Merge changes I080e6cb5,I4c2d76c9,I295ef3a6 into sc-v2-dev

* changes:
  [CP] Adjust chroma/lstar filters for seed colors
  [CP] If there are > 4 colors, maximize difference
  [CP] Use chroma max of 40 at tone 90

packages/SystemUI/monet/src/com/android/systemui/monet/ColorScheme.kt

@@ -37,8 +37,7 @@ const val NEUTRAL2_CHROMA = 8.0f
 
 const val GOOGLE_BLUE = 0xFF1b6ef3.toInt()
 
-const val MIN_CHROMA = 15
+const val MIN_CHROMA = 5
-const val MIN_LSTAR = 10
 
 public class ColorScheme(@ColorInt seed: Int, val darkTheme: Boolean) {
 
@@ -75,7 +74,14 @@ public class ColorScheme(@ColorInt seed: Int, val darkTheme: Boolean) {
         get() = ColorUtils.setAlphaComponent(if (darkTheme) accent1[2] else accent1[6], 0xFF)
 
     init {
-        val seedArgb = if (seed == Color.TRANSPARENT) GOOGLE_BLUE else seed
+        val proposedSeedCam = Cam.fromInt(seed)
+        val seedArgb = if (seed == Color.TRANSPARENT) {
+            GOOGLE_BLUE
+        } else if (proposedSeedCam.chroma < 5) {
+            GOOGLE_BLUE
+        } else {
+            seed
+        }
         val camSeed = Cam.fromInt(seedArgb)
         val hue = camSeed.hue
         val chroma = camSeed.chroma.coerceAtLeast(ACCENT1_CHROMA)
@@ -129,9 +135,7 @@ public class ColorScheme(@ColorInt seed: Int, val darkTheme: Boolean) {
                 val distinctColors = wallpaperColors.mainColors.map {
                     it.toArgb()
                 }.distinct().filter {
-                    val cam = Cam.fromInt(it)
+                    Cam.fromInt(it).chroma >= MIN_CHROMA
-                    val lstar = lstarFromInt(it)
-                    cam.chroma >= MIN_CHROMA && lstar >= MIN_LSTAR
                 }.toList()
 
                 if (distinctColors.isEmpty()) {
@@ -164,30 +168,38 @@ public class ColorScheme(@ColorInt seed: Int, val darkTheme: Boolean) {
                 val cam = it.value
                 val lstar = lstarFromInt(it.key)
                 val proportion = intToHueProportion[it.key]!!
-                cam.chroma >= MIN_CHROMA && lstar >= MIN_LSTAR &&
+                cam.chroma >= MIN_CHROMA &&
                         (totalPopulationMeaningless || proportion > 0.01)
             }
             // Sort the colors by score, from high to low.
-            val seeds = mutableListOf<Int>()
             val intToScoreIntermediate = filteredIntToCam.mapValues {
                 score(it.value, intToHueProportion[it.key]!!)
             }
             val intToScore = intToScoreIntermediate.entries.toMutableList()
             intToScore.sortByDescending { it.value }
 
-            // Go through the colors, from high score to low score. If there isn't already a seed
+            // Go through the colors, from high score to low score.
-            // color with a hue close to color being examined, add the color being examined to the
+            // If the color is distinct in hue from colors picked so far, pick the color.
-            // seed colors.
+            // Iteratively decrease the amount of hue distinctness required, thus ensuring we
+            // maximize difference between colors.
+            val minimumHueDistance = 15
+            val seeds = mutableListOf<Int>()
+            maximizeHueDistance@ for (i in 90 downTo minimumHueDistance step 1) {
+                seeds.clear()
                 for (entry in intToScore) {
                     val int = entry.key
                     val existingSeedNearby = seeds.find {
                         val hueA = intToCam[int]!!.hue
                         val hueB = intToCam[it]!!.hue
-                    hueDiff(hueA, hueB) < 15 } != null
+                        hueDiff(hueA, hueB) < i } != null
                     if (existingSeedNearby) {
                         continue
                     }
                     seeds.add(int)
+                    if (seeds.size >= 4) {
+                        break@maximizeHueDistance
+                    }
+                }
             }
 
             if (seeds.isEmpty()) {

packages/SystemUI/monet/src/com/android/systemui/monet/Shades.java

@@ -53,10 +53,15 @@ public class Shades {
      */
     public static @ColorInt int[] of(float hue, float chroma) {
         int[] shades = new int[12];
-        shades[0] = ColorUtils.CAMToColor(hue, chroma, 99);
+        // At tone 90 and above, blue and yellow hues can reach a much higher chroma.
-        shades[1] = ColorUtils.CAMToColor(hue, chroma, 95);
+        // To preserve a consistent appearance across all hues, use a maximum chroma of 40.
+        shades[0] = ColorUtils.CAMToColor(hue, Math.min(40f, chroma), 99);
+        shades[1] = ColorUtils.CAMToColor(hue, Math.min(40f, chroma), 95);
         for (int i = 2; i < 12; i++) {
             float lStar = (i == 6) ? MIDDLE_LSTAR : 100 - 10 * (i - 1);
+            if (lStar >= 90) {
+                chroma = Math.min(40f, chroma);
+            }
             shades[i] = ColorUtils.CAMToColor(hue, chroma, lStar);
         }
         return shades;