Perfect Shape 0.0.11

Geometric Algorithms

PerfectShape is a collection of pure Ruby geometric algorithms that are mostly useful for GUI (Graphical User Interface) manipulation like checking containment of a mouse click point in popular geometry shapes such as rectangle, square, arc (open, chord, and pie), ellipse, circle, polygon (ray casting algorithm/even-odd rule), polyline, polyquad, polycubic, and paths containing lines, bezier curves, and quadratic curves.

Additionally, PerfectShape::Math contains some purely mathematical algorithms.

To ensure high accuracy, this library does all its mathematical operations with BigDecimal numbers.

Setup

Run:

gem install perfect-shape -v 0.0.11

Or include in Bundler Gemfile:

gem 'perfect-shape', '~> 0.0.11'

And, run:

bundle

API

`PerfectShape::Math`

Module

::degrees_to_radians(angle): converts degrees to radians
::radians_to_degrees(angle): converts radians to degrees
::normalize_degrees(angle): normalizes the specified angle into the range -180 to 180.
::ieee_remainder(x, y) (alias: ieee754_remainder): IEEE 754-1985 Remainder (different from standard % modulo operator as it operates on floats and could return a negative result)

`PerfectShape::Shape`

Class

This is a base class for all shapes. It is not meant to be used directly. Subclasses implement/override its methods as needed.

#min_x: min x
#min_y: min y
#max_x: max x
#max_y: max y
#width: width
#height: height
#center_x: center x
#center_y: center y
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height just as those of shape
#normalize_point(x_or_point, y = nil): normalizes point into an Array of (x,y) coordinates
#==(other): Returns true if equal to other or false otherwise

`PerfectShape::PointLocation`

Module

#initialize(x: 0, y: 0): initializes a point location, usually representing the top-left point in a shape
#x: top-left x
#y: top-left y
#min_x: min x (x by default)
#min_y: min y (y by default)

`PerfectShape::RectangularShape`

Module

Includes PerfectShape::PointLocation

#initialize(x: 0, y: 0, width: 1, height: 1): initializes a rectangular shape
#x: top-left x
#y: top-left y
#width: width
#height: height
#min_x: min x
#min_y: min y
#max_x: max x
#max_y: max y
#center_x: center x
#center_y: center y
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height of shape

`PerfectShape::Point`

Class

Extends PerfectShape::Shape

Includes PerfectShape::PointLocation

point

Points are simply represented by an Array of (x,y) coordinates when used within other shapes, but when needing point-specific operations like point_distance, the PerfectShape::Point class can come in handy.

::point_distance(x, y, px, py): Returns the distance from a point to another point
::new(x_or_point=nil, y_arg=nil, x: nil, y: nil): constructs a point with (x,y) pair (default: 0,0) whether specified as Array of (x,y) pair, flat x,y args, or x:, y: kwargs.
#min_x: min x (always x)
#min_y: min y (always y)
#max_x: max x (always x)
#max_y: max y (always y)
#width: width (always 0)
#height: height (always 0)
#center_x: center x (always x)
#center_y: center y (always y)
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height of shape
#contain?(x_or_point, y=nil, distance: 0): checks if point matches self, with a distance tolerance (0 by default). Distance tolerance provides a fuzz factor that for example enables GUI users to mouse-click-select a point shape in a GUI more successfully.
#point_distance(x_or_point, y=nil): Returns the distance from a point to another point
#==(other): Returns true if equal to other or false otherwise

`PerfectShape::Line`

Class

Extends PerfectShape::Shape

line

::relative_counterclockwise(x1, y1, x2, y2, px, py): Returns an indicator of where the specified point (px,py) lies with respect to the line segment from (x1,y1) to (x2,y2). The return value can be either 1, -1, or 0 and indicates in which direction the specified line must pivot around its first end point, (x1,y1), in order to point at the specified point (px,py). A return value of 1 indicates that the line segment must turn in the direction that takes the positive X axis towards the negative Y axis. In the default coordinate system used by Java 2D, this direction is counterclockwise. A return value of -1 indicates that the line segment must turn in the direction that takes the positive X axis towards the positive Y axis. In the default coordinate system, this direction is clockwise. A return value of 0 indicates that the point lies exactly on the line segment. Note that an indicator value of 0 is rare and not useful for determining collinearity because of floating point rounding issues. If the point is colinear with the line segment, but not between the end points, then the value will be -1 if the point lies “beyond (x1,y1)” or 1 if the point lies “beyond (x2,y2)”.
::point_segment_distance_square(x1, y1, x2, y2, px, py): Returns the square of distance from a point to a line segment.
::point_segment_distance(x1, y1, x2, y2, px, py): Returns the distance from a point to a line segment.
::new(points: nil): constructs a polygon with points as Array of Arrays of (x,y) pairs or flattened Array of alternating x and y values
#min_x: min x
#min_y: min y
#max_x: max x
#max_y: max y
#width: width (from min x to max x)
#height: height (from min y to max y)
#center_x: center x
#center_y: center y
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height of shape
#contain?(x_or_point, y=nil, distance: 0): checks if point lies on line, with a distance tolerance (0 by default). Distance tolerance provides a fuzz factor that for example enables GUI users to mouse-click-select a line shape in a GUI more successfully.
#relative_counterclockwise(x_or_point, y=nil): Returns an indicator of where the specified point (px,py) lies with respect to the line segment from (x1,y1) to (x2,y2). The return value can be either 1, -1, or 0 and indicates in which direction the specified line must pivot around its first end point, (x1,y1), in order to point at the specified point (px,py). A return value of 1 indicates that the line segment must turn in the direction that takes the positive X axis towards the negative Y axis. In the default coordinate system used by Java 2D, this direction is counterclockwise. A return value of -1 indicates that the line segment must turn in the direction that takes the positive X axis towards the positive Y axis. In the default coordinate system, this direction is clockwise. A return value of 0 indicates that the point lies exactly on the line segment. Note that an indicator value of 0 is rare and not useful for determining collinearity because of floating point rounding issues. If the point is colinear with the line segment, but not between the end points, then the value will be -1 if the point lies “beyond (x1,y1)” or 1 if the point lies “beyond (x2,y2)”.
#point_segment_distance(x_or_point, y=nil): Returns the distance from a point to a line segment.
#==(other): Returns true if equal to other or false otherwise

`PerfectShape::Rectangle`

Class

Extends PerfectShape::Shape

Includes PerfectShape::RectangularShape

rectangle

::new(x: 0, y: 0, width: 1, height: 1): constructs a rectangle
#x: top-left x
#y: top-left y
#width: width
#height: height
#center_x: center x
#center_y: center y
#min_x: min x
#min_y: min y
#max_x: max x
#max_y: max y
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height of shape
#contain?(x_or_point, y=nil): checks if point is inside
#==(other): Returns true if equal to other or false otherwise

`PerfectShape::Square`

Class

Extends PerfectShape::Rectangle

square

::new(x: 0, y: 0, length: 1): constructs a square
#x: top-left x
#y: top-left y
#length: length
#width: width (equal to length)
#height: height (equal to length)
#center_x: center x
#center_y: center y
#min_x: min x
#min_y: min y
#max_x: max x
#max_y: max y
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height of shape
#contain?(x_or_point, y=nil): checks if point is inside
#==(other): Returns true if equal to other or false otherwise

`PerfectShape::Arc`

Class

Extends PerfectShape::Shape

Includes PerfectShape::RectangularShape

Arcs can be of type :open, :chord, or :pie

Open Arc	Chord Arc	Pie Arc

::new(type: :open, x: 0, y: 0, width: 1, height: 1, start: 0, extent: 360, center_x: nil, center_y: nil, radius_x: nil, radius_y: nil): constructs an arc of type :open (default), :chord, or :pie
#type: :open, :chord, or :pie
#x: top-left x
#y: top-left y
#width: width
#height: height
#start: start angle in degrees
#extent: extent angle in degrees
#center_x: center x
#center_y: center y
#radius_x: radius along the x-axis
#radius_y: radius along the y-axis
#min_x: min x
#min_y: min y
#max_x: max x
#max_y: max y
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height of shape
#contain?(x_or_point, y=nil): checks if point is inside
#==(other): Returns true if equal to other or false otherwise

`PerfectShape::Ellipse`

Class

Extends PerfectShape::Arc

ellipse

::new(x: 0, y: 0, width: 1, height: 1, center_x: nil, center_y: nil, radius_x: nil, radius_y: nil): constructs an ellipse
#x: top-left x
#y: top-left y
#width: width
#height: height
#center_x: center x
#center_y: center y
#radius_x: radius along the x-axis
#radius_y: radius along the y-axis
#type: always :open
#start: always 0
#extent: always 360
#min_x: min x
#min_y: min y
#max_x: max x
#max_y: max y
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height of shape
#contain?(x_or_point, y=nil): checks if point is inside
#==(other): Returns true if equal to other or false otherwise

`PerfectShape::Circle`

Class

Extends PerfectShape::Ellipse

circle

::new(x: 0, y: 0, diameter: 1, width: 1, height: 1, center_x: nil, center_y: nil, radius: nil, radius_x: nil, radius_y: nil): constructs a circle
#x: top-left x
#y: top-left y
#diameter: diameter
#width: width (equal to diameter)
#height: height (equal to diameter)
#center_x: center x
#center_y: center y
#radius: radius
#radius_x: radius along the x-axis (equal to radius)
#radius_y: radius along the y-axis (equal to radius)
#type: always :open
#start: always 0
#extent: always 360
#min_x: min x
#min_y: min y
#max_x: max x
#max_y: max y
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height of shape
#contain?(x_or_point, y=nil): checks if point is inside
#==(other): Returns true if equal to other or false otherwise

`PerfectShape::Polygon`

Class

Extends PerfectShape::Shape

polygon

::new(points: nil): constructs a polygon with points as Array of Arrays of (x,y) pairs or flattened Array of alternating x and y values
#min_x: min x
#min_y: min y
#max_x: max x
#max_y: max y
#width: width (from min x to max x)
#height: height (from min y to max y)
#center_x: center x
#center_y: center y
#bounding_box: bounding box is a rectangle with x = min x, y = min y, and width/height of shape
#contain?(x_or_point, y=nil): checks if point is inside using the Ray Casting Algorithm (aka Even-Odd Rule)
#==(other): Returns true if equal to other or false otherwise

Process

Glimmer Process

Resources

Rubydoc: https://www.rubydoc.info/gems/perfect-shape
AWT Geom JavaDoc (inspiration): https://docs.oracle.com/javase/8/docs/api/java/awt/geom/package-summary.html

TODO

TODO.md

Change Log

CHANGELOG.md

Contributing

Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet.
Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it.
Fork the project.
Start a feature/bugfix branch.
Commit and push until you are happy with your contribution.
Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright

MIT