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Appendix B

Binary File Format (*.CHV)

As the internal format of ChView is object based, the data file is comprised of serialised objects. Each fundamental data type has its own representation on disk.

Integers: are saved as 2 byte bitfields.

Longs: are saved as 4 byte bitfields.

Strings: are saved a a 1 byte length determinator followed

by that many bytes of data. This does not include the null

terminator. If the string is longer that 254 then a byte

containing FF is stored with two bytes following containing

the actual length.

Floats: are unusual. They are stored as string representations.

This is done because most of the floating point numbers we

wish to store are nice rounded numbers. It is more efficient

to store them as strings than 8-byte floating point values.

Colorref: this is a Windows RGB value. It is promoted to a long

and saved as that.

LogFont: a binary representation of the Windows structure.


This area stores overall information for the data file.

First is stored a long value containing the version number

of the data representation. The current representation is

version 00000101 (hex value). Future versions will increment

this number.

Next are the view preferences:

Grid |int |Display grid or not

GridSize |double |Granularity of grid

Link |int |Display Links or not

LinkNumbers |int |Display Link Numbers or not

LinkSize x 4 |double |Size of each link gradation

StarName |int |Display Star Names or not

Radius |double |View Radius

Scale |int |Display Scope or note

GridStyle |int |Style of grid lines

LinkStyle x 3 |int |Style of link lines

StemStyle |int |Style of stems

StarOutline |int |Display star outline or not

RouteDisp |int |Display routes or not

Dummy x 8 |long |Reserved

OColour |Colorref |Colour of spectral type O stars

BColour |Colorref |

AColour |Colorref |

FColour |Colorref |

GColour |Colorref |

KColour |Colorref |

MColour |Colorref |

XColour |Colorref |

BackColour |Colorref |Colour of background

TextColour |Colorref |Colour of text

LinkNumColour |Colorref |Colour of link numbers

LinkColour x 3 |Colorref |Colour of link gradations

GridColour |Colorref |Colour of grid

StemColour |Colorref |Colour of stems

ORad |int |Radius of spectral class O stars

BRad |int |

ARad |int |

FRad |int |

GRad |int |

KRad |int |

MRad |int |

XRad |int |

DwarfRad |int |

GiantRad |int |

SuperGiantRad |int |

CentreOrds x 3 |double |Galactic coordinates of centre

theta |double |Rotational position

phi |double |

rho |double |

tscale |double |Angular scales

pscale |double |

rscale |double |

xscale |double |Display scales

yscale |double |

GroupLabel x 4 |string |Names of groups

DisplayGroup x 4 |int |Display each group or not

RouteLabel \ |string |Name of Route label

RouteColour x 4 |colorref |Colour of Route

RouteStyle / |int |Style of Route lines

LinkF |logfont |Link Number font

NameF |logfont |StarName font

UNameF |logfont |Unused font


First here is a long containing the number of star objects that

follow. Each object consists of:

cjcName |string |Proper Name of Place

starName |string |Official name of star

dToEarth |double |Distance to earth

Spectra |string |Spectra

Mass |double |Collapsed mass

ActualMass |double |Uncollapsed mass

ords[0] |double |Galactic coordinates

ords[1] |double |

ords[2] |double |

Constellation |string |Constellation

Comment |string |Comment

Selected |int |Selected or not

index |int |Index in file

Group |int |Group of star

There is a single byte indicating if there is a subsidiary star

orbiting this one. If so this entire data structure repeats


Lastly we record the links. First is a integer value indicating

the number of following links. Each link is then represented by

a integer containing the type of link and a string containing the

starName of the destination.


This contains only a string giving general comments on the entire


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