exp2()

Syntax

float exp2(float x)
vec2 exp2(vec2 x)
vec3 exp2(vec3 x)

Live example

Edit the code and the preview updates as you type.

How it works

exp2(x) doubles for every step of x: exp2(0.0) is 1, exp2(1.0) is 2, exp2(3.0) is 8, and exp2(-1.0) is 0.5. It is the same as pow(2.0, x) but says the intent more directly.

The example uses the row number as x, so each row has twice as many stripes as the one below: 1, 2, 4, 8, 16.

Typical uses

• Noise octaves: frequency exp2(float(i)) and amplitude exp2(-float(i)) for fractal noise.
• Exposure: color * exp2(stops) brightens by whole camera stops.
• Smooth zoom: exp2(u_time) zooms in at a steady visual speed.

Common mistakes

• Large exponents overflow mediump precision quickly; exp2(16.0) is already 65536.
• Passing an int loop counter directly. Convert it first: exp2(float(i)).

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