Merge "Add luminance condition to validate color contrast." into sc-dev (2ddcaeb4) · Commits · e / os / android_frameworks_base

libs/WindowManager/Shell/src/com/android/wm/shell/startingsurface/SplashscreenContentDrawer.java

+21 −5

Original line number	Diff line number	Diff line
		@@ -435,6 +435,18 @@ public class SplashscreenContentDrawer {
		if (a == b) {
		return true;
		}
		final float lumA = Color.luminance(a);
		final float lumB = Color.luminance(b);
		final float contrastRatio = lumA > lumB
		? (lumA + 0.05f) / (lumB + 0.05f) : (lumB + 0.05f) / (lumA + 0.05f);
		if (DEBUG) {
		Slog.d(TAG, "isRgbSimilarInHsv a: " + Integer.toHexString(a)
		+ " b " + Integer.toHexString(b) + " contrast ratio: " + contrastRatio);
		}
		if (contrastRatio < 2) {
		return true;
		}

		final float[] aHsv = new float[3];
		final float[] bHsv = new float[3];
		Color.colorToHSV(a, aHsv);
		@@ -445,14 +457,18 @@ public class SplashscreenContentDrawer {

		// Calculate the difference between two colors based on the HSV dimensions.
		final float normalizeH = minAngle / 180f;
		final double square = Math.pow(normalizeH, 2)
		+ Math.pow(aHsv[1] - bHsv[1], 2)
		+ Math.pow(aHsv[2] - bHsv[2], 2);
		final double squareH = Math.pow(normalizeH, 2);
		final double squareS = Math.pow(aHsv[1] - bHsv[1], 2);
		final double squareV = Math.pow(aHsv[2] - bHsv[2], 2);
		final double square = squareH + squareS + squareV;
		final double mean = square / 3;
		final double root = Math.sqrt(mean);
		if (DEBUG) {
		Slog.d(TAG, "hsvDiff " + minAngle + " a: " + Integer.toHexString(a)
		+ " b " + Integer.toHexString(b) + " ah " + aHsv[0] + " bh " + bHsv[0]
		Slog.d(TAG, "hsvDiff " + minAngle
		+ " ah " + aHsv[0] + " bh " + bHsv[0]
		+ " as " + aHsv[1] + " bs " + bHsv[1]
		+ " av " + aHsv[2] + " bv " + bHsv[2]
		+ " sqH " + squareH + " sqS " + squareS + " sqV " + squareV
		+ " root " + root);
		}
		return root < 0.1;