Class: MTK::Patterns::Lines

Inherits:
Pattern
  • Object
show all
Defined in:
lib/mtk/patterns/lines.rb

Overview

A piecewise linear function (see src="http://en.wikipedia.org/wiki/File:PiecewiseLinear.png" />) defined in terms of [value, steps_to_reach_value] pairs.

The “steps_to_reach_value” for the first element is ignored and may be omitted, since it takes 0 steps to start.

Instance Attribute Summary

Attributes inherited from Pattern

#cycle_count, #element_count, #elements, #max_cycles, #max_elements, #min_elements, #options

Instance Method Summary collapse

Methods inherited from Pattern

#empty?, from_a, #initialize, #max_cycles_exceeded?, #max_elements_exceeded?, #min_elements_unmet?, #next, #rewind

Methods included from Groups::Collection

#==, #[], #clone, #concat, #each, #empty?, #enumerable_map, #first, #last, #map, #partition, #permute, #repeat, #reverse, #rotate, #size, #to_a

Constructor Details

This class inherits a constructor from MTK::Patterns::Pattern

Instance Method Details

#advance ⇒ Object (protected)

Update internal state (index, etc) and set @current to the next element.



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# File 'lib/mtk/patterns/lines.rb', line 23

def advance
  while @step_count >= @steps
    @step_count = 0

    @index += 1
    raise StopIteration if @index >= @elements.length

    @prev = @next
    next_elem = @elements[@index]
    if next_elem.is_a? Array
      @next = next_elem.first
      @steps = next_elem.last.to_f
    else
      @next = next_elem
      @steps = 1.0
    end
  end

  @step_count += 1

  if @prev and @next
    # linear interpolation
    @current = @prev + (@next - @prev)*@step_count/@steps
  else
    @current = @next
  end
end

#rewind_or_cycle(is_cycling = false) ⇒ Object (protected)

Reset the pattern to the beginning

Parameters:

  • is_cycling (Boolean) (defaults to: false) —

    true when #next is performing a cycle back to the beginning of the Pattern. false for a normal #rewind



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# File 'lib/mtk/patterns/lines.rb', line 14

def rewind_or_cycle(is_cycling=false)
  @steps = -1
  @step_count = -1
  @prev = nil
  @next = nil
  super
end