Class: Sunniesnow::Charter::Transform

Inherits:
Object
  • Object
show all
Includes:
Math
Defined in:
lib/sscharter/charter/events_manip.rb

Overview

Implements homography.

Instance Attribute Summary collapse

DSL Methods collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Transform

Returns a new instance of Transform.



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# File 'lib/sscharter/charter/events_manip.rb', line 15

def initialize
	@xx = @yy = @zz = 1.0
	@xy = @xz = @yx = @yz = @zx = @zy = 0.0
	@t1 = 0r
	@tt = 1r
end

Instance Attribute Details

#t1 ⇒ Rational (readonly)

Returns:

  • (Rational) 


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# File 'lib/sscharter/charter/events_manip.rb', line 13

def t1
  @t1
end

#tt ⇒ Rational (readonly)

Returns:

  • (Rational) 


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# File 'lib/sscharter/charter/events_manip.rb', line 13

def tt
  @tt
end

#xx ⇒ Float (readonly)

Returns:

  • (Float) 


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# File 'lib/sscharter/charter/events_manip.rb', line 10

def xx
  @xx
end

#xy ⇒ Float (readonly)

Returns:

  • (Float) 


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# File 'lib/sscharter/charter/events_manip.rb', line 10

def xy
  @xy
end

#xz ⇒ Float (readonly)

Returns:

  • (Float) 


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# File 'lib/sscharter/charter/events_manip.rb', line 10

def xz
  @xz
end

#yx ⇒ Float (readonly)

Returns:

  • (Float) 


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# File 'lib/sscharter/charter/events_manip.rb', line 10

def yx
  @yx
end

#yy ⇒ Float (readonly)

Returns:

  • (Float) 


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# File 'lib/sscharter/charter/events_manip.rb', line 10

def yy
  @yy
end

#yz ⇒ Float (readonly)

Returns:

  • (Float) 


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# File 'lib/sscharter/charter/events_manip.rb', line 10

def yz
  @yz
end

#zx ⇒ Float (readonly)

Returns:

  • (Float) 


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# File 'lib/sscharter/charter/events_manip.rb', line 10

def zx
  @zx
end

#zy ⇒ Float (readonly)

Returns:

  • (Float) 


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# File 'lib/sscharter/charter/events_manip.rb', line 10

def zy
  @zy
end

#zz ⇒ Float (readonly)

Returns:

  • (Float) 


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# File 'lib/sscharter/charter/events_manip.rb', line 10

def zz
  @zz
end

Instance Method Details

#apply(event) ⇒ Event

Returns same as event.

Parameters:

Returns:

  • (Event) —

    same as event.



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# File 'lib/sscharter/charter/events_manip.rb', line 24

def apply event
	event.beat = @t1 + @tt * event.beat
	return unless x = event[:x]
	return unless y = event[:y]
	rx = xx*x + xy*y + xz
	ry = yx*x + yy*y + yz
	d = zx*x + zy*y + zz
	event[:x] = xp = rx / d
	event[:y] = yp = ry / d
	
	return event unless angle = event[:angle]
	dx = cos angle
	dy = sin angle
	cross = y*dx - x*dy

	cx0 = zy*xx - xy*zx
	cxx = zz*xx - xz*zx
	cxy = zz*xy - xz*zy
	dxp = cx0*cross + cxx*dx + cxy*dy

	cy0 = zx*yy - yx*zy
	cyy = zz*yy - yz*zy
	cyx = zz*yx - yz*zx
	dyp = cy0*-cross + cyy*dy + cyx*dx

	event[:angle] = atan2 dyp, dxp
	event
end

#beat_translate(delta_beat) ⇒ void

This method returns an undefined value.

Parameters:

  • delta_beat (Integer, Rational)

Raises:

  • (ArgumentError) 


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# File 'lib/sscharter/charter/events_manip.rb', line 112

def beat_translate delta_beat
	raise ArgumentError, 'delta_beat must be a number' unless delta_beat.is_a? Numeric
	warn 'Rational is recommended over Float for delta_beat' if delta_beat.is_a? Float
	@t1 += delta_beat.to_r
	nil
end

#compound_linear(xx, xy, yx, yy) ⇒ void

This method returns an undefined value.

Parameters:

  • xx (Numeric)
  • xy (Numeric)
  • yx (Numeric)
  • yy (Numeric)

Raises:

  • (ArgumentError) 


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# File 'lib/sscharter/charter/events_manip.rb', line 60

def compound_linear xx, xy, yx, yy
	raise ArgumentError, 'arguments must be numbers' unless [xx, xy, yx, yy].all? { _1.is_a? Numeric }
	@xx, @xy, @xz, @yx, @yy, @yz = [
		xx * @xx + xy * @yx,
		xx * @xy + xy * @yy,
		xx * @xz + xy * @yz,
		yx * @xx + yy * @yx,
		yx * @xy + yy * @yy,
		yx * @xz + yy * @yz,
	]
	nil
end

#horizontal_flip ⇒ void

This method returns an undefined value.



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# File 'lib/sscharter/charter/events_manip.rb', line 83

def horizontal_flip
	compound_linear -1, 0, 0, 1
end

#rotate(angle) ⇒ void

This method returns an undefined value.

Parameters:

  • angle (Numeric) —

    in radians.

Raises:

  • (ArgumentError) 


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# File 'lib/sscharter/charter/events_manip.rb', line 94

def rotate angle
	raise ArgumentError, 'angle must be a number' unless angle.is_a? Numeric
	warn 'Are you using degrees as angle unit instead of radians?' if angle != 0 && angle % 45 == 0
	c = cos angle
	s = sin angle
	compound_linear c, -s, s, c
end

#scale(sx, sy = sx) ⇒ void

This method returns an undefined value.

Parameters:

  • sx (Numeric)
  • sy (Numeric) (defaults to: sx)

Raises:

  • (ArgumentError) 


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# File 'lib/sscharter/charter/events_manip.rb', line 105

def scale sx, sy = sx
	raise ArgumentError, 'sx and sy must be numbers' unless sx.is_a?(Numeric) && sy.is_a?(Numeric)
	compound_linear sx, 0, 0, sy
end

#translate(dx, dy) ⇒ void

This method returns an undefined value.

Parameters:

  • dx (Numeric)
  • dy (Numeric)

Raises:

  • (ArgumentError) 


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# File 'lib/sscharter/charter/events_manip.rb', line 76

def translate dx, dy
	raise ArgumentError, 'dx and dy must be numbers' unless dx.is_a?(Numeric) && dy.is_a?(Numeric)
	@xz += dx
	@yz += dy
end

#vertical_flip ⇒ void

This method returns an undefined value.



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# File 'lib/sscharter/charter/events_manip.rb', line 88

def vertical_flip
	compound_linear 1, 0, 0, -1
end