Class: HotCocoa::Graphics::SandPainter

Inherits:
Object
  • Object
show all
Defined in:
lib/hotcocoa/graphics/elements/sandpainter.rb

Overview

draw watercolor-like painted strokes (adapted from code by Jared Tarbell - complexification.net)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(canvas, color = Color.red) ⇒ SandPainter

Returns a new instance of SandPainter.



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 22

def initialize(canvas, color=Color.red)
  @canvas           = canvas
  @color            = color
  # set a random initial gain value
  @gain             = random(0.01, 0.1)
  @grainsize        = 6.0
  @grains           = 64
  @maxalpha         = 0.1
  @jitter           = 0
  @huedrift         = 0.2
  @saturationdrift  = 0.3
  @brightnessdrift  = 0.3
end

Instance Attribute Details

#brightnessdrift ⇒ Object

Returns the value of attribute brightnessdrift.



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 20

def brightnessdrift
  @brightnessdrift
end

#color ⇒ Object

Returns the value of attribute color.



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 20

def color
  @color
end

#grains ⇒ Object

Returns the value of attribute grains.



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 20

def grains
  @grains
end

#grainsize ⇒ Object

Returns the value of attribute grainsize.



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 20

def grainsize
  @grainsize
end

#huedrift ⇒ Object

Returns the value of attribute huedrift.



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 20

def huedrift
  @huedrift
end

#jitter ⇒ Object

Returns the value of attribute jitter.



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 20

def jitter
  @jitter
end

#maxalpha ⇒ Object

Returns the value of attribute maxalpha.



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 20

def maxalpha
  @maxalpha
end

#saturationdrift ⇒ Object

Returns the value of attribute saturationdrift.



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 20

def saturationdrift
  @saturationdrift
end

Instance Method Details

#render(ox, oy, x, y) ⇒ Object

render a line that fades out from ox,oy to x,y



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# File 'lib/hotcocoa/graphics/elements/sandpainter.rb', line 37

def render(ox, oy, x, y)
  @canvas.push
  # modulate gain
  @gain += random(-0.050, 0.050)
  @gain = inrange(@gain, 0.0, 1.0)
  # calculate grains by distance
  #@grains = (sqrt((ox-x)*(ox-x)+(oy-y)*(oy-y))).to_i

  # ramp from 0 to .015 for g = 0 to 1
  w = @gain / (@grains-1)

  #raycolor = @color.analog
  #@color.drift(0.2,0.1,0.1)
  @color.drift(huedrift, saturationdrift, brightnessdrift)
  #for i in 0..@grains do ##RACK change to fixnum.times
  (@grains + 1).times do |i|
    # set alpha for this grain (ramp from maxalpha to 0.0 for i = 0 to 64)
    a = @maxalpha - (i / @grains.to_f) * @maxalpha
    fillcolor = @color.copy.a(a)
    @canvas.fill(fillcolor)
    #C.rect(ox+(x-ox)*sin(sin(i*w)),oy+(y-oy)*sin(sin(i*w)),1,1)
    scaler = sin(sin(i * w)) # ramp sinusoidally from 0 to 1
    x1 = ox + (x - ox) * scaler + random(-@jitter, @jitter)
    y1 = oy + (y - oy) * scaler + random(-@jitter, @jitter)
    #puts "#{scaler} #{w} #{i} #{a} => #{x1},#{y1} #{scaler}"
    @canvas.oval(x1, y1, @grainsize, @grainsize, :center)
    #C.oval(x,y,@grainsize,@grainsize,:center)
    #C.oval(ox,oy,@grainsize,@grainsize,:center)
  end
  @canvas.pop
end