaceNew", dynlib: Lib.}
proc destroy*(space: PSpace) {.
  importc: "cpSpaceDestroy", dynlib: Lib.}
proc free*(space: PSpace) {.
  importc: "cpSpaceFree", dynlib: Lib.}

defProp(PSpace, cint, iterations, Iterations)
defProp(PSpace, TVector, gravity, Gravity)
defProp(PSpace, CpFloat, damping, Damping)
defProp(PSpace, CpFloat, idleSpeedThreshold, IdleSpeedThreshold)
defProp(PSpace, CpFloat, sleepTimeThreshold, SleepTimeThreshold)
defProp(PSpace, CpFloat, collisionSlop, CollisionSlop)
defProp(PSpace, CpFloat, collisionBias, CollisionBias)
defProp(PSpace, TTimestamp, collisionPersistence, CollisionPersistence)
defProp(PSpace, Bool32, enableContactGraph, EnableContactGraph)
defProp(PSpace, pointer, data, UserData)
defGetter(PSpace, PBody, staticBody, StaticBody)
defGetter(PSpace, CpFloat, currDt, CurrentTimeStep)


#/ returns true from inside a callback and objects cannot be added/removed.
proc isLocked*(space: PSpace): bool{.inline.} =
  result = space.locked.bool

#/ Set a default collision handler for this space.
#/ The default collision handler is invoked for each colliding pair of shapes
#/ that isn't explicitly handled by a specific collision handler.
#/ You can pass NULL for any function you don't want to implement.
proc setDefaultCollisionHandler*(space: PSpace; begin: TCollisionBeginFunc;
                                  preSolve: TCollisionPreSolveFunc;
                                  postSolve: TCollisionPostSolveFunc;
                                  separate: TCollisionSeparateFunc;
                                  data: pointer){.
  cdecl, importc: "cpSpaceSetDefaultCollisionHandler", dynlib: Lib.}
#/ Set a collision handler to be used whenever the two shapes with the given collision types collide.
#/ You can pass NULL for any function you don't want to implement.
proc addCollisionHandler*(space: PSpace; a, b: TCollisionType;
                           begin: TCollisionBeginFunc;
                           preSolve: TCollisionPreSolveFunc;
                           postSolve: TCollisionPostSolveFunc;
                           separate: TCollisionSeparateFunc; data: pointer){.
  cdecl, importc: "cpSpaceAddCollisionHandler", dynlib: Lib.}
#/ Unset a collision handler.
proc removeCollisionHandler*(space: PSpace; a: TCollisionType;
                                  b: TCollisionType){.
  cdecl, importc: "cpSpaceRemoveCollisionHandler", dynlib: Lib.}
#/ Add a collision shape to the simulation.
#/ If the shape is attached to a static body, it will be added as a static shape.
proc addShape*(space: PSpace; shape: PShape): PShape{.
  cdecl, importc: "cpSpaceAddShape", dynlib: Lib.}
#/ Explicity add a shape as a static shape to the simulation.
proc addStaticShape*(space: PSpace; shape: PShape): PShape{.
  cdecl, importc: "cpSpaceAddStaticShape", dynlib: Lib.}
#/ Add a rigid body to the simulation.
proc addBody*(space: PSpace; body: PBody): PBody{.
  cdecl, importc: "cpSpaceAddBody", dynlib: Lib.}
#/ Add a constraint to the simulation.
proc addConstraint*(space: PSpace; constraint: PConstraint): PConstraint{.
    cdecl, importc: "cpSpaceAddConstraint", dynlib: Lib.}
#/ Remove a collision shape from the simulation.
proc removeShape*(space: PSpace; shape: PShape){.
  cdecl, importc: "cpSpaceRemoveShape", dynlib: Lib.}
#/ Remove a collision shape added using cpSpaceAddStaticShape() from the simulation.
proc removeStaticShape*(space: PSpace; shape: PShape){.
  cdecl, importc: "cpSpaceRemoveStaticShape", dynlib: Lib.}
#/ Remove a rigid body from the simulation.
proc removeBody*(space: PSpace; body: PBody){.
  cdecl, importc: "cpSpaceRemoveBody", dynlib: Lib.}
#/ Remove a constraint from the simulation.
proc RemoveConstraint*(space: PSpace; constraint: PConstraint){.
  cdecl, importc: "cpSpaceRemoveConstraint", dynlib: Lib.}
#/ Test if a collision shape has been added to the space.
proc containsShape*(space: PSpace; shape: PShape): bool{.
  cdecl, importc: "cpSpaceContainsShape", dynlib: Lib.}
#/ Test if a rigid body has been added to the space.
proc containsBody*(space: PSpace; body: PBody): bool{.
  cdecl, importc: "cpSpaceContainsBody", dynlib: Lib.}
#/ Test if a constraint has been added to the space.

proc containsConstraint*(space: PSpace; constraint: PConstraint): bool{.
  cdecl, importc: "cpSpaceContainsConstraint", dynlib: Lib.}
#/ Schedule a post-step callback to be called when cpSpaceStep() finishes.
#/ @c obj is used a key, you can only register one callback per unique value for @c obj
proc addPostStepCallback*(space: PSpace; fun: TPostStepFunc;
                               obj: pointer; data: pointer){.
  cdecl, importc: "cpSpaceAddPostStepCallback", dynlib: Lib.}

#/ Query the space at a point and call @c func for each shape found.
proc pointQuery*(space: PSpace; point: TVector; layers: TLayers;
                      group: TGroup; fun: TSpacePointQueryFunc; data: pointer){.
  cdecl, importc: "cpSpacePointQuery", dynlib: Lib.}

#/ Query the space at a point and return the first shape found. Returns NULL if no shapes were found.
proc pointQueryFirst*(space: PSpace; point: TVector; layers: TLayers;
                       group: TGroup): PShape{.
  cdecl, importc: "cpSpacePointQueryFirst", dynlib: Lib.}

#/ Perform a directed line segment query (like a raycast) against the space calling @c func for each shape intersected.
proc segmentQuery*(space: PSpace; start: TVector; to: TVector;
                    layers: TLayers; group: TGroup;
                    fun: TSpaceSegmentQueryFunc; data: pointer){.
  cdecl, importc: "cpSpaceSegmentQuery", dynlib: Lib.}
#/ Perform a directed line segment query (like a raycast) against the space and return the first shape hit. Returns NULL if no shapes were hit.
proc segmentQueryFirst*(space: PSpace; start: TVector; to: TVector;
                         layers: TLayers; group: TGroup;
                         res: PSegmentQueryInfo): PShape{.
  cdecl, importc: "cpSpaceSegmentQueryFirst", dynlib: Lib.}

#/ Perform a fast rectangle query on the space calling @c func for each shape found.
#/ Only the shape's bounding boxes are checked for overlap, not their full shape.
proc BBQuery*(space: PSpace; bb: TBB; layers: TLayers; group: TGroup;
                   fun: TSpaceBBQueryFunc; data: pointer){.
  cdecl, importc: "cpSpaceBBQuery", dynlib: Lib.}

#/ Query a space for any shapes overlapping the given shape and call @c func for each shape found.
proc shapeQuery*(space: PSpace; shape: PShape; fun: TSpaceShapeQueryFunc; data: pointer): bool {.
  cdecl, importc: "cpSpaceShapeQuery", dynlib: Lib.}
#/ Call cpBodyActivate() for any shape that is overlaps the given shape.
proc activateShapesTouchingShape*(space: PSpace; shape: PShape){.
    cdecl, importc: "cpSpaceActivateShapesTouchingShape", dynlib: Lib.}

#/ Call @c func for each body in the space.
proc eachBody*(space: PSpace; fun: TSpaceBodyIteratorFunc; data: pointer){.
  cdecl, importc: "cpSpaceEachBody", dynlib: Lib.}

#/ Call @c func for each shape in the space.
proc eachShape*(space: PSpace; fun: TSpaceShapeIteratorFunc;
                     data: pointer){.
  cdecl, importc: "cpSpaceEachShape", dynlib: Lib.}
#/ Call @c func for each shape in the space.
proc eachConstraint*(space: PSpace; fun: TSpaceConstraintIteratorFunc;
                          data: pointer){.
  cdecl, importc: "cpSpaceEachConstraint", dynlib: Lib.}
#/ Update the collision detection info for the static shapes in the space.
proc reindexStatic*(space: PSpace){.
  cdecl, importc: "cpSpaceReindexStatic", dynlib: Lib.}
#/ Update the collision detection data for a specific shape in the space.
proc reindexShape*(space: PSpace; shape: PShape){.
  cdecl, importc: "cpSpaceReindexShape", dynlib: Lib.}
#/ Update the collision detection data for all shapes attached to a body.
proc reindexShapesForBody*(space: PSpace; body: PBody){.
  cdecl, importc: "cpSpaceReindexShapesForBody", dynlib: Lib.}
#/ Switch the space to use a spatial has as it's spatial index.
proc SpaceUseSpatialHash*(space: PSpace; dim: CpFloat; count: cint){.
  cdecl, importc: "cpSpaceUseSpatialHash", dynlib: Lib.}
#/ Step the space forward in time by @c dt.
proc step*(space: PSpace; dt: CpFloat) {.
  cdecl, importc: "cpSpaceStep", dynlib: Lib.}


#/ Convenience constructor for cpVect structs.
proc vector*(x, y: CpFloat): TVector {.inline.} =
  result.x = x
  result.y = y
proc newVector*(x, y: CpFloat): TVector {.inline.} =
  return vector(x, y)
#let VectorZero* = newVector(0.0, 0.0)
var VectorZero* = newVector(0.0, 0.0)

#/ Vector dot product.
proc dot*(v1, v2: TVector): CpFloat {.inline.} =
  result = v1.x * v2.x + v1.y * v2.y

#/ Returns the length of v.
#proc len*(v: TVector): CpFloat {.
#  cdecl, importc: "cpvlength", dynlib: Lib.}
proc len*(v: TVector): CpFloat {.inline.} =
  result = v.dot(v).sqrt
#/ Spherical linearly interpolate between v1 and v2.
proc slerp*(v1, v2: TVector; t: CpFloat): TVector {.
  cdecl, importc: "cpvslerp", dynlib: Lib.}
#/ Spherical linearly interpolate between v1 towards v2 by no more than angle a radians
proc slerpconst*(v1, v2: TVector; a: CpFloat): TVector {.
  cdecl, importc: "cpvslerpconst", dynlib: Lib.}
#/ Returns the unit length vector for the given angle (in radians).
#proc vectorForAngle*(a: CpFloat): TVector {.
#  cdecl, importc: "cpvforangle", dynlib: Lib.}
proc vectorForAngle*(a: CpFloat): TVector {.inline.} =
  result = newVector(math.cos(a), math.sin(a))
#/ Returns the angular direction v is pointing in (in radians).
proc toAngle*(v: TVector): CpFloat {.inline.} =
  result = math.arctan2(v.y, v.x)
#/	Returns a string representation of v. Intended mostly for debugging purposes and not production use.
#/	@attention The string points to a static local and is reset every time the function is called.
#/	If you want to print more than one vector you will have to split up your printing onto separate lines.
proc `$`*(v: TVector): cstring {.cdecl, importc: "cpvstr", dynlib: Lib.}


#/ Check if two vectors are equal. (Be careful when comparing floating point numbers!)
proc `==`*(v1, v2: TVector): bool {.inline.} =
  result = v1.x == v2.x and v1.y == v2.y

#/ Add two vectors
proc `+`*(v1, v2: TVector): TVector {.inline.} =
  result = newVector(v1.x + v2.x, v1.y + v2.y)
proc `+=`*(v1: var TVector; v2: TVector) =
  v1.x = v1.x + v2.x
  v1.y = v1.y + v2.y

#/ Subtract two vectors.
proc `-`*(v1, v2: TVector): TVector {.inline.} =
  result = newVector(v1.x - v2.x, v1.y - v2.y)
proc `-=`*(v1: var TVector; v2: TVector) =
  v1.x = v1.x - v2.x
  v1.y = v1.y - v2.y

#/ Negate a vector.
proc `-`*(v: TVector): TVector {.inline.} =
  result = newVector(- v.x, - v.y)

#/ Scalar multiplication.
proc `*`*(v: TVector, s: CpFloat): TVector {.inline.} =
  result.x = v.x * s
  result.y = v.y * s
proc `*=`*(v: var TVector; s: CpFloat) =
  v.x = v.x * s
  v.y = v.y * s

#/ 2D vector cross product analog.
#/ The cross product of 2D vectors results in a 3D vector with only a z component.
#/ This function returns the magnitude of the z value.
proc cross*(v1, v2: TVector): CpFloat {.inline.} =
  result = v1.x * v2.y - v1.y * v2.x

#/ Returns a perpendicular vector. (90 degree rotation)
proc perp*(v: TVector): TVector {.inline.} =
  result = newVector(- v.y, v.x)

#/ Returns a perpendicular vector. (-90 degree rotation)
proc rperp*(v: TVector): TVector {.inline.} =
  result = newVector(v.y, - v.x)

#/ Returns the vector projection of v1 onto v2.
proc project*(v1,v2: TVector): TVector {.inline.} =
  result = v2 * (v1.dot(v2) / v2.dot(v2))

#/ Uses complex number multiplication to rotate v1 by v2. Scaling will occur if v1 is not a unit vector.

proc rotate*(v1, v2: TVector): TVector {.inline.} =
  result = newVector(v1.x * v2.x - v1.y * v2.y, v1.x * v2.y + v1.y * v2.x)
#/ Inverse of cpvrotate().
proc unrotate*(v1, v2: TVector): TVector {.inline.} =
  result = newVector(v1.x * v2.x + v1.y * v2.y, v1.y * v2.x - v1.x * v2.y)
#/ Returns the squared length of v. Faster than cpvlength() when you only need to compare lengths.
proc lenSq*(v: TVector): CpFloat {.inline.} =
  result = v.dot(v)
#/ Linearly interpolate between v1 and v2.
proc lerp*(v1, v2: TVector; t: CpFloat): TVector {.inline.} =
  result = (v1 * (1.0 - t)) + (v2 * t)
#/ Returns a normalized copy of v.
proc normalize*(v: TVector): TVector {.inline.} =
  result = v * (1.0 / v.len)
#/ Returns a normalized copy of v or cpvzero if v was already cpvzero. Protects against divide by zero errors.
proc normalizeSafe*(v: TVector): TVector {.inline.} =
  result = if v.x == 0.0 and v.y == 0.0: VectorZero else: v.normalize
#/ Clamp v to length len.
proc clamp*(v: TVector; len: CpFloat): TVector {.inline.} =
  result = if v.dot(v) > len * len: v.normalize * len else: v
#/ Linearly interpolate between v1 towards v2 by distance d.
proc lerpconst*(v1, v2: TVector; d: CpFloat): TVector {.inline.} =
  result = v1 + clamp(v2 - v1, d)             #vadd(v1 + vclamp(vsub(v2, v1), d))
#/ Returns the distance between v1 and v2.
proc dist*(v1, v2: TVector): CpFloat {.inline.} =
  result = (v1 - v2).len #vlength(vsub(v1, v2))
#/ Returns the squared distance between v1 and v2. Faster than cpvdist() when you only need to compare distances.
proc distsq*(v1, v2: TVector): CpFloat {.inline.} =
  result = (v1 - v2).lenSq  #vlengthsq(vsub(v1, v2))
#/ Returns true if the distance between v1 and v2 is less than dist.
proc near*(v1, v2: TVector; dist: CpFloat): bool{.inline.} =
  result = v1.distSq(v2) < dist * dist



##cpBody.h
proc allocBody*(): PBody {.importc: "cpBodyAlloc", dynlib: Lib.}
proc init*(body: PBody; m: CpFloat; i: CpFloat): PBody {.
  importc: "cpBodyInit", dynlib: Lib.}
proc newBody*(m: CpFloat; i: CpFloat): PBody {.
  importc: "cpBodyNew", dynlib: Lib.}

proc initStaticBody*(body: PBody): PBody{.
  importc: "cpBodyInitStatic", dynlib: Lib.}
#/ Allocate and initialize a static cpBody.
proc newStatic*(): PBody{.importc: "cpBodyNewStatic", dynlib: Lib.}
#/ Destroy a cpBody.
proc destroy*(body: PBody){.importc: "cpBodyDestroy", dynlib: Lib.}
#/ Destroy and free a cpBody.
proc free*(body: PBody){.importc: "cpBodyFree", dynlib: Lib.}

#/ Wake up a sleeping or idle body.
proc activate*(body: PBody){.importc: "cpBodyActivate", dynlib: Lib.}
#/ Wake up any sleeping or idle bodies touching a static body.
proc activateStatic*(body: PBody; filter: PShape){.
    importc: "cpBodyActivateStatic", dynlib: Lib.}
#/ Force a body to fall asleep immediately.
proc Sleep*(body: PBody){.importc: "cpBodySleep", dynlib: Lib.}
#/ Force a body to fall asleep immediately along with other bodies in a group.
proc SleepWithGroup*(body: PBody; group: PBody){.
    importc: "cpBodySleepWithGroup", dynlib: Lib.}
#/ Returns true if the body is sleeping.
proc isSleeping*(body: PBody): bool {.inline.} =
  return body.node.root != nil
#/ Returns true if the body is static.
proc isStatic*(body: PBody): bool {.inline.} =
  return body.node.idleTime == CpInfinity
#/ Returns true if the body has not been added to a space.
proc isRogue*(body: PBody): bool {.inline.} =
  return body.space == nil

# #define CP_DefineBodyStructGetter(type, member, name) \
# static inline type cpBodyGet##name(const cpBody *body){return body->member;}
# #define CP_DefineBodyStructSetter(type, member, name) \
# static inline void cpBodySet##name(cpBody *body, const type value){ \
# 	cpBodyActivate(body); \
# 	cpBodyAssertSane(body); \
# 	body->member = value; \
# }
# #define CP_DefineBodyStructProperty(type, member, name) \
# CP_DefineBodyStructGetter(type, member, name) \
# CP_DefineBodyStructSetter(type, member, name)

defGetter(PBody, CpFloat, m, Mass)
#/ Set the mass of a body.
when defined(MoreNim):
  defSetter(PBody, CpFloat, m, Mass)
else:
  proc setMass*(body: PBody; m: CpFloat){.
    cdecl, importc: "cpBodySetMass", dynlib: Lib.}

#/ Get the moment of a body.
defGetter(PBody, CpFloat, i, Moment)
#/ Set the moment of a body.
when defined(MoreNim):
  defSetter(PBody, CpFloat, i, Moment)
else:
  proc SetMoment*(body: PBody; i: CpFloat) {.
    cdecl, importc: "cpBodySetMoment", dynlib: Lib.}

#/ Get the position of a body.
defGetter(PBody, TVector, p, Pos)
#/ Set the position of a body.
when defined(MoreNim):
  defSetter(PBody, TVector, p, Pos)
else:
  proc setPos*(body: PBody; pos: TVector) {.
    cdecl, importc: "cpBodySetPos", dynlib: Lib.}

defProp(PBody, TVector, v, Vel)
defProp(PBody, TVector, f, Force)

#/ Get the angle of a body.
defGetter(PBody, CpFloat, a, Angle)
#/ Set the angle of a body.
proc setAngle*(body: PBody; a: CpFloat){.
  cdecl, importc: "cpBodySetAngle", dynlib: Lib.}

defProp(PBody, CpFloat, w, AngVel)
defProp(PBody, CpFloat, t, Torque)
defGetter(PBody, TVector, rot, Rot)
defProp(PBody, CpFloat, v_limit, VelLimit)
defProp(PBody, CpFloat, w_limit, AngVelLimit)
defProp(PBody, pointer, data, UserData)

#/ Default Integration functions.
proc UpdateVelocity*(body: PBody; gravity: TVector; damping: CpFloat; dt: CpFloat){.
  cdecl, importc: "cpBodyUpdateVelocity", dynlib: Lib.}
proc UpdatePosition*(body: PBody; dt: CpFloat){.
  cdecl, importc: "cpBodyUpdatePosition", dynlib: Lib.}
#/ Convert body relative/local coordinates to absolute/world coordinates.
proc Local2World*(body: PBody; v: TVector): TVector{.inline.} =
  result = body.p + v.rotate(body.rot) ##return cpvadd(body.p, cpvrotate(v, body.rot))
#/ Convert body absolute/world coordinates to  relative/local coordinates.
proc world2Local*(body: PBody; v: TVector): TVector{.inline.} =
  result = (v - body.p).unrotate(body.rot)
#/ Set the forces and torque or a body to zero.
proc resetForces*(body: PBody){.
  cdecl, importc: "cpBodyResetForces", dynlib: Lib.}
#/ Apply an force (in world coordinates) to the body at a point relative to the center of gravity (also in world coordinates).
proc applyForce*(body: PBody; f, r: TVector){.
  cdecl, importc: "cpBodyApplyForce", dynlib: Lib.}
#/ Apply an impulse (in world coordinates) to the body at a point relative to the center of gravity (also in world coordinates).
proc applyImpulse*(body: PBody; j, r: TVector){.
  cdecl, importc: "cpBodyApplyImpulse", dynlib: Lib.}
#/ Get the velocity on a body (in world units) at a point on the body in world coordinates.

proc getVelAtWorldPoint*(body: PBody; point: TVector): TVector{.
  cdecl, importc: "cpBodyGetVelAtWorldPoint", dynlib: Lib.}
#/ Get the velocity on a body (in world units) at a point on the body in local coordinates.
proc getVelAtLocalPoint*(body: PBody; point: TVector): TVector{.
  cdecl, importc: "cpBodyGetVelAtLocalPoint", dynlib: Lib.}
#/ Get the kinetic energy of a body.
# static inline CpFloat cpBodyKineticEnergy(const cpBody *body)
# {
# 	// Need to do some fudging to avoid NaNs
# 	cpFloat vsq = cpvdot(body->v, body->v);
# 	cpFloat wsq = body->w*body->w;
# 	return (vsq ? vsq*body->m : 0.0f) + (wsq ? wsq*body->i : 0.0f);
# }
proc kineticEnergy*(body: PBOdy): CpFloat =
  result = (body.v.dot(body.v) * body.m) + (body.w * body.w * body.i)

#/ Call @c func once for each shape attached to @c body and added to the space.
proc eachShape*(body: PBody; fun: TBodyShapeIteratorFunc;
                      data: pointer){.
  cdecl, importc: "cpBodyEachShape", dynlib: Lib.}
#/ Call @c func once for each constraint attached to @c body and added to the space.
proc eachConstraint*(body: PBody; fun: TBodyConstraintIteratorFunc;
                           data: pointer) {.
  cdecl, importc: "cpBodyEachConstraint", dynlib: Lib.}
#/ Call @c func once for each arbiter that is currently active on the body.
proc eachArbiter*(body: PBody; fun: TBodyArbiterIteratorFunc;
                        data: pointer){.
  cdecl, importc: "cpBodyEachArbiter", dynlib: Lib.}
#/ Allocate a spatial hash.
proc SpaceHashAlloc*(): PSpaceHash{.
  cdecl, importc: "cpSpaceHashAlloc", dynlib: Lib.}
#/ Initialize a spatial hash.
proc SpaceHashInit*(hash: PSpaceHash; celldim: CpFloat; numcells: cint;
                    bbfun: TSpatialIndexBBFunc; staticIndex: PSpatialIndex): PSpatialIndex{.
  cdecl, importc: "cpSpaceHashInit", dynlib: Lib.}
#/ Allocate and initialize a spatial hash.
proc SpaceHashNew*(celldim: CpFloat; cells: cint; bbfun: TSpatialIndexBBFunc;
                   staticIndex: PSpatialIndex): PSpatialIndex{.
  cdecl, importc: "cpSpaceHashNew", dynlib: Lib.}
#/ Change the cell dimensions and table size of the spatial hash to tune it.
#/ The cell dimensions should roughly match the average size of your objects
#/ and the table size should be ~10 larger than the number of objects inserted.
#/ Some trial and error is required to find the optimum numbers for efficiency.
proc SpaceHashResize*(hash: PSpaceHash; celldim: CpFloat; numcells: cint){.
  cdecl, importc: "cpSpaceHashResize", dynlib: Lib.}
#MARK: AABB Tree


#/ Allocate a bounding box tree.
proc BBTreeAlloc*(): PBBTree{.cdecl, importc: "cpBBTreeAlloc", dynlib: Lib.}
#/ Initialize a bounding box tree.
proc BBTreeInit*(tree: PBBTree; bbfun: TSpatialIndexBBFunc;
                 staticIndex: ptr TSpatialIndex): ptr TSpatialIndex{.cdecl,
    importc: "cpBBTreeInit", dynlib: Lib.}
#/ Allocate and initialize a bounding box tree.
proc BBTreeNew*(bbfun: TSpatialIndexBBFunc; staticIndex: PSpatialIndex): PSpatialIndex{.
    cdecl, importc: "cpBBTreeNew", dynlib: Lib.}
#/ Perform a static top down optimization of the tree.
proc BBTreeOptimize*(index: PSpatialIndex){.
  cdecl, importc: "cpBBTreeOptimize", dynlib: Lib.}
#/ Set the velocity function for the bounding box tree to enable temporal coherence.

proc BBTreeSetVelocityFunc*(index: PSpatialIndex; fun: TBBTreeVelocityFunc){.
    cdecl, importc: "cpBBTreeSetVelocityFunc", dynlib: Lib.}
#MARK: Single Axis Sweep


#/ Allocate a 1D sort and sweep broadphase.

proc Sweep1DAlloc*(): ptr TSweep1D{.cdecl, importc: "cpSweep1DAlloc",
                                    dynlib: Lib.}
#/ Initialize a 1D sort and sweep broadphase.

proc Sweep1DInit*(sweep: ptr TSweep1D; bbfun: TSpatialIndexBBFunc;
                  staticIndex: ptr TSpatialIndex): ptr TSpatialIndex{.cdecl,
    importc: "cpSweep1DInit", dynlib: Lib.}
#/ Allocate and initialize a 1D sort and sweep broadphase.

proc Sweep1DNew*(bbfun: TSpatialIndexBBFunc; staticIndex: ptr TSpatialIndex): ptr TSpatialIndex{.
    cdecl, importc: "cpSweep1DNew", dynlib: Lib.}



defProp(PArbiter, CpFloat, e, Elasticity)
defProp(PArbiter, CpFloat, u, Friction)
defProp(PArbiter, TVector, surface_vr, SurfaceVelocity)

#/ Calculate the total impulse that was applied by this
#/ This function should only be called from a post-solve, post-step or cpBodyEachArbiter callback.
proc totalImpulse*(obj: PArbiter): TVector {.cdecl, importc: "cpArbiterTotalImpulse", dynlib: Lib.}

#/ Calculate the total impulse including the friction that was applied by this arbiter.
#/ This function should only be called from a post-solve, post-step or cpBodyEachArbiter callback.
proc totalImpulseWithFriction*(obj: PArbiter): TVector {.cdecl, importc: "cpArbiterTotalImpulseWithFriction", dynlib: Lib.}

#/ Calculate the amount of energy lost in a collision including static, but not dynamic friction.
#/ This function should only be called from a post-solve, post-step or cpBodyEachArbiter callback.
proc totalKE*(obj: PArbiter): CpFloat {.cdecl, importc: "cpArbiterTotalKE", dynlib: Lib.}


#/ Causes a collision pair to be ignored as if you returned false from a begin callback.
#/ If called from a pre-step callback, you will still need to return false
#/ if you want it to be ignored in the current step.
proc ignore*(arb: PArbiter) {.cdecl, importc: "cpArbiterIgnore", dynlib: Lib.}

#/ Return the colliding shapes involved for this arbiter.
#/ The order of their cpSpace.collision_type values will match
#/ the order set when the collision handler was registered.
proc getShapes*(arb: PArbiter, a, b: var PShape) {.inline.} =
  if arb.swappedColl.bool:
    a = arb.b
    b = arb.a
  else:
    a = arb.a
    b = arb.b

#/ A macro shortcut for defining and retrieving the shapes from an arbiter.
#define CP_ARBITER_GET_SHAPES(arb, a, b) cpShape *a, *b; cpArbiterGetShapes(arb, &a, &b);
template getShapes*(arb: PArbiter, name1, name2: expr): stmt {.immediate.} =
  var name1, name2: PShape
  getShapes(arb, name1, name2)


#/ Return the colliding bodies involved for this arbiter.
#/ The order of the cpSpace.collision_type the bodies are associated with values will match
#/ the order set when the collision handler was registered.
#proc getBodies*(arb: PArbiter, a, b: var PBody) {.inline.} =
#  getShapes(arb, shape1, shape2)
#  a = shape1.body
#  b = shape2.body

#/ A macro shortcut for defining and retrieving the bodies from an arbiter.
#define CP_ARBITER_GET_BODIES(arb, a, b) cpBody *a, *b; cpArbiterGetBodies(arb, &a, &b);
template getBodies*(arb: PArbiter, name1, name2: expr): stmt {.immediate.} =
  var name1, name2: PBOdy
  getBodies(arb, name1, name2)

proc isFirstContact*(arb: PArbiter): bool {.inline.} =
  result = arb.state == ArbiterStateFirstColl

proc getCount*(arb: PArbiter): cint {.inline.} =
  result = arb.numContacts

#/ Return a contact set from an arbiter.
proc getContactPointSet*(arb: PArbiter): TContactPointSet {.
  cdecl, importc: "cpArbiterGetContactPointSet", dynlib: Lib.}
#/ Get the normal of the @c ith contact point.
proc getNormal*(arb: PArbiter; i: cint): TVector {.
  cdecl, importc: "cpArbiterGetNormal", dynlib: Lib.}
#/ Get the position of the @c ith contact point.
proc getPoint*(arb: PArbiter; i: cint): TVector {.
  cdecl, importc: "cpArbiterGetPoint", dynlib: Lib.}
#/ Get the depth of the @c ith contact point.
proc getDepth*(arb: PArbiter; i: cint): CpFloat {.
  cdecl, importc: "cpArbiterGetDepth", dynlib: Lib.}

##Shapes
template defShapeSetter(memberType: typedesc, memberName: expr, procName: expr, activates: bool): stmt {.immediate.} =
  proc `set procName`*(obj: PShape, value: memberType) {.cdecl.} =
    if activates and obj.body != nil: obj.body.activate()
    obj.memberName = value
template defShapeProp(memberType: typedesc, memberName: expr, procName: expr, activates: bool): stmt {.immediate.} =
  defGetter(PShape, memberType, memberName, procName)
  defShapeSetter(memberType, memberName, procName, activates)

#/ Destroy a shape.
proc destroy*(shape: PShape) {.
  cdecl, importc: "cpShapeDestroy", dynlib: Lib.}
#/ Destroy and Free a shape.
proc free*(shape: PShape){.
  cdecl, importc: "cpShapeFree", dynlib: Lib.}
#/ Update, cache and return the bounding box of a shape based on the body it's attached to.
proc cacheBB*(shape: PShape): TBB{.
  cdecl, importc: "cpShapeCacheBB", dynlib: Lib.}
#/ Update, cache and return the bounding box of a shape with an explicit transformation.
proc update*(shape: PShape; pos: TVector; rot: TVector): TBB {.
  cdecl, importc: "cpShapeUpdate", dynlib: Lib.}
#/ Test if a point lies within a shape.
proc pointQuery*(shape: PShape; p: TVector): Bool32 {.
  cdecl, importc: "cpShapePointQuery", dynlib: Lib.}

#/ Perform a nearest point query. It finds the closest point on the surface of shape to a specific point.
#/ The value returned is the distance between the points. A negative distance means the point is inside the shape.
proc nearestPointQuery*(shape: PShape; p: TVector; res: PNearestPointQueryInfo): CpFloat {.
  cdecl, importc: "cpShapeNearestPointQuery", dynlib: Lib.}
#/ Perform a segment query against a shape. @c info must be a pointer to a valid cpSegmentQueryInfo structure.
proc segmentQuery*(shape: PShape, a, b: TVector, info: PSegmentQueryInfo): bool {.
  cdecl, importc: "cpShapeSegmentQuery", dynlib: Lib.}

#/ Get the hit point for a segment query.
## Possibly change; info to PSegmentQueryInfo
proc queryHitPoint*(start, to: TVector, info: TSegmentQueryInfo): TVector {.inline.} =
  result = start.lerp(to, info.t)

#/ Get the hit distance for a segment query.
proc queryHitDist*(start, to: TVector, info: TSegmentQueryInfo): CpFloat {.inline.} =
  result = start.dist(to) * info.t

defGetter(PShape, PSpace, space, Space)

defGetter(PShape, PBody, body, Body)
proc setBody*(shape: PShape, value: PBody) {.
  cdecl, importc: "cpShapeSetBody", dynlib: Lib.}


defGetter(PShape, TBB, bb, BB)
defShapeProp(Bool32, sensor, Sensor, true)
defShapeProp(CpFloat, e, Elasticity, false)
defShapeProp(CpFloat, u, Friction, true)
defShapeProp(TVector, surface_v, SurfaceVelocity, true)
defShapeProp(pointer, data, UserData, false)
defShapeProp(TCollisionType, collision_type, CollisionType, true)
defShapeProp(TGroup, group, Group, true)
defShapeProp(TLayers, layers, Layers, true)

#/ When initializing a shape, it's hash value comes from a counter.
#/ Because the hash value may affect iteration order, you can reset the shape ID counter
#/ when recreating a space. This will make the simulation be deterministic.
proc resetShapeIdCounter*(): void {.cdecl, importc: "cpResetShapeIdCounter", dynlib: Lib.}
#/ Allocate a circle shape.
proc CircleShapeAlloc*(): PCircleShape {.cdecl, importc: "cpCircleShapeAlloc", dynlib: Lib.}
#/ Initialize a circle shape.
proc init*(circle: PCircleShape, body: PBody, radius: CpFloat, offset: TVector): PCircleShape {.
  cdecl, importc: "cpCircleShapeInit", dynlib: Lib.}
#/ Allocate and initialize a circle shape.
proc newCircleShape*(body: PBody, radius: CpFloat, offset: TVector): PShape {.
  cdecl, importc: "cpCircleShapeNew", dynlib: Lib.}

proc getCircleOffset*(shape: PShape): TVector {.
  cdecl, importc: "cpCircleShapeGetOffset", dynlib: Lib.}
proc getCircleRadius*(shape: PShape): CpFloat {.
  cdecl, importc: "cpCircleShapeGetRadius", dynlib: Lib.}


#/ Allocate a polygon shape.
proc allocPolyShape*(): PPolyShape {.
  cdecl, importc: "cpPolyShapeAlloc", dynlib: Lib.}
#/ Initialize a polygon shape.
#/ A convex hull will be created from the vertexes.
proc init*(poly: PPolyShape; body: PBody, numVerts: cint;
            verts: ptr TVector; offset: TVector): PPolyShape {.
  cdecl, importc: "cpPolyShapeInit", dynlib: Lib.}
#/ Allocate and initialize a polygon shape.
#/ A convex hull will be created from the vertexes.
proc newPolyShape*(body: PBody; numVerts: cint; verts: ptr TVector;
                    offset: TVector): PShape {.
  cdecl, importc: "cpPolyShapeNew", dynlib: Lib.}
#/ Initialize a box shaped polygon shape.
proc init*(poly: PPolyShape; body: PBody; width, height: CpFloat): PPolyShape {.
  cdecl, importc: "cpBoxShapeInit", dynlib: Lib.}
#/ Initialize an offset box shaped polygon shape.
proc init*(poly: PPolyShape; body: PBody; box: TBB): PPolyShape {.
  cdecl, importc: "cpBoxShapeInit2", dynlib: Lib.}
#/ Allocate and initialize a box shaped polygon shape.
proc newBoxShape*(body: PBody; width, height: CpFloat): PShape {.
  cdecl, importc: "cpBoxShapeNew", dynlib: Lib.}
#/ Allocate and initialize an offset box shaped polygon shape.
proc newBoxShape*(body: PBody; box: TBB): PShape {.
  cdecl, importc: "cpBoxShapeNew2", dynlib: Lib.}

#/ Check that a set of vertexes is convex and has a clockwise winding.
#/ NOTE: Due to floating point precision issues, hulls created with cpQuickHull() are not guaranteed to validate!
proc validatePoly*(verts: ptr TVector; numVerts: cint): bool {.
  cdecl, importc: "cpPolyValidate", dynlib: Lib.}
#/ Get the number of verts in a polygon shape.
proc getNumVerts*(shape: PShape): cint {.
  cdecl, importc: "cpPolyShapeGetNumVerts", dynlib: Lib.}
#/ Get the @c ith vertex of a polygon shape.
proc getVert*(shape: PShape; index: cint): TVector {.
  cdecl, importc: "cpPolyShapeGetVert", dynlib: Lib.}

#/ Allocate a segment shape.
proc allocSegmentShape*(): PSegmentShape {.
  cdecl, importc: "cpSegmentShapeAlloc", dynlib: Lib.}
#/ Initialize a segment shape.
proc init*(seg: PSegmentShape, body: PBody, a, b: TVector, radius: CpFloat): PSegmentShape {.
  cdecl, importc: "cpSegmentShapeInit", dynlib: Lib.}
#/ Allocate and initialize a segment shape.
proc newSegmentShape*(body: PBody, a, b: TVector, radius: CpFloat): PShape {.
  cdecl, importc: "cpSegmentShapeNew", dynlib: Lib.}

proc setSegmentNeighbors*(shape: PShape, prev, next: TVector) {.
  cdecl, importc: "cpSegmentShapeSetNeighbors", dynlib: Lib.}
proc getSegmentA*(shape: PShape): TVector {.
  cdecl, importc: "cpSegmentShapeGetA", dynlib: Lib.}
proc getSegmentB*(shape: PShape): TVector {.
  cdecl, importc: "cpSegmentShapeGetB", dynlib: Lib.}
proc getSegmentNormal*(shape: PShape): TVector {.
  cdecl, importc: "cpSegmentShapeGetNormal", dynlib: Lib.}
proc getSegmentRadius*(shape: PShape): CpFloat {.
  cdecl, importc: "cpSegmentShapeGetRadius", dynlib: Lib.}


#/ Version string.
#var VersionString*{.importc: "cpVersionString", dynlib: Lib.}: cstring
#/ Calculate the moment of inertia for a circle.
#/ @c r1 and @c r2 are the inner and outer diameters. A solid circle has an inner diameter of 0.
when defined(MoreNim):
  proc momentForCircle*(m, r1, r2: CpFloat; offset: TVector): CpFloat {.cdecl.} =
    result = m * (0.5 * (r1 * r1 + r2 * r2) + lenSq(offset))
else:
  proc momentForCircle*(m, r1, r2: CpFloat; offset: TVector): CpFloat {.
    cdecl, importc: "cpMomentForCircle", dynlib: Lib.}

#/ Calculate area of a hollow circle.
#/ @c r1 and @c r2 are the inner and outer diameters. A solid circle has an inner diameter of 0.
proc AreaForCircle*(r1: CpFloat; r2: CpFloat): CpFloat {.
  cdecl, importc: "cpAreaForCircle", dynlib: Lib.}
#/ Calculate the moment of inertia for a line segment.
#/ Beveling radius is not supported.
proc MomentForSegment*(m: CpFloat; a, b: TVector): CpFloat {.
  cdecl, importc: "cpMomentForSegment", dynlib: Lib.}
#/ Calculate the area of a fattened (capsule shaped) line segment.
proc AreaForSegment*(a, b: TVector; r: CpFloat): CpFloat {.
  cdecl, importc: "cpAreaForSegment", dynlib: Lib.}
#/ Calculate the moment of inertia for a solid polygon shape assuming it's center of gravity is at it's centroid. The offset is added to each vertex.
proc MomentForPoly*(m: CpFloat; numVerts: cint; verts: ptr TVector; offset: TVector): CpFloat {.
  cdecl, importc: "cpMomentForPoly", dynlib: Lib.}
#/ Calculate the signed area of a polygon. A Clockwise winding gives positive area.
#/ This is probably backwards from what you expect, but matches Chipmunk's the winding for poly shapes.
proc AreaForPoly*(numVerts: cint; verts: ptr TVector): CpFloat {.
  cdecl, importc: "cpAreaForPoly", dynlib: Lib.}
#/ Calculate the natural centroid of a polygon.
proc CentroidForPoly*(numVerts: cint; verts: ptr TVector): TVector {.
  cdecl, importc: "cpCentroidForPoly", dynlib: Lib.}
#/ Center the polygon on the origin. (Subtracts the centroid of the polygon from each vertex)
proc RecenterPoly*(numVerts: cint; verts: ptr TVector) {.
  cdecl, importc: "cpRecenterPoly", dynlib: Lib.}
#/ Calculate the moment of inertia for a solid box.
proc MomentForBox*(m, width, height: CpFloat): CpFloat {.
  cdecl, importc: "cpMomentForBox", dynlib: Lib.}
#/ Calculate the moment of inertia for a solid box.
proc MomentForBox2*(m: CpFloat; box: TBB): CpFloat {.
  cdecl, importc: "cpMomentForBox2", dynlib: Lib.}



##constraints
type
  #TODO: all these are private
  #TODO: defConstraintProp()
  PPinJoint = ptr TPinJoint
  TPinJoint{.pf.} = object
    constraint: PConstraint
    anchr1: TVector
    anchr2: TVector
    dist: CpFloat
    r1: TVector
    r2: TVector
    n: TVector
    nMass: CpFloat
    jnAcc: CpFloat
    jnMax: CpFloat
    bias: CpFloat
  PSlideJoint = ptr TSlideJoint
  TSlideJoint{.pf.} = object
    constraint: PConstraint
    anchr1: TVector
    anchr2: TVector
    min: CpFloat
    max: CpFloat
    r1: TVector
    r2: TVector
    n: TVector
    nMass: CpFloat
    jnAcc: CpFloat
    jnMax: CpFloat
    bias: CpFloat
  PPivotJoint = ptr TPivotJoint
  TPivotJoint{.pf.} = object
    constraint: PConstraint
    anchr1: TVector
    anchr2: TVector
    r1: TVector
    r2: TVector
    k1: TVector
    k2: TVector
    jAcc: TVector
    jMaxLen: CpFloat
    bias: TVector
  PGrooveJoint = ptr TGrooveJoint
  TGrooveJoint{.pf.} = object
    constraint: PConstraint
    grv_n: TVector
    grv_a: TVector
    grv_b: TVector
    anchr2: TVector
    grv_tn: TVector
    clamp: CpFloat
    r1: TVector
    r2: TVector
    k1: TVector
    k2: TVector
    jAcc: TVector
    jMaxLen: CpFloat
    bias: TVector
  PDampedSpring = ptr TDampedSpring
  TDampedSpring{.pf.} = object
    constraint: PConstraint
    anchr1: TVector
    anchr2: TVector
    restLength: CpFloat
    stiffness: CpFloat
    damping: CpFloat
    springForceFunc: TDampedSpringForceFunc
    target_vrn: CpFloat
    v_coef: CpFloat
    r1: TVector
    r2: TVector
    nMass: CpFloat
    n: TVector
  PDampedRotarySpring = ptr TDampedRotarySpring
  TDampedRotarySpring{.pf.} = object
    constraint: PConstraint
    restAngle: CpFloat
    stiffness: CpFloat
    damping: CpFloat
    springTorqueFunc: TDampedRotarySpringTorqueFunc
    target_wrn: CpFloat
    w_coef: CpFloat
    iSum: CpFloat
  PRotaryLimitJoint = ptr TRotaryLimitJoint
  TRotaryLimitJoint{.pf.} = object
    constraint: PConstraint
    min: CpFloat
    max: CpFloat
    iSum: CpFloat
    bias: CpFloat
    jAcc: CpFloat
    jMax: CpFloat
  PRatchetJoint = ptr TRatchetJoint
  TRatchetJoint{.pf.} = object
    constraint: PConstraint
    angle: CpFloat
    phase: CpFloat
    ratchet: CpFloat
    iSum: CpFloat
    bias: CpFloat
    jAcc: CpFloat
    jMax: CpFloat
  PGearJoint = ptr TGearJoint
  TGearJoint{.pf.} = object
    constraint: PConstraint
    phase: CpFloat
    ratio: CpFloat
    ratio_inv: CpFloat
    iSum: CpFloat
    bias: CpFloat
    jAcc: CpFloat
    jMax: CpFloat
  PSimpleMotor = ptr TSimpleMotor
  TSimpleMotor{.pf.} = object
    constraint: PConstraint
    rate: CpFloat
    iSum: CpFloat
    jAcc: CpFloat
    jMax: CpFloat
  TDampedSpringForceFunc* = proc (spring: PConstraint; dist: CpFloat): CpFloat{.
    cdecl.}
  TDampedRotarySpringTorqueFunc* = proc (spring: PConstraint;
      relativeAngle: CpFloat): CpFloat {.cdecl.}
#/ Destroy a constraint.
proc destroy*(constraint: PConstraint){.
  cdecl, importc: "cpConstraintDestroy", dynlib: Lib.}
#/ Destroy and free a constraint.111
proc free*(constraint: PConstraint){.
  cdecl, importc: "cpConstraintFree", dynlib: Lib.}

#/ @private
proc activateBodies(constraint: PConstraint) {.inline.} =
  if not constraint.a.isNil: constraint.a.activate()
  if not constraint.b.isNil: constraint.b.activate()

# /// @private
# #define CP_DefineConstraintStructGetter(type, member, name) \
# static inline type cpConstraint##Get##name(const cpConstraint *constraint){return constraint->member;}
# /// @private
# #define CP_DefineConstraintStructSetter(type, member, name) \
# static inline void cpConstraint##Set##name(cpConstraint *constraint, type value){ \
# 	cpConstraintActivateBodies(constraint); \
# 	constraint->member = value; \
# }
template defConstraintSetter(memberType: typedesc, member: expr, name: expr): stmt {.immediate.} =
  proc `set name`*(constraint: PConstraint, value: memberType) {.cdecl.} =
    activateBodies(constraint)
    constraint.member = value
template defConstraintProp(memberType: typedesc, member: expr, name: expr): stmt {.immediate.} =
  defGetter(PConstraint, memberType, member, name)
  defConstraintSetter(memberType, member, name)
# CP_DefineConstraintStructGetter(cpSpace*, CP_PRIVATE(space), Space)
defGetter(PConstraint, PSpace, space, Space)
defGetter(PConstraint, PBody, a, A)
defGetter(PConstraint, PBody, a, B)
defGetter(PConstraint, CpFloat, maxForce, MaxForce)
defGetter(PConstraint, CpFloat, errorBias, ErrorBias)
defGetter(PConstraint, CpFloat, maxBias, MaxBias)
defGetter(PConstraint, TConstraintPreSolveFunc, preSolve, PreSolveFunc)
defGetter(PConstraint, TConstraintPostSolveFunc, postSolve, PostSolveFunc)
defGetter(PConstraint, CpDataPointer, data, UserData)
# Get the last impulse applied by this constraint.
proc getImpulse*(constraint: PConstraint): CpFloat {.inline.} =
  return constraint.klass.getImpulse(constraint)

# #define cpConstraintCheckCast(constraint, struct) \
# 	cpAssertHard(constraint->CP_PRIVATE(klass) == struct##GetClass(), "Constraint is not a "#struct)
# #define CP_DefineConstraintGetter(struct, type, member, name) \
# static inline type struct##Get##name(const cpConstraint *constraint){ \
# 	cpConstraintCheckCast(constraint, struct); \
# 	return ((struct *)constraint)->member; \
# }
# #define CP_DefineConstraintSetter(struct, type, member, name) \
# static inline void struct##Set##name(cpConstraint *constraint, type value){ \
# 	cpConstraintCheckCast(constraint, struct); \
# 	cpConstraintActivateBodies(constraint); \
# 	((struct *)constraint)->member = value; \
# }
template constraintCheckCast(constraint: PConstraint, ctype: expr): stmt {.immediate.} =
  assert(constraint.klass == `ctype getClass`(), "Constraint is the wrong class")
template defCGetter(ctype: expr, memberType: typedesc, member: expr, name: expr): stmt {.immediate.} =
  proc `get ctype name`*(constraint: PConstraint): memberType {.cdecl.} =
    constraintCheckCast(constraint, ctype)
    result = cast[`P ctype`](constraint).member
template defCSetter(ctype: expr, memberType: typedesc, member: expr, name: expr): stmt {.immediate.} =
  proc `set ctype name`*(constraint: PConstraint, value: memberType) {.cdecl.} =
    constraintCheckCast(constraint, ctype)
    activateBodies(constraint)
    cast[`P ctype`](constraint).member = value
template defCProp(ctype: expr, memberType: typedesc, member: expr, name: expr): stmt {.immediate.} =
  defCGetter(ctype, memberType, member, name)
  defCSetter(ctype, memberType, member, name)

proc PinJointGetClass*(): PConstraintClass{.
  cdecl, importc: "cpPinJointGetClass", dynlib: Lib.}
#/ @private

#/ Allocate a pin joint.
proc AllocPinJoint*(): PPinJoint{.
  cdecl, importc: "cpPinJointAlloc", dynlib: Lib.}
#/ Initialize a pin joint.
proc PinJointInit*(joint: PPinJoint; a: PBody; b: PBody; anchr1: TVector;
                   anchr2: TVector): PPinJoint{.
  cdecl, importc: "cpPinJointInit", dynlib: Lib.}
#/ Allocate and initialize a pin joint.
proc newPinJoint*(a: PBody; b: PBody; anchr1: TVector; anchr2: TVector): PConstraint{.
  cdecl, importc: "cpPinJointNew", dynlib: Lib.}
# CP_DefineConstraintProperty(cpPinJoint, cpVect, anchr1, Anchr1)
defCProp(PinJoint, TVector, anchr1, Anchr1)
defCProp(PinJoint, TVector, anchr2, Anchr2)
defCProp(PinJoint, CpFloat, dist, Dist)

proc SlideJointGetClass*(): PConstraintClass{.
  cdecl, importc: "cpSlideJointGetClass", dynlib: Lib.}
#/ Allocate a slide joint.
proc AllocSlideJoint*(): PSlideJoint{.
  cdecl, importc: "cpSlideJointAlloc", dynlib: Lib.}
#/ Initialize a slide joint.
proc init*(joint: PSlideJoint; a, b: PBody; anchr1, anchr2: TVector;
            min, max: CpFloat): PSlideJoint{.
  cdecl, importc: "cpSlideJointInit", dynlib: Lib.}
#/ Allocate and initialize a slide joint.
proc newSlideJoint*(a, b: PBody; anchr1, anchr2: TVector; min, max: CpFloat): PConstraint{.
  cdecl, importc: "cpSlideJointNew", dynlib: Lib.}

defCProp(SlideJoint, TVector, anchr1, Anchr1)
defCProp(SlideJoint, TVector, anchr2, Anchr2)
defCProp(SlideJoint, CpFloat, min, Min)
defCProp(SlideJoint, CpFloat, max, Max)

proc PivotJointGetClass*(): PConstraintClass {.
  cdecl, importc: "cpPivotJointGetClass", dynlib: Lib.}

#/ Allocate a pivot joint
proc allocPivotJoint*(): PPivotJoint{.
  cdecl, importc: "cpPivotJointAlloc", dynlib: Lib.}
#/ Initialize a pivot joint.
proc init*(joint: PPivotJoint; a, b: PBody; anchr1, anchr2: TVector): PPivotJoint{.
  cdecl, importc: "cpPivotJointInit", dynlib: Lib.}
#/ Allocate and initialize a pivot joint.
proc newPivotJoint*(a, b: PBody; pivot: TVector): PConstraint{.
  cdecl, importc: "cpPivotJointNew", dynlib: Lib.}
#/ Allocate and initialize a pivot joint with specific anchors.
proc newPivotJoint*(a, b: PBody; anchr1, anchr2: TVector): PConstraint{.
  cdecl, importc: "cpPivotJointNew2", dynlib: Lib.}

defCProp(PivotJoint, TVector, anchr1, Anchr1)
defCProp(PivotJoint, TVector, anchr2, Anchr2)


proc GrooveJointGetClass*(): PConstraintClass{.
  cdecl, importc: "cpGrooveJointGetClass", dynlib: Lib.}
#/ Allocate a groove joint.
proc GrooveJointAlloc*(): ptr TGrooveJoint{.
  cdecl, importc: "cpGrooveJointAlloc", dynlib: Lib.}
#/ Initialize a groove joint.
proc Init*(joint: PGrooveJoint; a, b: PBody; groove_a, groove_b, anchr2: TVector): PGrooveJoint{.
  cdecl, importc: "cpGrooveJointInit", dynlib: Lib.}
#/ Allocate and initialize a groove joint.
proc newGrooveJoint*(a, b: PBody; groove_a, groove_b, anchr2: TVector): PConstraint{.
  cdecl, importc: "cpGrooveJointNew", dynlib: Lib.}

defCGetter(GrooveJoint, TVector, grv_a, GrooveA)
defCGetter(GrooveJoint, TVector, grv_b, GrooveB)
# /// Set endpoint a of a groove joint's groove
proc SetGrooveA*(constraint: PConstraint, value: TVector) {.
  cdecl, importc: "cpGrooveJointSetGrooveA", dynlib: Lib.}
# /// Set endpoint b of a groove joint's groove
proc SetGrooveB*(constraint: PConstraint, value: TVector) {.
  cdecl, importc: "cpGrooveJointSetGrooveB", dynlib: Lib.}
defCProp(GrooveJoint, TVector, anchr2, Anchr2)

proc DampedSpringGetClass*(): PConstraintClass{.
  cdecl, importc: "cpDampedSpringGetClass", dynlib: Lib.}
#/ Allocate a damped spring.
proc AllocDampedSpring*(): PDampedSpring{.
  cdecl, importc: "cpDampedSpringAlloc", dynlib: Lib.}
#/ Initialize a damped spring.
proc init*(joint: PDampedSpring; a, b: PBody; anchr1, anchr2: TVector;
            restLength, stiffness, damping: CpFloat): PDampedSpring{.
  cdecl, importc: "cpDampedSpringInit", dynlib: Lib.}
#/ Allocate and initialize a damped spring.
proc newDampedSpring*(a, b: PBody; anchr1, anchr2: TVector;
                      restLength, stiffness, damping: CpFloat): PConstraint{.
  cdecl, importc: "cpDampedSpringNew", dynlib: Lib.}

# CP_DefineConstraintProperty(cpDampedSpring, cpVect, anchr1, Anchr1)
defCProp(DampedSpring, TVector, anchr1, Anchr1)
defCProp(DampedSpring, TVector, anchr2, Anchr2)
defCProp(DampedSpring, CpFloat, restLength, RestLength)
defCProp(DampedSpring, CpFloat, stiffness, Stiffness)
defCProp(DampedSpring, CpFloat, damping, Damping)
defCProp(DampedSpring, TDampedSpringForceFunc, springForceFunc, SpringForceFunc)


proc DampedRotarySpringGetClass*(): PConstraintClass{.
  cdecl, importc: "cpDampedRotarySpringGetClass", dynlib: Lib.}

#/ Allocate a damped rotary spring.
proc DampedRotarySpringAlloc*(): PDampedRotarySpring{.
  cdecl, importc: "cpDampedRotarySpringAlloc", dynlib: Lib.}
#/ Initialize a damped rotary spring.
proc init*(joint: PDampedRotarySpring; a, b: PBody;
            restAngle, stiffness, damping: CpFloat): PDampedRotarySpring{.
  cdecl, importc: "cpDampedRotarySpringInit", dynlib: Lib.}
#/ Allocate and initialize a damped rotary spring.
proc DampedRotarySpringNew*(a, b: PBody; restAngle, stiffness, damping: CpFloat): PConstraint{.
  cdecl, importc: "cpDampedRotarySpringNew", dynlib: Lib.}

defCProp(DampedRotarySpring, CpFloat, restAngle, RestAngle)
defCProp(DampedRotarySpring, CpFloat, stiffness, Stiffness)
defCProp(DampedRotarySpring, CpFloat, damping, Damping)
defCProp(DampedRotarySpring, TDampedRotarySpringTorqueFunc, springTorqueFunc, SpringTorqueFunc)


proc RotaryLimitJointGetClass*(): PConstraintClass{.
  cdecl, importc: "cpRotaryLimitJointGetClass", dynlib: Lib.}
#/ Allocate a damped rotary limit joint.
proc allocRotaryLimitJoint*(): PRotaryLimitJoint{.
  cdecl, importc: "cpRotaryLimitJointAlloc", dynlib: Lib.}
#/ Initialize a damped rotary limit joint.
proc init*(joint: PRotaryLimitJoint; a, b: PBody; min, max: CpFloat): PRotaryLimitJoint{.
  cdecl, importc: "cpRotaryLimitJointInit", dynlib: Lib.}
#/ Allocate and initialize a damped rotary limit joint.
proc newRotaryLimitJoint*(a, b: PBody; min, max: CpFloat): PConstraint{.
  cdecl, importc: "cpRotaryLimitJointNew", dynlib: Lib.}

defCProp(RotaryLimitJoint, CpFloat, min, Min)
defCProp(RotaryLimitJoint, CpFloat, max, Max)


proc RatchetJointGetClass*(): PConstraintClass{.
  cdecl, importc: "cpRatchetJointGetClass", dynlib: Lib.}
#/ Allocate a ratchet joint.
proc AllocRatchetJoint*(): PRatchetJoint{.
  cdecl, importc: "cpRatchetJointAlloc", dynlib: Lib.}
#/ Initialize a ratched joint.
proc init*(joint: PRatchetJoint; a, b: PBody; phase, ratchet: CpFloat): PRatchetJoint{.
  cdecl, importc: "cpRatchetJointInit", dynlib: Lib.}
#/ Allocate and initialize a ratchet joint.
proc NewRatchetJoint*(a, b: PBody; phase, ratchet: CpFloat): PConstraint{.
  cdecl, importc: "cpRatchetJointNew", dynlib: Lib.}

defCProp(RatchetJoint, CpFloat, angle, Angle)
defCProp(RatchetJoint, CpFloat, phase, Phase)
defCProp(RatchetJoint, CpFloat, ratchet, Ratchet)


proc GearJointGetClass*(): PConstraintClass{.cdecl,
    importc: "cpGearJointGetClass", dynlib: Lib.}
#/ Allocate a gear joint.
proc AllocGearJoint*(): PGearJoint{.
  cdecl, importc: "cpGearJointAlloc", dynlib: Lib.}
#/ Initialize a gear joint.
proc init*(joint: PGearJoint; a, b: PBody, phase, ratio: CpFloat): PGearJoint{.
  cdecl, importc: "cpGearJointInit", dynlib: Lib.}
#/ Allocate and initialize a gear joint.
proc NewGearJoint*(a, b: PBody; phase, ratio: CpFloat): PConstraint{.
  cdecl, importc: "cpGearJointNew", dynlib: Lib.}

defCProp(GearJoint, CpFloat, phase, Phase)
defCGetter(GearJoint, CpFloat, ratio, Ratio)
#/ Set the ratio of a gear joint.
proc GearJointSetRatio*(constraint: PConstraint; value: CpFloat){.
  cdecl, importc: "cpGearJointSetRatio", dynlib: Lib.}


proc SimpleMotorGetClass*(): PConstraintClass{.
  cdecl, importc: "cpSimpleMotorGetClass", dynlib: Lib.}
#/ Allocate a simple motor.
proc AllocSimpleMotor*(): PSimpleMotor{.
  cdecl, importc: "cpSimpleMotorAlloc", dynlib: Lib.}
#/ initialize a simple motor.
proc init*(joint: PSimpleMotor; a, b: PBody;
                      rate: CpFloat): PSimpleMotor{.
  cdecl, importc: "cpSimpleMotorInit", dynlib: Lib.}
#/ Allocate and initialize a simple motor.
proc newSimpleMotor*(a, b: PBody; rate: CpFloat): PConstraint{.
  cdecl, importc: "cpSimpleMotorNew", dynlib: Lib.}

defCProp(SimpleMotor, CpFloat, rate, Rate)



