corrected wrong implementation of Color.toXYZ() and CIEXYZ.toRGB()

Former-commit-id: a2d68b1a3a48b17b54562bd3c90b5dde0fe4dbc4
Former-commit-id: e4284b113b2af11538333f74546ce6692be9dd39

README.md

@@ -24,19 +24,27 @@ Any contribution in this project must be made sorely in English, so be sure to u
 * Writing tests
 * Code review
 * Guidelines
-    - Quintessential: write code that even an imbecile can understand.
+    - Well-documented. (comments, people, comments!)
 
 
 ### Contributing translations ###
 
 * Writing text
-  You will need to fiddle with .csv files in ./res/locales
+  You will need to fiddle with .json files in ./res/locales/<Language code>
 * Languagus with apparent grammatical gender
   Any gender discrimination should *not* exist in this game, so please choose vocabularies that is gender-neutral. If such behaviour is not possible in the target language, please use male gender, but try your best to avoid the situation.
 
 Note: Right-to-left languages (arabic, hebrew, etc.) are not supported.
 
 
+### Contributing artworks ###
+
+* RGB we mean is always sRGB, _pure white_ we say is always D65 (6 500 K). If you have a monitor calibration device, this is our desired target.
+* Master material for picture (e.g. psd) can be either RGB/8 or Lab/16.
+* To comply with the game's art style, only the 12-bit colours must be used (each channel: 0x00, 0x11, 0x22 .. 0xEE, 0xFF), though there is some exception.
+* Every final audio must be in OGG/Vorbis, q 10.
+
+
 ## Who do I talk to? ##
 
 * Repo owner or admin

src/net/torvald/colourutil/CIELChUtil.kt

@@ -13,14 +13,14 @@ import org.newdawn.slick.Color
  * Created by minjaesong on 16-09-01.
  */
 
-object CIELchUtil {
+object CIELChUtil {
 
     /** Sweet Lch linear gradient */
     fun getGradient(scale: Float, fromCol: Color, toCol: Color): Color {
-        val from = fromCol.toLch()
-        val to = toCol.toLch()
+        val from = fromCol.toLCh()
+        val to = toCol.toLCh()
         val newL = FastMath.interpolateLinear(scale, from.L, to.L)
-        val newC = FastMath.interpolateLinear(scale, from.c, to.c)
+        val newC = FastMath.interpolateLinear(scale, from.C, to.C)
         val newAlpha = FastMath.interpolateLinear(scale, from.alpha, to.alpha)
         val newH: Float
 
@@ -31,25 +31,25 @@ object CIELchUtil {
         else
             newH = FastMath.interpolateLinear(scale, from.h, to.h)
 
-        return CIELch(newL, newC, newH, newAlpha).toRGB()
+        return CIELCh(newL, newC, newH, newAlpha).toRGB()
     }
 
-    fun CIELab.toLch(): CIELch {
+    fun CIELab.toLCh(): CIELCh {
         val c = (a.sqr() + b.sqr()).sqrt()
         val h = FastMath.atan2(b, a)
 
-        return CIELch(L, c, h, alpha)
+        return CIELCh(L, c, h, alpha)
     }
 
-    fun CIELch.toLab(): CIELab {
-        val a = c * FastMath.cos(h)
-        val b = c * FastMath.sin(h)
+    fun CIELCh.toLab(): CIELab {
+        val a = C * FastMath.cos(h)
+        val b = C * FastMath.sin(h)
 
         return CIELab(L, a, b, alpha)
     }
 
-    private fun Color.toLch() = this.toXYZ().toLab().toLch()
-    private fun CIELch.toRGB() = this.toLab().toXYZ().toRGB()
+    private fun Color.toLCh() = this.toXYZ().toLab().toLCh()
+    private fun CIELCh.toRGB() = this.toLab().toXYZ().toRGB()
 
     private fun Float.sqr() = this * this
     private fun Float.sqrt() = Math.sqrt(this.toDouble()).toFloat()
@@ -59,7 +59,7 @@ object CIELchUtil {
 
 /**
  * @param L : Luminosity in 0.0 - 1.0
- * @param c : Chroma (saturation) in 0.0 - 1.0
+ * @param C : Chroma (saturation) in 0.0 - 1.0
  * @param h : Hue in radian (-pi to pi)
  */
-data class CIELch(var L: Float = 0f, var c: Float = 0f, var h: Float = 0f, var alpha: Float = 1f)
+data class CIELCh(var L: Float = 0f, var C: Float = 0f, var h: Float = 0f, var alpha: Float = 1f)

src/net/torvald/colourutil/CIELabUtil.kt

@@ -42,17 +42,40 @@ object CIELabUtil {
     private fun CIELab.toRGB() = this.toXYZ().toRGB()
 
     fun Color.toXYZ(): CIEXYZ {
-        val x = 0.4124564f * r + 0.3575761f * g + 0.1804375f * b
-        val y = 0.2126729f * r + 0.7151522f * g + 0.0721750f * b
-        val z = 0.0193339f * r + 0.1191920f * g + 0.9503041f * b
+        val newR = if (r > 0.04045f)
+            ((r + 0.055f) / 1.055f).powerOf(2.4f)
+        else r / 12.92f
+        val newG = if (g > 0.04045f)
+            ((g + 0.055f) / 1.055f).powerOf(2.4f)
+        else g / 12.92f
+        val newB = if (b > 0.04045f)
+            ((b + 0.055f) / 1.055f).powerOf(2.4f)
+        else b / 12.92f
+
+        val x = 0.4124564f * newR + 0.3575761f * newG + 0.1804375f * newB
+        val y = 0.2126729f * newR + 0.7151522f * newG + 0.0721750f * newB
+        val z = 0.0193339f * newR + 0.1191920f * newG + 0.9503041f * newB
 
         return CIEXYZ(x, y, z, a)
     }
 
     fun CIEXYZ.toRGB(): Color {
-        val r =  3.2404542f * x + -1.5371385f * y + -0.4985314f * z
-        val g = -0.9692660f * x +  1.8760108f * y +  0.0415560f * z
-        val b =  0.0556434f * x + -0.2040259f * y +  1.0572252f * z
+        var r =  3.2404542f * x + -1.5371385f * y + -0.4985314f * z
+        var g = -0.9692660f * x +  1.8760108f * y +  0.0415560f * z
+        var b =  0.0556434f * x + -0.2040259f * y +  1.0572252f * z
+
+        if (r > 0.0031308f)
+            r = 1.055f * r.powerOf(1f / 2.4f) - 0.055f
+        else
+            r *= 12.92f
+        if (g > 0.0031308f)
+            g = 1.055f * r.powerOf(1f / 2.4f) - 0.055f
+        else
+            g *= 12.92f
+        if (b > 0.0031308f)
+            b = 1.055f * r.powerOf(1f / 2.4f) - 0.055f
+        else
+            b *= 12.92f
 
         return Color(r, g, b, alpha)
     }
@@ -93,6 +116,7 @@ object CIELabUtil {
 
     private fun Float.cbrt() = FastMath.pow(this, 1f / 3f)
     private fun Float.cube() = this * this * this
+    private fun Float.powerOf(exp: Float) = FastMath.pow(this, exp)
 }
 
 data class CIEXYZ(var x: Float = 0f, var y: Float = 0f, var z: Float = 0f, val alpha: Float = 1f)

src/net/torvald/terrarum/weather/WeatherMixer.kt

@@ -2,7 +2,7 @@ package net.torvald.terrarum.weather
 
 import com.jme3.math.FastMath
 import net.torvald.JsonFetcher
-import net.torvald.colourutil.CIELchUtil
+import net.torvald.colourutil.CIELChUtil
 import net.torvald.colourutil.ColourUtil
 import net.torvald.random.HQRNG
 import net.torvald.terrarum.Terrarum
@@ -110,7 +110,7 @@ object WeatherMixer {
         val scale = (timeInSec % dataPointDistance).toFloat() / dataPointDistance // [0.0, 1.0]
 
         //val newCol = ColourUtil.getGradient(scale, colourThis, colourNext)
-        val newCol = CIELchUtil.getGradient(scale, colourThis, colourNext)
+        val newCol = CIELChUtil.getGradient(scale, colourThis, colourNext)
 
         /* // very nice monitor code
         // 65 -> 66 | 300 | 19623 | RGB8(255, 0, 255) -[41%]-> RGB8(193, 97, 23) | * `230`40`160`