Class VerTableBuilder
- All Implemented Interfaces:
MultiTableBuilder
,TableBuilder
There are usually two parts, which are read by this handler as two tables: a list of 3d vertices, and a list of polygons referencing these vertices. The first line contains two integers, for the vertex and face counts.
At present, the vertices are represented as 3 columns X,Y,Z,
and the plates must be triangular and are represented as an intial
3-element position followed by a 6-element array of "other" positions.
This is just because those are in the form that's easy to plot
using the plot2 * polygon
layer.
But there might be better ways to do this.
This implementation is hacky, mainly because I don't have a robust definition of the format(s). It should and maybe could be improved. See MKDSK documentation referenced below.
Some examples are:
- DAMIT variant: example file
- SBN (Gaskell?) format: example file
- Comsim(?) variant: example file
Resources:
- Since:
- 6 Feb 2025
- Author:
- Mark Taylor
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionboolean
canImport
(DataFlavor flavor) Indicates whether this builder is able to turn a resource of media type indicated byflavor
into a table.boolean
Currently returns false.Returns the name of the format which can be read by this handler.boolean
looksLikeFile
(String location) Indicates whether the given location string is of a familiar form for this builder.makeStarTable
(uk.ac.starlink.util.DataSource datsrc, boolean wantRandom, StoragePolicy storagePolicy) Constructs aStarTable
based on a givenDataSource
.makeStarTables
(uk.ac.starlink.util.DataSource datsrc, StoragePolicy policy) Constructs a sequence of StarTables based on a given DataSource.void
streamStarTable
(InputStream in, TableSink sink, String pos) Reads a table from an input stream and writes it a row at a time to a sink.
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Constructor Details
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VerTableBuilder
public VerTableBuilder()
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Method Details
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getFormatName
Description copied from interface:TableBuilder
Returns the name of the format which can be read by this handler. Matching against this string may be used by callers to identify or select this handler from a list.- Specified by:
getFormatName
in interfaceTableBuilder
- Returns:
- one-word description of this handler's format
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looksLikeFile
Description copied from interface:TableBuilder
Indicates whether the given location string is of a familiar form for this builder. Implementations should returntrue
if there is a good chance that a file with the givenlocation
can be interpreted by this reader, for instance if it has a suitable file extension.This method may be used to guess, on a best-efforts basis, whether this builder is suitable for reading a file from a given location. Attempts may still be made to read inputs for which this method returns false. It is less important for builders that can recognise files by magic number, which is generally preferable to using filenames.
- Specified by:
looksLikeFile
in interfaceTableBuilder
- Parameters:
location
- the location string, such as a filename or URL (not null)- Returns:
- true iff there is a good chance that the named input can be interpreted by this reader
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canImport
Description copied from interface:TableBuilder
Indicates whether this builder is able to turn a resource of media type indicated byflavor
into a table. It should returntrue
if it thinks that itsTableBuilder.streamStarTable(java.io.InputStream, uk.ac.starlink.table.TableSink, java.lang.String)
method stands a reasonable chance of successfully constructing aStarTable
from aDataSource
whose input stream is described by theDataFlavor
flavor
. It will typically make this determination based on the flavor's MIME type.This method should only return
true
if the flavor looks like it is targeted at this builder; for instance a builder which uses a text-based format should return false for a flavor which indicates a MIME type oftext/plain
.This method is used in supporting drag and drop functionality (see
StarTableFactory.canImport(java.awt.datatransfer.DataFlavor[])
).- Specified by:
canImport
in interfaceTableBuilder
- Parameters:
flavor
- the DataFlavor whose suitability as stream input is to be assessed- Returns:
true
iff this builder reckons it stands a good chance of turning a stream of typeflavor
into aStarTable
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canStream
public boolean canStream()Currently returns false. This wouldn't be so hard to do, but it's not that useful since it can only return one table. Maybe do it at some point, but work out first what format variants we will support. -
streamStarTable
Description copied from interface:TableBuilder
Reads a table from an input stream and writes it a row at a time to a sink. Not all implementations will be able to do this; for instance, extracting the table from the data may be a two-pass process. Implementations which are unable to perform this function should throw aTableFormatException
.The input stream should be prepared for use prior to calling this method, so implementations should not in general attempt to decompress or buffer
istrm
.- Specified by:
streamStarTable
in interfaceTableBuilder
- Parameters:
in
- input stream containing table datasink
- destination of the tablepos
- position identifier describing the location of the table within the stream; seeDataSource.getPosition()
(may be null)- Throws:
IOException
- if some other error occurs
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makeStarTables
public TableSequence makeStarTables(uk.ac.starlink.util.DataSource datsrc, StoragePolicy policy) throws IOException Description copied from interface:MultiTableBuilder
Constructs a sequence of StarTables based on a given DataSource. If the source is not recognised or this object does not know how to make tables from it, then aTableFormatException
should be thrown. If this builder thinks it should be able to handle the source but an error occurs during processing, anIOException
can be thrown.If the
position
of the data source is not null, then this method should return a sequence containing a single table, the one which would be returned by themakeStarTable
method with that position.- Specified by:
makeStarTables
in interfaceMultiTableBuilder
- Parameters:
datsrc
- the DataSource containing the table resourcepolicy
- a StoragePolicy object which may be used to supply scratch storage if the builder needs it- Returns:
- an array of StarTables read from
datsrc
- Throws:
IOException
- if an unexpected I/O error occurs during processing
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makeStarTable
public StarTable makeStarTable(uk.ac.starlink.util.DataSource datsrc, boolean wantRandom, StoragePolicy storagePolicy) throws IOException Description copied from interface:TableBuilder
Constructs aStarTable
based on a givenDataSource
. If the source is not recognised or this builder does not know how to construct a table from it, then aTableFormatException
should be thrown. If this builder thinks it should be able to handle the source but an error occurs during processing, anIOException
can be thrown.The
wantRandom
parameter is used to indicate whether, ideally, a random-access table should be returned. There is no requirement for the builder to honour this request, but if it knows how to make both random and non-random tables, it can use this flag to decide which to return.Note: the presence of the
wantRandom
parameter is somewhat misleading. TableBuilder implementations usually should, and do, ignore it (it would be removed from the interface if it were not for backward compatibility issues). Regardless of the value of this parameter, implementations should return a random-access table only if it is easy for them to do so; in particular they should not use the suppliedstoragePolicy
, or any other resource-expensive measure, to randomise a sequential table just because thewantRandom
parameter is true.- Specified by:
makeStarTable
in interfaceTableBuilder
- Parameters:
datsrc
- the DataSource containing the table resourcewantRandom
- whether, preferentially, a random access table should be returnedstoragePolicy
- a StoragePolicy object which may be used to supply scratch storage if the builder needs it- Returns:
- a StarTable made out of
datsrc
- Throws:
IOException
- if an unexpected I/O error occurs during processing
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