From e2a87d0e14c0d862a041ed8165a4aa09f56d8250 Mon Sep 17 00:00:00 2001
From: minjaesong <alswo9628@gmail.com>
Date: Thu, 18 Apr 2024 00:51:34 +0900
Subject: [PATCH] OKHsv util

---
 src/com/jme3/math/FastMath.java               |   4 +
 src/net/torvald/colourutil/OKHsvUtil.kt       | 644 ++++++++++++++++++
 src/net/torvald/colourutil/OKLabUtil.kt       |  81 ---
 .../gameactors/FixtureMechanicalTines.kt      |  13 +-
 .../modulebasegame/gameitems/MusicDisc.kt     |   4 -
 src/shaders/bayeralpha.frag                   |   1 +
 6 files changed, 657 insertions(+), 90 deletions(-)
 delete mode 100644 src/net/torvald/colourutil/OKLabUtil.kt

diff --git a/src/com/jme3/math/FastMath.java b/src/com/jme3/math/FastMath.java
index 391796318..3da4f24a6 100644
--- a/src/com/jme3/math/FastMath.java
+++ b/src/com/jme3/math/FastMath.java
@@ -597,6 +597,10 @@ final public class FastMath {
         return (float) Math.sqrt(fValue);
     }
 
+    public static float cbrt(float fValue) {
+        return (float) Math.cbrt(fValue);
+    }
+
     /**
      * Returns the tangent of a value.  If USE_FAST_TRIG is enabled, an approximate value
      * is returned.  Otherwise, a direct value is used.
diff --git a/src/net/torvald/colourutil/OKHsvUtil.kt b/src/net/torvald/colourutil/OKHsvUtil.kt
index f9e1aea62..3c3842bf3 100644
--- a/src/net/torvald/colourutil/OKHsvUtil.kt
+++ b/src/net/torvald/colourutil/OKHsvUtil.kt
@@ -1,6 +1,650 @@
 package net.torvald.colourutil
 
+import com.jme3.math.FastMath.*
+import net.torvald.colourutil.OKHsvUtil.find_cusp
+import net.torvald.colourutil.OKHsvUtil.get_Cs
+import net.torvald.colourutil.OKHsvUtil.to_ST
+import net.torvald.colourutil.OKHsvUtil.toe
+import net.torvald.colourutil.OKHsvUtil.toe_inv
+import kotlin.math.max
+import kotlin.math.min
+
+
 /**
+ * This file contains translated code originally written by Björn Ottosson.
+ *
+ * Copyright (c) 2021 Björn Ottosson
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is furnished to do
+ * so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
  * Created by minjaesong on 2024-04-17.
  */
 
+/**
+ * @param h Hue in Radians
+ * @param s Saturation `[0-1]`
+ * @param v Value `[0-1]`
+ */
+data class OKHsv(var h: Float, var s: Float, var v: Float)
+data class OKHsl(var h: Float, var s: Float, var l: Float)
+data class OKLab(var L: Float, var a: Float, var b: Float)
+
+object OKHsvUtil {
+    internal data class LC(var L: Float, var C: Float)
+    internal data class ST(var S: Float, var T: Float)
+    internal data class Cs(var C_0: Float, var C_mid: Float, var C_max: Float)
+
+    private const val FLT_MAX = 1e+37f
+
+    private fun clamp(x: Float, min: Float, max: Float): Float {
+        if (x < min) return min
+        if (x > max) return max
+
+        return x
+    }
+
+    private fun sgn(x: Float): Float {
+        return (if (0f < x) 1f else 0f) - (if (x < 0f) 1f else 0f)
+    }
+
+
+    // 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
+    internal fun compute_max_saturation(a: Float, b: Float): Float {
+        // 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
+
+        val k0: Float
+        val k1: Float
+        val k2: Float
+        val k3: Float
+        val k4: Float
+        val wl: Float
+        val wm: Float
+        val ws: Float
+
+        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 S = 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 sufficient for most applications, otherwise do two/three steps
+        val k_l = +0.3963377774f * a + 0.2158037573f * b
+        val k_m = -0.1055613458f * a - 0.0638541728f * b
+        val k_s = -0.0894841775f * a - 1.2914855480f * b
+
+        run {
+            val l_ = 1f + S * k_l
+            val m_ = 1f + S * k_m
+            val s_ = 1f + S * k_s
+
+            val l = l_ * l_ * l_
+            val m = m_ * m_ * m_
+            val s = s_ * s_ * s_
+
+            val l_dS = 3f * k_l * l_ * l_
+            val m_dS = 3f * k_m * m_ * m_
+            val s_dS = 3f * k_s * s_ * s_
+
+            val l_dS2 = 6f * k_l * k_l * l_
+            val m_dS2 = 6f * k_m * k_m * m_
+            val s_dS2 = 6f * k_s * k_s * s_
+
+            val f = wl * l + wm * m + ws * s
+            val f1 = wl * l_dS + wm * m_dS + ws * s_dS
+            val f2 = wl * l_dS2 + wm * m_dS2 + ws * s_dS2
+            S = S - f * f1 / (f1 * f1 - 0.5f * f * f2)
+        }
+
+        return S
+    }
+
+    // finds L_cusp and C_cusp for a given hue
+// a and b must be normalized so a^2 + b^2 == 1
+    internal fun find_cusp(a: Float, b: Float): LC {
+        // First, find the maximum saturation (saturation S = C/L)
+        val S_cusp = compute_max_saturation(a, b)
+
+        // Convert to linear sRGB to find the first point where at least one of r,g or b >= 1:
+        val rgb_at_max = OKLab(1f, S_cusp * a, S_cusp * b).toLinearRGB()
+        val L_cusp = cbrt(1f / max(max(rgb_at_max.r, rgb_at_max.g), rgb_at_max.b))
+        val C_cusp = L_cusp * S_cusp
+
+        return LC(L_cusp, C_cusp)
+    }
+
+    // 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
+    internal fun find_gamut_intersection(a: Float, b: Float, L1: Float, C1: Float, L0: Float, cusp: LC): Float {
+        // Find the intersection for upper and lower half seprately
+        var t: Float
+        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
+            run {
+                val dL = L1 - L0
+                val dC = C1
+
+                val k_l = +0.3963377774f * a + 0.2158037573f * b
+                val k_m = -0.1055613458f * a - 0.0638541728f * b
+                val k_s = -0.0894841775f * a - 1.2914855480f * b
+
+                val l_dt = dL + dC * k_l
+                val m_dt = dL + dC * k_m
+                val s_dt = dL + dC * k_s
+
+
+                // If higher accuracy is required, 2 or 3 iterations of the following block can be used:
+                run {
+                    val L = L0 * (1f - t) + t * L1
+                    val C = t * C1
+
+                    val l_ = L + C * k_l
+                    val m_ = L + C * k_m
+                    val s_ = L + C * k_s
+
+                    val l = l_ * l_ * l_
+                    val m = m_ * m_ * m_
+                    val s = s_ * s_ * s_
+
+                    val ldt = 3 * l_dt * l_ * l_
+                    val mdt = 3 * m_dt * m_ * m_
+                    val sdt = 3 * s_dt * s_ * s_
+
+                    val ldt2 = 6 * l_dt * l_dt * l_
+                    val mdt2 = 6 * m_dt * m_dt * m_
+                    val sdt2 = 6 * s_dt * s_dt * s_
+
+                    val r = 4.0767416621f * l - 3.3077115913f * m + 0.2309699292f * s - 1
+                    val r1 = 4.0767416621f * ldt - 3.3077115913f * mdt + 0.2309699292f * sdt
+                    val r2 = 4.0767416621f * ldt2 - 3.3077115913f * mdt2 + 0.2309699292f * sdt2
+
+                    val u_r = r1 / (r1 * r1 - 0.5f * r * r2)
+                    var t_r = -r * u_r
+
+                    val g = -1.2684380046f * l + 2.6097574011f * m - 0.3413193965f * s - 1
+                    val g1 = -1.2684380046f * ldt + 2.6097574011f * mdt - 0.3413193965f * sdt
+                    val g2 = -1.2684380046f * ldt2 + 2.6097574011f * mdt2 - 0.3413193965f * sdt2
+
+                    val u_g = g1 / (g1 * g1 - 0.5f * g * g2)
+                    var t_g = -g * u_g
+
+                    val b = -0.0041960863f * l - 0.7034186147f * m + 1.7076147010f * s - 1
+                    val b1 = -0.0041960863f * ldt - 0.7034186147f * mdt + 1.7076147010f * sdt
+                    val b2 = -0.0041960863f * ldt2 - 0.7034186147f * mdt2 + 1.7076147010f * sdt2
+
+                    val u_b = b1 / (b1 * b1 - 0.5f * b * b2)
+                    var t_b = -b * u_b
+
+                    t_r = if (u_r >= 0f) t_r else FLT_MAX
+                    t_g = if (u_g >= 0f) t_g else FLT_MAX
+                    t_b = if (u_b >= 0f) t_b else FLT_MAX
+                    t += min(t_r, min(t_g, t_b))
+                }
+            }
+        }
+
+        return t
+    }
+
+    internal fun find_gamut_intersection(a: Float, b: Float, L1: Float, C1: Float, L0: Float): Float {
+        // Find the cusp of the gamut triangle
+        val cusp: LC = find_cusp(a, b)
+
+        return find_gamut_intersection(a, b, L1, C1, L0, cusp)
+    }
+
+    internal fun gamut_clip_preserve_chroma(rgb: RGB): RGB {
+        if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0) return rgb
+
+        val lab: OKLab = rgb.linearToOKLab()
+
+        val L: Float = lab.L
+        val eps = 0.00001f
+        val C: Float = max(eps, sqrt(lab.a * lab.a + lab.b * lab.b))
+        val a_: Float = lab.a / C
+        val b_: Float = lab.b / C
+
+        val L0 = clamp(L, 0f, 1f)
+
+        val t = find_gamut_intersection(a_, b_, L, C, L0)
+        val L_clipped = L0 * (1 - t) + t * L
+        val C_clipped = t * C
+
+        return OKLab(L_clipped, C_clipped * a_, C_clipped * b_).toLinearRGB()
+    }
+
+    internal fun gamut_clip_project_to_0_5(rgb: RGB): RGB {
+        if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0) return rgb
+
+        val lab: OKLab = rgb.linearToOKLab()
+
+        val L: Float = lab.L
+        val eps = 0.00001f
+        val C: Float = max(eps, sqrt(lab.a * lab.a + lab.b * lab.b))
+        val a_: Float = lab.a / C
+        val b_: Float = lab.b / C
+
+        val L0 = 0.5.toFloat()
+
+        val t = find_gamut_intersection(a_, b_, L, C, L0)
+        val L_clipped = L0 * (1 - t) + t * L
+        val C_clipped = t * C
+
+        return OKLab(L_clipped, C_clipped * a_, C_clipped * b_).toLinearRGB()
+    }
+
+    internal fun gamut_clip_project_to_L_cusp(rgb: RGB): RGB {
+        if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0) return rgb
+
+        val lab: OKLab = rgb.linearToOKLab()
+
+        val L: Float = lab.L
+        val eps = 0.00001f
+        val C: Float = max(eps, sqrt(lab.a * lab.a + lab.b * lab.b))
+        val a_: Float = lab.a / C
+        val b_: Float = lab.b / C
+
+        // The cusp is computed here and in find_gamut_intersection, an optimized solution would only compute it once.
+        val cusp: LC = find_cusp(a_, b_)
+
+        val L0: Float = cusp.L
+
+        val t = find_gamut_intersection(a_, b_, L, C, L0)
+
+        val L_clipped = L0 * (1 - t) + t * L
+        val C_clipped = t * C
+
+        return OKLab(L_clipped, C_clipped * a_, C_clipped * b_).toLinearRGB()
+    }
+
+    internal fun gamut_clip_adaptive_L0_0_5(rgb: RGB, alpha: Float): RGB /* alpha = 0.05f */ {
+        if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0) return rgb
+
+        val lab: OKLab = rgb.linearToOKLab()
+
+        val L: Float = lab.L
+        val eps = 0.00001f
+        val C: Float = max(eps, sqrt(lab.a * lab.a + lab.b * lab.b))
+        val a_: Float = lab.a / C
+        val b_: Float = lab.b / C
+
+        val Ld = L - 0.5f
+        val e1: Float = 0.5f + abs(Ld) + alpha * C
+        val L0: Float = 0.5f * (1f + sgn(Ld) * (e1 - sqrt(e1 * e1 - 2f * abs(Ld))))
+
+        val t = find_gamut_intersection(a_, b_, L, C, L0)
+        val L_clipped = L0 * (1f - t) + t * L
+        val C_clipped = t * C
+
+        return OKLab(L_clipped, C_clipped * a_, C_clipped * b_).toLinearRGB()
+    }
+
+    internal fun gamut_clip_adaptive_L0_L_cusp(rgb: RGB, alpha: Float): RGB /* alpha = 0.05f */ {
+        if (rgb.r < 1 && rgb.g < 1 && rgb.b < 1 && rgb.r > 0 && rgb.g > 0 && rgb.b > 0) return rgb
+
+        val lab: OKLab = rgb.linearToOKLab()
+
+        val L: Float = lab.L
+        val eps = 0.00001f
+        val C: Float = max(eps, sqrt(lab.a * lab.a + lab.b * lab.b))
+        val a_: Float = lab.a / C
+        val b_: Float = lab.b / C
+
+        // The cusp is computed here and in find_gamut_intersection, an optimized solution would only compute it once.
+        val cusp: LC = find_cusp(a_, b_)
+
+        val Ld: Float = L - cusp.L
+        val k: Float = 2f * (if (Ld > 0) 1f - cusp.L else cusp.L)
+
+        val e1: Float = 0.5f * k + abs(Ld) + alpha * C / k
+        val L0: Float = cusp.L + 0.5f * (sgn(Ld) * (e1 - sqrt(e1 * e1 - 2f * k * abs(Ld))))
+
+        val t = find_gamut_intersection(a_, b_, L, C, L0)
+        val L_clipped = L0 * (1f - t) + t * L
+        val C_clipped = t * C
+
+        return OKLab(L_clipped, C_clipped * a_, C_clipped * b_).toLinearRGB()
+    }
+
+    internal fun toe(x: Float): Float {
+        val k_1 = 0.206f
+        val k_2 = 0.03f
+        val k_3 = (1f + k_1) / (1f + k_2)
+        return 0.5f * (k_3 * x - k_1 + sqrt((k_3 * x - k_1) * (k_3 * x - k_1) + 4 * k_2 * k_3 * x))
+    }
+
+    internal fun toe_inv(x: Float): Float {
+        val k_1 = 0.206f
+        val k_2 = 0.03f
+        val k_3 = (1f + k_1) / (1f + k_2)
+        return (x * x + k_1 * x) / (k_3 * (x + k_2))
+    }
+
+    internal fun to_ST(cusp: OKHsvUtil.LC): ST {
+        val L: Float = cusp.L
+        val C: Float = cusp.C
+        return ST(C / L, C / (1 - L))
+    }
+
+    // Returns a smooth approximation of the location of the cusp
+// This polynomial was created by an optimization process
+// It has been designed so that S_mid < S_max and T_mid < T_max
+    internal fun get_ST_mid(a_: Float, b_: Float): ST {
+        val S =
+            0.11516993f + 1f / (+7.44778970f + 4.15901240f * b_ + a_ * (-2.19557347f + 1.75198401f * b_ + a_ * (-2.13704948f - 10.02301043f * b_
+                    + a_ * (-4.24894561f + 5.38770819f * b_ + 4.69891013f * a_
+                    )))
+                    )
+
+        val T = 0.11239642f + 1f / (+1.61320320f - 0.68124379f * b_
+                + a_ * (+0.40370612f + 0.90148123f * b_ + a_ * (-0.27087943f + 0.61223990f * b_ + a_ * (+0.00299215f - 0.45399568f * b_ - 0.14661872f * a_
+                ))))
+
+        return ST(S, T)
+    }
+
+    internal fun get_Cs(L: Float, a_: Float, b_: Float): Cs {
+        val cusp: LC = find_cusp(a_, b_)
+
+        val C_max = find_gamut_intersection(a_, b_, L, 1f, L, cusp)
+        val ST_max: ST = to_ST(cusp)
+
+        // Scale factor to compensate for the curved part of gamut shape:
+        val k: Float = C_max / min((L * ST_max.S), (1 - L) * ST_max.T)
+
+        var C_mid: Float
+        run {
+            val ST_mid: ST = get_ST_mid(a_, b_)
+            // Use a soft minimum function, instead of a sharp triangle shape to get a smooth value for chroma.
+            val C_a: Float = L * ST_mid.S
+            val C_b: Float = (1f - L) * ST_mid.T
+            C_mid = 0.9f * k * sqrt(sqrt(1f / (1f / (C_a * C_a * C_a * C_a) + 1f / (C_b * C_b * C_b * C_b))))
+        }
+
+        var C_0: Float
+        run {
+            // for C_0, the shape is independent of hue, so ST are constant. Values picked to roughly be the average values of ST.
+            val C_a = L * 0.4f
+            val C_b = (1f - L) * 0.8f
+
+            // Use a soft minimum function, instead of a sharp triangle shape to get a smooth value for chroma.
+            C_0 = sqrt(1f / (1f / (C_a * C_a) + 1f / (C_b * C_b)))
+        }
+
+        return Cs(C_0, C_mid, C_max)
+    }
+}
+
+fun RGB.linearToOKLab(): OKLab {
+    val l = 0.4122214708f * this.r + 0.5363325363f * this.g + 0.0514459929f * this.b
+    val m = 0.2119034982f * this.r + 0.6806995451f * this.g + 0.1073969566f * this.b
+    val s = 0.0883024619f * this.r + 0.2817188376f * this.g + 0.6299787005f * this.b
+
+    val l_ = cbrt(l)
+    val m_ = cbrt(m)
+    val s_ = cbrt(s)
+
+    return OKLab(
+        0.2104542553f * l_ + 0.7936177850f * m_ - 0.0040720468f * s_,
+        1.9779984951f * l_ - 2.4285922050f * m_ + 0.4505937099f * s_,
+        0.0259040371f * l_ + 0.7827717662f * m_ - 0.8086757660f * s_
+    )
+}
+
+fun OKLab.toLinearRGB(): RGB {
+    val l_: Float = this.L + 0.3963377774f * this.a + 0.2158037573f * this.b
+    val m_: Float = this.L - 0.1055613458f * this.a - 0.0638541728f * this.b
+    val s_: Float = this.L - 0.0894841775f * this.a - 1.2914855480f * this.b
+
+    val l = l_ * l_ * l_
+    val m = m_ * m_ * m_
+    val s = s_ * s_ * s_
+
+    return 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
+    )
+}
+
+fun OKHsl.tosRGB(): RGB {
+    val h: Float = this.h
+    val s: Float = this.s
+    val l: Float = this.l
+
+    if (l == 1.0f) {
+        return RGB(1f, 1f, 1f)
+    }
+    else if (l == 0f) {
+        return RGB(0f, 0f, 0f)
+    }
+
+    val a_: Float = cos(h)
+    val b_: Float = sin(h)
+    val L = toe_inv(l)
+
+    val cs: OKHsvUtil.Cs = get_Cs(L, a_, b_)
+    val C_0: Float = cs.C_0
+    val C_mid: Float = cs.C_mid
+    val C_max: Float = cs.C_max
+
+    val mid = 0.8f
+    val mid_inv = 1.25f
+
+    val C: Float
+    val t: Float
+    val k_0: Float
+    val k_1: Float
+    val k_2: Float
+
+    if (s < mid) {
+        t = mid_inv * s
+
+        k_1 = mid * C_0
+        k_2 = (1f - k_1 / C_mid)
+
+        C = t * k_1 / (1f - k_2 * t)
+    }
+    else {
+        t = (s - mid) / (1 - mid)
+
+        k_0 = C_mid
+        k_1 = (1f - mid) * C_mid * C_mid * mid_inv * mid_inv / C_0
+        k_2 = (1f - (k_1) / (C_max - C_mid))
+
+        C = k_0 + t * k_1 / (1f - k_2 * t)
+    }
+
+    val rgb = OKLab(L, C * a_, C * b_).toLinearRGB()
+    return rgb.unLinearise()
+}
+
+fun RGB.sRGBtoOKHsl(): OKHsl {
+    val lab: OKLab = this.linearise().linearToOKLab()
+
+    val C: Float = sqrt(lab.a * lab.a + lab.b * lab.b)
+    val a_: Float = lab.a / C
+    val b_: Float = lab.b / C
+
+    val L: Float = lab.L
+    val h: Float = 0.5f + 0.5f * atan2(-lab.b, -lab.a) / PI
+
+    val cs: OKHsvUtil.Cs = get_Cs(L, a_, b_)
+    val C_0: Float = cs.C_0
+    val C_mid: Float = cs.C_mid
+    val C_max: Float = cs.C_max
+
+    // Inverse of the interpolation in okhsl_to_srgb:
+    val mid = 0.8f
+    val mid_inv = 1.25f
+
+    val s: Float
+    if (C < C_mid) {
+        val k_1 = mid * C_0
+        val k_2 = (1f - k_1 / C_mid)
+
+        val t = C / (k_1 + k_2 * C)
+        s = t * mid
+    }
+    else {
+        val k_0 = C_mid
+        val k_1 = (1f - mid) * C_mid * C_mid * mid_inv * mid_inv / C_0
+        val k_2 = (1f - (k_1) / (C_max - C_mid))
+
+        val t = (C - k_0) / (k_1 + k_2 * (C - k_0))
+        s = mid + (1f - mid) * t
+    }
+
+    val l = toe(L)
+    return OKHsl(h, s, l)
+}
+
+
+fun OKHsv.tosRGB(): RGB {
+    val h = this.h
+    val s = this.s
+    val v = this.v
+
+    val a_: Float = cos(h)
+    val b_: Float = sin(h)
+
+    val cusp: OKHsvUtil.LC = find_cusp(a_, b_)
+    val ST_max: OKHsvUtil.ST = to_ST(cusp)
+    val S_max: Float = ST_max.S
+    val T_max: Float = ST_max.T
+    val S_0 = 0.5f
+    val k = 1 - S_0 / S_max
+
+    // first we compute L and V as if the gamut is a perfect triangle:
+
+    // L, C when v==1:
+    val L_v = 1 - s * S_0 / (S_0 + T_max - T_max * k * s)
+    val C_v = s * T_max * S_0 / (S_0 + T_max - T_max * k * s)
+
+    var L = v * L_v
+    var C = v * C_v
+
+    // then we compensate for both toe and the curved top part of the triangle:
+    val L_vt = toe_inv(L_v)
+    val C_vt = C_v * L_vt / L_v
+
+    val L_new = toe_inv(L)
+    C = C * L_new / L
+    L = L_new
+
+    val rgb_scale = OKLab(L_vt, a_ * C_vt, b_ * C_vt).toLinearRGB()
+    val scale_L = cbrt(1f / max(max(rgb_scale.r, rgb_scale.g), max(rgb_scale.b, 0f)))
+
+    L = L * scale_L
+    C = C * scale_L
+
+    val rgb = OKLab(L, C * a_, C * b_).toLinearRGB()
+    return rgb.unLinearise()
+}
+
+fun RGB.sRGBtoOKHsv(): OKHsv {
+    val lab: OKLab = this.linearise().linearToOKLab()
+
+    var C: Float = sqrt(lab.a * lab.a + lab.b * lab.b)
+    val a_: Float = lab.a / C
+    val b_: Float = lab.b / C
+
+    var L: Float = lab.L
+    val h: Float = 0.5f + 0.5f * atan2(-lab.b, -lab.a) / PI
+
+    val cusp: OKHsvUtil.LC = find_cusp(a_, b_)
+    val ST_max: OKHsvUtil.ST = to_ST(cusp)
+    val S_max: Float = ST_max.S
+    val T_max: Float = ST_max.T
+    val S_0 = 0.5f
+    val k = 1 - S_0 / S_max
+
+    // first we find L_v, C_v, L_vt and C_vt
+    val t = T_max / (C + L * T_max)
+    val L_v = t * L
+    val C_v = t * C
+
+    val L_vt = toe_inv(L_v)
+    val C_vt = C_v * L_vt / L_v
+
+    // we can then use these to invert the step that compensates for the toe and the curved top part of the triangle:
+    val rgb_scale = OKLab(L_vt, a_ * C_vt, b_ * C_vt).toLinearRGB()
+    val scale_L = cbrt(1f / max(max(rgb_scale.r, rgb_scale.g), max(rgb_scale.b, 0f)))
+
+    L = L / scale_L
+    C = C / scale_L
+
+    C = C * toe(L) / L
+    L = toe(L)
+
+    // we can now compute v and s:
+    val v = L / L_v
+    val s = (S_0 + T_max) * C_v / ((T_max * S_0) + T_max * k * C_v)
+
+    return OKHsv(h, s, v)
+}
diff --git a/src/net/torvald/colourutil/OKLabUtil.kt b/src/net/torvald/colourutil/OKLabUtil.kt
deleted file mode 100644
index 2475987ce..000000000
--- a/src/net/torvald/colourutil/OKLabUtil.kt
+++ /dev/null
@@ -1,81 +0,0 @@
-package net.torvald.colourutil
-
-import kotlin.math.atan2
-import kotlin.math.pow
-
-/**
- * OKLab is a colour space devised by Björn Ottosson. https://bottosson.github.io/posts/oklab/
- *
- * Created by minjaesong on 2022-12-02.
- */
-object OKLabUtil {
-
-
-
-}
-
-/**
- * @param L Luminosity. Scale depends on the scale of the conversion (if source Lab had 0..100, this value will also be 0..100).
- * @param C Chrominance. Scale depends on the scale of the conversion.
- * @param h Hue in RADIANS (-pi..pi).
- */
-data class OKLCh(var L: Float = 0f, val C: Float = 0f, val h: Float = 0f, val alpha: Float = 1f)
-
-data class OKLab(var L: Float = 0f, val a: Float = 0f, val b: Float = 0f, val alpha: Float = 1f) {
-    fun toOKLCh(): OKLCh {
-        val c = (a*a + b*b).pow(0.5f)
-        val h = atan2(a, b)
-
-        return OKLCh(L, c, h, alpha)
-    }
-
-    fun toSRGB(): RGB {
-        val l_ = L + 0.3963377774f * a + 0.2158037573f * b
-        val m_ = L - 0.1055613458f * a - 0.0638541728f * b
-        val s_ = L - 0.0894841775f * a - 1.2914855480f * b
-
-        val l = l_ * l_ * l_
-        val m = m_ * m_ * m_
-        val s = s_ * s_ * s_
-
-        val lrgb = 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,
-                alpha
-        )
-
-        return lrgb.unLinearise()
-    }
-}
-
-fun CIEXYZ.toOKLab(): OKLab {
-    val l = (0.8189330101f * this.X + 0.3618667424f * this.Y - 0.1288597137f * this.Z).pow(0.333333333333f)
-    val m = (0.0329845436f * this.X + 0.9293118715f * this.Y + 0.0361456387f * this.Z).pow(0.333333333333f)
-    val s = (0.0482003018f * this.X + 0.2643662691f * this.Y + 0.6338517070f * this.Z).pow(0.333333333333f)
-
-    val L = 0.2104542553f*l + 0.7936177850f*m - 0.0040720468f*s
-    val a = 1.9779984951f*l - 2.4285922050f*m + 0.4505937099f*s
-    val b = 0.0259040371f*l + 0.7827717662f*m - 0.8086757660f*s
-
-    return OKLab(L, a, b, alpha)
-}
-
-fun RGB.toOKLab(): OKLab {
-    val c = this.linearise()
-
-    val l = 0.4122214708f * c.r + 0.5363325363f * c.g + 0.0514459929f * c.b
-    val m = 0.2119034982f * c.r + 0.6806995451f * c.g + 0.1073969566f * c.b
-    val s = 0.0883024619f * c.r + 0.2817188376f * c.g + 0.6299787005f * c.b
-
-    val l_ = l.pow(0.3333333333333f)
-    val m_ = m.pow(0.3333333333333f)
-    val s_ = s.pow(0.3333333333333f)
-
-
-    val L = 0.2104542553f * l_ + 0.7936177850f * m_ - 0.0040720468f * s_
-    val a = 1.9779984951f * l_ - 2.4285922050f * m_ + 0.4505937099f * s_
-    val b = 0.0259040371f * l_ + 0.7827717662f * m_ - 0.8086757660f * s_
-
-    return OKLab(L, a, b, c.alpha)
-}
diff --git a/src/net/torvald/terrarum/modulebasegame/gameactors/FixtureMechanicalTines.kt b/src/net/torvald/terrarum/modulebasegame/gameactors/FixtureMechanicalTines.kt
index 97d493449..0c5877dd9 100644
--- a/src/net/torvald/terrarum/modulebasegame/gameactors/FixtureMechanicalTines.kt
+++ b/src/net/torvald/terrarum/modulebasegame/gameactors/FixtureMechanicalTines.kt
@@ -2,7 +2,11 @@ package net.torvald.terrarum.modulebasegame.gameactors
 
 import com.badlogic.gdx.graphics.Color
 import com.jme3.math.FastMath
+import com.jme3.math.FastMath.DEG_TO_RAD
 import net.torvald.colourutil.HUSLColorConverter
+import net.torvald.colourutil.OKHsv
+import net.torvald.colourutil.toColor
+import net.torvald.colourutil.tosRGB
 import net.torvald.random.HQRNG
 import net.torvald.terrarum.App
 import net.torvald.terrarum.App.printdbg
@@ -202,11 +206,10 @@ object ParticleMusicalNoteFactory {
     private const val ANGLE_RIGHTMOST = -(HALF_PI + 1.0)
 
     private val noteColours = (0..60).map {
-        val hue = it / 60f * 270f
-        val saturation = 100f
-        val lightness = 70f
-        val (r, g, b) = HUSLColorConverter.hsluvToRgb(floatArrayOf(hue, saturation, lightness))
-        Color(r, g, b, 1f)
+        val h = (it / 60f * 360f) * DEG_TO_RAD
+        val s = 0.75f
+        val v = 1f
+        OKHsv(h, s, v).tosRGB().toColor()
     }
 
     private val angles = (0..60).map {
diff --git a/src/net/torvald/terrarum/modulebasegame/gameitems/MusicDisc.kt b/src/net/torvald/terrarum/modulebasegame/gameitems/MusicDisc.kt
index f588663d2..4e9a61ac8 100644
--- a/src/net/torvald/terrarum/modulebasegame/gameitems/MusicDisc.kt
+++ b/src/net/torvald/terrarum/modulebasegame/gameitems/MusicDisc.kt
@@ -6,14 +6,10 @@ import com.badlogic.gdx.graphics.Pixmap
 import com.badlogic.gdx.graphics.Texture
 import com.badlogic.gdx.graphics.g2d.TextureRegion
 import net.torvald.colourutil.HUSLColorConverter
-import net.torvald.colourutil.OKLCh
 import net.torvald.random.HQRNG
-import net.torvald.random.XXHash32
 import net.torvald.random.XXHash64
-import net.torvald.terrarum.App.printdbg
 import net.torvald.terrarum.ModMgr
 import net.torvald.terrarum.gameitems.ItemID
-import net.torvald.terrarum.savegame.toHex
 import net.torvald.terrarum.utils.JsonFetcher
 import net.torvald.terrarum.worlddrawer.toRGBA
 import net.torvald.unicode.EMDASH
diff --git a/src/shaders/bayeralpha.frag b/src/shaders/bayeralpha.frag
index 6c56ce515..9ce59946c 100644
--- a/src/shaders/bayeralpha.frag
+++ b/src/shaders/bayeralpha.frag
@@ -43,6 +43,7 @@ void main() {
     vec2 entry = mod(gl_FragCoord.xy + entryOffset, vec2(bayerSize, bayerSize));
 
 
+//    float alpha = nearestAlpha((inColor.a * 16.0 / 15.0) + (bayer[int(entry.y) * int(bayerSize) + int(entry.x)] / bayerDivider - 0.5));
     float alpha = nearestAlpha((inColor.a * 16.0 / 15.0) + (bayer[int(entry.y) * int(bayerSize) + int(entry.x)] / bayerDivider - 0.5));
 
     fragColor = vec4(inColor.rgb, alpha);