path: root/externals/gridflow/base/grid.h

/*
	$Id: grid.h,v 1.2 2006-03-15 04:37:08 matju Exp $

	GridFlow
	Copyright (c) 2001,2002,2003,2004,2005 by Mathieu Bouchard

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.

	See file ../COPYING for further informations on licensing terms.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/

#ifndef __GF_GRID_H
#define __GF_GRID_H

// current version number as string literal
#define GF_VERSION "0.8.1"
#define GF_COMPILE_TIME __DATE__ ", " __TIME__

#include <new>
#include <vector>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <stdio.h>
#include <math.h>

#ifdef __APPLE__
static inline void *memalign (size_t a, size_t n) {return malloc(n);}
#else
#include <malloc.h>
#endif

extern "C" {
#include <ruby.h>
#include <rubyio.h>
#include <version.h>
};

#ifndef RUBY_H
#error "Can't do anything without ruby.h"
#endif

#include "../config.h"

#ifdef __WIN32__
#define INT winINT
#define random rand
#undef send
#undef close
#define sigjmp_buf jmp_buf
#define siglongjmp longjmp
#endif

#define BUG(s,args...) {fprintf(stderr,s "\nat: %s\n",args,__PRETTY_FUNCTION__); ::raise(11);}
#define L gfpost("%s:%d in %s",__FILE__,__LINE__,__PRETTY_FUNCTION__);

#ifdef IS_BRIDGE
#define RAISE(args...) rb_raise(rb_eArgError,args)
#else
#define RAISE(args...) rb_raise0(__FILE__,__LINE__,__PRETTY_FUNCTION__,rb_eArgError,args)
#endif

// avoid ruby warning
#ifndef rb_enable_super
#define rb_enable_super(a,b) \
	if (RUBY_RELEASE_CODE < 20030716) rb_enable_super(a,b)
#endif

typedef VALUE Ruby;

/* undocumented function from Ruby that is one thing we need to fix a very elusive bug
that manifests itself when embedding ruby inside a plugin of another app. This exists
for all versions of Ruby up to now, and I don't know when it gets fixed. */
extern "C" void Init_stack(VALUE *addr);

extern "C" {
void rb_raise0(
const char *file, int line, const char *func, VALUE exc, const char *fmt, ...)
__attribute__ ((noreturn));
};
#define SI(_sym_) (rb_intern(#_sym_))
#define SYM(_sym_) (ID2SYM(SI(_sym_)))
#define DGS(_class_) \
	_class_ *self; \
	Data_Get_Struct(rself,_class_,self); \
	self->check_magic();

// returns the size of a statically defined array
// warning: does not work with STACK_ARRAY()
#define COUNT(_array_) ((int)(sizeof(_array_) / sizeof((_array_)[0])))

static inline long  rb_str_len(Ruby s) {return RSTRING(s)->len;}
static inline char *rb_str_ptr(Ruby s) {return RSTRING(s)->ptr;}
static inline long  rb_ary_len(Ruby s) {return  RARRAY(s)->len;}
static inline Ruby *rb_ary_ptr(Ruby s) {return  RARRAY(s)->ptr;}
static inline const char *rb_sym_name(Ruby sym) {return rb_id2name(SYM2ID(sym));}
#define rb_str_pt(s,t) Pt<t>((t*)rb_str_ptr(s),rb_str_len(s))
#define IEVAL(_self_,s) rb_funcall(_self_,SI(instance_eval),1,rb_str_new2(s))
#define EVAL(s) rb_eval_string(s)
#define rassert(_p_) if (!(_p_)) RAISE(#_p_);
// because of older versions of Ruby (1.6.?)
#define rb_obj_class(o) rb_funcall((o),SI(class),0)

#define WATCH(n,ar) { \
	char foo[16*1024], *p=foo; p += sprintf(p,"%s: ",#ar); \
	for (int q=0; q<n; q++) p += sprintf(p,"%lld ",(long long)ar[q]); \
	gfpost("%s",foo);}

// we're gonna override assert, so load it first, to avoid conflicts
#include <assert.h>

#undef assert
#define assert(_expr_) \
	if (!(_expr_)) { \
		fprintf(stderr, "%s:%d: assertion failed: %s is false\n", \
			__FILE__, __LINE__, #_expr_); \
		::abort(); }

// disabling assertion checking?
#ifndef HAVE_DEBUG
#undef assert
#define assert(_foo_)
#endif

#ifdef HAVE_TSC_PROFILING
#define HAVE_PROFILING
#endif

#ifdef HAVE_PROFILING
#define PROF(_self_) for (GFStackMarker gf_marker(_self_);gf_marker.once();)
#else
#define PROF(_self_)
#endif // HAVE_PROFILING

static inline Ruby PTR2FIX (const void *ptr) {
	long p = (long)ptr;
	if ((p&3)!=0) BUG("unaligned pointer: %p\n",ptr);
	return LONG2NUM(p>>2);
}
#define FIX2PTR(type,ruby) ((type *)(TO(long,ruby)<<2))

//****************************************************************

/* int32 was long before, now int, because of amd64 */
typedef char  int8;     typedef unsigned char  uint8;
typedef short int16;    typedef unsigned short uint16;
typedef int   int32;    typedef unsigned int  uint32;
typedef long long int64;typedef unsigned long long uint64;
typedef float  float32;
typedef double float64;

// three-way comparison (T is assumed Comparable)
template <class T> static inline T cmp(T a, T b) { return a<b ? -1 : a>b; }

// a remainder function such that div2(a,b)*b+mod(a,b) = a and for which
// mod(a,b) is in [0;b) or (b;0]. in contrast to C-language builtin a%b,
// this one has uniform behaviour around zero.
static inline int mod(int a, int b) {
int c=a%b; c+=b&-(c&&(a<0)^(b<0)); return c;}

// counterpart of mod(a,b), just like a/b and a%b are counterparts
static inline int div2(int a, int b) {
int c=a<0; return (a/b)-(c&&!!(a%b));}

static inline int32   gf_abs(  int32 a) { return a>0?a:-a; }
static inline int64   gf_abs(  int64 a) { return a>0?a:-a; }
static inline float32 gf_abs(float32 a) { return fabs(a); }
static inline float64 gf_abs(float64 a) { return fabs(a); }

// integer powers in log(b) time. T is assumed Integer
template <class T> static inline T ipow(T a, T b) {
	for(T r=1;;) {if (b&1) r*=a; b>>=1; if (!b) return r; a*=a;}
}

// kludge
static inline float32 ipow(float32 a, float32 b) { return pow(a,b); }
static inline float64 ipow(float64 a, float64 b) { return pow(a,b); }

#undef min
#undef max
// minimum/maximum functions; T is assumed to be Comparable
template <class T> static inline T min(T a, T b) { return a<b?a:b; }
template <class T> static inline T max(T a, T b) { return a>b?a:b; }
//template <class T> inline T min(T a, T b) { T c = (a-b)>>31; return (a&c)|(b&~c); }

// greatest common divisor, by euclid's algorithm
// this runs in log(a+b) number operations
template <class T> static T gcd (T a, T b) {
	while (b) {T c=mod(a,b); a=b; b=c;}
	return a;
}

// greatest common divisor, the binary algorithm. haven't tried yet.
template <class T> static T gcd2 (T a, T b) {
	int s=0;
	while ((a|b)&1==0) { a>>=1; b>>=1; s++; }
	while (a) {
		if (a&1==0) a>>=1;
		else if (b&1==0) b>>=1;
		else {T t=abs(a-b); if (a<b) b=t; else a=t;}
	}
	return b<<s;
}

// least common multiple; this runs in log(a+b) like gcd.
template <class T> static inline T lcm (T a, T b) {return a*b/gcd(a,b);}

// returns the position (0..31) of highest bit set in a word, or 0 if none.
#define Z(N) if ((x>>N)&(((typeof(x))1<<N)-1)) { x>>=N; i+=N; }
static int highest_bit(uint8  x) {int i=0;              Z(4)Z(2)Z(1)return i;}
static int highest_bit(uint16 x) {int i=0;          Z(8)Z(4)Z(2)Z(1)return i;}
static int highest_bit(uint32 x) {int i=0;     Z(16)Z(8)Z(4)Z(2)Z(1)return i;}
static int highest_bit(uint64 x) {int i=0;Z(32)Z(16)Z(8)Z(4)Z(2)Z(1)return i;}
#undef Z
// returns the position (0..31) of lowest bit set in a word, or 0 if none.
template <class T> static int lowest_bit(T n) { return highest_bit((~n+1)&n); }

static double drand() { return 1.0*rand()/(RAND_MAX+1.0); }

// is little-endian
static inline bool is_le() {int x=1; return ((char *)&x)[0];}

#if defined(HAVE_PENTIUM)
static inline uint64 rdtsc() {
	uint64 x; __asm__ volatile (".byte 0x0f, 0x31":"=A"(x)); return x;
}
#elif defined(HAVE_PPC)
static inline uint64 rdtsc() {
#include <mach/mach.h>
#include <mach/mach_time.h>
/* see AbsoluteToNanoseconds(), Microseconds()
http://www.simdtech.org/apps/group_public/email/altivec/msg01956.html
and mach_absolute_time() and mach_timebase_info(&info),
then ns=(time*info.numer)/info.denom;
and the timebase_info is constant
(double)mach_absolute_time*gTimeBaseToNS*/
return 0;
}
#else
static inline uint64 rdtsc() {return 0;}
#endif

#ifdef HAVE_LITE
#define EACH_INT_TYPE(MACRO) MACRO(uint8) MACRO(int16) MACRO(int32)
#define EACH_FLOAT_TYPE(MACRO)
#else
#define EACH_INT_TYPE(MACRO) MACRO(uint8) MACRO(int16) MACRO(int32) MACRO(int64)
#define EACH_FLOAT_TYPE(MACRO) MACRO(float32) MACRO(float64)
#endif
#define EACH_NUMBER_TYPE(MACRO) EACH_INT_TYPE(MACRO) EACH_FLOAT_TYPE(MACRO) MACRO(ruby)

// note: loop unrolling macros assume N!=0
// btw this may cause alignment problems when 8 does not divide N
#define UNROLL_8(MACRO,N,PTR,ARGS...) \
	int n__=(-N)&7; PTR-=n__; N+=n__; \
	switch (n__) { start: \
		case 0:MACRO(0); case 1:MACRO(1); case 2:MACRO(2); case 3:MACRO(3); \
		case 4:MACRO(4); case 5:MACRO(5); case 6:MACRO(6); case 7:MACRO(7); \
		PTR+=8; N-=8; ARGS; if (N) goto start; }
#define UNROLL_4(MACRO,N,PTR,ARGS...) \
	int n__=(-N)&3; PTR-=n__; N+=n__; \
	switch (n__) { start: \
		case 0:MACRO(0); case 1:MACRO(1); case 2:MACRO(2); case 3:MACRO(3); \
		PTR+=4; N-=4; ARGS; if (N) goto start; }

//****************************************************************
// my own little Ruby <-> C++ layer

//struct Arg { Ruby a; };
//struct ArgList { int n; Pt<Arg> v; };
static inline bool INTEGER_P(Ruby x) {return FIXNUM_P(x)||TYPE(x)==T_BIGNUM;}
static inline bool FLOAT_P(Ruby x)   {return TYPE(x)==T_FLOAT;}
#define INT(x) TO(int32,x)
#define TO(t,x) convert(x,(t*)0)

// not using NUM2INT because Ruby can convert Symbol to int
// (by compatibility with Ruby 1.4)
static inline int32 convert(Ruby x, int32 *foo) {
	if (INTEGER_P(x)) return NUM2INT(x);
	if (FLOAT_P(x)) return NUM2INT(rb_funcall(x,SI(round),0));
	RAISE("expected Integer or Float (got %s)",
		rb_str_ptr(rb_funcall(x,SI(inspect),0)));
}
static int16 convert(Ruby x, int16 *foo) {
	int v = INT(x);
	if (v<-0x8000 || v>=0x8000) RAISE("value %d is out of range",v);
	return v;}
static uint16 convert(Ruby x, uint16 *foo) {
	int v = INT(x);
	if (v<0 || v>=0x10000) RAISE("value %d is out of range",v);
	return v;}
static bool  convert(Ruby x, bool  *foo) {
	if (x==Qtrue) return true;
	if (x==Qfalse) return false;
	switch (TYPE(x)) {
		case T_FIXNUM: case T_BIGNUM: case T_FLOAT: return !!INT(x);
		default: RAISE("can't convert to bool");
	}
}

#ifdef HAVE_GCC64
static uint64 convert(Ruby val, uint64 *foo) { return NUM2ULONG(val); }
static  int64 convert(Ruby val,  int64 *foo) { return NUM2ULONG(val); }
static Ruby gf_ull2num(uint64 val) { return ULONG2NUM(val); }
static  Ruby gf_ll2num(uint64 val) { return  LONG2NUM(val); }
#else
static uint64 convert(Ruby val, uint64 *foo) {
	if (FIXNUM_P(val)) return (uint64)FIX2LONG(val);
	if (TYPE(val)!=T_BIGNUM) RAISE("type error");
	uint64 v = (uint64)NUM2UINT(rb_funcall(val,SI(>>),1,INT2FIX(32))) << 32;
	return v + NUM2UINT(rb_funcall(val,SI(&),1,UINT2NUM(0xffffffff)));}
static int64 convert(Ruby val, int64 *foo) {
	if (FIXNUM_P(val)) return (int64)FIX2LONG(val);
	if (TYPE(val)!=T_BIGNUM) RAISE("type error");
	int64 v = (int64)NUM2INT(rb_funcall(val,SI(>>),1,INT2FIX(32))) << 32;
	return v + NUM2UINT(rb_funcall(val,SI(&),1,UINT2NUM(0xffffffff)));}
static Ruby gf_ull2num(uint64 val) {
    Ruby x = rb_funcall(UINT2NUM((uint32)(val>>32)),SI(<<),1,INT2FIX(32));
    return rb_funcall(x,SI(+),1,UINT2NUM((uint32)val));}
static Ruby gf_ll2num(int64 val) {
    Ruby x = rb_funcall( INT2NUM(( int32)(val>>32)),SI(<<),1,INT2FIX(32));
    return rb_funcall(x,SI(+),1,UINT2NUM((uint32)val));}
#endif
    
static long convert(Ruby x, long *foo) {
	return sizeof(long)==sizeof(int32) ?
		convert(x,(int32 *)0) :
		convert(x,(int64 *)0);
}

static float64 convert(Ruby x, float64 *foo) {
	if (INTEGER_P(x)) return INT(x);
	if (TYPE(x)!=T_FLOAT) RAISE("not a Float");
	return ((RFloat*)x)->value;}
static float32 convert(Ruby x, float32 *foo) {
	return (float32) convert(x,(float64 *)0);}
typedef Ruby Symbol, Array, String, Integer;
static Ruby convert(Ruby x, Ruby *bogus) { return x; }
typedef Ruby (*RMethod)(...); /* !@#$ fishy */

#define BUILTIN_SYMBOLS(MACRO) \
	MACRO(_grid,"grid") MACRO(_bang,"bang") MACRO(_float,"float") \
	MACRO(_list,"list") MACRO(_sharp,"#") \
	MACRO(iv_outlets,"@outlets") \
	MACRO(iv_ninlets,"@ninlets") \
	MACRO(iv_noutlets,"@noutlets")
extern struct BuiltinSymbols {
#define FOO(_sym_,_str_) Ruby _sym_;
BUILTIN_SYMBOLS(FOO)
#undef FOO
} bsym;

typedef struct R {
	VALUE r;
	R() {r=Qnil;}
	R(int x) {r=INT2NUM(x);}
	R(unsigned x) {r=UINT2NUM(x);}
	R(long x) {r=LONG2NUM(x);}
	R(unsigned long x) {r=ULONG2NUM(x);}
	R(double x) {r=rb_float_new(x);}
	R( int64 x) {r= gf_ll2num(x);}
	R(uint64 x) {r=gf_ull2num(x);}
	operator bool() {return !!INT2NUM(r);}
	operator uint8 () {return INT2NUM(r);}
	operator int16 () {return INT2NUM(r);}
	operator int32 () {return INT2NUM(r);}
	operator int64 () {return convert(r,(int64*)0);}
	operator float32 () {return convert(r,(float32*)0);}
	operator float64 () {return convert(r,(float64*)0);}
#define FOO(As,Op) \
	R &operator As (int x) {r=rb_funcall(r, SI(Op),1,INT2NUM(x)); return *this;}
	FOO(+=,+) FOO(-=,-) FOO(*=,*) FOO(/=,/) FOO(%=,%)
	FOO(&=,&) FOO(|=,|) FOO(^=,^) FOO(<<=,<<) FOO(>>=,>>)
#undef FOO
//	bool operator  == (int x) {return rb_funcall(r,SI(==),1,INT2NUM(x));}
#define FOO(Op) \
	R operator Op (R x)   {return rb_funcall(r,SI(Op),1,x.r);} \
	R operator Op (int x) {return rb_funcall(r,SI(Op),1,INT2NUM(x));}
	FOO(+) FOO(-) FOO(*) FOO(/) FOO(%)
	FOO(&) FOO(|) FOO(^) FOO(<<) FOO(>>)
	FOO(<) FOO(>) FOO(<=) FOO(>=) FOO(==) FOO(!=)
#undef FOO
	static R value(VALUE r) {R x; x.r=r; return x;}
} ruby;

static R operator -(int a, R b) {return rb_funcall(a,SI(Op),1,INT2NUM(b.r));}

static inline R ipow(R a, R b) {return R::value(rb_funcall(a.r,SI(**),1,b.r));}
static inline R gf_abs(R a) { return R::value(rb_funcall(a.r,SI(abs),0)); }
static inline R cmp(R a, R b) { return R::value(rb_funcall(a.r,SI(<=>),1,b.r));}

//****************************************************************
// hook into pointer manipulation. will help find memory corruption bugs.

template <class T> class Pt {
typedef ptrdiff_t /* and not int nor long */ Z;
public:
	T *p;
#ifdef HAVE_DEBUG
	T *start;
	Z n;
	Pt() : p(0), start(0), n(0) {}
	Pt(T *q, Z _n) : p(q), start(q), n(_n) {}
	Pt(T *q, Z _n, T *_start) : p(q), start(_start), n(_n) {}
#else
	Pt() : p(0) {}
	Pt(T *q, Z _n, T *_start=0) : p(q) {}
#endif
	T &operator *() { return *p; }
	Pt operator+=(Z i) { p+=i; return *this; }
	Pt operator-=(Z	i) { p-=i; return *this; }
	Pt operator++(   ) { p++;  return *this; }
	Pt operator--(   ) { p--;  return *this; }
	Pt operator++(int) { Pt f(*this); ++*this; return f; }
	Pt operator--(int) { Pt f(*this); --*this; return f; }
	T &operator[](Z i) {
#ifdef HAVE_DEBUG_HARDER
		if (!(p+i>=start && p+i<start+n))
			BUG("BUFFER OVERFLOW: 0x%08lx[%ld]=0x%08lx is not in 0x%08lx..0x%08lx",
				(long)p, (long)i, (long)(p+i),(long)start,(long)(start+n));
#endif
		return p[i];
	}

	void will_use(int k) {
#ifdef HAVE_DEBUG_HARDER
		if (k==0) return;
		T *q = p+k;
		if (!(p>=start && p<start+n && q>=start && q<=start+n))
			BUG("BUFFER OVERFLOW: 0x%08lx...0x%08lx is not all inside 0x%08lx...0x%08lx",
				(long)p,(long)q,start,(long)(start+n));
#endif
	}

	Z operator-(Pt x) { return p-x.p; }
	operator bool   () { return (bool   )p; }
	operator void  *() { return (void  *)p; }
	operator int8  *() { return (int8  *)p; }

/* how do i make typecast operators that are not also default conversions??? */
/* this should be found so i can clean up the following: */
#define FOO(S) operator S *() { return (S *)p; }
EACH_NUMBER_TYPE(FOO)
#undef FOO
#ifdef HAVE_DEBUG
#define FOO(S) operator Pt<S>() { return Pt<S>((S *)p,n*sizeof(T)/1,(S *)start); }
EACH_NUMBER_TYPE(FOO)
#undef FOO
#else
#define FOO(S) operator Pt<S>() { return Pt<S>((S *)p,0); }
EACH_NUMBER_TYPE(FOO)
#undef FOO
#endif
/* end 0.8 (TESTING) */
	
#ifdef HAVE_DEBUG
	template <class U> Pt operator+(U x) { return Pt(p+x,n,start); }
	template <class U> Pt operator-(U x) { return Pt(p-x,n,start); }
#else
	template <class U> Pt operator+(U x) { return Pt(p+x,0); }
	template <class U> Pt operator-(U x) { return Pt(p-x,0); }
#endif
};

//template <class T> class P : Pt<T> {};
//a reference counting pointer class
template <class T> class P {
public:
#define INCR if (p) p->refcount++;
#define DECR if (p) {p->refcount--; if (!p->refcount) delete p;}
	T *p;
	P() : p(0) {}
	P(T *_p)            { p = _p; INCR; }
	P(const P<T> &_p) { p = _p.p; INCR; }
	P<T> &operator =(T *  _p) { DECR; p=_p;   INCR; return *this; }
	P<T> &operator =(P<T> _p) { DECR; p=_p.p; INCR; return *this; }
	bool operator ==(P<T> _p) { return p == _p.p; }
	bool operator !=(P<T> _p) { return p != _p.p; }
	~P() { DECR; }
	bool operator !(){ return  !p; }
	operator bool()  { return !!p; }
	T &operator *()  { return  *p; }
	T *operator ->() { return   p; }
//#undef INCR
//#undef DECR
};

#ifndef IS_BRIDGE
extern "C" void *gfmalloc(size_t n);
extern "C" void gffree(void *p);
// note that C++ (GCC 3.4) now refuses the :: prefix so i removed it in the 4 following lines:
inline void *operator new   (size_t n) { return gfmalloc(n); }
inline void *operator new[] (size_t n) { return gfmalloc(n); }
inline void  operator delete   (void *p) { gffree(p); }
inline void  operator delete[] (void *p) { gffree(p); }
#endif

#define STACK_ARRAY(T,V,N) T V##_foo[N]; Pt<T> V(V##_foo,N);
#define ARRAY_NEW(T,N) (Pt<T>((T *)new T[N],N))

void gfmemcopy(uint8 *out, const uint8 *in, int n);
template <class T> inline void COPY(Pt<T> dest, Pt<T> src, int n) {
	src.will_use(n); dest.will_use(n);
	gfmemcopy((uint8*)dest,(const uint8*)src,n*sizeof(T));
}
template <class T> inline void CLEAR(Pt<T> dest, int n) {
	dest.will_use(n);
	memset(dest,0,n*sizeof(T));
}
template <class T> static void memswap (Pt<T> a, Pt<T> b, int n) {
	STACK_ARRAY(T,c,n); COPY(c,a,n); COPY(a,b,n); COPY(b,c,n);
}

//****************************************************************
// CObject is the base class for C++ classes that get exported to Ruby.
// BTW: It's quite convenient to have virtual-methods in the base class
// because otherwise the vtable* isn't at the beginning of the object
// and that's pretty confusing to a lot of people, especially when simple
// casting causes a pointer to change its value.
struct CObject {
#define OBJECT_MAGIC 1618033989
	int32 magic;
	int32 refcount;
	Ruby rself; // point to Ruby peer
	CObject() : magic(OBJECT_MAGIC), refcount(0), rself(0) {}
	void check_magic () {
		if (magic != OBJECT_MAGIC) {
			fprintf(stderr,"Object memory corruption! (ask the debugger)\n");
			for (int i=-2; i<=2; i++)
				fprintf(stderr,"this[%d]=0x%08x\n",i,((int*)this)[i]);
			raise(11);
		}
	}
	virtual ~CObject() { magic = 0xDEADBEEF; }
	virtual void mark() {} // not used for now
};
void CObject_free (void *);

// you shouldn't use MethodDecl directly (used by source_filter.rb)
struct MethodDecl { const char *selector; RMethod method; };
void define_many_methods(Ruby rself, int n, MethodDecl *methods);
extern Ruby mGridFlow, cFObject, cGridObject, cFormat;

//****************************************************************
// a Dim is a list of dimensions that describe the shape of a grid
\class Dim < CObject
struct Dim : CObject {
	static const int MAX_DIM=16; // maximum number of dimensions in a grid
	int n;
	Pt<int32> v; // safe pointer
	int32 v2[MAX_DIM]; // real stuff
	void check(); // test invariants
	Dim(int n, Pt<int32> v) { this->v = Pt<int32>(v2,MAX_DIM); this->n = n; COPY(this->v,v,n); check();}
	Dim(int n,    int32 *v) { this->v = Pt<int32>(v2,MAX_DIM); this->n = n; COPY(this->v,Pt<int32>(v,n),n); check();}
	Dim()                 {v=Pt<int32>(v2,MAX_DIM); n=0;                     check();}
	Dim(int a)            {v=Pt<int32>(v2,MAX_DIM); n=1;v[0]=a;              check();}
	Dim(int a,int b)      {v=Pt<int32>(v2,MAX_DIM); n=2;v[0]=a;v[1]=b;       check();}
	Dim(int a,int b,int c){v=Pt<int32>(v2,MAX_DIM); n=3;v[0]=a;v[1]=b;v[2]=c;check();}
	int count() {return n;}
	int get(int i) { return v[i]; }
	int32 prod(int start=0, int end=-1) {
		if (end<0) end+=n;
		int32 tot=1;
		for (int i=start; i<=end; i++) tot *= v[i];
		return tot;
	}
	char *to_s();
	bool equal(P<Dim> o) {
		if (n!=o->n) return false;
		for (int i=0; i<n; i++) if (v[i]!=o->v[i]) return false;
		return true;
	}
};
\end class Dim

//****************************************************************
//BitPacking objects encapsulate optimised loops of conversion
struct BitPacking;
// those are the types of the optimised loops of conversion 
// inputs are const
struct Packer {
#define FOO(S) void (*as_##S)(BitPacking *self, int n, Pt<S> in,   Pt<uint8> out);
EACH_INT_TYPE(FOO)
#undef FOO
};
struct Unpacker {
#define FOO(S) void (*as_##S)(BitPacking *self, int n, Pt<uint8> in, Pt<S> out);
EACH_INT_TYPE(FOO)
#undef FOO
};

\class BitPacking < CObject
struct BitPacking : CObject {
	Packer *packer;
	Unpacker *unpacker;
	unsigned int endian; // 0=big, 1=little, 2=same, 3=different
	int bytes;
	int size;
	uint32 mask[4];
	BitPacking(){::abort();} // don't call, but don't remove. sorry.
	BitPacking(int endian, int bytes, int size, uint32 *mask,
		Packer *packer=0, Unpacker *unpacker=0);
	bool is_le();
	bool eq(BitPacking *o);
	\decl void initialize(Ruby foo1, Ruby foo2, Ruby foo3);
	\decl String pack2(String ins, String outs=Qnil);
	\decl String unpack2(String ins, String outs=Qnil);
	\decl String to_s();
// main entrances to Packers/Unpackers
	template <class T> void pack(  int n, Pt<T> in, Pt<uint8> out);
	template <class T> void unpack(int n, Pt<uint8> in, Pt<T> out);
};
\end class

int high_bit(uint32 n);
int  low_bit(uint32 n);
void swap32 (int n, Pt<uint32> data);
void swap16 (int n, Pt<uint16> data);

#define NT_UNSIGNED (1<<0)
#define NT_FLOAT    (1<<1)
#define NT_UNIMPL   (1<<2)
#define NUMBER_TYPE_LIMITS(T,a,b,c) \
	inline T nt_smallest(T *bogus) {return a;} \
	inline T nt_greatest(T *bogus) {return b;} \
	inline T nt_all_ones(T *bogus) {return c;}

NUMBER_TYPE_LIMITS(  uint8,0,255,255)
NUMBER_TYPE_LIMITS(  int16,-0x8000,0x7fff,-1)
NUMBER_TYPE_LIMITS(  int32,-0x80000000,0x7fffffff,-1)
NUMBER_TYPE_LIMITS(  int64,-0x8000000000000000LL,0x7fffffffffffffffLL,-1)
NUMBER_TYPE_LIMITS(float32,-HUGE_VAL,+HUGE_VAL,(RAISE("all_ones"),0))
NUMBER_TYPE_LIMITS(float64,-HUGE_VAL,+HUGE_VAL,(RAISE("all_ones"),0))
NUMBER_TYPE_LIMITS(   ruby,ruby(-HUGE_VAL),ruby(+HUGE_VAL),(RAISE("all_ones"),0))

#ifdef HAVE_LITE
#define NT_NOTLITE NT_UNIMPL
#define NONLITE(x...)
#else
#define NT_NOTLITE 0
#define NONLITE(x...) x
#endif
#define NUMBER_TYPES(MACRO) \
	MACRO(  uint8, 8,NT_UNSIGNED, "u8,b")          MACRO( int8, 8,NT_UNIMPL, "i8") \
	MACRO( uint16,16,NT_UNSIGNED|NT_UNIMPL, "u16") MACRO(int16,16,0, "i16,s") \
	MACRO( uint32,32,NT_UNSIGNED|NT_UNIMPL, "u32") MACRO(int32,32,0, "i32,i") \
	MACRO( uint64,64,NT_UNSIGNED|NT_UNIMPL, "u64") MACRO(int64,64,NT_NOTLITE, "i64,l") \
	MACRO(float32,32,NT_NOTLITE|NT_FLOAT, "f32,f") \
	MACRO(float64,64,NT_NOTLITE|NT_FLOAT, "f64,d") \
	MACRO(   ruby,sizeof(long),NT_NOTLITE,"r")

enum NumberTypeE {
#define FOO(_sym_,args...) _sym_##_e,
NUMBER_TYPES(FOO)
#undef FOO
	number_type_table_end
};

#define FOO(_type_) \
inline NumberTypeE NumberTypeE_type_of(_type_ &x) { \
	return _type_##_e; }
EACH_NUMBER_TYPE(FOO)
#undef FOO

\class NumberType < CObject
struct NumberType : CObject {
	Ruby /*Symbol*/ sym;
	const char *name;
	int size;
	int flags;
	const char *aliases;
	NumberTypeE index;
	NumberType(const char *name_, int size_, int flags_, const char *aliases_) :
		name(name_), size(size_), flags(flags_), aliases(aliases_) {}
	\decl Symbol sym_m();
	\decl int size_m();
	\decl int flags_m();
	\decl int index_m();
};
\end class

NumberTypeE NumberTypeE_find (Ruby sym);

#define TYPESWITCH(T,C,E) switch (T) { \
  case uint8_e:   C(uint8) break;         case int16_e: C(int16) break; \
  case int32_e:   C(int32) break; NONLITE(case int64_e: C(int64) break; \
  case float32_e: C(float32) break; case float64_e: C(float64) break; \
  case ruby_e: C(ruby) break;) \
  default: E; RAISE("type '%s' not available here",number_type_table[T].sym);}
#define TYPESWITCH_JUSTINT(T,C,E) switch (T) { \
  case uint8_e: C(uint8) break; case int16_e: C(int16) break; \
  case int32_e: C(int32) break;   NONLITE(case int64_e: C(int64) break;) \
  default: E; RAISE("type '%s' not available here",number_type_table[T].sym);}

// Numop objects encapsulate optimised loops of simple operations

enum LeftRight { at_left, at_right };

template <class T>
struct NumopOn : CObject {
	// Function Vectorisations
	typedef void (*Map )(        int n, T *as, T  b ); Map  op_map;
	typedef void (*Zip )(        int n, T *as, T *bs); Zip  op_zip;
	typedef void (*Fold)(int an, int n, T *as, T *bs); Fold op_fold;
	typedef void (*Scan)(int an, int n, T *as, T *bs); Scan op_scan;
	// Algebraic Properties (those involving simply numeric types)
	typedef bool (*AlgebraicCheck)(T x, LeftRight side);
	// neutral: right: forall y {f(x,y)=x}; left: forall x {f(x,y)=y};
	// absorbent: right: exists a forall y {f(x,y)=a}; ...
	T (*neutral)(LeftRight); // default neutral: e.g. 0 for addition, 1 for multiplication
	AlgebraicCheck is_neutral, is_absorbent;
	NumopOn(Map m, Zip z, Fold f, Scan s, T (*neu)(LeftRight), AlgebraicCheck n, AlgebraicCheck a) :
		op_map(m), op_zip(z), op_fold(f), op_scan(s), neutral(neu), is_neutral(n), is_absorbent(a) {}
	NumopOn() {}
	NumopOn(const NumopOn &z) {
		op_map  = z.op_map;  op_zip  = z.op_zip;
		op_fold = z.op_fold; op_scan = z.op_scan;
		is_neutral = z.is_neutral; neutral = z.neutral;
		is_absorbent = z.is_absorbent; }
};

// semigroup property: associativity: f(a,f(b,c))=f(f(a,b),c)
#define OP_ASSOC (1<<0)
// abelian property: commutativity: f(a,b)=f(b,a)
#define OP_COMM (1<<1)

\class Numop < CObject
struct Numop : CObject {
	Ruby /*Symbol*/ sym;
	const char *name;
	int flags;
//private:
#define FOO(T) \
	NumopOn<T> on_##T; \
	NumopOn<T> *on(T &foo) { \
		if (!on_##T.op_map) \
			RAISE("operator %s does not support type "#T,rb_sym_name(sym)); \
		return &on_##T;}
EACH_NUMBER_TYPE(FOO)
#undef FOO
//public:
	template <class T> inline void map(int n, Pt<T> as, T b) {
		as.will_use(n);
		on(*as)->op_map(n,(T *)as,b);}
	template <class T> inline void zip(int n, Pt<T> as, Pt<T> bs) {
		as.will_use(n);
		bs.will_use(n);
		on(*as)->op_zip(n,(T *)as,(T *)bs);}
	template <class T> inline void fold(int an, int n, Pt<T> as, Pt<T> bs) {
		as.will_use(an);
		bs.will_use(an*n);
		typename NumopOn<T>::Fold f = on(*as)->op_fold;
		if (!f) RAISE("operator %s does not support fold",rb_sym_name(sym));
		f(an,n,(T *)as,(T *)bs);}
	template <class T> inline void scan(int an, int n, Pt<T> as, Pt<T> bs) {
		as.will_use(an);
		bs.will_use(an*n);
		typename NumopOn<T>::Scan f = on(*as)->op_scan;
		if (!f) RAISE("operator %s does not support scan",rb_sym_name(sym));
		f(an,n,(T *)as,(T *)bs);}

	\decl void map_m  (NumberTypeE nt, int n, String as, String b);
	\decl void zip_m  (NumberTypeE nt, int n, String as, String bs);
	\decl void fold_m (NumberTypeE nt, int an, int n, String as, String bs);
	\decl void scan_m (NumberTypeE nt, int an, int n, String as, String bs);

	Numop(Ruby /*Symbol*/ sym_, const char *name_,
#define FOO(T) NumopOn<T> op_##T, 
EACH_NUMBER_TYPE(FOO)
#undef FOO
	int flags_) : sym(sym_), name(name_), flags(flags_) {
#define FOO(T) on_##T = op_##T;
EACH_NUMBER_TYPE(FOO)
#undef FOO
	}
};
\end class

extern NumberType number_type_table[];
extern Ruby number_type_dict; // GridFlow.@number_type_dict={}
extern Ruby op_dict; // GridFlow.@op_dict={}

static inline NumberTypeE convert(Ruby x, NumberTypeE *bogus) {
	return NumberTypeE_find(x);
}

#ifndef IS_BRIDGE
static Numop *convert(Ruby x, Numop **bogus) {
	Ruby s = rb_hash_aref(rb_ivar_get(mGridFlow,SI(@op_dict)),x);
	if (s==Qnil) RAISE("expected two-input-operator");
	return FIX2PTR(Numop,s);
}
#endif

// ****************************************************************
\class Grid < CObject
struct Grid : CObject {
	P<Dim> dim;
	NumberTypeE nt;
	void *data;
	Grid(P<Dim> dim, NumberTypeE nt, bool clear=false) : dim(0), nt(int32_e), data(0) {
		if (!dim) RAISE("hell");
		init(dim,nt);
		if (clear) {int size = bytes(); CLEAR(Pt<char>((char *)data,size),size);}
	}
	Grid(Ruby x) : dim(0), nt(int32_e), data(0) { init_from_ruby(x); }
	Grid(int n, Ruby *a, NumberTypeE nt=int32_e) : dim(0), nt(int32_e), data(0) {
		init_from_ruby_list(n,a,nt);
	}
	int32 bytes() { return dim->prod()*number_type_table[nt].size/8; }
	P<Dim> to_dim () { return new Dim(dim->prod(),(Pt<int32>)*this); }
#define FOO(type) \
	operator type *() { return (type *)data; } \
	operator Pt<type>() { return Pt<type>((type *)data,dim->prod()); }
EACH_NUMBER_TYPE(FOO)
#undef FOO
	Grid *dup () {
		Grid *foo=new Grid(dim,nt);
		memcpy(foo->data,data,bytes());
		return foo;
	}
	~Grid() {if (data) free(data);}
private:
	void init(P<Dim> dim, NumberTypeE nt) {
		this->dim = dim;
		this->nt = nt;
		data = 0;
		if (dim) data = memalign(16,bytes()+16);
		//fprintf(stderr,"rdata=%p data=%p align=%d\n",rdata,data,align);
	}
	void init_from_ruby(Ruby x);
	void init_from_ruby_list(int n, Ruby *a, NumberTypeE nt=int32_e);
};
\end class Grid

static inline Grid *convert (Ruby r, Grid **bogus) {
	return r ? new Grid(r) : 0;
}

// DimConstraint interface:
// return if d is acceptable
// else RAISE with proper descriptive message
typedef void (*DimConstraint)(P<Dim> d);

struct PtrGrid : public P<Grid> {
	DimConstraint dc;
	void constrain(DimConstraint dc_) { dc=dc_; }
	P<Grid> next;
	PtrGrid()                  : P<Grid>(), dc(0), next(0) {}
	PtrGrid(const PtrGrid &_p) : P<Grid>(), dc(0), next(0) {dc=_p.dc; p=_p.p; INCR;}
	PtrGrid &operator =(  Grid *_p) {if(dc&&p)dc(_p->dim); DECR; p=_p;   INCR; return *this;}
	PtrGrid &operator =(P<Grid> _p) {if(dc&&p)dc(_p->dim); DECR; p=_p.p; INCR; return *this;}
	PtrGrid &operator =(PtrGrid _p) {if(dc&&p)dc(_p->dim); DECR; p=_p.p; INCR; return *this;}
};

#ifndef IS_BRIDGE
static inline P<Dim> convert(Ruby x, P<Dim> *foo) {
	Grid *d = convert(x,(Grid **)0);
	if (!d) RAISE("urgh");
	if (d->dim->n!=1) RAISE("dimension list must have only one dimension itself");
	return new Dim(d->dim->v[0],(int32 *)(d->data));
}

static inline PtrGrid convert(Ruby x, PtrGrid *foo) {
	PtrGrid pg;
	pg = convert(x,(Grid **)0);
	return pg;
}
#endif

//****************************************************************
// GridInlet represents a grid-aware inlet

// four-part macro for defining the behaviour of a gridinlet in a class
// C:Class I:Inlet
#define GRID_INLET(C,I) \
	template <class T> void C::grinw_##I (GridInlet *in, int n, Pt<T> data) { \
		((C*)(in->parent))->grin_##I(in,n,data); } \
	template <class T> void  C::grin_##I (GridInlet *in, int n, Pt<T> data) { \
	if (n==-1)
#define GRID_ALLOC  else if (n==-3)
#define GRID_FLOW   else if (n>=0)
#define GRID_FINISH else if (n==-2)
#define GRID_END }

/* macro for defining a gridinlet's behaviour as just storage (no backstore) */
// V is a PtrGrid instance-var
#define GRID_INPUT(C,I,V) \
GRID_INLET(C,I) { V=new Grid(in->dim,NumberTypeE_type_of(*data)); } \
GRID_FLOW { COPY((Pt<T>)*(V)+in->dex, data, n); } GRID_FINISH

// macro for defining a gridinlet's behaviour as just storage (with backstore)
// V is a PtrGrid instance-var
#define GRID_INPUT2(C,I,V) \
	GRID_INLET(C,I) { \
		if (is_busy_except(in)) { \
			V.next = new Grid(in->dim,NumberTypeE_type_of(*data)); \
		} else V=        new Grid(in->dim,NumberTypeE_type_of(*data)); \
	} GRID_FLOW { \
		COPY(((Pt<T>)*(V.next?V.next.p:&*V.p))+in->dex, data, n); \
	} GRID_FINISH

typedef struct GridInlet GridInlet;
typedef struct GridHandler {
#define FOO(T) \
	void (*flow_##T)(GridInlet *in, int n, Pt<T> data); \
	void flow(GridInlet *in, int n, Pt<T> data) const { \
		assert(flow_##T); flow_##T(in,n,data); }
EACH_NUMBER_TYPE(FOO)
#undef FOO
} GridHandler;

typedef struct  GridObject GridObject;
\class GridInlet < CObject
struct GridInlet : CObject {
	GridObject *parent;
	const GridHandler *gh;
	GridObject *sender;
	P<Dim> dim;
	NumberTypeE nt;
	int dex;
	PtrGrid buf;// factor-chunk buffer
	int bufi;   // buffer index: how much of buf is filled
	int mode; // 0=ignore; 4=ro; 6=rw

	int allocfactor,allocmin,allocmax,allocn;
	Pt<uint8> alloc;

// methods
	GridInlet(GridObject *parent_, const GridHandler *gh_) :
		parent(parent_), gh(gh_), sender(0),
		dim(0), nt(int32_e), dex(0), bufi(0), mode(4) {}
	~GridInlet() {}
	void set_factor(int factor);
	void set_mode(int mode_) { mode=mode_; }
	int32 factor() {return buf?buf->dim->prod():1;}
	Ruby begin(int argc, Ruby *argv);

	// n=-1 is begin, and n=-2 is _finish_. the name "end" is now used
	// as an end-marker for inlet definitions... sorry for the confusion
	// GF-0.8: n=-3 is alloc.
	template <class T> void flow(int mode, int n, Pt<T> data);
	void end(); // this one ought to be called finish().
	void from_ruby_list(int argc, Ruby *argv, NumberTypeE nt=int32_e) {
		Grid t(argc,argv,nt); from_grid(&t);
	}
	void from_ruby(int argc, Ruby *argv) {
		Grid t(argv[0]); from_grid(&t);
	}
	void from_grid(Grid *g);
	bool supports_type(NumberTypeE nt);
private:
	template <class T> void from_grid2(Grid *g, T foo);
};
\end class GridInlet

//****************************************************************
// for use by source_filter.rb ONLY (for \grin and \classinfo)

// C is for class, I for inlet number
// GRIN1 : int32 only
// GRIN4 : all types
// GRIN2 : integers only; no floats (no R either actually)
// GRINF : floats only; no integers
#ifndef HAVE_LITE
#define GRIN(TB,TS,TI,TL,TF,TD,TR) {TB,TS,TI,TL,TF,TD,TR}
#else
#define GRIN(TB,TS,TI,TL,TF,TD,TR) {TB,TS,TI}
#endif // HAVE_LITE

#define GRIN1(C,I) GRIN(0,0,C::grinw_##I,0,0,0,0)
#define GRIN4(C,I) GRIN(C::grinw_##I,C::grinw_##I,C::grinw_##I,C::grinw_##I,C::grinw_##I,C::grinw_##I,C::grinw_##I)
#define GRIN2(C,I) GRIN(C::grinw_##I,C::grinw_##I,C::grinw_##I,C::grinw_##I,0,0,0)
#define GRINF(C,I) GRIN(0,0,0,0,C::grinw_##I,C::grinw_##I,0)

struct FClass { // 0.7.8: removed all GridObject-specific stuff.
	void *(*allocator)(); // returns a new C++ object
	void (*startup)(Ruby rself); // initializer for the Ruby class
	const char *name; // C++/Ruby name (not PD name)
	int methodsn; MethodDecl *methods; // C++ -> Ruby methods
};

//****************************************************************
// GridOutlet represents a grid-aware outlet
\class GridOutlet < CObject
struct GridOutlet : CObject {
// number of (minimum,maximum) BYTES to send at once
// starting with version 0.8, this is amount of BYTES, not amount of NUMBERS.
	static const int MIN_PACKET_SIZE = 1<<8;
	static const int MAX_PACKET_SIZE = 1<<12;
// those are set only once
	GridObject *parent; // not a P<> because of circular refs
	P<Dim> dim; // dimensions of the grid being sent
	NumberTypeE nt;
	PtrGrid buf; // temporary buffer
	bool frozen; // is the "begin" phase finished?
	std::vector<GridInlet *> inlets; // which inlets are we connected to
// those are updated during transmission
	int dex;  // how many numbers were already sent in this connection
	int bufi; // number of bytes used in the buffer
// methods
	GridOutlet(GridObject *parent_, int woutlet, P<Dim> dim_, NumberTypeE nt_=int32_e) :
	parent(parent_), dim(dim_), nt(nt_), frozen(false), dex(0), bufi(0) {
		int ntsz = number_type_table[nt].size;
		buf=new Grid(new Dim(MAX_PACKET_SIZE/*/ntsz*/), nt);
		begin(woutlet,dim,nt);
	}
	~GridOutlet() {}
	void callback(GridInlet *in);

	// send/send_direct: data belongs to caller, may be stack-allocated,
	// receiver doesn't modify the data; in send(), there is buffering;
	// in send_direct(), there is not. When switching from buffered to
	// unbuffered mode, flush() must be called
	template <class T> void send(int n, Pt<T> data);
	void flush(); // goes with send();

	// give: data must be dynamically allocated as a whole: the data
	// will be deleted eventually, and should not be used by the caller
	// beyond the call to give().
	template <class T> void give(int n, Pt<T> data);

	// third way to send (upcoming, in GF-0.8.??) is called "ask".
	template <class T> void ask(int &n, Pt<T> &data, int factor, int min, int max);

private:
	void begin(int woutlet, P<Dim> dim, NumberTypeE nt=int32_e);
	template <class T> void send_direct(int n, Pt<T> data);
	void end() {
		flush();
		for (uint32 i=0; i<inlets.size(); i++) inlets[i]->end();
		dim=0;
	}
};
\end class GridOutlet

//****************************************************************

typedef struct BFObject BFObject; // Pd t_object or something

// represents objects that have inlets/outlets
\class FObject < CObject
struct FObject : CObject {
	BFObject *bself; // point to PD peer
	uint64 total_time;
	FObject() : bself(0), total_time(0) {}
	const char *args() {
		Ruby s=rb_funcall(rself,SI(args),0);
		if (s==Qnil) return 0;
		return rb_str_ptr(s);
	}
	\decl Ruby total_time_get();
	\decl Ruby total_time_set(Ruby x);
	\decl void send_in (...);
	\decl void send_out (...);
	\decl void delete_m ();
};
\end class FObject

\class GridObject < FObject
struct GridObject : FObject {
	std::vector<P<GridInlet> >  in;
	P<GridOutlet> out;
	// Make sure you distinguish #close/#delete, and C++'s delete. The first
	// two are quite equivalent and should never make an object "crashable".
	// C++'s delete is called by Ruby's garbage collector or by PureData's delete.
	GridObject() {}
	~GridObject() {check_magic();}
	bool is_busy_except(P<GridInlet> gin) {
		for (uint32 i=0; i<in.size(); i++)
			if (in[i] && in[i]!=gin && in[i]->dim) return true;
		return false;
	}
	\decl Ruby method_missing(...);
	\decl Array inlet_dim(int inln);
	\decl Symbol inlet_nt(int inln);
	\decl void inlet_set_factor(int inln, int factor);
	\decl void send_out_grid_begin(int outlet, Array dim,  NumberTypeE nt=int32_e);
	\decl void send_out_grid_flow (int outlet, String buf, NumberTypeE nt=int32_e);
};
\end class GridObject

uint64 gf_timeofday();
extern "C" void Init_gridflow ();
void gfpost(const char *fmt, ...);
extern Numop *op_add,*op_sub,*op_mul,*op_div,*op_mod,*op_shl,*op_and,*op_put;

#define INFO(OBJ) rb_str_ptr(rb_funcall(OBJ->rself,SI(info),0))
//#define INFO(OBJ) "(bleh)"
#define NOTEMPTY(_a_) if (!(_a_)) RAISE("in [%s], '%s' is empty",INFO(this), #_a_);
#define SAME_TYPE(_a_,_b_) \
	if ((_a_)->nt != (_b_)->nt) RAISE("%s: same type please (%s has %s; %s has %s)", \
		INFO(this), \
		#_a_, number_type_table[(_a_)->nt].name, \
		#_b_, number_type_table[(_b_)->nt].name);
static void SAME_DIM(int n, P<Dim> a, int ai, P<Dim> b, int bi) {
	if (ai+n > a->n) RAISE("left hand: not enough dimensions");
	if (bi+n > b->n) RAISE("right hand: not enough dimensions");
	for (int i=0; i<n; i++) {
		if (a->v[ai+i] != b->v[bi+i]) {
			RAISE("mismatch: left dim #%d is %d, right dim #%d is %d",
				ai+i, a->v[ai+i],
				bi+i, b->v[bi+i]);}}}

// a stack for the profiler, etc.
#define GF_STACK_MAX 256
//#define NO_INLINE(decl) decl __attribute__((noinline))
#define NO_INLINE(decl) decl
struct GFStack {
	struct GFStackFrame {
		FObject *o;
		void *bp; // a pointer into system stack
		uint64 time;
	}; // sizeof() == 16 (in 32-bit mode)
	GFStackFrame s[GF_STACK_MAX];
	int n;
	GFStack() { n = 0; }
	NO_INLINE(void push (FObject *o));
	NO_INLINE(void pop ());
};
extern GFStack gf_stack;
struct GFStackMarker {
	int n;
	bool flag;
	GFStackMarker(FObject *o) { n = gf_stack.n; gf_stack.push(o); flag=true; }
	~GFStackMarker() { while (gf_stack.n != n) gf_stack.pop(); }
	bool once () {
		if (flag) { flag=false; return true; } else return false;
	}
};

typedef GridObject Format;

#endif // __GF_GRID_H