Class: Tracksperanto::NukeGrammarUtils

Inherits:
Object
  • Object
show all
Defined in:
lib/import/nuke_grammar/utils.rb

Constant Summary collapse

SECTION_START = 
/^x(\d+)$/
KEYFRAME = 
/^([-\d\.]+)$/

Instance Method Summary collapse

Instance Method Details

#parse_curve(curve_text) ⇒ Object

Scan a TCL curve expression into a number of tuples of [frame, value]



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# File 'lib/import/nuke_grammar/utils.rb', line 7

def parse_curve(curve_text)
  # Replace the closing curly brace with a curly brace with space so that it gets caught by split
  atoms, tuples = curve_text.gsub(/\}/m, ' }').split, []
  # Nuke saves curves very efficiently. x(keyframe_number) means that an uninterrupted sequence of values will start,
  # after which values follow. When the curve is interrupted in some way a new x(keyframe_number) will signifu that we
  # skip to that specified keyframe and the curve continues from there, in gap size defined by the last fragment.
  # That is, x1 1 x3 2 3 4 will place 2, 3 and 4 at 2-frame increments
  
  last_processed_keyframe = 1
  intraframe_gap_size = 1
  while atom = atoms.shift
    if atom =~ SECTION_START
      last_processed_keyframe = $1.to_i
      if tuples.any?
        last_captured_frame = tuples[-1][0]
        intraframe_gap_size = last_processed_keyframe - last_captured_frame
      end
    elsif  atom =~ KEYFRAME
      tuples << [last_processed_keyframe, $1.to_f]
      last_processed_keyframe += intraframe_gap_size
    elsif atom == '}'
      return tuples
    end
  end
  tuples
end