Merge "Make ColorSpace#isSrgb more restrictive" (151b6729) · Commits · e / os / android_frameworks_base

graphics/java/android/graphics/ColorSpace.java

+22 −5

Original line number	Diff line number	Diff line
		@@ -984,11 +984,12 @@ public abstract class ColorSpace {
		* {@link Named#SRGB sRGB} primaries.
		* </li>
		* <li>
		* Its white point is withing 1e-3 of the CIE standard
		* Its white point is within 1e-3 of the CIE standard
		* illuminant {@link #ILLUMINANT_D65 D65}.
		* </li>
		* <li>Its opto-electronic transfer function is not linear.</li>
		* <li>Its electro-optical transfer function is not linear.</li>
		* <li>Its transfer functions yield values within 1e-3 of {@link Named#SRGB}.</li>
		* <li>Its range is \([0..1]\).</li>
		* </ul>
		* <p>This method always returns true for {@link Named#SRGB}.</p>
		@@ -3145,19 +3146,35 @@ public abstract class ColorSpace {
		float max,
		@IntRange(from = MIN_ID, to = MAX_ID) int id) {
		if (id == 0) return true;
		if (!compare(primaries, SRGB_PRIMARIES)) {
		if (!ColorSpace.compare(primaries, SRGB_PRIMARIES)) {
		return false;
		}
		if (!compare(whitePoint, ILLUMINANT_D65)) {
		if (!ColorSpace.compare(whitePoint, ILLUMINANT_D65)) {
		return false;
		}
		if (OETF.applyAsDouble(0.5) < 0.5001) return false;
		if (EOTF.applyAsDouble(0.5) > 0.5001) return false;

		if (min != 0.0f) return false;
		if (max != 1.0f) return false;

		// We would have already returned true if this was SRGB itself, so
		// it is safe to reference it here.
		ColorSpace.Rgb srgb = (ColorSpace.Rgb) get(Named.SRGB);

		for (double x = 0.0; x <= 1.0; x += 1 / 255.0) {
		if (!compare(x, OETF, srgb.mOetf)) return false;
		if (!compare(x, EOTF, srgb.mEotf)) return false;
		}

		return true;
		}

		private static boolean compare(double point, @NonNull DoubleUnaryOperator a,
		@NonNull DoubleUnaryOperator b) {
		double rA = a.applyAsDouble(point);
		double rB = b.applyAsDouble(point);
		return Math.abs(rA - rB) <= 1e-3;
		}

		/**
		* Computes whether the specified CIE xyY or XYZ primaries (with Y set to 1) form
		* a wide color gamut. A color gamut is considered wide if its area is > 90%