text: /* Copyright (c) 2013 Scott Lembcke and Howling Moon Software
   * 
   * 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.
   */
  
  #ifndef CHIPMUNK_H
  #define CHIPMUNK_H
  
  #ifdef _MSC_VER
      #define _USE_MATH_DEFINES
  #endif
  
  #include <stdlib.h>
  #include <math.h>
  
  #if defined(WIN32) || defined(_WIN32)
  	// For alloca().
  	#include <malloc.h>
  #else
  	#include <alloca.h>
  #endif
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  // NUKE
  #ifndef CP_ALLOW_PRIVATE_ACCESS
  	#define CP_ALLOW_PRIVATE_ACCESS 0
  #endif
  
  #if CP_ALLOW_PRIVATE_ACCESS == 1
  	#define CP_PRIVATE(__symbol__) __symbol__
  #else
  	#define CP_PRIVATE(__symbol__) __symbol__##_private
  #endif
  
  void cpMessage(const char *condition, const char *file, int line, int isError, int isHardError, const char *message, ...);
  #ifdef NDEBUG
  	#define	cpAssertWarn(__condition__, ...)
  #else
  	#define cpAssertWarn(__condition__, ...) if(!(__condition__)) cpMessage(#__condition__, __FILE__, __LINE__, 0, 0, __VA_ARGS__)
  #endif
  
  #ifdef NDEBUG
  	#define	cpAssertSoft(__condition__, ...)
  #else
  	#define cpAssertSoft(__condition__, ...) if(!(__condition__)){cpMessage(#__condition__, __FILE__, __LINE__, 1, 0, __VA_ARGS__), abort();}
  #endif
  
  // Hard assertions are used in situations where the program definitely will crash anyway, and the reason is inexpensive to detect.
  #define cpAssertHard(__condition__, ...) if(!(__condition__)){cpMessage(#__condition__, __FILE__, __LINE__, 1, 1, __VA_ARGS__); abort();}
  
  #include "chipmunk_types.h"
  	
  /// @defgroup misc Misc
  /// @{
  
  /// Allocated size for various Chipmunk buffers
  #ifndef CP_BUFFER_BYTES
  	#define CP_BUFFER_BYTES (32*1024)
  #endif
  
  #ifndef cpcalloc
  	/// Chipmunk calloc() alias.
  	#define cpcalloc calloc
  #endif
  
  #ifndef cprealloc
  	/// Chipmunk realloc() alias.
  	#define cprealloc realloc
  #endif
  
  #ifndef cpfree
  	/// Chipmunk free() alias.
  	#define cpfree free
  #endif
  
  typedef struct cpArray cpArray;
  typedef struct cpHashSet cpHashSet;
  
  typedef struct cpBody cpBody;
  
  typedef struct cpShape cpShape;
  typedef struct cpCircleShape cpCircleShape;
  typedef struct cpSegmentShape cpSegmentShape;
  typedef struct cpPolyShape cpPolyShape;
  
  typedef struct cpConstraint cpConstraint;
  typedef struct cpPinJoint cpPinJoint;
  typedef struct cpSlideJoint cpSlideJoint;
  typedef struct cpPivotJoint cpPivotJoint;
  typedef struct cpGrooveJoint cpGrooveJoint;
  typedef struct cpDampedSpring cpDampedSpring;
  typedef struct cpDampedRotarySpring cpDampedRotarySpring;
  typedef struct cpRotaryLimitJoint cpRotaryLimitJoint;
  typedef struct cpRatchetJoint cpRatchetJoint;
  typedef struct cpGearJoint cpGearJoint;
  typedef struct cpSimpleMotorJoint cpSimpleMotorJoint;
  
  typedef struct cpCollisionHandler cpCollisionHandler;
  typedef struct cpContactPointSet cpContactPointSet;
  typedef struct cpArbiter cpArbiter;
  
  typedef struct cpSpace cpSpace;
  
  #include "cpVect.h"
  #include "cpBB.h"
  #include "cpTransform.h"
  #include "cpSpatialIndex.h"
  
  #include "cpArbiter.h"	
  
  #include "cpBody.h"
  #include "cpShape.h"
  #include "cpPolyShape.h"
  
  #include "cpConstraint.h"
  
  #include "cpSpace.h"
  
  // Chipmunk 7.0.0
  #define CP_VERSION_MAJOR 7
  #define CP_VERSION_MINOR 0
  #define CP_VERSION_RELEASE 0
  
  /// Version string.
  extern const char *cpVersionString;
  
  /// 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.
  cpFloat cpMomentForCircle(cpFloat m, cpFloat r1, cpFloat r2, cpVect offset);
  
  /// 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.
  cpFloat cpAreaForCircle(cpFloat r1, cpFloat r2);
  
  /// Calculate the moment of inertia for a line segment.
  /// Beveling radius is not supported.
  cpFloat cpMomentForSegment(cpFloat m, cpVect a, cpVect b, cpFloat radius);
  
  /// Calculate the area of a fattened (capsule shaped) line segment.
  cpFloat cpAreaForSegment(cpVect a, cpVect b, cpFloat radius);
  
  /// 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.
  cpFloat cpMomentForPoly(cpFloat m, int count, const cpVect *verts, cpVect offset, cpFloat radius);
  
  /// 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.
  cpFloat cpAreaForPoly(const int count, const cpVect *verts, cpFloat radius);
  
  /// Calculate the natural centroid of a polygon.
  cpVect cpCentroidForPoly(const int count, const cpVect *verts);
  
  /// Calculate the moment of inertia for a solid box.
  cpFloat cpMomentForBox(cpFloat m, cpFloat width, cpFloat height);
  
  /// Calculate the moment of inertia for a solid box.
  cpFloat cpMomentForBox2(cpFloat m, cpBB box);
  
  /// Calculate the convex hull of a given set of points. Returns the count of points in the hull.
  /// @c result must be a pointer to a @c cpVect array with at least @c count elements. If @c verts == @c result, then @c verts will be reduced inplace.
  /// @c first is an optional pointer to an integer to store where the first vertex in the hull came from (i.e. verts[first] == result[0])
  /// @c tol is the allowed amount to shrink the hull when simplifying it. A tolerance of 0.0 creates an exact hull.
  int cpConvexHull(int count, const cpVect *verts, cpVect *result, int *first, cpFloat tol);
  
  #ifdef _MSC_VER
  #include "malloc.h"
  #endif
  
  /// Convenience macro to work with cpConvexHull.
  /// @c count and @c verts is the input array passed to cpConvexHull().
  /// @c count_var and @c verts_var are the names of the variables the macro creates to store the result.
  /// The output vertex array is allocated on the stack using alloca() so it will be freed automatically, but cannot be returned from the current scope.
  #define CP_CONVEX_HULL(__count__, __verts__, __count_var__, __verts_var__) \
  cpVect *__verts_var__ = (cpVect *)alloca(__count__*sizeof(cpVect)); \
  int __count_var__ = cpConvexHull(__count__, __verts__, __verts_var__, NULL, 0.0); \
  
  /// Returns the closest point on the line segment ab, to the point p.
  static inline cpVect
  cpClosetPointOnSegment(const cpVect p, const cpVect a, const cpVect b)
  {
  	cpVect delta = cpvsub(a, b);
  	cpFloat t = cpfclamp01(cpvdot(delta, cpvsub(p, b))/cpvlengthsq(delta));
  	return cpvadd(b, cpvmult(delta, t));
  }
  
  #if defined(__has_extension)
  #if __has_extension(blocks)
  // Define alternate block based alternatives for a few of the callback heavy functions.
  // Collision handlers are post-step callbacks are not included to avoid memory management issues.
  // If you want to use blocks for those and are aware of how to correctly manage the memory, the implementation is trivial. 
  
  void cpSpaceEachBody_b(cpSpace *space, void (^block)(cpBody *body));
  void cpSpaceEachShape_b(cpSpace *space, void (^block)(cpShape *shape));
  void cpSpaceEachConstraint_b(cpSpace *space, void (^block)(cpConstraint *constraint));
  
  void cpBodyEachShape_b(cpBody *body, void (^block)(cpShape *shape));
  void cpBodyEachConstraint_b(cpBody *body, void (^block)(cpConstraint *constraint));
  void cpBodyEachArbiter_b(cpBody *body, void (^block)(cpArbiter *arbiter));
  
  typedef void (^cpSpacePointQueryBlock)(cpShape *shape, cpVect point, cpFloat distance, cpVect gradient);
  void cpSpacePointQuery_b(cpSpace *space, cpVect point, cpFloat maxDistance, cpShapeFilter filter, cpSpacePointQueryBlock block);
  
  typedef void (^cpSpaceSegmentQueryBlock)(cpShape *shape, cpVect point, cpVect normal, cpFloat alpha);
  void cpSpaceSegmentQuery_b(cpSpace *space, cpVect start, cpVect end, cpFloat radius, cpShapeFilter filter, cpSpaceSegmentQueryBlock block);
  
  typedef void (^cpSpaceBBQueryBlock)(cpShape *shape);
  void cpSpaceBBQuery_b(cpSpace *space, cpBB bb, cpShapeFilter filter, cpSpaceBBQueryBlock block);
  
  typedef void (^cpSpaceShapeQueryBlock)(cpShape *shape, cpContactPointSet *points);
  cpBool cpSpaceShapeQuery_b(cpSpace *space, cpShape *shape, cpSpaceShapeQueryBlock block);
  
  #endif
  #endif
  
  
  //@}
  
  #ifdef __cplusplus
  }
  
  static inline cpVect operator *(const cpVect v, const cpFloat s){return cpvmult(v, s);}
  static inline cpVect operator +(const cpVect v1, const cpVect v2){return cpvadd(v1, v2);}
  static inline cpVect operator -(const cpVect v1, const cpVect v2){return cpvsub(v1, v2);}
  static inline cpBool operator ==(const cpVect v1, const cpVect v2){return cpveql(v1, v2);}
  static inline cpVect operator -(const cpVect v){return cpvneg(v);}
  
  #endif
  #endif
  