[orx-color] Adjust ColorOKLABa / ColorOKLCHa luminosity and chroma ranges. Add maxChroma

orx-color/src/commonMain/kotlin/spaces/ColorOKLABa.kt

@@ -3,7 +3,9 @@ package org.openrndr.extra.color.spaces
 import kotlinx.serialization.Serializable
 import org.openrndr.color.*
 import org.openrndr.math.Vector4
+import kotlin.math.abs
 import kotlin.math.pow
+import kotlin.math.sign
 
 /**
  * Color in OKLab color space.
@@ -27,9 +29,10 @@ data class ColorOKLABa(val l: Double, val a: Double, val b: Double, override val
             val m = 0.2119034982 * c.r + 0.6806995451 * c.g + 0.1073969566 * c.b
             val s = 0.0883024619 * c.r + 0.2817188376 * c.g + 0.6299787005 * c.b
 
-            val lnl = l.pow(1.0 / 3.0)
+            val lnl = abs(l).pow(1.0 / 3.0) * sign(l)
-            val mnl = m.pow(1.0 / 3.0)
+            val mnl = abs(m).pow(1.0 / 3.0) * sign(m)
-            val snl = s.pow(1.0 / 3.0)
+            val snl = abs(s).pow(1.0 / 3.0) * sign(s)
+
 
             val L = 0.2104542553 * lnl + 0.7936177850 * mnl - 0.0040720468 * snl
             val a = 1.9779984951 * lnl - 2.4285922050 * mnl + 0.4505937099 * snl
@@ -68,9 +71,9 @@ data class ColorOKLABa(val l: Double, val a: Double, val b: Double, override val
 
     override fun toVector4() = Vector4(l, a, b, alpha)
     override val luminosity: Double
-        get() = l
+        get() = l * 100.0
 
-    override fun withLuminosity(luminosity: Double): ColorOKLABa = copy(l = luminosity)
+    override fun withLuminosity(luminosity: Double): ColorOKLABa = copy(l = luminosity / 100.0)
 }
 
 fun ColorRGBa.toOKLABa() = ColorOKLABa.fromRGBa(this)

orx-color/src/commonMain/kotlin/spaces/ColorOKLCHa.kt

@@ -51,16 +51,16 @@ data class ColorOKLCHa(val l: Double, val c: Double, val h: Double, override val
     override fun toRGBa(): ColorRGBa = toOKLABa().toRGBa()
     override fun toVector4(): Vector4 = Vector4(l, c, h, alpha)
     override val chroma: Double
-        get() = c
+        get() = c * 100.0
-    override fun withChroma(chroma: Double): ColorOKLCHa = copy(c = chroma)
+    override fun withChroma(chroma: Double): ColorOKLCHa = copy(c = chroma / 100.0)
     override val hue: Double
         get() = h
 
     override fun withHue(hue: Double): ColorOKLCHa = copy(h = hue)
     override val luminosity: Double
-        get() = l
+        get() = l * 100.0
 
-    override fun withLuminosity(luminosity: Double): ColorOKLCHa = copy(l = luminosity)
+    override fun withLuminosity(luminosity: Double): ColorOKLCHa = copy(l = luminosity / 100.0)
 }
 
 fun mix(left: ColorOKLCHa, right: ColorOKLCHa, x: Double): ColorOKLCHa {

orx-color/src/commonMain/kotlin/tools/ChromaColorExtensions.kt

@@ -0,0 +1,47 @@
+package org.openrndr.extra.color.tools
+
+import org.openrndr.color.ChromaColor
+import org.openrndr.color.ConvertibleToColorRGBa
+
+
+private fun binarySearchMax(min: Double, max: Double, start: Double, threshold: Double = 1E-5, f: (Double) -> Boolean): Double {
+    var low = min
+    var high = max
+
+    var best = min
+    var mid = start
+    while (low <= high) {
+
+        val res = f(mid)
+
+        if (res) {
+            best = mid
+            low = mid
+        } else {
+            high = mid
+        }
+
+        if (high - low < threshold) {
+            return best
+        }
+        mid = (low + high) / 2.0
+    }
+    return best
+}
+
+fun <T> T.findMaxChroma(): Double
+        where T : ChromaColor<T>,
+              T : ConvertibleToColorRGBa {
+    return binarySearchMax(0.0, 200.0, chroma, 1E-5) {
+        val c = withChroma(it).toRGBa()
+        !c.isOutOfGamut
+    }
+}
+
+fun<T> T.clipChroma(): T
+        where T : ChromaColor<T>,
+              T : ConvertibleToColorRGBa {
+
+    val maxChroma = findMaxChroma()
+    return withChroma(maxChroma)
+}

orx-color/src/commonMain/kotlin/tools/ColorRGBaExtensions.kt

@@ -3,6 +3,10 @@ package org.openrndr.extra.color.tools
 import org.openrndr.color.*
 import org.openrndr.extra.color.spaces.*
 
+val ColorRGBa.isOutOfGamut: Boolean
+    get() {
+        return (r !in -1E-3..1.0) || (g !in -1E-3..1.0) || (b !in -1E-3..1.0) || (alpha !in 0.0..1.0)
+    }
 fun ColorRGBa.matchLinearity(other: ColorRGBa): ColorRGBa {
     return if (other.linearity.isEquivalent(linearity)) {
         this
@@ -100,6 +104,31 @@ inline fun <reified T> ColorRGBa.mixedWith(other: ColorRGBa, factor: Double): Co
     return source.mix(target, factor).toRGBa().matchLinearity(this)
 }
 
+inline fun <reified T> ColorRGBa.mixChroma(chroma: Double, factor: Double): ColorRGBa
+        where T : ChromaColor<T>,
+              T : ColorModel<T>,
+              T : ConvertibleToColorRGBa =
+    convertTo<T>().mixChroma(chroma, factor).toRGBa().matchLinearity(this)
+
+inline fun <reified T> ColorRGBa.withChroma(chroma: Double): ColorRGBa
+        where T : ChromaColor<T>,
+              T : ColorModel<T>,
+              T : ConvertibleToColorRGBa =
+    convertTo<T>().withChroma(chroma).toRGBa().matchLinearity(this)
+
+inline fun <reified T> ColorRGBa.chroma(): Double
+        where T : ChromaColor<T>,
+              T : ColorModel<T>,
+              T : ConvertibleToColorRGBa =
+    convertTo<T>().chroma
+
+inline fun <reified T> ColorRGBa.modulateChroma(factor: Double): ColorRGBa
+        where T : ChromaColor<T>,
+              T : ColorModel<T>,
+              T : ConvertibleToColorRGBa =
+    convertTo<T>().modulateChroma(factor).toRGBa().matchLinearity(this)
+
+
 inline fun <reified T> ColorRGBa.saturate(factor: Double): ColorRGBa
         where T : SaturatableColor<T>,
               T : ColorModel<T>,
@@ -110,3 +139,13 @@ inline fun <reified T> ColorRGBa.shiftHue(degrees: Double): ColorRGBa where
         T : ColorModel<T>,
         T : ConvertibleToColorRGBa = convertTo<T>().shiftHue(degrees).toRGBa().matchLinearity(this)
 
+inline fun <reified T> ColorRGBa.clipChroma(): ColorRGBa
+        where T : ChromaColor<T>,
+              T : ColorModel<T>,
+              T : ConvertibleToColorRGBa =
+
+    if (isOutOfGamut) {
+        convertTo<T>().clipChroma().toRGBa().matchLinearity(this).clip()
+    } else {
+        this
+    }

orx-color/src/commonTest/kotlin/spaces/TestOKLCHa.kt

@@ -0,0 +1,26 @@
+package spaces
+
+import org.openrndr.color.ColorRGBa
+import org.openrndr.extra.color.spaces.OKLCH
+import org.openrndr.extra.color.spaces.toOKLCHa
+import org.openrndr.extra.color.tools.chroma
+import org.openrndr.extra.color.tools.withLuminosity
+import kotlin.test.Test
+
+class TestOKLCHa {
+    @Test
+    fun testLowLuminosity() {
+        val c = ColorRGBa.GREEN.withLuminosity<OKLCH>(10.0)
+        println(c)
+        println(c.chroma<OKLCH>())
+
+
+        val g = ColorRGBa.GREEN.toOKLCHa()
+        val gl10 = g.withLuminosity(10.0)
+        val rgb10 = gl10.toRGBa()
+        println(gl10)
+        println(rgb10)
+        println(rgb10.toOKLCHa())
+
+    }
+}

orx-color/src/commonTest/kotlin/tools/TestChromaColorExtensions.kt

@@ -0,0 +1,31 @@
+package tools
+
+import org.openrndr.color.ColorRGBa
+import org.openrndr.extra.color.spaces.toOKLCHa
+import org.openrndr.extra.color.tools.findMaxChroma
+import org.openrndr.extra.color.tools.isOutOfGamut
+import kotlin.test.Test
+
+class TestChromaColorExtensions {
+    @Test
+    fun testFindMaxChroma() {
+
+        run {
+            val i = ColorRGBa.BLUE.toLCHABa()//.withLuminosity(50.0)
+            val maxChroma = i.findMaxChroma()
+            println(i.chroma)
+            println(maxChroma)
+        }
+        run {
+            val i = ColorRGBa.BLUE.toOKLCHa()//.withLuminosity(50.0)
+            val maxChroma = i.findMaxChroma()
+            println(ColorRGBa.BLUE.isOutOfGamut)
+            println(i.chroma)
+            println(maxChroma)
+            println(i.toRGBa())
+        }
+
+    }
+
+
+}