Class: PerfectShape::Path
- Includes:
- MultiPoint
- Defined in:
- lib/perfect_shape/path.rb
Overview
Mostly ported from java.awt.geom: docs.oracle.com/javase/8/docs/api/java/awt/geom/Path2D.html
Constant Summary collapse
- SHAPE_TYPES =
Available class types for path shapes
[Array, PerfectShape::Point, PerfectShape::Line, PerfectShape::QuadraticBezierCurve, PerfectShape::CubicBezierCurve]
- WINDING_RULES =
Available winding rules
[:wind_non_zero, :wind_even_odd]
Instance Attribute Summary collapse
-
#closed ⇒ Object
(also: #closed?)
Returns the value of attribute closed.
-
#shapes ⇒ Object
Returns the value of attribute shapes.
-
#winding_rule ⇒ Object
Returns the value of attribute winding_rule.
Instance Method Summary collapse
-
#contain?(x_or_point, y = nil) ⇒ Boolean
Checks if path contains point (two-number Array or x, y args) using the Nonzero-Rule (aka Winding Number Algorithm): en.wikipedia.org/wiki/Nonzero-rule or using the Even-Odd Rule (aka Ray Casting Algorithm): en.wikipedia.org/wiki/Even%E2%80%93odd_rule.
- #drawing_types ⇒ Object
-
#initialize(shapes: [], closed: false, winding_rule: :wind_non_zero) ⇒ Path
constructor
Constructs Path with winding rule, closed status, and shapes (must always start with PerfectShape::Point or Array of [x,y] coordinates) Shape class types can be any of SHAPE_TYPES: Array (x,y coordinates), PerfectShape::Point, PerfectShape::Line, PerfectShape::QuadraticBezierCurve, or PerfectShape::CubicBezierCurve winding_rule can be any of WINDING_RULES: :wind_non_zero (default) or :wind_even_odd closed can be true or false.
-
#point_crossings(x_or_point, y = nil) ⇒ Object
Calculates the number of times the given path crosses the ray extending to the right from (x,y).
- #points ⇒ Object
- #points=(some_points) ⇒ Object
Methods included from MultiPoint
#max_x, #max_y, #min_x, #min_y
Methods inherited from Shape
#==, #bounding_box, #center_x, #center_y, #height, #max_x, #max_y, #min_x, #min_y, #normalize_point, #width
Constructor Details
#initialize(shapes: [], closed: false, winding_rule: :wind_non_zero) ⇒ Path
Constructs Path with winding rule, closed status, and shapes (must always start with PerfectShape::Point or Array of [x,y] coordinates) Shape class types can be any of SHAPE_TYPES: Array (x,y coordinates), PerfectShape::Point, PerfectShape::Line, PerfectShape::QuadraticBezierCurve, or PerfectShape::CubicBezierCurve winding_rule can be any of WINDING_RULES: :wind_non_zero (default) or :wind_even_odd closed can be true or false
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# File 'lib/perfect_shape/path.rb', line 49 def initialize(shapes: [], closed: false, winding_rule: :wind_non_zero) self.closed = closed self.winding_rule = winding_rule self.shapes = shapes end |
Instance Attribute Details
#closed ⇒ Object Also known as: closed?
Returns the value of attribute closed.
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# File 'lib/perfect_shape/path.rb', line 42 def closed @closed end |
#shapes ⇒ Object
Returns the value of attribute shapes.
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# File 'lib/perfect_shape/path.rb', line 42 def shapes @shapes end |
#winding_rule ⇒ Object
Returns the value of attribute winding_rule.
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# File 'lib/perfect_shape/path.rb', line 41 def winding_rule @winding_rule end |
Instance Method Details
#contain?(x_or_point, y = nil) ⇒ Boolean
Checks if path contains point (two-number Array or x, y args) using the Nonzero-Rule (aka Winding Number Algorithm): en.wikipedia.org/wiki/Nonzero-rule or using the Even-Odd Rule (aka Ray Casting Algorithm): en.wikipedia.org/wiki/Even%E2%80%93odd_rule
the path or false if the point lies outside of the path’s bounds.
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# File 'lib/perfect_shape/path.rb', line 117 def contain?(x_or_point, y = nil) x, y = normalize_point(x_or_point, y) return unless x && y if (x * 0.0 + y * 0.0) == 0.0 # N * 0.0 is 0.0 only if N is finite. # Here we know that both x and y are finite. return false if shapes.count < 2 mask = winding_rule == :wind_non_zero ? -1 : 1 (point_crossings(x, y) & mask) != 0 else # Either x or y was infinite or NaN. # A NaN always produces a negative response to any test # and Infinity values cannot be "inside" any path so # they should return false as well. false end end |
#drawing_types ⇒ Object
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# File 'lib/perfect_shape/path.rb', line 83 def drawing_types the_drawing_shapes = @shapes.map do |shape| case shape when Point :move_to when Array :move_to when Line :line_to when QuadraticBezierCurve :quad_to when CubicBezierCurve :cubic_to end end the_drawing_shapes << :close if closed? the_drawing_shapes end |
#point_crossings(x_or_point, y = nil) ⇒ Object
Calculates the number of times the given path crosses the ray extending to the right from (x,y). If the point lies on a part of the path, then no crossings are counted for that intersection. +1 is added for each crossing where the Y coordinate is increasing -1 is added for each crossing where the Y coordinate is decreasing The return value is the sum of all crossings for every segment in the path. The path must start with a PerfectShape::Point (initial location) The caller must check for NaN values. The caller may also reject infinite values as well.
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# File 'lib/perfect_shape/path.rb', line 146 def point_crossings(x_or_point, y = nil) x, y = normalize_point(x_or_point, y) return unless x && y return 0 if shapes.count == 0 movx = movy = curx = cury = endx = endy = 0 coords = points.flatten curx = movx = coords[0] cury = movy = coords[1] crossings = 0 ci = 2 1.upto(shapes.count - 1).each do |i| case drawing_types[i] when :move_to if cury != movy line = PerfectShape::Line.new(points: [[curx, cury], [movx, movy]]) crossings += line.point_crossings(x, y) end movx = curx = coords[ci] ci += 1 movy = cury = coords[ci] ci += 1 when :line_to endx = coords[ci] ci += 1 endy = coords[ci] ci += 1 line = PerfectShape::Line.new(points: [[curx, cury], [endx, endy]]) crossings += line.point_crossings(x, y) curx = endx; cury = endy; when :quad_to quad_ctrlx = coords[ci] ci += 1 quad_ctrly = coords[ci] ci += 1 endx = coords[ci] ci += 1 endy = coords[ci] ci += 1 quad = PerfectShape::QuadraticBezierCurve.new(points: [[curx, cury], [quad_ctrlx, quad_ctrly], [endx, endy]]) crossings += quad.point_crossings(x, y) curx = endx; cury = endy; when :cubic_to cubic_ctrl1x = coords[ci] ci += 1 cubic_ctrl1y = coords[ci] ci += 1 cubic_ctrl2x = coords[ci] ci += 1 cubic_ctrl2y = coords[ci] ci += 1 endx = coords[ci] ci += 1 endy = coords[ci] ci += 1 cubic = PerfectShape::CubicBezierCurve.new(points: [[curx, cury], [cubic_ctrl1x, cubic_ctrl1y], [cubic_ctrl2x, cubic_ctrl2y], [endx, endy]]) crossings += cubic.point_crossings(x, y) curx = endx; cury = endy; when :close if cury != movy line = PerfectShape::Line.new(points: [[curx, cury], [movx, movy]]) crossings += line.point_crossings(x, y) end curx = movx cury = movy end end if cury != movy line = PerfectShape::Line.new(points: [[curx, cury], [movx, movy]]) crossings += line.point_crossings(x, y) end crossings end |
#points ⇒ Object
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# File 'lib/perfect_shape/path.rb', line 55 def points the_points = [] @shapes.each do |shape| case shape when Point the_points << shape.to_a when Array the_points << shape.map {|n| BigDecimal(n.to_s)} when Line the_points << shape.points.last.to_a when QuadraticBezierCurve shape.points.each do |point| the_points << point.to_a end when CubicBezierCurve shape.points.each do |point| the_points << point.to_a end end end the_points << @shapes.first.to_a if closed? the_points end |
#points=(some_points) ⇒ Object
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# File 'lib/perfect_shape/path.rb', line 79 def points=(some_points) raise "Cannot assign points directly! Must set shapes instead and points are calculated from them automatically." end |