cpShape.h

/* 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.
 */
 

typedef struct cpShapeClass cpShapeClass;

typedef struct cpNearestPointQueryInfo {
  cpShape *shape;
  cpVect p;
  cpFloat d;
} cpNearestPointQueryInfo;

typedef struct cpSegmentQueryInfo {
  cpShape *shape;
  cpFloat t;
  cpVect n;
} cpSegmentQueryInfo;

typedef enum cpShapeType{
  CP_CIRCLE_SHAPE,
  CP_SEGMENT_SHAPE,
  CP_POLY_SHAPE,
  CP_NUM_SHAPES
} cpShapeType;

typedef cpBB (*cpShapeCacheDataImpl)(cpShape *shape, cpVect p, cpVect rot);
typedef void (*cpShapeDestroyImpl)(cpShape *shape);
typedef void (*cpShapeNearestPointQueryImpl)(cpShape *shape, cpVect p, cpNearestPointQueryInfo *info);
typedef void (*cpShapeSegmentQueryImpl)(cpShape *shape, cpVect a, cpVect b, cpSegmentQueryInfo *info);

struct cpShapeClass {
  cpShapeType type;
  
  cpShapeCacheDataImpl cacheData;
  cpShapeDestroyImpl destroy;
  cpShapeNearestPointQueryImpl nearestPointQuery;
  cpShapeSegmentQueryImpl segmentQuery;
};

struct cpShape {
  CP_PRIVATE(const cpShapeClass *klass);
  
  cpBody *body;

  cpBB bb;
  
  cpBool sensor;
  
  cpFloat e;
  cpFloat u;
  cpVect surface_v;

  cpDataPointer data;
  
  cpCollisionType collision_type;
  cpGroup group;
  // Layer bitmask for this shape. Shapes only collide if the bitwise and of their layers is non-zero.
  cpLayers layers;
  
  CP_PRIVATE(cpSpace *space);
  
  CP_PRIVATE(cpShape *next);
  CP_PRIVATE(cpShape *prev);
  
  CP_PRIVATE(cpHashValue hashid);
};

void cpShapeDestroy(cpShape *shape);
void cpShapeFree(cpShape *shape);

cpBB cpShapeCacheBB(cpShape *shape);
cpBB cpShapeUpdate(cpShape *shape, cpVect pos, cpVect rot);

cpBool cpShapePointQuery(cpShape *shape, cpVect p);

cpFloat cpShapeNearestPointQuery(cpShape *shape, cpVect p, cpNearestPointQueryInfo *out);

cpBool cpShapeSegmentQuery(cpShape *shape, cpVect a, cpVect b, cpSegmentQueryInfo *info);

static inline cpVect cpSegmentQueryHitPoint(const cpVect start, const cpVect end, const cpSegmentQueryInfo info)
{
  return cpvlerp(start, end, info.t);
}

static inline cpFloat cpSegmentQueryHitDist(const cpVect start, const cpVect end, const cpSegmentQueryInfo info)
{
  return cpvdist(start, end)*info.t;
}

#define CP_DefineShapeStructGetter(type, member, name) \
static inline type cpShapeGet##name(const cpShape *shape){return shape->member;}

#define CP_DefineShapeStructSetter(type, member, name, activates) \
static inline void cpShapeSet##name(cpShape *shape, type value){ \
  if(activates && shape->body) cpBodyActivate(shape->body); \
  shape->member = value; \
}

#define CP_DefineShapeStructProperty(type, member, name, activates) \
CP_DefineShapeStructGetter(type, member, name) \
CP_DefineShapeStructSetter(type, member, name, activates)

CP_DefineShapeStructGetter(cpSpace*, CP_PRIVATE(space), Space)

CP_DefineShapeStructGetter(cpBody*, body, Body)
void cpShapeSetBody(cpShape *shape, cpBody *body);

CP_DefineShapeStructGetter(cpBB, bb, BB)
CP_DefineShapeStructProperty(cpBool, sensor, Sensor, cpTrue)
CP_DefineShapeStructProperty(cpFloat, e, Elasticity, cpFalse)
CP_DefineShapeStructProperty(cpFloat, u, Friction, cpTrue)
CP_DefineShapeStructProperty(cpVect, surface_v, SurfaceVelocity, cpTrue)
CP_DefineShapeStructProperty(cpDataPointer, data, UserData, cpFalse)
CP_DefineShapeStructProperty(cpCollisionType, collision_type, CollisionType, cpTrue)
CP_DefineShapeStructProperty(cpGroup, group, Group, cpTrue)
CP_DefineShapeStructProperty(cpLayers, layers, Layers, cpTrue)

void cpResetShapeIdCounter(void);

#define CP_DeclareShapeGetter(struct, type, name) type struct##Get##name(const cpShape *shape)


typedef struct cpCircleShape {
  cpShape shape;
  
  cpVect c, tc;
  cpFloat r;
} cpCircleShape;

cpCircleShape* cpCircleShapeAlloc(void);
cpCircleShape* cpCircleShapeInit(cpCircleShape *circle, cpBody *body, cpFloat radius, cpVect offset);
cpShape* cpCircleShapeNew(cpBody *body, cpFloat radius, cpVect offset);

CP_DeclareShapeGetter(cpCircleShape, cpVect, Offset);
CP_DeclareShapeGetter(cpCircleShape, cpFloat, Radius);


typedef struct cpSegmentShape {
  cpShape shape;
  
  cpVect a, b, n;
  cpVect ta, tb, tn;
  cpFloat r;
  
  cpVect a_tangent, b_tangent;
} cpSegmentShape;

cpSegmentShape* cpSegmentShapeAlloc(void);
cpSegmentShape* cpSegmentShapeInit(cpSegmentShape *seg, cpBody *body, cpVect a, cpVect b, cpFloat radius);
cpShape* cpSegmentShapeNew(cpBody *body, cpVect a, cpVect b, cpFloat radius);

void cpSegmentShapeSetNeighbors(cpShape *shape, cpVect prev, cpVect next);

CP_DeclareShapeGetter(cpSegmentShape, cpVect, A);
CP_DeclareShapeGetter(cpSegmentShape, cpVect, B);
CP_DeclareShapeGetter(cpSegmentShape, cpVect, Normal);
CP_DeclareShapeGetter(cpSegmentShape, cpFloat, Radius);