+/************************************************************************
+ ************************************************************************
+ FAUST compiler
+ Copyright (C) 2003-2004 GRAME, Centre National de Creation Musicale
+ ---------------------------------------------------------------------
+ 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.
+
+ 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ ************************************************************************
+ ************************************************************************/
+
+
+
+#ifndef __signals_intervals__
+#define __signals_intervals__
+
+#include <math.h>
+#include <iostream>
+
+#ifdef WIN32
+inline double log2(double e) { return log(e)/log(double(2)); }
+#endif
+
+using namespace std;
+
+struct interval
+{
+ bool valid; ///< true if it is a valid interval
+ double lo; ///< minimal value
+ double hi; ///< maximal value
+
+ interval () : valid(false), lo(-HUGE_VAL), hi(HUGE_VAL) {}
+ interval (double n) : valid(true), lo(n), hi(n) {}
+ interval (double n, double m) : valid(true), lo(min(n,m)), hi(max(n,m)) {}
+ interval (const interval& r) : valid(r.valid), lo(r.lo), hi(r.hi) {}
+
+ bool isconst() { return valid & (lo == hi); }
+};
+
+inline ostream& operator<<(ostream& dst, const interval& i)
+{
+ if (i.valid) {
+ return dst << "interval(" << i.lo << ", " << i.hi << ")";
+ } else {
+ return dst << "interval()";
+ }
+}
+
+inline double min(double x, double y) { return (x<y) ? x:y; }
+inline double max(double x, double y) { return (x>y) ? x:y; }
+inline double min4(double a, double b, double c, double d) { return min(min(a,b),min(c,d)); }
+inline double max4(double a, double b, double c, double d) { return max(max(a,b),max(c,d)); }
+
+inline interval reunion(const interval& x, const interval& y)
+{
+ if (x.valid & y.valid) {
+ return interval(min(x.lo,y.lo), max(x.hi,y.hi));
+ } else {
+ return interval();
+ }
+}
+
+
+inline interval operator+(const interval& x, const interval& y)
+{
+ return (x.valid&y.valid) ? interval(x.lo+y.lo, x.hi+y.hi) : interval();
+}
+
+inline interval operator-(const interval& x, const interval& y)
+{
+ return (x.valid & y.valid) ? interval(x.lo-y.hi, x.hi-y.lo) : interval();;
+}
+
+inline interval operator*(const interval& x, const interval& y)
+{
+ if (x.valid&y.valid) {
+ double a=x.lo*y.lo;
+ double b=x.lo*y.hi;
+ double c=x.hi*y.lo;
+ double d=x.hi*y.hi;
+ return interval(min4(a,b,c,d), max4(a,b,c,d));
+ } else {
+ return interval();
+ }
+}
+
+inline interval operator/(const interval& x, const interval& y)
+{
+ return (x.valid && y.valid && (y.lo > 0 | y.hi < 0))
+ ? x * interval(1/y.hi,1/y.lo)
+ : interval();
+}
+
+inline interval operator%(const interval& x, const interval& y)
+{
+ return (x.valid && y.valid && x.lo >= 0 && y.lo > 0)
+ ? interval(0,y.hi)
+ : interval();
+}
+
+/**
+ * Convert a number 1bbb..b into a bit mask 1111..1 of same width
+ */
+inline int bitmask (double x) {
+ int v = int(x);
+ for (int i=1; i<32; i*=2) { v |= v>>i; }
+ return v;
+}
+
+//----------------------booleans&bits--------------------------------------
+
+inline interval operator&(const interval& x, const interval& y)
+{
+ if (x.valid && y.valid) {
+ if (x.lo >= 0 & y.lo >= 0) {
+ return interval(0, bitmask(x.hi) & bitmask(y.hi));
+ } else if (y.lo >= 0) {
+ return interval(0, bitmask(y.hi));
+ } else if (x.lo >= 0) {
+ return interval(0, bitmask(y.hi));
+ } else {
+ return interval();
+ }
+ } else if (x.valid & x.lo >= 0) {
+ return interval(0, bitmask(x.hi));
+ } else if (y.valid & y.lo >= 0) {
+ return interval(0, bitmask(y.hi));
+ } else {
+ return interval();
+ }
+}
+
+inline interval operator|(const interval& x, const interval& y)
+{
+ if (x.valid && y.valid && x.lo >= 0 && y.lo >= 0) {
+ return interval(0, bitmask(x.hi) | bitmask(y.hi));
+ } else {
+ return interval();
+ }
+}
+
+inline interval operator^(const interval&, const interval&)
+{
+ return interval();
+}
+
+inline interval operator<<(const interval&, const interval&)
+{
+ return interval();
+}
+
+inline interval operator>>(const interval&, const interval&)
+{
+ return interval();
+}
+
+// ---------------------comparaisons------------------------------
+// note : les comparaisons ne portent pas sur les intervals
+// mais l'interval des comparaisons de signaux
+
+inline interval operator<(const interval&, const interval&)
+{
+ return interval(0,1);
+}
+
+inline interval operator<=(const interval&, const interval&)
+{
+ return interval(0,1);
+}
+
+inline interval operator>(const interval&, const interval&)
+{
+ return interval(0,1);
+}
+
+inline interval operator>=(const interval&, const interval&)
+{
+ return interval(0,1);
+}
+
+inline interval operator==(const interval&, const interval&)
+{
+ return interval(0,1);
+}
+
+inline interval operator!=(const interval&, const interval&)
+{
+ return interval(0,1);
+}
+
+//-----------------------------------------------------------------------
+
+inline interval min(const interval& x, const interval& y)
+{
+ return interval(min(x.lo,y.lo), min(x.hi,y.hi));
+}
+
+inline interval max(const interval& x, const interval& y)
+{
+ return interval(max(x.lo,y.lo), max(x.hi,y.hi));
+}
+
+inline interval abs(const interval& x)
+{
+ if (x.valid) {
+ if (x.lo >= 0) {
+ return x;
+ } else if (x.hi < 0) {
+ return interval(fabs(x.hi), fabs(x.lo));
+ } else {
+ return interval(0, max(fabs(x.lo), x.hi));
+ }
+ } else {
+ return x;
+ }
+}
+
+#endif