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Isis 3.0 Object Programmers' Reference |
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Calculate light intensity reflected off a local slope of DEM. More...
#include <Hillshade.h>
Public Member Functions | |
| Hillshade () | |
| Create a default-constructed Hillshade. | |
| Hillshade (Angle azimuth, Angle zenith, double resolution) | |
| Construct and fully initialize a Hillshade. | |
| Hillshade (const Hillshade &other) | |
| Copy constructor. | |
| void | setAzimuth (Angle azimuth) |
| The azimuth is the direction of the light. | |
| void | setZenith (Angle zenith) |
| The zenith is the altitude/solar elevation of the light. | |
| void | setResolution (double resolution) |
| The resolution is the meters per pixel of the input to shadedValue(). | |
| Angle | azimuth () const |
| Get the current azimuth angle. | |
| Angle | zenith () const |
| Get the current zenith angle. | |
| double | resolution () const |
| Get the current resolution (meters per pixel). | |
| double | shadedValue (Buffer &input) const |
| Calculate the shaded value from a 3x3x1 window. | |
| void | swap (Hillshade &other) |
| Swap class data with other; this cannot throw an exception. | |
| Hillshade & | operator= (const Hillshade &rhs) |
| Assignment operator. | |
| QString | toString () const |
Private Attributes | |
| Angle * | m_azimuth |
| This is direction of the light, with 0 at north. | |
| Angle * | m_zenith |
| This is the altitide of the light, with 0 directly overhead and 90 at the horizon. | |
| double | m_pixelResolution |
| meters per pixel | |
Calculate light intensity reflected off a local slope of DEM.
This class basically does what the 'shade' application does. This calculates a shaded-relief cube given 3x3 topographic portals. Inputs include the sun angle (azimuth), solar elevation (zenith), and resolution (meters per pixel). This was abstracted out from the shade application, which uses the algorithm described at: http://people.csail.mit.edu/bkph/papers/Hill-Shading.pdf
I (Steven Lambright) took the code, originally authored by Tracie Sucharski, from the shade program and re-implemented it in this class.
This class is re-entrant and const methods are thread-safe.
Definition at line 29 of file Hillshade.h.
| Isis::Hillshade::Hillshade | ( | ) |
Create a default-constructed Hillshade.
You must use mutators to initialize this instance before it can be used to calculate shaded values.
Definition at line 18 of file Hillshade.cpp.
References m_azimuth, m_pixelResolution, m_zenith, and Isis::Null.
Construct and fully initialize a Hillshade.
This can immediately calculate shaded values.
Definition at line 32 of file Hillshade.cpp.
References m_azimuth, m_pixelResolution, m_zenith, Isis::Null, setAzimuth(), setResolution(), and setZenith().
| Isis::Hillshade::Hillshade | ( | const Hillshade & | other | ) |
Copy constructor.
Definition at line 46 of file Hillshade.cpp.
References m_azimuth, m_pixelResolution, and m_zenith.
| Angle Isis::Hillshade::azimuth | ( | ) | const |
Get the current azimuth angle.
Definition at line 119 of file Hillshade.cpp.
References m_azimuth.
Referenced by Isis::operator<<().
Assignment operator.
This utilizes copy-and-swap.
Definition at line 298 of file Hillshade.cpp.
References swap().
| double Isis::Hillshade::resolution | ( | ) | const |
Get the current resolution (meters per pixel).
Definition at line 149 of file Hillshade.cpp.
References m_pixelResolution.
Referenced by Isis::operator<<(), and setResolution().
| void Isis::Hillshade::setAzimuth | ( | Angle | azimuth | ) |
The azimuth is the direction of the light.
0 is north; this angle rotates the sun.
An invalid angle will silently fail; if shadedValue() is called without a valid azimuth angle then an exception will be thrown.
Definition at line 76 of file Hillshade.cpp.
References Isis::Angle::isValid(), and m_azimuth.
Referenced by Hillshade().
| void Isis::Hillshade::setResolution | ( | double | resolution | ) |
The resolution is the meters per pixel of the input to shadedValue().
A special pixel value will silently fail; if shadedValue() is called without a valid resolution angle then an exception will be thrown.
Definition at line 109 of file Hillshade.cpp.
References m_pixelResolution, and resolution().
Referenced by Hillshade().
| void Isis::Hillshade::setZenith | ( | Angle | zenith | ) |
The zenith is the altitude/solar elevation of the light.
0 is directly above and 90 is the horizon; this angle raises and lowers the sun.
An invalid angle will silently fail; if shadedValue() is called without a valid zenith angle then an exception will be thrown.
Definition at line 93 of file Hillshade.cpp.
References Isis::Angle::isValid(), and m_zenith.
Referenced by Hillshade().
| double Isis::Hillshade::shadedValue | ( | Buffer & | input | ) | const |
Calculate the shaded value from a 3x3x1 window.
Definition at line 157 of file Hillshade.cpp.
References _FILEINFO_, Isis::Buffer::BandDimension(), Isis::Angle::Degrees, Isis::Angle::fullRotation(), Isis::IsSpecial(), Isis::Buffer::LineDimension(), m_azimuth, m_pixelResolution, m_zenith, Isis::Null, Isis::IException::Programmer, Isis::Angle::radians(), Isis::Buffer::SampleDimension(), Isis::Buffer::size(), Isis::Angle::toString(), and Isis::IException::Unknown.
| void Isis::Hillshade::swap | ( | Hillshade & | other | ) |
Swap class data with other; this cannot throw an exception.
Definition at line 288 of file Hillshade.cpp.
References m_azimuth, m_pixelResolution, and m_zenith.
Referenced by operator=().
| Angle Isis::Hillshade::zenith | ( | ) | const |
Get the current zenith angle.
Definition at line 134 of file Hillshade.cpp.
References m_zenith.
Referenced by Isis::operator<<().
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private |
This is direction of the light, with 0 at north.
Definition at line 53 of file Hillshade.h.
Referenced by azimuth(), Hillshade(), setAzimuth(), shadedValue(), and swap().
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private |
meters per pixel
Definition at line 57 of file Hillshade.h.
Referenced by Hillshade(), resolution(), setResolution(), shadedValue(), and swap().
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private |
This is the altitide of the light, with 0 directly overhead and 90 at the horizon.
Definition at line 55 of file Hillshade.h.
Referenced by Hillshade(), setZenith(), shadedValue(), swap(), and zenith().