/usr/include/CLAM/RulerTicks.hxx is in libclam-dev 1.4.0-7.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 | #ifndef RulerTicks_hxx
#define RulerTicks_hxx
#include <cmath>
#include "Assert.hxx"
namespace CLAM
{
/*
Implements the logic to place graphically several markers
in a ruler so that the markers are placed with a given
minimal separation and corresponds to round numbers
on the mapped domain interval.
So, given a domain value range, a pixel size and a minimal pixel gap,
it gives you the domain offset for the first tick and the intertick gap
also in domain units.
Chosen round numbers are series so that the last non zero
decimal steps in 1, 2 or 5 jumps and include 0. For instance:
- 3.1, 3.2, 3.3...
- 22, 24, 26...
- 0.35, 0.40, 0.45...
*/
class RulerTicks
{
mutable bool _needsUpdate;
double _min;
double _max;
double _minGap;
double _width;
mutable double _markOffset;
mutable double _markGap;
public:
RulerTicks()
: _needsUpdate(true)
, _min(0)
, _max(1)
, _minGap(5)
, _width(100)
, _markOffset(666)
, _markGap(69)
{
}
/// Sets the domain value range
void setRange(double min, double max)
{
CLAM_ASSERT(min<max, "RulerTicks: Empty or inverse order range");
_min = min;
_max = max;
_needsUpdate = true;
}
/// Sets the width in pixels to be mapped the range into
void setWidth(double width)
{
CLAM_ASSERT(width>0, "RulerTicks: Pixel width should be greater than zero");
_width = width;
_needsUpdate = true;
}
/// Sets the minimum phisical space in pixels between between marks
void setMinGap(double minGap)
{
_minGap = minGap;
_needsUpdate = true;
}
double markOffset() const
{
if (_needsUpdate) update();
return _markOffset;
}
double markGap() const
{
if (_needsUpdate) update();
return _markGap;
}
void update() const
{
double mappedMinGap = std::fabs(_minGap*(_max-_min)/_width);
_markGap=1;
if (mappedMinGap>=1)
{
while (true)
{
if (_markGap>=mappedMinGap) break;
if (_markGap*2>=mappedMinGap) {_markGap*=2; break;}
if (_markGap*5>=mappedMinGap) {_markGap*=5; break;}
_markGap*=10;
}
}
else
{
while (true)
{
if (_markGap<1e-8) {_markGap=1e-8; break;}
if (_markGap<mappedMinGap) {break;}
if (_markGap/2<mappedMinGap) {_markGap/=2; break;}
if (_markGap/5<mappedMinGap) {_markGap/=5; break;}
_markGap/=10;
}
}
double ceil = std::ceil(_min/_markGap);
_markOffset = (std::fabs(ceil)<1e-5)? 0. : ceil*_markGap;
_needsUpdate = false;
}
/// Returns the domain value corresponding to tick i
double tickValue(unsigned i) const
{
if (_needsUpdate) update();
return _markOffset+_markGap*i;
}
/// Returns the pixel position of tick i
double pixelTickPos(unsigned i) const
{
return toPixel(tickValue(i));
}
// Returns the pixel position of a given domain value
double toPixel(double value) const
{
return (value-_min)*_width/(_max-_min);
}
// Returns the number of ticks that will appear
unsigned nTicks() const
{
if (_needsUpdate) update();
return std::ceil((_max-_markOffset)/_markGap);
}
};
} // namespace CLAM
#endif//RulerTicks_hxx
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