class Tracksperanto::Export::Base
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)
Attributes
Public Class Methods
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
# File lib/export/base.rb, line 37 def self.desc_and_extension "data.txt" end
Should return the human-readable (read: properly capitalized and with spaces) name of the export module
# File lib/export/base.rb, line 42 def self.human_name "Abstract export format" end
# File lib/export/base.rb, line 30 def self.inherited(by) Tracksperanto.exporters << by super end
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
# File lib/export/base.rb, line 49 def initialize(write_to_io) @io = write_to_io end
Public Instance Methods
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
# File lib/export/base.rb, line 60 def end_export end
Called on tracker end, once for each tracker
# File lib/export/base.rb, line 73 def end_tracker_segment end
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
# File lib/export/base.rb, line 69 def export_point(at_frame_i, abs_float_x, abs_float_y, float_residual) end
Called on export start. Will receive the width and height of the comp being exported as Integers
# File lib/export/base.rb, line 54 def start_export( img_width, img_height) end
Called on tracker start, once for each tracker. Receives the name of the tracker.
# File lib/export/base.rb, line 64 def start_tracker_segment(tracker_name) end