lerp.glsl

#pragma glslify: range = require('glsl-range');

void main () {
  // Your incoming value
  float x = 25.0;

  // Map value to 0..1 domain
  // (no need if x is already in 0..1 range)
  float min = 10.0;
  float max = 100.0;
  float t = range(min, max, x);

  // Now linear interpolate to new domain
  float outMin = 0.25;
  float outMax = 0.75;
  float result = mix(outMin, outMax, t);

  // Or, linear scale from one color to another
  vec3 colorA = vec3(0.15, 0.5, 1.0);
  vec3 colorB = vec3(0.5, 0.0, 0.25);
  vec3 color = mix(colorA, colorB, t);
}