Class: Tracksperanto::Export::Base

Inherits:
Object
  • Object
show all
Includes:
ConstName, SimpleExport
Defined in:
lib/export/base.rb

Overview

Base exporter. Inherit from this class to automatically register another export format. The exporters in Tracksperanto are event-driven and follow the same conventions - your exporter will be notified when a tracker will be exported and when a tracker has been passed (the last keyframe has been sent). Here’s how you can operate any exporter module separately (this also demonstrates the calling convention and sequence):

File.open("destination.txt", "wb") do | f |
  exporter = SomeExporter.new(f)
  exporter.start_export(720, 576)

  # Export the first tracker
  exporter.start_tracker_segment("FirstPoint")
  exporter.export_point(2, 123.43, 456.2, 0.2)
  exporter.export_point(3, 23423.43, 768.1, 0.1)
  exporter.end_tracker_segment

  # Export the second tracker
  exporter.start_tracker_segment("AnotherPoint")
  ....
  exported.end_tracker_segment
  exporter.end_export
end

By contract export_point will be called at least once for each tracker being exported (no empty trackers will be sent)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from ConstName

#const_name, included

Methods included from SimpleExport

#just_export

Constructor Details

#initialize(write_to_io) ⇒ Base

The constructor for an exporter should accept a handle to the IO object that you can write to. This gets assigned to @io ivar by default, but you can do whatever you wish By convention, the caller owns the IO handle and will close it when you are done, so don’t close t yourself



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# File 'lib/export/base.rb', line 50

def initialize(write_to_io)
  @io = write_to_io
end

Instance Attribute Details

#io ⇒ Object (readonly)

Returns the value of attribute io.



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# File 'lib/export/base.rb', line 29

def io
  @io
end

Class Method Details

.desc_and_extension ⇒ Object

Should return the suffix and extension of this export file (like “flame.stabilizer”), without the leading underscore. It’s a class method because it gets requested before the exporter is instantiated



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# File 'lib/export/base.rb', line 38

def self.desc_and_extension
  "data.txt"
end

.human_name ⇒ Object

Should return the human-readable (read: properly capitalized and with spaces) name of the export module



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# File 'lib/export/base.rb', line 43

def self.human_name
  "Abstract export format"
end

.inherited(by) ⇒ Object 



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# File 'lib/export/base.rb', line 31

def self.inherited(by)
  Tracksperanto.exporters << by
  super
end

Instance Method Details

#end_export ⇒ Object

Called on export end. By convention, the caller will close the main IO when you are done so don’t do it here. However if you’ve allocated anything during export (like some Tempfiles) here will be the place to get rid of them



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# File 'lib/export/base.rb', line 61

def end_export
end

#end_tracker_segment ⇒ Object

Called on tracker end, once for each tracker



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# File 'lib/export/base.rb', line 74

def end_tracker_segment
end

#export_point(at_frame_i, abs_float_x, abs_float_y, float_residual) ⇒ Object

Called for each tracker keyframe, with the Tracksperanto internal coordinates and frame numbers. The calls come after start_tracker_segment and before end_tracker_segment



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# File 'lib/export/base.rb', line 70

def export_point(at_frame_i, abs_float_x, abs_float_y, float_residual)
end

#start_export(img_width, img_height) ⇒ Object

Called on export start. Will receive the width and height of the comp being exported as Fixnums



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# File 'lib/export/base.rb', line 55

def start_export( img_width, img_height)
end

#start_tracker_segment(tracker_name) ⇒ Object

Called on tracker start, once for each tracker. Receives the name of the tracker.



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# File 'lib/export/base.rb', line 65

def start_tracker_segment(tracker_name)
end