[M3][Color] Interal changes

PiperOrigin-RevId: 492161895
material-components · Dec 1, 2022 · ef76670 · ef76670
1 parent 4bdfb8b
commit ef76670
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Showing 3 changed files with 12 additions and 8 deletions.
diff --git a/lib/java/com/google/android/material/color/utilities/QuantizerMap.java b/lib/java/com/google/android/material/color/utilities/QuantizerMap.java
@@ -19,7 +19,7 @@
 import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;
 
 import androidx.annotation.RestrictTo;
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.Map;
 
 // TODO(b/254603377): Use copybara to release material color utilities library directly to github.
@@ -34,7 +34,7 @@ public final class QuantizerMap implements Quantizer {
 
  @Override
  public QuantizerResult quantize(int[] pixels, int colorCount) {
- final HashMap<Integer, Integer> pixelByCount = new HashMap<>();
+ final Map<Integer, Integer> pixelByCount = new LinkedHashMap<>();
  for (int pixel : pixels) {
  final Integer currentPixelCount = pixelByCount.get(pixel);
  final int newPixelCount = currentPixelCount == null ? 1 : currentPixelCount + 1;

diff --git a/lib/java/com/google/android/material/color/utilities/QuantizerWsmeans.java b/lib/java/com/google/android/material/color/utilities/QuantizerWsmeans.java
@@ -21,8 +21,9 @@
 
 import androidx.annotation.RestrictTo;
 import java.util.Arrays;
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.Random;
 
 // TODO(b/254603377): Use copybara to release material color utilities library directly to github.
 /**
@@ -75,7 +76,10 @@ public int compareTo(Distance other) {
  */
  public static Map<Integer, Integer> quantize(
  int[] inputPixels, int[] startingClusters, int maxColors) {
- Map<Integer, Integer> pixelToCount = new HashMap<>();
+ // Uses a seeded random number generator to ensure consistent results.
+ Random random = new Random(0x42688);
+
+ Map<Integer, Integer> pixelToCount = new LinkedHashMap<>();
  double[][] points = new double[inputPixels.length][];
  int[] pixels = new int[inputPixels.length];
  PointProvider pointProvider = new PointProviderLab();
@@ -121,7 +125,7 @@ public static Map<Integer, Integer> quantize(
 
  int[] clusterIndices = new int[pointCount];
  for (int i = 0; i < pointCount; i++) {
- clusterIndices[i] = (int) Math.floor(Math.random() * clusterCount);
+ clusterIndices[i] = random.nextInt(clusterCount);
  }
 
  int[][] indexMatrix = new int[clusterCount][];
@@ -215,7 +219,7 @@ public static Map<Integer, Integer> quantize(
  }
  }
 
- Map<Integer, Integer> argbToPopulation = new HashMap<>();
+ Map<Integer, Integer> argbToPopulation = new LinkedHashMap<>();
  for (int i = 0; i < clusterCount; i++) {
  int count = pixelCountSums[i];
  if (count == 0) {

diff --git a/lib/java/com/google/android/material/color/utilities/QuantizerWu.java b/lib/java/com/google/android/material/color/utilities/QuantizerWu.java
@@ -20,7 +20,7 @@
 
 import androidx.annotation.RestrictTo;
 import java.util.ArrayList;
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -57,7 +57,7 @@ public QuantizerResult quantize(int[] pixels, int colorCount) {
  createMoments();
  CreateBoxesResult createBoxesResult = createBoxes(colorCount);
  List<Integer> colors = createResult(createBoxesResult.resultCount);
- HashMap<Integer, Integer> resultMap = new HashMap<>();
+ Map<Integer, Integer> resultMap = new LinkedHashMap<>();
  for (int color : colors) {
  resultMap.put(color, 0);
  }