1 files changed, 29 insertions, 0 deletions
diff --git a/platform_tools/android/apps/skar_java/src/main/java/com/google/skar/PaintUtil.java b/platform_tools/android/apps/skar_java/src/main/java/com/google/skar/PaintUtil.java
new file mode 100644
index 0000000000..75fa86bc27
--- /dev/null
+++ b/platform_tools/android/apps/skar_java/src/main/java/com/google/skar/PaintUtil.java
@@ -0,0 +1,29 @@
+package com.google.skar;
+
+import android.graphics.ColorFilter;
+import android.graphics.ColorMatrix;
+import android.graphics.ColorMatrixColorFilter;
+
+import java.util.Arrays;
+
+public class PaintUtil {
+
+    private static final float MIDDLE_GRAY_GAMMA = 0.466f;
+
+    /**
+     * Returns a ColorFilter that can be used on a Paint to apply color correction effects
+     * as documented by ARCore.
+     *
+     * @param colorCorr output array of getColorCorrection() from ARCore
+     * @return ColorFilter with effects applied
+     */
+    public static ColorFilter createLightCorrectionColorFilter(float[] colorCorr) {
+        float[] colorCorrCopy = Arrays.copyOf(colorCorr, 4);
+        for (int i = 0; i < 3; i++) {
+            colorCorrCopy[i] *= colorCorrCopy[3] / MIDDLE_GRAY_GAMMA;
+        }
+        ColorMatrix m = new ColorMatrix();
+        m.setScale(colorCorrCopy[0], colorCorrCopy[1], colorCorrCopy[2], 1);
+        return new ColorMatrixColorFilter(m);
+    }
+}