Class: ChunkyPNG::Vector

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/chunky_png/vector.rb

Overview

Class that represents a vector of points, i.e. a list of Point instances.

Vectors can be created quite flexibly. See the Vector factory methods for more information on how to construct vectors.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(points = []) ⇒ Vector

Initializes a vector based on a list of Point instances.

You usually do not want to use this method directly, but call ChunkyPNG::Vector instead.

See Also:



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# File 'lib/chunky_png/vector.rb', line 46

def initialize(points = [])
  @points = points
end

Instance Attribute Details

#points ⇒ Array<ChunkyPNG::Point> (readonly) 



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# File 'lib/chunky_png/vector.rb', line 38

def points
  @points
end

Class Method Details

.multiple_from_array(source) ⇒ Array<ChunkyPNG::Point> 



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# File 'lib/chunky_png/vector.rb', line 167

def self.multiple_from_array(source)
  return [] if source.empty?
  if source.first.is_a?(Numeric) || source.first =~ /^\d+$/
    raise ArgumentError, "The points array is expected to have an even number of items!" if source.length % 2 != 0

    points = []
    source.each_slice(2) { |x, y| points << ChunkyPNG::Point.new(x, y) }
    return points
  else
    source.map { |p| ChunkyPNG::Point(p) }
  end
end

.multiple_from_string(source_str) ⇒ Array<ChunkyPNG::Point> 



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# File 'lib/chunky_png/vector.rb', line 181

def self.multiple_from_string(source_str)
  multiple_from_array(source_str.scan(/[\(\[\{]?(\d+)\s*[,x]?\s*(\d+)[\)\]\}]?/))
end

Instance Method Details

#[](index) ⇒ ChunkyPNG::Point

Returns the point with the given indexof this vector.



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# File 'lib/chunky_png/vector.rb', line 69

def [](index)
  points[index]
end

#dimension ⇒ ChunkyPNG::Dimension

Returns the dimension of the minimal bounding rectangle of the points in this vector.



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# File 'lib/chunky_png/vector.rb', line 162

def dimension
  ChunkyPNG::Dimension.new(width, height)
end

#each {|ChunkyPNG::Point| ... }

This method returns an undefined value.

Iterates over all the points in this vector

Yields:



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# File 'lib/chunky_png/vector.rb', line 91

def each(&block)
  points.each(&block)
end

#each_edge(close = true) {|points.last, points.first| ... }

This method returns an undefined value.

Iterates over all the edges in this vector.

An edge is a combination of two subsequent points in the vector. Together, they will form a path from the first point to the last point

Yields:

Raises:

See Also:



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# File 'lib/chunky_png/vector.rb', line 60

def each_edge(close = true)
  raise ChunkyPNG::ExpectationFailed, "Not enough points in this path to draw an edge!" if length < 2
  points.each_cons(2) { |a, b| yield(a, b) }
  yield(points.last, points.first) if close
end

#edges(close = true) ⇒ Enumerator

Returns an enumerator that will iterate over all the edges in this vector.

Raises:

See Also:



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# File 'lib/chunky_png/vector.rb', line 78

def edges(close = true)
  to_enum(:each_edge, close)
end

#eql?(other) ⇒ true, false Also known as: ==

Comparison between two vectors for quality.



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# File 'lib/chunky_png/vector.rb', line 98

def eql?(other)
  other.points == points
end

#height ⇒ Integer

Returns the height of the minimal bounding box of all the points in this vector.



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# File 'lib/chunky_png/vector.rb', line 156

def height
  1 + (max_y - min_y)
end

#length ⇒ Integer

Returns the number of points in this vector.



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# File 'lib/chunky_png/vector.rb', line 84

def length
  points.length
end

#max_x ⇒ Integer

Finds the highest x-coordinate in this vector.



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# File 'lib/chunky_png/vector.rb', line 124

def max_x
  x_range.last
end

#max_y ⇒ Integer

Finds the highest y-coordinate in this vector.



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# File 'lib/chunky_png/vector.rb', line 136

def max_y
  y_range.last
end

#min_x ⇒ Integer

Finds the lowest x-coordinate in this vector.



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# File 'lib/chunky_png/vector.rb', line 118

def min_x
  x_range.first
end

#min_y ⇒ Integer

Finds the lowest y-coordinate in this vector.



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# File 'lib/chunky_png/vector.rb', line 130

def min_y
  y_range.first
end

#offset ⇒ ChunkyPNG::Point

Returns the offset from (0,0) of the minimal bounding box of all the points in this vector



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# File 'lib/chunky_png/vector.rb', line 144

def offset
  ChunkyPNG::Point.new(min_x, min_y)
end

#width ⇒ Integer

Returns the width of the minimal bounding box of all the points in this vector.



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# File 'lib/chunky_png/vector.rb', line 150

def width
  1 + (max_x - min_x)
end

#x_range ⇒ Range

Returns the range in x-coordinates for all the points in this vector.



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# File 'lib/chunky_png/vector.rb', line 106

def x_range
  Range.new(*points.map { |p| p.x }.minmax)
end

#y_range ⇒ Range

Returns the range in y-coordinates for all the points in this vector.



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# File 'lib/chunky_png/vector.rb', line 112

def y_range
  Range.new(*points.map { |p| p.y }.minmax)
end