Class: Pdfrb::Content::GraphicObject::Arc

Inherits:
Object
  • Object
show all
Defined in:
lib/pdfrb/content/graphic_object/arc.rb

Overview

Circular or elliptical arc, approximated with cubic Beziers (s8.3.8.3 in PDF reference). One segment per 90 degrees.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(cx:, cy:, radius:, radius_y: nil, start_angle: 0, end_angle: 360) ⇒ Arc

Returns a new instance of Arc.



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# File 'lib/pdfrb/content/graphic_object/arc.rb', line 15

def initialize(cx:, cy:, radius:, radius_y: nil,
               start_angle: 0, end_angle: 360)
  @cx = cx.to_f
  @cy = cy.to_f
  @radius_x = radius.to_f
  @radius_y = (radius_y || radius).to_f
  @start_angle = start_angle.to_f
  @end_angle = end_angle.to_f
end

Instance Attribute Details

#cx ⇒ Object (readonly)

Returns the value of attribute cx.



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# File 'lib/pdfrb/content/graphic_object/arc.rb', line 12

def cx
  @cx
end

#cy ⇒ Object (readonly)

Returns the value of attribute cy.



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# File 'lib/pdfrb/content/graphic_object/arc.rb', line 12

def cy
  @cy
end

#end_angle ⇒ Object (readonly)

Returns the value of attribute end_angle.



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# File 'lib/pdfrb/content/graphic_object/arc.rb', line 12

def end_angle
  @end_angle
end

#radius_x ⇒ Object (readonly)

Returns the value of attribute radius_x.



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# File 'lib/pdfrb/content/graphic_object/arc.rb', line 12

def radius_x
  @radius_x
end

#radius_y ⇒ Object (readonly)

Returns the value of attribute radius_y.



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# File 'lib/pdfrb/content/graphic_object/arc.rb', line 12

def radius_y
  @radius_y
end

#start_angle ⇒ Object (readonly)

Returns the value of attribute start_angle.



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# File 'lib/pdfrb/content/graphic_object/arc.rb', line 12

def start_angle
  @start_angle
end

Instance Method Details

#draw(canvas) ⇒ Object

Emit the path operators onto canvas starting with a moveto.



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# File 'lib/pdfrb/content/graphic_object/arc.rb', line 26

def draw(canvas)
  steps = tessellate
  return if steps.empty?

  first = steps.first
  canvas.move_to(first[:p0][0], first[:p0][1])
  steps.each do |seg|
    canvas.curve_to(seg[:c1][0], seg[:c1][1],
                    seg[:c2][0], seg[:c2][1],
                    seg[:p3][0], seg[:p3][1])
  end
  canvas
end