Module: Prawn::Graphics

Defined in:
lib/prawn_shapes/arc.rb,
lib/prawn_shapes/star.rb

Instance Method Summary collapse

Instance Method Details

#arc_around(center, options) ⇒ Object

options must include :radius, :start_angle, and :end_angle startAngle and endAngle are in degrees

0 degrees is directly right and 90 degrees is straight up arc will be drawn counterclockwise from startAngle to endAngle



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# File 'lib/prawn_shapes/arc.rb', line 79

def arc_around(center, options)
  open_curve(arc_vertices(center, options))
end

#closed_curve(vertices) ⇒ Object

vertices is an array of hashes containing :vertex and optional :handle1 and :handle2 elements



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# File 'lib/prawn_shapes/arc.rb', line 101

def closed_curve(vertices)
  return if vertices.empty?
  vertices = vertices.dup
  origin = vertices.shift
  move_to(origin[:point])
  previous_handle2 = origin[:handle2]
  vertices.each do |vertex|
    curve_to(vertex[:point],
             :bounds => [previous_handle2 || vertex[:point],
                         vertex[:handle1] || vertex[:point]])
    previous_handle2 = vertex[:handle2]
  end
  curve_to(origin[:point],
           :bounds => [previous_handle2 || origin[:point],
                       origin[:handle1] || origin[:point]])
end

#half_circle(center, options) ⇒ Object

options must include :radius and :side side is either :left or :right see pie_slice for explanation of optional :stroke_both_sides option



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# File 'lib/prawn_shapes/arc.rb', line 8

def half_circle(center, options)
  case options[:side]
  when :left
    start_angle = 90
    end_angle = 270
  when :right
    start_angle = 270
    end_angle = 90
  end
  pie_slice(center,
            :radius => options[:radius],
            :start_angle => start_angle,
            :end_angle => end_angle,
            :stroke_both_sides => options[:stroke_both_sides])
end

#half_star(point, options) ⇒ Object 



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# File 'lib/prawn_shapes/star.rb', line 8

def half_star(point, options)
  points = star_points(point, options)
  case options[:side]
  when :left
    points.slice!(1..4)
  when :right
    points.slice!(6..9)
  end
  polygon(*points)
end

#open_curve(vertices) ⇒ Object

vertices is an array of hashes containing :vertex and optional :handle1 and :handle2 elements



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# File 'lib/prawn_shapes/arc.rb', line 85

def open_curve(vertices)
  return if vertices.empty?
  vertices = vertices.dup
  origin = vertices.shift
  move_to(origin[:point])
  previous_handle2 = origin[:handle2]
  vertices.each do |vertex|
    curve_to(vertex[:point],
             :bounds => [previous_handle2 || vertex[:point],
                         vertex[:handle1] || vertex[:point]])
    previous_handle2 = vertex[:handle2]
  end
end

#pie_slice(center, options) ⇒ Object

options must include :radius, :start_angle, and :end_angle startAngle and endAngle are in degrees if an optional :stroke_both_sides option is true, then both sides of the slice will be included for stroking. the default is to just stroke one side since this will tend to be used to build up an entire circle, and if both sides were stroked, then we would get double-stroked lines where two pie slices shared a (not usually noticeable, but would be if transparency were used)

0 degrees is directly right and 90 degrees is straight up arc will be drawn counterclockwise from startAngle to endAngle



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# File 'lib/prawn_shapes/arc.rb', line 63

def pie_slice(center, options)
  vertices = arc_vertices(center, options)
  vertices.unshift(:point => center)
  if options[:stroke_both_sides]
    closed_curve(vertices)
  else
    open_curve(vertices)
  end
end

#quarter_circle(center, options) ⇒ Object

options must include :radius and :quadrant quadrant is 1, 2, 3, or 4 see pie_slice for explanation of optional :stroke_both_sides option



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# File 'lib/prawn_shapes/arc.rb', line 29

def quarter_circle(center, options)
  case options[:quadrant]
  when 1
    start_angle = 0
    end_angle = 90
  when 2
    start_angle = 90
    end_angle = 180
  when 3
    start_angle = 180
    end_angle = 270
  when 4
    start_angle = 270
    end_angle = 360
  end
  pie_slice(center,
            :radius => options[:radius],
            :start_angle => start_angle,
            :end_angle => end_angle,
            :stroke_both_sides => options[:stroke_both_sides])
end

#star(point, options) ⇒ Object 



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# File 'lib/prawn_shapes/star.rb', line 3

def star(point, options)
  x, y = point
  polygon(*star_points(point, options))
end