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author	Qt Continuous Integration System <qt-info@nokia.com>	2011-10-10 13:38:02 (GMT)
committer	Qt Continuous Integration System <qt-info@nokia.com>	2011-10-10 13:38:02 (GMT)
commit	22d7b6c1afb3e8558941052b09f755cceb0a46fd (patch)
tree	9e9a09f2fdbce16500f99a09ee286c82785d3aa3 /doc/src/snippets/code/src_gui_image_qimage.cpp
parent	95e5e8ff45d2aa8acda595186136b54f695bb9cb (diff)
parent	e9712d60c6e40c2b81b10611a3573c4638121a85 (diff)
download	Qt-22d7b6c1afb3e8558941052b09f755cceb0a46fd.zip Qt-22d7b6c1afb3e8558941052b09f755cceb0a46fd.tar.gz Qt-22d7b6c1afb3e8558941052b09f755cceb0a46fd.tar.bz2

Merge branch 'master' of scm.dev.nokia.troll.no:qt/qt-fire-staging into master-integration

* 'master' of scm.dev.nokia.troll.no:qt/qt-fire-staging: Fixes: libpng symbols exported from QtGui.dll on Windows omit unassigned (and too recent codepoints) from the text Normalization process Fixed broken window surface flush when depth is 24 and bpp is not 32.

Diffstat (limited to 'doc/src/snippets/code/src_gui_image_qimage.cpp')

0 files changed, 0 insertions, 0 deletions

#include "Python.h" #ifndef HAVE_HYPOT double hypot(double x, double y) { double yx; x = fabs(x); y = fabs(y); if (x < y) { double temp = x; x = y; y = temp; } if (x == 0.) return 0.; else { yx = y/x; return x*sqrt(1.+yx*yx); } } #endif /* HAVE_HYPOT */ #ifndef HAVE_COPYSIGN static double copysign(double x, double y) { /* use atan2 to distinguish -0. from 0. */ if (y > 0. || (y == 0. && atan2(y, -1.) > 0.)) { return fabs(x); } else { return -fabs(x); } } #endif /* HAVE_COPYSIGN */ #ifndef HAVE_LOG1P double log1p(double x) { /* For x small, we use the following approach. Let y be the nearest float to 1+x, then 1+x = y * (1 - (y-1-x)/y) so log(1+x) = log(y) + log(1-(y-1-x)/y). Since (y-1-x)/y is tiny, the second term is well approximated by (y-1-x)/y. If abs(x) >= DBL_EPSILON/2 or the rounding-mode is some form of round-to-nearest then y-1-x will be exactly representable, and is computed exactly by (y-1)-x. If abs(x) < DBL_EPSILON/2 and the rounding mode is not known to be round-to-nearest then this method is slightly dangerous: 1+x could be rounded up to 1+DBL_EPSILON instead of down to 1, and in that case y-1-x will not be exactly representable any more and the result can be off by many ulps. But this is easily fixed: for a floating-point number |x| < DBL_EPSILON/2., the closest floating-point number to log(1+x) is exactly x. */ double y; if (fabs(x) < DBL_EPSILON/2.) { return x; } else if (-0.5 <= x && x <= 1.) { /* WARNING: it's possible than an overeager compiler will incorrectly optimize the following two lines to the equivalent of "return log(1.+x)". If this happens, then results from log1p will be inaccurate for small x. */ y = 1.+x; return log(y)-((y-1.)-x)/y; } else { /* NaNs and infinities should end up here */ return log(1.+x); } } #endif /* HAVE_LOG1P */ /* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. * * Developed at SunPro, a Sun Microsystems, Inc. business. * Permission to use, copy, modify, and distribute this * software is freely granted, provided that this notice * is preserved. * ==================================================== */ static const double ln2 = 6.93147180559945286227E-01; static const double two_pow_m28 = 3.7252902984619141E-09; /* 2**-28 */ static const double two_pow_p28 = 268435456.0; /* 2**28 */ static const double zero = 0.0; /* asinh(x) * Method : * Based on * asinh(x) = sign(x) * log [ |x| + sqrt(x*x+1) ] * we have * asinh(x) := x if 1+x*x=1, * := sign(x)*(log(x)+ln2)) for large |x|, else * := sign(x)*log(2|x|+1/(|x|+sqrt(x*x+1))) if|x|>2, else * := sign(x)*log1p(|x| + x^2/(1 + sqrt(1+x^2))) */ #ifndef HAVE_ASINH double asinh(double x) { double w; double absx = fabs(x); if (Py_IS_NAN(x) || Py_IS_INFINITY(x)) { return x+x; } if (absx < two_pow_m28) { /* |x| < 2**-28 */ return x; /* return x inexact except 0 */ } if (absx > two_pow_p28) { /* |x| > 2**28 */ w = log(absx)+ln2; } else if (absx > 2.0) { /* 2 < |x| < 2**28 */ w = log(2.0*absx + 1.0 / (sqrt(x*x + 1.0) + absx)); } else { /* 2**-28 <= |x| < 2= */ double t = x*x; w = log1p(absx + t / (1.0 + sqrt(1.0 + t))); } return copysign(w, x); } #endif /* HAVE_ASINH */ /* acosh(x) * Method : * Based on * acosh(x) = log [ x + sqrt(x*x-1) ] * we have * acosh(x) := log(x)+ln2, if x is large; else * acosh(x) := log(2x-1/(sqrt(x*x-1)+x)) if x>2; else * acosh(x) := log1p(t+sqrt(2.0*t+t*t)); where t=x-1. * * Special cases: * acosh(x) is NaN with signal if x<1. * acosh(NaN) is NaN without signal. */ #ifndef HAVE_ACOSH double acosh(double x) { if (Py_IS_NAN(x)) { return x+x; } if (x < 1.) { /* x < 1; return a signaling NaN */ errno = EDOM; #ifdef Py_NAN return Py_NAN; #else return (x-x)/(x-x); #endif } else if (x >= two_pow_p28) { /* x > 2**28 */ if (Py_IS_INFINITY(x)) { return x+x; } else { return log(x)+ln2; /* acosh(huge)=log(2x) */ } } else if (x == 1.) { return 0.0; /* acosh(1) = 0 */ } else if (x > 2.) { /* 2 < x < 2**28 */ double t = x*x; return log(2.0*x - 1.0 / (x + sqrt(t - 1.0))); } else { /* 1 < x <= 2 */ double t = x - 1.0; return log1p(t + sqrt(2.0*t + t*t)); } } #endif /* HAVE_ACOSH */ /* atanh(x) * Method : * 1.Reduced x to positive by atanh(-x) = -atanh(x) * 2.For x>=0.5 * 1 2x x * atanh(x) = --- * log(1 + -------) = 0.5 * log1p(2 * --------) * 2 1 - x 1 - x * * For x<0.5 * atanh(x) = 0.5*log1p(2x+2x*x/(1-x)) * * Special cases: * atanh(x) is NaN if |x| >= 1 with signal; * atanh(NaN) is that NaN with no signal; * */ #ifndef HAVE_ATANH double atanh(double x) { double absx; double t; if (Py_IS_NAN(x)) { return x+x; } absx = fabs(x); if (absx >= 1.) { /* |x| >= 1 */ errno = EDOM; #ifdef Py_NAN return Py_NAN; #else return x/zero; #endif } if (absx < two_pow_m28) { /* |x| < 2**-28 */ return x; } if (absx < 0.5) { /* |x| < 0.5 */ t = absx+absx; t = 0.5 * log1p(t + t*absx / (1.0 - absx)); } else { /* 0.5 <= |x| <= 1.0 */ t = 0.5 * log1p((absx + absx) / (1.0 - absx)); } return copysign(t, x); } #endif /* HAVE_ATANH */


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