Class: FlameChannelParser::Interpolator

Inherits:
Object
  • Object
show all
Includes:
Segments
Defined in:
lib/interpolator.rb

Overview

Used to sample Flame animation curves. Pass a Channel object to the interpolator and you can then sample values at arbitrary frames.

i = Interpolator.new(parsed_channel)
i.value_at(245.5) # => will interpolate and return the value at frame 245.5

Constant Summary collapse

NEG_INF = 
(-1.0/0.0)
POS_INF = 
(1.0/0.0)

Instance Method Summary collapse

Constructor Details

#initialize(channel) ⇒ Interpolator

The constructor will accept a ChannelBlock object and convert it internally to a number of segments from which samples can be made



17
18
19
20
21
22
23
24
25
26
27
 
# File 'lib/interpolator.rb', line 17

def initialize(channel)
  @segments = []
  @extrap = channel.extrapolation
  
  # Edge case - channel has no anim at all
  @segments = if channel.length.zero?
    [ConstantFunction.new(channel.base_value)]
  else
    create_segments_from_channel(channel)
  end
end

Instance Method Details

#first_defined_frame ⇒ Object

Returns the first frame number that is concretely defined as a keyframe after the prepolation ends



42
43
44
45
46
 
# File 'lib/interpolator.rb', line 42

def first_defined_frame
  first_f = @segments[0].end_frame
  return 1 if first_f == NEG_INF
  return first_f
end

#last_defined_frame ⇒ Object

Returns the last frame number that is concretely defined as a keyframe before the extrapolation starts



50
51
52
53
54
 
# File 'lib/interpolator.rb', line 50

def last_defined_frame
  last_f = @segments[-1].start_frame
  return 100 if last_f == POS_INF
  return last_f
end

#sample_at(frame) ⇒ Object

Sample the value of the animation curve at this frame



30
31
32
33
34
35
36
37
38
 
# File 'lib/interpolator.rb', line 30

def sample_at(frame)
  if :cycle == @extrap
    return sample_from_segments(frame_number_in_cycle(frame))
  elsif :revcycle == @extrap
    return sample_from_segments(frame_number_in_revcycle(frame))
  else
    sample_from_segments(frame)
  end
end