Ticket #9141: 01-rational.patch

common/algorithm.h

@@ -222 +222 @@
         sort(first, last, Common::Less<typename T::ValueType>());
 }
 
+/**
+ * Euclid's algorithm to compute the greatest common divisor.
+ */
+template<class T>
+T gcd(T a, T b) {
+        while (a > 0) {
+                T tmp = a;
+                a = b % a;
+                b = tmp;
+        }
+        return b;
+}
+
 } // End of namespace Common
 #endif
 

common/module.mk

@@ -16 +16 @@
         md5.o \
         mutex.o \
         random.o \
+        rational.o \
         str.o \
         stream.o \
         system.o \

new file common/rational.cpp

@@ +1 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ */
+
+#include "common/rational.h"
+#include "common/util.h"
+#include "common/algorithm.h"
+
+namespace Common {
+
+Rational::Rational() {
+        _num   = 1;
+        _denom = 1;
+}
+
+Rational::Rational(int num) {
+        _num   = num;
+        _denom = 1;
+}
+
+Rational::Rational(int num, int denom) {
+        assert(denom != 0);
+
+        _num   = num;
+        _denom = denom;
+
+        normalize();
+}
+
+void Rational::cancel() {
+        // Cancel the fraction by dividing both the num and the denom
+        // by their greatest common denom.
+
+        int gcd = Common::gcd(_num, _denom);
+
+        _num   /= gcd;
+        _denom /= gcd;
+}
+
+void Rational::normalize() {
+        // Is the fraction negative?
+        bool negative = !((!(_num < 0)) == (!(_denom < 0)));
+
+        // Make both integers positive
+        _num   = ABS(_num);
+        _denom = ABS(_denom);
+
+        // Cancel the fraction
+        cancel();
+
+        // If the fraction is supposed to be negative, make the num negative
+        if (negative)
+                _num = -_num;
+}
+
+Rational &Rational::operator=(const Rational &right) {
+        _num   = right._num;
+        _denom = right._denom;
+
+        return *this;
+}
+
+Rational &Rational::operator=(int right) {
+        _num   = right;
+        _denom = 1;
+
+        return *this;
+}
+
+Rational &Rational::operator+=(const Rational &right) {
+        _num   = _num * right._denom + right._num * _denom;
+        _denom = _denom * right._denom;
+
+        normalize();
+
+        return *this;
+}
+
+Rational &Rational::operator-=(const Rational &right) {
+        _num   = _num * right._denom - right._num * _denom;
+        _denom = _denom * right._denom;
+
+        normalize();
+
+        return *this;
+}
+
+Rational &Rational::operator*=(const Rational &right) {
+        // Try to cross-cancel first, to avoid unnecessary overflow
+        int gcd1 = Common::gcd(_num, right._denom);
+        int gcd2 = Common::gcd(right._num, _denom);
+
+        _num   = (_num    / gcd1) * (right._num    / gcd2);
+        _denom = (_denom  / gcd2) * (right._denom  / gcd1);
+
+        normalize();
+
+        return *this;
+}
+
+Rational &Rational::operator/=(const Rational &right) {
+        return *this *= Rational(right._denom, right._num);
+}
+
+Rational &Rational::operator+=(int right) {
+        return *this += Rational(right);
+}
+
+Rational &Rational::operator-=(int right) {
+        return *this -= Rational(right);
+}
+
+Rational &Rational::operator*=(int right) {
+        return *this *= Rational(right);
+}
+
+Rational &Rational::operator/=(int right) {
+        return *this /= Rational(right);
+}
+
+const Rational Rational::operator-() const {
+        return Rational(-_num, _denom);
+}
+
+const Rational Rational::operator+(const Rational &right) const {
+        Rational tmp = *this;
+
+        tmp += right;
+
+        return tmp;
+}
+
+const Rational Rational::operator-(const Rational &right) const {
+        Rational tmp = *this;
+
+        tmp -= right;
+
+        return tmp;
+}
+
+const Rational Rational::operator*(const Rational &right) const {
+        Rational tmp = *this;
+
+        tmp *= right;
+
+        return tmp;
+}
+
+const Rational Rational::operator/(const Rational &right) const {
+        Rational tmp = *this;
+
+        tmp /= right;
+
+        return tmp;
+}
+
+const Rational Rational::operator+(int right) const {
+        Rational tmp = *this;
+
+        tmp += right;
+
+        return tmp;
+}
+
+const Rational Rational::operator-(int right) const {
+        Rational tmp = *this;
+
+        tmp -= right;
+
+        return tmp;
+}
+
+const Rational Rational::operator*(int right) const {
+        Rational tmp = *this;
+
+        tmp *= right;
+
+        return tmp;
+}
+
+const Rational Rational::operator/(int right) const {
+        Rational tmp = *this;
+
+        tmp /= right;
+
+        return tmp;
+}
+
+bool Rational::operator==(const Rational &right) const {
+        return (_num == right._num) && (_denom == right._denom);
+}
+
+bool Rational::operator!=(const Rational &right) const {
+        return (_num != right._num) || (_denom != right._denom);
+}
+
+bool Rational::operator>(const Rational &right) const {
+        return (_num * right._denom) > (right._num * _denom);
+}
+
+bool Rational::operator<(const Rational &right) const {
+        return (_num * right._denom) < (right._num * _denom);
+}
+
+bool Rational::operator>=(const Rational &right) const {
+        return (_num * right._denom) >= (right._num * _denom);
+}
+
+bool Rational::operator<=(const Rational &right) const {
+        return (_num * right._denom) <= (right._num * _denom);
+}
+
+bool Rational::operator==(int right) const {
+        return (_denom == 1) && (_num == right);
+}
+
+bool Rational::operator!=(int right) const {
+        return (_denom == 1) && (_num != right);
+}
+
+bool Rational::operator>(int right) const {
+        return *this > Rational(right, 1);
+}
+
+bool Rational::operator<(int right) const {
+        return *this < Rational(right, 1);
+}
+
+bool Rational::operator>=(int right) const {
+        return *this >= Rational(right, 1);
+}
+
+bool Rational::operator<=(int right) const {
+        return *this <= Rational(right, 1);
+}
+
+void Rational::invert() {
+        assert(_num != 0);
+
+        SWAP(_num, _denom);
+
+        normalize();
+}
+
+Rational Rational::getInverse() const {
+        Rational inverse = *this;
+
+        inverse.invert();
+
+        return inverse;
+}
+
+int Rational::toInt() const {
+        assert(_denom != 0);
+
+        return _num / _denom;
+}
+
+double Rational::toDouble() const {
+        assert(_denom != 0);
+
+        return ((double) _num) / ((double) _denom);
+}
+
+frac_t Rational::toFrac() const {
+        return (_num * FRAC_ONE) / _denom;
+}
+
+Rational::operator int() const {
+        return toInt();
+}
+
+Rational::operator double() const {
+        return toDouble();
+}
+
+const Rational operator+(int left, const Rational &right) {
+        Rational tmp = right;
+
+        tmp += left;
+
+        return tmp;
+}
+
+const Rational operator-(int left, const Rational &right) {
+        Rational tmp = right;
+
+        tmp -= left;
+
+        return tmp;
+}
+
+const Rational operator*(int left, const Rational &right) {
+        Rational tmp = right;
+
+        tmp *= left;
+
+        return tmp;
+}
+
+const Rational operator/(int left, const Rational &right) {
+        Rational tmp = right;
+
+        tmp /= left;
+
+        return tmp;
+}
+
+bool operator==(int left, const Rational &right) {
+        return right == left;
+}
+
+bool operator!=(int left, const Rational &right) {
+        return right != left;
+}
+
+bool operator>(int left, const Rational &right) {
+        return right < left;
+}
+
+bool operator<(int left, const Rational &right) {
+        return right > left;
+}
+
+bool operator>=(int left, const Rational &right) {
+        return right <= left;
+}
+
+bool operator<=(int left, const Rational &right) {
+        return right >= left;
+}
+
+} // End of namespace Common

new file common/rational.h

@@ +1 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * $URL$
+ * $Id$
+ */
+
+#ifndef COMMON_RATIONAL_H
+#define COMMON_RATIONAL_H
+
+#include "common/scummsys.h"
+#include "common/frac.h"
+
+namespace Common {
+
+/** A simple rational class that holds fractions. */
+class Rational {
+public:
+        Rational();
+        Rational(int num);
+        Rational(int num, int denom);
+
+        Rational &operator=(const Rational &right);
+        Rational &operator=(int right);
+
+        Rational &operator+=(const Rational &right);
+        Rational &operator-=(const Rational &right);
+        Rational &operator*=(const Rational &right);
+        Rational &operator/=(const Rational &right);
+
+        Rational &operator+=(int right);
+        Rational &operator-=(int right);
+        Rational &operator*=(int right);
+        Rational &operator/=(int right);
+
+        const Rational operator-() const;
+
+        const Rational operator+(const Rational &right) const;
+        const Rational operator-(const Rational &right) const;
+        const Rational operator*(const Rational &right) const;
+        const Rational operator/(const Rational &right) const;
+
+        const Rational operator+(int right) const;
+        const Rational operator-(int right) const;
+        const Rational operator*(int right) const;
+        const Rational operator/(int right) const;
+
+        bool operator==(const Rational &right) const;
+        bool operator!=(const Rational &right) const;
+        bool operator>(const Rational &right) const;
+        bool operator<(const Rational &right) const;
+        bool operator>=(const Rational &right) const;
+        bool operator<=(const Rational &right) const;
+
+        bool operator==(int right) const;
+        bool operator!=(int right) const;
+        bool operator>(int right) const;
+        bool operator<(int right) const;
+        bool operator>=(int right) const;
+        bool operator<=(int right) const;
+
+        operator int() const;
+        operator double() const;
+
+        void invert();
+        Rational getInverse() const;
+
+        int toInt() const;
+        double toDouble() const;
+        frac_t toFrac() const;
+
+private:
+        int _num;
+        int _denom;
+
+        void cancel();
+        void normalize();
+};
+
+const Rational operator+(int left, const Rational &right);
+const Rational operator-(int left, const Rational &right);
+const Rational operator*(int left, const Rational &right);
+const Rational operator/(int left, const Rational &right);
+
+bool operator==(int left, const Rational &right);
+bool operator!=(int left, const Rational &right);
+bool operator>(int left, const Rational &right);
+bool operator<(int left, const Rational &right);
+bool operator>=(int left, const Rational &right);
+bool operator<=(int left, const Rational &right);
+
+} // End of namespace Common
+
+#endif

sound/timestamp.cpp

@@ -24 +24 @@
  */
 
 #include "sound/timestamp.h"
+#include "common/algorithm.h"
 
 namespace Audio {
 
-static uint gcd(uint a, uint b) {
-        while (a > 0) {
-                int tmp = a;
-                a = b % a;
-                b = tmp;
-        }
-        return b;
-}
-
 Timestamp::Timestamp(uint ms, uint fr) {
         assert(fr > 0);
 
         _secs = ms / 1000;
-        _framerateFactor = 1000 / gcd(1000, fr);
+        _framerateFactor = 1000 / Common::gcd<uint>(1000, fr);
         _framerate = fr * _framerateFactor;
 
         // Note that _framerate is always divisible by 1000.
@@ -51 +43 @@
         assert(fr > 0);
 
         _secs = s;
-        _framerateFactor = 1000 / gcd(1000, fr);
+        _framerateFactor = 1000 / Common::gcd<uint>(1000, fr);
         _framerate = fr * _framerateFactor;
         _numFrames = frames * _framerateFactor;
 
@@ -62 +54 @@
         Timestamp ts(*this);
 
         if (ts.framerate() != newFramerate) {
-                ts._framerateFactor = 1000 / gcd(1000, newFramerate);
+                ts._framerateFactor = 1000 / Common::gcd<uint>(1000, newFramerate);
                 ts._framerate = newFramerate * ts._framerateFactor;
 
-                const uint g = gcd(_framerate, ts._framerate);
+                const uint g = Common::gcd(_framerate, ts._framerate);
                 const uint p = _framerate / g;
                 const uint q = ts._framerate / g;
 
@@ -122 +114 @@
 int Timestamp::cmp(const Timestamp &ts) const {
         int delta = _secs - ts._secs;
         if (!delta) {
-                const uint g = gcd(_framerate, ts._framerate);
+                const uint g = Common::gcd(_framerate, ts._framerate);
                 const uint p = _framerate / g;
                 const uint q = ts._framerate / g;
 
@@ -164 +156 @@
                 // We need to multiply by the quotient of the two framerates.
                 // We cancel the GCD in this fraction to reduce the risk of
                 // overflows.
-                const uint g = gcd(_framerate, ts._framerate);
+                const uint g = Common::gcd(_framerate, ts._framerate);
                 const uint p = _framerate / g;
                 const uint q = ts._framerate / g;
 
@@ -227 +219 @@
                 // We need to multiply by the quotient of the two framerates.
                 // We cancel the GCD in this fraction to reduce the risk of
                 // overflows.
-                const uint g = gcd(_framerate, ts._framerate);
+                const uint g = Common::gcd(_framerate, ts._framerate);
                 const uint p = _framerate / g;
                 const uint q = ts._framerate / g;