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21 
22 
23 
24 // MARKER(update_precomp.py): autogen include statement, do not remove
25 #include "precompiled_basegfx.hxx"
26 
27 #include "basegfx/tools/keystoplerp.hxx"
28 #include <com/sun/star/uno/Sequence.hxx>
29 
30 #include <algorithm>
31 
validateInput(const std::vector<double> & rKeyStops)32 static void validateInput(const std::vector<double>& rKeyStops)
33 {
34     (void)rKeyStops;
35 #ifdef DBG_UTIL
36     OSL_ENSURE( rKeyStops.size() > 1,
37                 "KeyStopLerp::KeyStopLerp(): key stop vector must have two entries or more" );
38 
39     // rKeyStops must be sorted in ascending order
40     for( ::std::size_t i=1, len=rKeyStops.size(); i<len; ++i )
41     {
42         if( rKeyStops[i-1] > rKeyStops[i] )
43             OSL_ENSURE( false,
44                         "KeyStopLerp::KeyStopLerp(): time vector is not sorted in ascending order!" );
45     }
46 #endif
47 }
48 
49 namespace basegfx
50 {
51     namespace tools
52     {
KeyStopLerp(const std::vector<double> & rKeyStops)53         KeyStopLerp::KeyStopLerp( const std::vector<double>& rKeyStops ) :
54             maKeyStops(rKeyStops),
55             mnLastIndex(0)
56         {
57             validateInput(maKeyStops);
58         }
59 
KeyStopLerp(const::com::sun::star::uno::Sequence<double> & rKeyStops)60         KeyStopLerp::KeyStopLerp( const ::com::sun::star::uno::Sequence<double>& rKeyStops ) :
61             maKeyStops(rKeyStops.getLength()),
62             mnLastIndex(0)
63         {
64             std::copy( rKeyStops.getConstArray(),
65                        rKeyStops.getConstArray()+rKeyStops.getLength(),
66                        maKeyStops.begin() );
67             validateInput(maKeyStops);
68         }
69 
lerp(double fAlpha) const70         KeyStopLerp::ResultType KeyStopLerp::lerp(double fAlpha) const
71         {
72             // cached value still okay?
73             if( maKeyStops.at(mnLastIndex) < fAlpha ||
74                 maKeyStops.at(mnLastIndex+1) >= fAlpha )
75             {
76                 // nope, find new index
77                 mnLastIndex = std::min<std::ptrdiff_t>(
78                     maKeyStops.size()-2,
79                     // range is ensured by max below
80                     std::max<std::ptrdiff_t>(
81                         0,
82                         std::distance( maKeyStops.begin(),
83                                        std::lower_bound( maKeyStops.begin(),
84                                                          maKeyStops.end(),
85                                                          fAlpha )) - 1 ));
86             }
87 
88             // lerp between stop and stop+1
89             const double fRawLerp=
90                 (fAlpha-maKeyStops.at(mnLastIndex)) /
91                 (maKeyStops.at(mnLastIndex+1) - maKeyStops.at(mnLastIndex));
92 
93             // clamp to permissible range (input fAlpha might be
94             // everything)
95             return ResultType(
96                 mnLastIndex,
97                 clamp(fRawLerp,0.0,1.0));
98         }
99     }
100 }
101