public cpShape(cpBody body, cpShapeMassInfo massInfo)
{
/// The rigid body this collision shape is attached to.
this.body = body;
this.massInfo = massInfo;
/// The current bounding box of the shape.
/// The current bounding box of the shape.
///
//this.bb_l = this.bb_b = this.bb_r = this.bb_t = 0;
this.bb = new cpBB(0, 0, 0, 0);
//this.hashid = (cp.shapeIDCounter++).ToString();
/// Sensor flag.
/// Sensor shapes call collision callbacks but don't produce collisions.
this.sensor = false;
filter = new cpShapeFilter(cp.NO_GROUP, cp.ALL_CATEGORIES, cp.ALL_CATEGORIES);
/// Coefficient of restitution. (elasticity)
this.e = 0;
/// Coefficient of friction.
this.u = 0;
/// Surface velocity used when solving for friction.
this.surfaceV = cpVect.Zero;
/// Collision type of this shape used when picking collision handlers.
this.type = 0;
this.space = null;
}
public static cpShapeMassInfo cpCircleShapeMassInfo(float mass, float radius, cpVect center)
{
var info = new cpShapeMassInfo(
mass, cp.MomentForCircle(1.0f, 0.0f, radius, cpVect.Zero),
center,
cp.AreaForCircle(0.0f, radius)
);
return info;
}
public static cpShapeMassInfo cpCircleShapeMassInfo(float mass, float radius, cpVect center)
{
var info = new cpShapeMassInfo(
mass, cp.MomentForCircle(1.0f, 0.0f, radius, cpVect.Zero),
center,
cp.AreaForCircle(0.0f, radius)
);
return(info);
}
public static cpShapeMassInfo cpSegmentShapeMassInfo(float mass, cpVect a, cpVect b, float r)
{
var info = new cpShapeMassInfo(
mass, cp.MomentForBox(1.0f, cpVect.cpvdist(a, b) + 2.0f * r, 2.0f * r), // TODO is an approximation.
cpVect.cpvlerp(a, b, 0.5f),
cp.AreaForSegment(a, b, r)
);
return(info);
}
public static cpShapeMassInfo MassInfo(float mass, int count, cpVect[] verts, float radius)
{
// TODO moment is approximate due to radius.
cpVect centroid = cp.CentroidForPoly(count, verts);
cpShapeMassInfo info = new cpShapeMassInfo(
mass, cp.MomentForPoly(1.0f, count, verts, cpVect.cpvneg(centroid), radius),
centroid,
cp.AreaForPoly(count, verts, radius)
);
return(info);
}
public static cpShapeMassInfo cpPolyShapeMassInfo(float mass, int count, cpVect[] verts, float radius)
{
cpVect centroid = cp.CentroidForPoly(count, verts);
var info = new cpShapeMassInfo(
mass,
cp.MomentForPoly(1.0f, count, verts, cpVect.cpvneg(centroid), radius),
centroid,
cp.AreaForCircle(0.0f, radius)
);
return(info);
}
// Should *only* be called when shapes with mass info are modified, added or removed.
public void AccumulateMassFromShapes()
{
if (bodyType != cpBodyType.DYNAMIC)
{
return;
}
// Reset the body's mass data.
this.m = this.i = 0.0f;
this.cog = cpVect.Zero;
// Cache the position to realign it at the end.
cpVect pos = GetPosition();
// Accumulate mass from shapes.
eachShape((shape, o) =>
{
cpShapeMassInfo info = shape.massInfo;
float m = info.m;
if (m > 0.0f)
{
float msum = this.m + m;
this.i += m * info.i + cpVect.cpvdistsq(this.cog, info.cog) * (m * this.m) / msum;
this.cog = cpVect.cpvlerp(this.cog, info.cog, m / msum);
this.m = msum;
}
}, null);
// Recalculate the inverses.
this.m_inv = 1.0f / this.m;
this.i_inv = 1.0f / this.i;
// Realign the body since the CoG has probably moved.
SetPosition(pos);
AssertSaneBody();
}
public static cpShapeMassInfo cpSegmentShapeMassInfo(float mass, cpVect a, cpVect b, float r)
{
var info = new cpShapeMassInfo(
mass, cp.MomentForBox(1.0f, cpVect.cpvdist(a, b) + 2.0f * r, 2.0f * r), // TODO is an approximation.
cpVect.cpvlerp(a, b, 0.5f),
cp.AreaForSegment(a, b, r)
);
return info;
}
public static cpShapeMassInfo cpPolyShapeMassInfo(float mass, int count, cpVect[] verts, float radius)
{
cpVect centroid = cp.CentroidForPoly(count, verts);
var info = new cpShapeMassInfo(
mass,
cp.MomentForPoly(1.0f, count, verts, cpVect.cpvneg(centroid), radius),
centroid,
cp.AreaForCircle(0.0f, radius)
);
return info;
}
public cpShape(cpBody body, cpShapeMassInfo massInfo)
{
/// The rigid body this collision shape is attached to.
this.body = body;
this.massInfo = massInfo;
/// The current bounding box of the shape.
/// The current bounding box of the shape.
///
//this.bb_l = this.bb_b = this.bb_r = this.bb_t = 0;
this.bb = new cpBB(0, 0, 0, 0);
//this.hashid = (cp.shapeIDCounter++).ToString();
/// Sensor flag.
/// Sensor shapes call collision callbacks but don't produce collisions.
this.sensor = false;
filter = new cpShapeFilter(cp.NO_GROUP, cp.ALL_CATEGORIES, cp.ALL_CATEGORIES);
/// Coefficient of restitution. (elasticity)
this.e = 0;
/// Coefficient of friction.
this.u = 0;
/// Surface velocity used when solving for friction.
this.surfaceV = cpVect.Zero;
/// Collision type of this shape used when picking collision handlers.
this.type = 0;
this.space = null;
}
public static cpShapeMassInfo MassInfo(float mass, int count, cpVect[] verts, float radius)
{
// TODO moment is approximate due to radius.
cpVect centroid = cp.CentroidForPoly(count, verts);
cpShapeMassInfo info = new cpShapeMassInfo(
mass, cp.MomentForPoly(1.0f, count, verts, cpVect.cpvneg(centroid), radius),
centroid,
cp.AreaForPoly(count, verts, radius)
);
return info;
}