Cos

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cos( angle )
Calculates the cosine of an angle.
angle
The angle, using a full circle range of 0.0-1.0.

The cos() function calculates the cosine of an angle.

PICO-8 uses an input range of 0.0 to 1.0 to represent the angle, a percentage of the unit circle. Some refer to these units as "turns". For instance, 180° or π (3.14159) radians corresponds to 0.5 turns in PICO-8's representation of angles. In fact, for fans of τ (tau), it's just a matter of dropping τ from your expression.

Important: PICO-8 measures the angle in a clockwise direction on the Cartesian plane, with 0.0 to the right, 0.25 downward, and so on. This is inverted from the convention used in traditional geometry, though the inversion only affects sin(), not cos().

Pico8sincos v2.png

Examples

for t=0,1,0.125 do
  print('cos('..t..') = '..cos(t))
end

prints:

cos(0) = 1
cos(0.125) = 0.7071
cos(0.25) = 0
cos(0.375) = -0.7071
cos(0.5) = -1
cos(0.625) = -0.7071
cos(0.75) = 0
cos(0.875) = 0.7071
cos(1) = 1

See also