public void ShatterShape(cpPolyShape shape, float cellSize, cpVect focus)
{
space.RemoveShape(shape);
space.RemoveBody(shape.GetBody());
cpBB bb = shape.bb;
int width = (int)((bb.r - bb.l) / cellSize) + 1;
int height = (int)((bb.t - bb.b) / cellSize) + 1;
// printf("Splitting as %dx%d\n", width, height);
WorleyContex context = new WorleyContex((int)RandomHelper.frand(), cellSize, width, height, bb, focus);
for (int i = 0; i < context.width; i++)
{
for (int j = 0; j < context.height; j++)
{
cpVect cell = WorleyPoint(i, j, ref context);
cpPointQueryInfo cp = null;
if (shape.PointQuery(cell, ref cp) < 0.0f)
{
ShatterCell(shape, cell, i, j, ref context);
}
}
}
//cpBodyFree(cpShapeGetBody(shape));
//cpShapeFree(shape);
}
int ClipCell(cpShape shape, cpVect center, int i, int j, WorleyContex context, cpVect[] verts, cpVect[] clipped, int count)
{
cpVect other = WorleyPoint(i, j, ref context);
// printf(" other %dx%d: (% 5.2f, % 5.2f) ", i, j, other.x, other.y);
cpPointQueryInfo queryInfo = null;
if (shape.PointQuery(other, ref queryInfo) > 0.0f)
{
for (int x = 0; x < count; x++)
{
clipped[x] = new cpVect(verts[x]);
}
return(count);
}
else
{
// printf("clipped\n");
}
cpVect n = cpVect.cpvsub(other, center);
float dist = cpVect.cpvdot(n, cpVect.cpvlerp(center, other, 0.5f));
int clipped_count = 0;
for (j = 0, i = count - 1; j < count; i = j, j++)
{
cpVect a = verts[i];
float a_dist = cpVect.cpvdot(a, n) - dist;
if (a_dist <= 0.0f)
{
clipped[clipped_count] = a;
clipped_count++;
}
cpVect b = verts[j];
float b_dist = cpVect.cpvdot(b, n) - dist;
if (a_dist * b_dist < 0.0f)
{
float t = cp.cpfabs(a_dist) / (cp.cpfabs(a_dist) + cp.cpfabs(b_dist));
clipped[clipped_count] = cpVect.cpvlerp(a, b, t);
clipped_count++;
}
}
return(clipped_count);
}
cpVect WorleyPoint(int i, int j, ref WorleyContex context)
{
float size = context.cellSize;
int width = context.width;
int height = context.height;
cpBB bb = context.bb;
// cpVect fv = cpv(0.5, 0.5);
cpVect fv = HashVect(i, j, context.seed);
return(new cpVect(
cp.cpflerp(bb.l, bb.r, 0.5f) + size * (i + fv.x - width * 0.5f),
cp.cpflerp(bb.b, bb.t, 0.5f) + size * (j + fv.y - height * 0.5f)
));
}
public void ShatterCell(cpPolyShape shape, cpVect cell, int cell_i, int cell_j, ref WorleyContex context)
{
// printf("cell %dx%d: (% 5.2f, % 5.2f)\n", cell_i, cell_j, cell.x, cell.y);
cpBody body = shape.body; // cpShapeGetBody(shape);
cpVect[] ping = new cpVect[MAX_VERTEXES_PER_VORONOI]; // cpVect[ (cpVect*)alloca( * sizeof(cpVect));
cpVect[] pong = new cpVect[MAX_VERTEXES_PER_VORONOI]; //(cpVect*)alloca(MAX_VERTEXES_PER_VORONOI * sizeof(cpVect));
int count = shape.Count; // cpPolyShapeGetCount();
count = (count > MAX_VERTEXES_PER_VORONOI ? MAX_VERTEXES_PER_VORONOI : count);
for (int i = 0; i < count; i++)
{
ping[i] = body.LocalToWorld(shape.GetVert(i));
}
cpPointQueryInfo info = null;
for (int i = 0; i < context.width; i++)
{
for (int j = 0; j < context.height; j++)
{
if (
!(i == cell_i && j == cell_j) &&
shape.PointQuery(cell, ref info) < 0
)
{
count = ClipCell(shape, cell, i, j, context, ping, pong, count);
for (int u = 0; u < pong.Length; u++)
{
if (pong[u] != null)
{
ping[u] = new cpVect(pong[u]);
}
}
}
}
}
cpVect centroid = cp.CentroidForPoly(count, ping);
float mass = cp.AreaForPoly(count, ping, 0) * DENSITY;
float moment = cp.MomentForPoly(mass, count, ping, cpVect.cpvneg(centroid), 0);
cpBody new_body = space.AddBody(new cpBody(mass, moment));
new_body.SetPosition(centroid);
new_body.SetPosition(centroid);
new_body.SetVelocity(body.GetVelocityAtLocalPoint(centroid));
new_body.SetAngularVelocity(body.GetAngularVelocity());
cpTransform transform = cpTransform.Translate(cpVect.cpvneg(centroid));
cpShape new_shape = space.AddShape(new cpPolyShape(new_body, count, ping, transform, 0));
// Copy whatever properties you have set on the original shape that are important
new_shape.SetFriction(shape.GetFriction());
}
