Class: Drawille::Brush

Inherits:
Object
  • Object
show all
Defined in:
lib/drawille/brush.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(canvas) ⇒ Brush

Returns a new instance of Brush.



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# File 'lib/drawille/brush.rb', line 9

def initialize canvas
  @canvas = canvas
  @state  = {
    x:        0, 
    y:        0,
    up:       true,
    rotation: 0
  }
end

Instance Attribute Details

#canvas ⇒ Object

Returns the value of attribute canvas.



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# File 'lib/drawille/brush.rb', line 7

def canvas
  @canvas
end

Instance Method Details

#back(length) ⇒ Object Also known as: bk 



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# File 'lib/drawille/brush.rb', line 35

def back length
  forward -length
end

#down ⇒ Object Also known as: pd 



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# File 'lib/drawille/brush.rb', line 19

def down
  @state[:up] = false
end

#forward(length) ⇒ Object Also known as: fd 



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# File 'lib/drawille/brush.rb', line 27

def forward length
  theta = ((@state[:rotation]) / 180.0 * Math::PI)
  x     = (@state[:x] + length * Math::cos(theta)).round
  y     = (@state[:y] + length * Math::sin(theta)).round

  move x, y
end

#left(angle) ⇒ Object Also known as: lt 



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# File 'lib/drawille/brush.rb', line 43

def left angle
  @state[:rotation] -= angle
end

#line(coordinates = {}) ⇒ Object 



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# File 'lib/drawille/brush.rb', line 72

def line coordinates={}
  last_state = @state[:up]

  up
  move *coordinates[:from]
  down
  move *coordinates[:to]

  @state[:up] = last_state
end

#move(x, y) ⇒ Object Also known as: mv 



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# File 'lib/drawille/brush.rb', line 47

def move x, y
  unless @state[:up]
    x1 = @state[:x].round
    y1 = @state[:y].round
    x2 = x
    y2 = y

    xdiff = [x1, x2].max - [x1, x2].min
    ydiff = [y1, y2].max - [y1, y2].min

    xdir = x1 <= x2 ? 1 : -1
    ydir = y1 <= y2 ? 1 : -1

    r = [xdiff, ydiff].max

    (0..r).each do |i|
      x, y = x1, y1
      y += (i.to_f*ydiff)/r*ydir if ydiff > 0
      x += (i.to_f*xdiff)/r*xdir if xdiff > 0
      @canvas.set(x, y)
    end
  end
  @state[:x], @state[:y] = x, y
end

#right(angle) ⇒ Object Also known as: rt 



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# File 'lib/drawille/brush.rb', line 39

def right angle
  @state[:rotation] += angle
end

#up ⇒ Object Also known as: pu 



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# File 'lib/drawille/brush.rb', line 23

def up
  @state[:up] = true
end