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authorArmin Le Grand <alg@apache.org>2012-08-23 14:03:21 +0000
committerCaolán McNamara <caolanm@redhat.com>2013-05-19 16:50:31 +0100
commit5a6ed660ec74e445a827c7aa41e4793c64a46271 (patch)
treede8dedebb69847d3e96c371e0c19554051364470 /basegfx/source
parent2d55b2e5ae0d4f1a05e1ce5b20a7b342d6ea8b1d (diff)
Resolves: #i120596# Optimized grid primitive
added some tooling to basegfx (cherry picked from commit 97fa4faaa0b09724cf98dbf22390b283ba57b41c) Conflicts: basegfx/inc/basegfx/numeric/ftools.hxx Change-Id: Ib15c43cf4d5b50605ec596dab498e3a678f3734a
Diffstat (limited to 'basegfx/source')
-rw-r--r--basegfx/source/numeric/ftools.cxx77
1 files changed, 77 insertions, 0 deletions
diff --git a/basegfx/source/numeric/ftools.cxx b/basegfx/source/numeric/ftools.cxx
index 0c9a1734ec50..1cbbe5cc2136 100644
--- a/basegfx/source/numeric/ftools.cxx
+++ b/basegfx/source/numeric/ftools.cxx
@@ -18,11 +18,88 @@
*/
#include <basegfx/numeric/ftools.hxx>
+#include <algorithm>
namespace basegfx
{
// init static member of class fTools
double ::basegfx::fTools::mfSmallValue = 0.000000001;
+
+ double snapToNearestMultiple(double v, const double fStep)
+ {
+ if(fTools::equalZero(fStep))
+ {
+ // with a zero step, all snaps to 0.0
+ return 0.0;
+ }
+ else
+ {
+ const double fHalfStep(fStep * 0.5);
+ const double fChange(fHalfStep - fmod(v + fHalfStep, fStep));
+
+ if(basegfx::fTools::equal(fabs(v), fabs(fChange)))
+ {
+ return 0.0;
+ }
+ else
+ {
+ return v + fChange;
+ }
+ }
+ }
+
+ double snapToZeroRange(double v, double fWidth)
+ {
+ if(fTools::equalZero(fWidth))
+ {
+ // with no range all snaps to range bound
+ return 0.0;
+ }
+ else
+ {
+ if(v < 0.0 || v > fWidth)
+ {
+ double fRetval(fmod(v, fWidth));
+
+ if(fRetval < 0.0)
+ {
+ fRetval += fWidth;
+ }
+
+ return fRetval;
+ }
+ else
+ {
+ return v;
+ }
+ }
+ }
+
+ double snapToRange(double v, double fLow, double fHigh)
+ {
+ if(fTools::equal(fLow, fHigh))
+ {
+ // with no range all snaps to range bound
+ return 0.0;
+ }
+ else
+ {
+ if(fLow > fHigh)
+ {
+ // correct range order. Evtl. assert this (?)
+ std::swap(fLow, fHigh);
+ }
+
+ if(v < fLow || v > fHigh)
+ {
+ return snapToZeroRange(v - fLow, fHigh - fLow) + fLow;
+ }
+ else
+ {
+ return v;
+ }
+ }
+ }
} // end of namespace basegfx
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */