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39
40#include "qmultimediautils_p.h"
41
42QT_BEGIN_NAMESPACE
43
44void qt_real_to_fraction(qreal value, int *numerator, int *denominator)
45{
46 if (!numerator || !denominator)
47 return;
48
49 const int dMax = 1000;
50 int n1 = 0, d1 = 1, n2 = 1, d2 = 1;
51 qreal mid = 0.;
52 while (d1 <= dMax && d2 <= dMax) {
53 mid = qreal(n1 + n2) / (d1 + d2);
54
55 if (qAbs(t: value - mid) < 0.000001) {
56 if (d1 + d2 <= dMax) {
57 *numerator = n1 + n2;
58 *denominator = d1 + d2;
59 return;
60 } else if (d2 > d1) {
61 *numerator = n2;
62 *denominator = d2;
63 return;
64 } else {
65 *numerator = n1;
66 *denominator = d1;
67 return;
68 }
69 } else if (value > mid) {
70 n1 = n1 + n2;
71 d1 = d1 + d2;
72 } else {
73 n2 = n1 + n2;
74 d2 = d1 + d2;
75 }
76 }
77
78 if (d1 > dMax) {
79 *numerator = n2;
80 *denominator = d2;
81 } else {
82 *numerator = n1;
83 *denominator = d1;
84 }
85}
86
87QT_END_NAMESPACE
88

source code of qtmultimedia/src/multimedia/qmultimediautils.cpp