diff --git a/ColourMeOKGame/Assets/Scripts/Colorimetry.cs b/ColourMeOKGame/Assets/Scripts/Colorimetry.cs
new file mode 100644
index 0000000..f3922b4
--- /dev/null
+++ b/ColourMeOKGame/Assets/Scripts/Colorimetry.cs
@@ -0,0 +1,363 @@
+using System;
+
+public static class Colorimetry
+{
+ ///
+ /// transform a linear srgb value to a non-linear srgb value
+ ///
+ /// the linear srgb value to transform
+ /// the non-linear srgb value
+ // https://bottosson.github.io/posts/colorwrong/#what-can-we-do%3F (no licence specified)
+ public static double srgb_nonlinear_transform_f(double x)
+ {
+ if (x >= 0.0031308d)
+ return 1.055d * Math.Pow(x, 1d / 2.4d) - 0.055d;
+ return 12.92d * x;
+ }
+
+ ///
+ /// transform a non-linear srgb value to a linear srgb value
+ ///
+ /// the non-linear srgb value to transform
+ /// the linear srgb value
+ // https://bottosson.github.io/posts/colorwrong/#what-can-we-do%3F (no licence specified)
+ public static double srgb_nonlinear_transform_f_inv(double x)
+ {
+ if (x >= 0.04045d)
+ return Math.Pow((x + 0.055d) / (1d + 0.055d), 2.4d);
+ return x / 12.92d;
+ }
+
+ ///
+ /// clips a color to the sRGB gamut while preserving chroma
+ ///
+ // https://bottosson.github.io/posts/gamutclipping/ (MIT)
+ public static RGB gamut_clip_preserve_chroma(RGB rgb)
+ {
+ if (rgb is { r: < 1 and > 0, g: < 1 and > 0, b: < 1 and > 0 })
+ return rgb;
+
+ var lab = linear_srgb_to_oklab(rgb);
+
+ var lchL = lab.L;
+ const float eps = 0.00001f;
+ var lchC = Math.Max(eps, Math.Sqrt(lab.a * lab.a + lab.b * lab.b));
+ var interimA = lab.a / lchC;
+ var interimB = lab.b / lchC;
+
+ var lchL0 = Math.Clamp(lchL, 0, 1);
+
+ var t = find_gamut_intersection((float)interimA, (float)interimB, lchL, (float)lchC, lchL0);
+ var lchClippedL = lchL0 * (1 - t) + t * lchL;
+ var lchClippedC = t * lchC;
+
+ return oklab_to_linear_srgb(new Lab(lchClippedL, (float)(lchClippedC * interimA), (float)(lchClippedC *
+ interimB)));
+ }
+
+ ///
+ /// Finds intersection of the line defined by
+ /// L = L0 * (1 - t) + t * L1;
+ /// C = t * C1;
+ /// a and b must be normalized so a^2 + b^2 == 1
+ ///
+ // https://bottosson.github.io/posts/gamutclipping/ (MIT)
+ // ReSharper disable once MemberCanBePrivate.Global
+ public static float find_gamut_intersection(
+ float a,
+ float b,
+ // ReSharper disable once InconsistentNaming
+ float L1,
+ // ReSharper disable once InconsistentNaming
+ float C1,
+ // ReSharper disable once InconsistentNaming
+ float L0)
+ {
+ // Find the cusp of the gamut triangle
+ var cusp = find_cusp(a, b);
+
+ // Find the intersection for upper and lower half separately
+ float t;
+ if ((L1 - L0) * cusp.C - (cusp.L - L0) * C1 <= 0f)
+ {
+ // Lower half
+ t = cusp.C * L0 / (C1 * cusp.L + cusp.C * (L0 - L1));
+ }
+ else
+ {
+ // Upper half
+ // First intersect with triangle
+ t = cusp.C * (L0 - 1f) / (C1 * (cusp.L - 1f) + cusp.C * (L0 - L1));
+
+ // Then one-step Halley's method
+ {
+ var dL = L1 - L0;
+
+ var kL = +0.3963377774f * a + 0.2158037573f * b;
+ var kM = -0.1055613458f * a - 0.0638541728f * b;
+ var kS = -0.0894841775f * a - 1.2914855480f * b;
+
+ // C1 = dC
+ var dtL = dL + C1 * kL;
+ var dtM = dL + C1 * kM;
+ var dtS = dL + C1 * kS;
+
+
+ // If higher accuracy is required, 2 or 3 iterations of the following block can be used:
+ {
+ // ReSharper disable once InconsistentNaming
+ var L = L0 * (1f - t) + t * L1;
+ // ReSharper disable once InconsistentNaming
+ var C = t * C1;
+
+ var interimL = L + C * kL;
+ var interimM = L + C * kM;
+ var interimS = L + C * kS;
+
+ var l = interimL * interimL * interimL;
+ var m = interimM * interimM * interimM;
+ var s = interimS * interimS * interimS;
+
+ var ldt = 3 * dtL * interimL * interimL;
+ var mdt = 3 * dtM * interimM * interimM;
+ var sdt = 3 * dtS * interimS * interimS;
+
+ var ldt2 = 6 * dtL * dtL * interimL;
+ var mdt2 = 6 * dtM * dtM * interimM;
+ var sdt2 = 6 * dtS * dtS * interimS;
+
+ var r = 4.0767416621f * l - 3.3077115913f * m + 0.2309699292f * s - 1;
+ var r1 = 4.0767416621f * ldt - 3.3077115913f * mdt + 0.2309699292f * sdt;
+ var r2 = 4.0767416621f * ldt2 - 3.3077115913f * mdt2 + 0.2309699292f * sdt2;
+
+ var uR = r1 / (r1 * r1 - 0.5f * r * r2);
+ var tR = -r * uR;
+
+ var g = -1.2684380046f * l + 2.6097574011f * m - 0.3413193965f * s - 1;
+ var g1 = -1.2684380046f * ldt + 2.6097574011f * mdt - 0.3413193965f * sdt;
+ var g2 = -1.2684380046f * ldt2 + 2.6097574011f * mdt2 - 0.3413193965f * sdt2;
+
+ var uG = g1 / (g1 * g1 - 0.5f * g * g2);
+ var tG = -g * uG;
+
+ var newB = -0.0041960863f * l - 0.7034186147f * m + 1.7076147010f * s - 1;
+ var newB1 = -0.0041960863f * ldt - 0.7034186147f * mdt + 1.7076147010f * sdt;
+ var newB2 = -0.0041960863f * ldt2 - 0.7034186147f * mdt2 + 1.7076147010f * sdt2;
+
+ var uB = newB1 / (newB1 * newB1 - 0.5f * newB * newB2);
+ var tB = -newB * uB;
+
+ tR = uR >= 0f ? tR : float.MaxValue;
+ tG = uG >= 0f ? tG : float.MaxValue;
+ tB = uB >= 0f ? tB : float.MaxValue;
+
+ t += Math.Min(tR, Math.Min(tG, tB));
+ }
+ }
+ }
+
+ return t;
+ }
+
+
+ ///
+ /// finds L_cusp and C_cusp for a given hue
+ /// a and b must be normalized so a^2 + b^2 == 1
+ ///
+ // https://bottosson.github.io/posts/gamutclipping/ (MIT)
+ // ReSharper disable once MemberCanBePrivate.Global
+ public static LC find_cusp(float a, float b)
+ {
+ // First, find the maximum saturation (saturation S = C/L)
+ var maxS = compute_max_saturation(a, b);
+
+ // Convert to linear sRGB to find the first point where at least one of r,g or b >= 1:
+ var maxedRgb = oklab_to_linear_srgb(new Lab(1, maxS * a, maxS * b));
+ var cuspL = Math.Cbrt(1f / Math.Max(Math.Max(maxedRgb.r, maxedRgb.g), maxedRgb.b));
+ var cuspC = cuspL * maxS;
+
+ return new LC((float)cuspL, (float)cuspC);
+ }
+
+ // https://bottosson.github.io/posts/oklab/#converting-from-linear-srgb-to-oklab (public domain)
+ // ReSharper disable once MemberCanBePrivate.Global
+ public static Lab linear_srgb_to_oklab(RGB c)
+ {
+ var l = 0.4122214708f * c.r + 0.5363325363f * c.g + 0.0514459929f * c.b;
+ var m = 0.2119034982f * c.r + 0.6806995451f * c.g + 0.1073969566f * c.b;
+ var s = 0.0883024619f * c.r + 0.2817188376f * c.g + 0.6299787005f * c.b;
+
+ var interimL = Math.Cbrt(l);
+ var interimM = Math.Cbrt(m);
+ var interimS = Math.Cbrt(s);
+
+ return new Lab(
+ (float)(0.2104542553f * interimL + 0.7936177850f * interimM - 0.0040720468f * interimS),
+ (float)(1.9779984951f * interimL - 2.4285922050f * interimM + 0.4505937099f * interimS),
+ (float)(0.0259040371f * interimL + 0.7827717662f * interimM - 0.8086757660f * interimS)
+ );
+ }
+
+ // https://bottosson.github.io/posts/oklab/#converting-from-linear-srgb-to-oklab (public domain)
+ // ReSharper disable once MemberCanBePrivate.Global
+ public static RGB oklab_to_linear_srgb(Lab c)
+ {
+ var interimL = c.L + 0.3963377774f * c.a + 0.2158037573f * c.b;
+ var interimM = c.L - 0.1055613458f * c.a - 0.0638541728f * c.b;
+ var interimS = c.L - 0.0894841775f * c.a - 1.2914855480f * c.b;
+
+ var l = interimL * interimL * interimL;
+ var m = interimM * interimM * interimM;
+ var s = interimS * interimS * interimS;
+
+ return new RGB(
+ +4.0767416621f * l - 3.3077115913f * m + 0.2309699292f * s,
+ -1.2684380046f * l + 2.6097574011f * m - 0.3413193965f * s,
+ -0.0041960863f * l - 0.7034186147f * m + 1.7076147010f * s
+ );
+ }
+
+ ///
+ /// Finds the maximum saturation possible for a given hue that fits in sRGB
+ /// Saturation here is defined as S = C/L
+ /// a and b must be normalized so a^2 + b^2 == 1
+ ///
+ // https://bottosson.github.io/posts/gamutclipping/ (MIT)
+ // ReSharper disable once MemberCanBePrivate.Global
+ public static float compute_max_saturation(float a, float b)
+ {
+ // Max saturation will be when one of r, g or b goes below zero.
+
+ // Select different coefficients depending on which component goes below zero first
+ float k0, k1, k2, k3, k4, wl, wm, ws;
+
+ if (-1.88170328f * a - 0.80936493f * b > 1)
+ {
+ // Red component
+ k0 = +1.19086277f;
+ k1 = +1.76576728f;
+ k2 = +0.59662641f;
+ k3 = +0.75515197f;
+ k4 = +0.56771245f;
+ wl = +4.0767416621f;
+ wm = -3.3077115913f;
+ ws = +0.2309699292f;
+ }
+ else if (1.81444104f * a - 1.19445276f * b > 1)
+ {
+ // Green component
+ k0 = +0.73956515f;
+ k1 = -0.45954404f;
+ k2 = +0.08285427f;
+ k3 = +0.12541070f;
+ k4 = +0.14503204f;
+ wl = -1.2684380046f;
+ wm = +2.6097574011f;
+ ws = -0.3413193965f;
+ }
+ else
+ {
+ // Blue component
+ k0 = +1.35733652f;
+ k1 = -0.00915799f;
+ k2 = -1.15130210f;
+ k3 = -0.50559606f;
+ k4 = +0.00692167f;
+ wl = -0.0041960863f;
+ wm = -0.7034186147f;
+ ws = +1.7076147010f;
+ }
+
+ // Approximate max saturation using a polynomial:
+ var maxSaturation = k0 + k1 * a + k2 * b + k3 * a * a + k4 * a * b;
+
+ // Do one-step Halley's method to get closer
+ // this gives an error less than 10e6, except for some blue hues where the dS/dh is close to infinite
+ // this should be enough for most applications, otherwise do two/three steps
+
+ var kL = +0.3963377774f * a + 0.2158037573f * b;
+ var kM = -0.1055613458f * a - 0.0638541728f * b;
+ var kS = -0.0894841775f * a - 1.2914855480f * b;
+
+ {
+ var interimL = 1f + maxSaturation * kL;
+ var interimM = 1f + maxSaturation * kM;
+ var interimS = 1f + maxSaturation * kS;
+
+ var l = interimL * interimL * interimL;
+ var m = interimM * interimM * interimM;
+ var s = interimS * interimS * interimS;
+
+ var sDerivL = 3f * kL * interimL * interimL;
+ var sDerivM = 3f * kM * interimM * interimM;
+ var sDerivS = 3f * kS * interimS * interimS;
+
+ var sDeriv2L = 6f * kL * kL * interimL;
+ var sDeriv2M = 6f * kM * kM * interimM;
+ var sDeriv2S = 6f * kS * kS * interimS;
+
+ var f = wl * l + wm * m + ws * s;
+ var f1 = wl * sDerivL + wm * sDerivM + ws * sDerivS;
+ var f2 = wl * sDeriv2L + wm * sDeriv2M + ws * sDeriv2S;
+
+ maxSaturation -= f * f1 / (f1 * f1 - 0.5f * f * f2);
+ }
+
+ return maxSaturation;
+ }
+
+ public readonly struct Lab
+ {
+ public readonly float L;
+
+ // ReSharper disable once InconsistentNaming
+ public readonly float a;
+
+ // ReSharper disable once InconsistentNaming
+ public readonly float b;
+
+ // ReSharper disable once InconsistentNaming
+ public Lab(float L, float a, float b)
+ {
+ this.L = L;
+ this.a = a;
+ this.b = b;
+ }
+ }
+
+ public readonly struct RGB
+ {
+ // ReSharper disable once InconsistentNaming
+ public readonly float r;
+
+ // ReSharper disable once InconsistentNaming
+ public readonly float g;
+
+ // ReSharper disable once InconsistentNaming
+ public readonly float b;
+
+ public RGB(float r, float g, float b)
+ {
+ this.r = r;
+ this.g = g;
+ this.b = b;
+ }
+ }
+
+ // ReSharper disable once InconsistentNaming
+ public readonly struct LC
+ {
+ public readonly float L;
+ public readonly float C;
+
+ public LC(
+ // ReSharper disable once InconsistentNaming
+ float L,
+ // ReSharper disable once InconsistentNaming
+ float C)
+ {
+ this.L = L;
+ this.C = C;
+ }
+ }
+}
\ No newline at end of file
diff --git a/ColourMeOKGame/Assets/Scripts/Colorimetry.cs.meta b/ColourMeOKGame/Assets/Scripts/Colorimetry.cs.meta
new file mode 100644
index 0000000..19323da
--- /dev/null
+++ b/ColourMeOKGame/Assets/Scripts/Colorimetry.cs.meta
@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: b33b945390b24a5fae72556c879ea1da
+timeCreated: 1731730299
\ No newline at end of file
diff --git a/ColourMeOKGame/Assets/Scripts/OklchColourPicker.cs b/ColourMeOKGame/Assets/Scripts/OklchColourPicker.cs
new file mode 100644
index 0000000..9c48f28
--- /dev/null
+++ b/ColourMeOKGame/Assets/Scripts/OklchColourPicker.cs
@@ -0,0 +1,135 @@
+using System;
+using UnityEngine;
+using UnityEngine.UIElements;
+
+public class OklchColourPicker : MonoBehaviour
+{
+ ///
+ /// perceptual lightness value of the colour (0-100)
+ ///
+ public double lightness;
+
+ ///
+ /// chroma value of the colour (0-0.5)
+ ///
+ public double chroma;
+
+ ///
+ /// hue value of the colour (0-360)
+ ///
+ public double hue;
+
+ ///
+ /// slider for the chroma value
+ ///
+ private Slider _chromaSlider;
+
+ ///
+ /// slider for the hue value
+ ///
+ private Slider _hueSlider;
+
+ ///
+ /// slider for the lightness value
+ ///
+ private Slider _lightnessSlider;
+
+ ///
+ /// visual element for the response colour preview
+ ///
+ private VisualElement _responseColour;
+
+ ///
+ /// function to set the initial values of the sliders
+ ///
+ private void Start()
+ {
+ _lightnessSlider.value = 74.61f;
+ _chromaSlider.value = 0.0868f;
+ _hueSlider.value = 335.72f;
+ }
+
+ ///
+ /// function to subscribe slider events to their respective functions
+ ///
+ public void OnEnable()
+ {
+ var ui = GetComponent().rootVisualElement;
+
+ _lightnessSlider = ui.Q("ResponseLightnessSlider");
+ _lightnessSlider.RegisterCallback>(OnLightnessChange);
+
+ _chromaSlider = ui.Q("ResponseChromaSlider");
+ _chromaSlider.RegisterCallback>(OnChromaChange);
+
+ _hueSlider = ui.Q("ResponseHueSlider");
+ _hueSlider.RegisterCallback>(OnHueChange);
+
+ _responseColour = ui.Q("ResponseColour");
+ }
+
+ // ///
+ // /// update the response preview colour
+ // ///
+ // private void Update()
+ // {
+ // _responseColour.style.backgroundColor = ToColor();
+ // }
+
+ ///
+ /// handle lightness slider change
+ ///
+ /// change event
+ private void OnLightnessChange(ChangeEvent evt)
+ {
+ lightness = Math.Clamp(evt.newValue, 0d, 100d);
+ _responseColour.style.backgroundColor = ToColor();
+ }
+
+ ///
+ /// handle chroma slider change
+ ///
+ /// change event
+ private void OnChromaChange(ChangeEvent evt)
+ {
+ chroma = Math.Clamp(evt.newValue, 0d, 0.5d);
+ _responseColour.style.backgroundColor = ToColor();
+ }
+
+ ///
+ /// handle hue slider change
+ ///
+ /// change event
+ private void OnHueChange(ChangeEvent evt)
+ {
+ hue = Math.Clamp(evt.newValue, 0d, 360d);
+ _responseColour.style.backgroundColor = ToColor();
+ }
+
+ ///
+ /// convert the oklch colour to a unity rgba colour object
+ ///
+ /// a unity rgba color object
+ private Color ToColor()
+ {
+ // clamp values
+ var cL = Math.Clamp(lightness / 100.0d, 0d, 1d);
+ var cC = Math.Clamp(chroma, 0d, 0.5d);
+ var cH = Math.Clamp(hue, 0d, 360d);
+
+ // convert [OKL]Ch to [OKL]ab
+ var hueRadians = cH * Math.PI / 180.0d;
+ var a = cC * Math.Cos(hueRadians);
+ var b = cC * Math.Sin(hueRadians);
+
+ // bring it to linear sRGB, clip it, then bring it back to non-linear sRGB
+ var lsrgb = Colorimetry.oklab_to_linear_srgb(new Colorimetry.Lab((float)cL, (float)a, (float)b));
+ var clippedLsrgb = Colorimetry.gamut_clip_preserve_chroma(lsrgb);
+ var srgb = new Color(
+ Math.Clamp((float)Colorimetry.srgb_nonlinear_transform_f(clippedLsrgb.r), 0.0f, 1.0f),
+ Math.Clamp((float)Colorimetry.srgb_nonlinear_transform_f(clippedLsrgb.g), 0.0f, 1.0f),
+ Math.Clamp((float)Colorimetry.srgb_nonlinear_transform_f(clippedLsrgb.b), 0.0f, 1.0f));
+
+ return srgb;
+ }
+}
\ No newline at end of file
diff --git a/ColourMeOKGame/Assets/Scripts/OklchColourPicker.cs.meta b/ColourMeOKGame/Assets/Scripts/OklchColourPicker.cs.meta
new file mode 100644
index 0000000..baf0f8d
--- /dev/null
+++ b/ColourMeOKGame/Assets/Scripts/OklchColourPicker.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 7b7c3f177f7c8ac4eb4b8b61373e37b4
+MonoImporter:
+ externalObjects: {}
+ serializedVersion: 2
+ defaultReferences: []
+ executionOrder: 0
+ icon: {instanceID: 0}
+ userData:
+ assetBundleName:
+ assetBundleVariant: