Module: Mittsu::Math

Defined in:
lib/mittsu/math.rb

Constant Summary collapse

DEGREE_TO_RADIANS_FACTOR = 
::Math::PI / 180
RADIANS_TO_DEGREES_FACTOR = 
180 / ::Math::PI

Class Method Summary collapse

Class Method Details

.clamp(x, a, b) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 30

def self.clamp(x, a, b)
  ( x < a ) ? a : ( ( x > b ) ? b : x )
end

.clamp_bottom(x, a) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 34

def self.clamp_bottom(x, a)
  x < a ? a : x
end

.deg_to_rad(degrees) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 77

def self.deg_to_rad(degrees)
  degrees * DEGREE_TO_RADIANS_FACTOR
end

.map_linear(x, a1, a2, b1, b2) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 38

def self.map_linear(x, a1, a2, b1, b2)
  b1 + ( x - a1 ) * ( b2 - b1 ) / ( a2 - a1 )
end

.next_power_of_two(value) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 90

def self.next_power_of_two(value)
value -= 1
value |= value >> 1
value |= value >> 2
value |= value >> 4
value |= value >> 8
value |= value >> 16
value += 1
end

.power_of_two?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mittsu/math.rb', line 86

def self.power_of_two?(value)
  ( value & ( value - 1 ) ) == 0 && value != 0
end

.rad_to_deg(radians) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 82

def self.rad_to_deg(radians)
  radians * RADIANS_TO_DEGREES_FACTOR
end

.rand_float(low, high) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 68

def self.rand_float(low, high)
  low + rand * ( high - low )
end

.rand_float_spread(range) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 72

def self.rand_float_spread(range)
  range * ( 0.5 - rand )
end

.rand_int(low, high) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 64

def self.rand_int(low, high)
  self.rand_float( low, high ).floor
end

.random16 ⇒ Object 



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# File 'lib/mittsu/math.rb', line 60

def self.random16
  ( 65280 * rand + 255 * rand ) / 65535
end

.sign(x) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 23

def self.sign(x)
  return Float::NAN unless x.is_a? Numeric
  return Float::NAN if x.to_f.nan?
  return x.to_f if x.zero?
  return (x < 0) ? -1.0 : (x > 0) ? 1.0 : +x
end

.smooth_step(x, min, max) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 42

def self.smooth_step(x, min, max)
return 0.0 if x <= min
return 1.0 if x >= max

x = ( x - min ) / ( max - min )

  x * x * ( 3.0 - 2.0 * x )
end

.smoother_step(x, min, max) ⇒ Object 



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# File 'lib/mittsu/math.rb', line 51

def self.smoother_step(x, min, max)
return 0.0 if x <= min
return 1.0 if x >= max

x = ( x - min ) / ( max - min )

x * x * x * ( x * ( x * 6.0 - 15.0 ) + 10.0 )
end