- * The Color class provides methods for creating, converting and
+ * manipulating colors. Colors have three different representations:
Color instancesThe section below describe each representation in detail.
+ * + *Color ints are the most common representation of colors on Android and + * have been used since {@link android.os.Build.VERSION_CODES#BASE API level 1}.
+ * + *A color int always defines a color in the {@link ColorSpace.Named#SRGB sRGB} + * color space using 4 components packed in a single 32 bit integer value:
+ * + *| Component | Name | Size | Range | + *
|---|---|---|---|
| A | Alpha | 8 bits | \([0..255]\) |
| R | Red | 8 bits | \([0..255]\) |
| G | Green | 8 bits | \([0..255]\) |
| B | Blue | 8 bits | \([0..255]\) |
The components in this table are listed in encoding order (see below), + * which is why color ints are called ARGB colors.
+ * + *To avoid confusing color ints with arbitrary integer values, it is a
+ * good practice to annotate them with the @ColorInt annotation
+ * found in the Android Support Library.
The four components of a color int are encoded in the following way:
+ *+ * int color = (A & 0xff) << 24 | (R & 0xff) << 16 | (G & 0xff) << 16 | (B & 0xff); + *+ * + *
Because of this encoding, color ints can easily be described as an integer
+ * constant in source. For instance, opaque blue is 0xff0000ff
+ * and yellow is 0xffffff00.
To easily encode color ints, it is recommended to use the static methods + * {@link #argb(int, int, int, int)} and {@link #rgb(int, int, int)}. The second + * method omits the alpha component and assumes the color is opaque (alpha is 255). + * As a convenience this class also offers methods to encode color ints from components + * defined in the \([0..1]\) range: {@link #argb(float, float, float, float)} and + * {@link #rgb(float, float, float)}.
+ * + *Color longs (defined below) can be easily converted to color ints by invoking + * the {@link #toArgb(long)} method. This method performs a color space conversion + * if needed.
+ * + *It is also possible to create a color int by invoking the method {@link #toArgb()} + * on a color instance.
+ * + *The four ARGB components can be individually extracted from a color int + * using the following expressions:
+ *+ * int A = (color >> 24) & 0xff; // or color >>> 24 + * int R = (color >> 16) & 0xff; + * int G = (color >> 8) & 0xff; + * int B = (color ) & 0xff; + *+ * + *
This class offers convenience methods to easily extract these components:
+ *Color longs are a representation introduced in + * {@link android.os.Build.VERSION_CODES#O Android O} to store colors in different + * {@link ColorSpace color spaces}, with more precision than color ints.
+ * + *A color long always defines a color using 4 components packed in a single + * 64 bit long value. One of these components is always alpha while the other + * three components depend on the color space's {@link ColorSpace.Model color model}. + * The most common color model is the {@link ColorSpace.Model#RGB RGB} model in + * which the components represent red, green and blue values.
+ * + *Component ranges: the ranges defined in the tables + * below indicate the ranges that can be encoded in a color long. They do not + * represent the actual ranges as they may differ per color space. For instance, + * the RGB components of a color in the {@link ColorSpace.Named#DISPLAY_P3 Display P3} + * color space use the \([0..1]\) range. Please refer to the documentation of the + * various {@link ColorSpace.Named color spaces} to find their respective ranges.
+ * + *Alpha range: while alpha is encoded in a color long using + * a 10 bit integer (thus using a range of \([0..1023]\)), it is converted to and + * from \([0..1]\) float values when decoding and encoding color longs.
+ * + *sRGB color space: for compatibility reasons and ease of + * use, color longs encoding {@link ColorSpace.Named#SRGB sRGB} colors do not + * use the same encoding as other color longs.
+ * + *| Component | Name | Size | Range | + *
|---|---|---|---|
| {@link ColorSpace.Model#RGB RGB} color model | |||
| R | Red | 16 bits | \([-65504.0, 65504.0]\) |
| G | Green | 16 bits | \([-65504.0, 65504.0]\) |
| B | Blue | 16 bits | \([-65504.0, 65504.0]\) |
| A | Alpha | 10 bits | \([0..1023]\) |
| Color space | 6 bits | \([0..63]\) | |
| {@link ColorSpace.Named#SRGB sRGB} color space | |||
| A | Alpha | 8 bits | \([0..255]\) |
| R | Red | 8 bits | \([0..255]\) |
| G | Green | 8 bits | \([0..255]\) |
| B | Blue | 8 bits | \([0..255]\) |
| X | Unused | 32 bits | \(0\) |
| {@link ColorSpace.Model#XYZ XYZ} color model | |||
| X | X | 16 bits | \([-65504.0, 65504.0]\) |
| Y | Y | 16 bits | \([-65504.0, 65504.0]\) |
| Z | Z | 16 bits | \([-65504.0, 65504.0]\) |
| A | Alpha | 10 bits | \([0..1023]\) |
| Color space | 6 bits | \([0..63]\) | |
| {@link ColorSpace.Model#XYZ Lab} color model | |||
| L | L | 16 bits | \([-65504.0, 65504.0]\) |
| a | a | 16 bits | \([-65504.0, 65504.0]\) |
| b | b | 16 bits | \([-65504.0, 65504.0]\) |
| A | Alpha | 10 bits | \([0..1023]\) |
| Color space | 6 bits | \([0..63]\) | |
| {@link ColorSpace.Model#CMYK CMYK} color model | |||
| Unsupported | |||
The components in this table are listed in encoding order (see below), + * which is why color longs in the RGB model are called RGBA colors (even if + * this doesn't quite hold for the special case of sRGB colors).
+ * + *The color long encoding relies on half-precision float values (fp16). If you + * wish to know more about the limitations of half-precision float values, please + * refer to the documentation of the {@link Half} class.
+ * + *To avoid confusing color longs with arbitrary long values, it is a
+ * good practice to annotate them with the @ColorLong annotation
+ * found in the Android Support Library.
Given the complex nature of color longs, it is strongly encouraged to use + * the various methods provided by this class to encode them.
+ * + *The most flexible way to encode a color long is to use the method + * {@link #pack(float, float, float, float, ColorSpace)}. This method allows you + * to specify three color components (typically RGB), an alpha component and a + * color space. To encode sRGB colors, use {@link #pack(float, float, float)} + * and {@link #pack(float, float, float, float)} which are the + * equivalent of {@link #rgb(int, int, int)} and {@link #argb(int, int, int, int)} + * for color ints. If you simply need to convert a color int into a color long, + * use {@link #pack(int)}.
+ * + *It is also possible to create a color long value by invoking the method + * {@link #pack()} on a color instance.
+ * + *This class offers convenience methods to easily extract the components + * of a color long:
+ *The values returned by these methods depend on the color space encoded + * in the color long. The values are however typically in the \([0..1]\) range + * for RGB colors. Please refer to the documentation of the various + * {@link ColorSpace.Named color spaces} for the exact ranges.
+ * + *Color instances are a representation introduced in + * {@link android.os.Build.VERSION_CODES#O Android O} to store colors in different + * {@link ColorSpace color spaces}, with more precision than both color ints and + * color longs. Color instances also offer the ability to store more than 4 + * components if necessary.
+ * + *Colors instances are immutable and can be created using one of the various
+ * valueOf methods. For instance:
+ * // sRGB
+ * Color opaqueRed = Color.valueOf(0xffff0000); // from a color int
+ * Color translucentRed = Color.valueOf(1.0f, 0.0f, 0.0f, 0.5f);
+ *
+ * // Wide gamut color
+ * {@literal @}ColorLong long p3 = pack(1.0f, 1.0f, 0.0f, 1.0f, colorSpaceP3);
+ * Color opaqueYellow = Color.valueOf(p3); // from a color long
+ *
+ * // CIE L*a*b* color space
+ * ColorSpace lab = ColorSpace.get(ColorSpace.Named.LAB);
+ * Color green = Color.valueOf(100.0f, -128.0f, 128.0f, 1.0f, lab);
+ *
+ *
+ * Color instances can be converted to color ints ({@link #toArgb()}) or + * color longs ({@link #pack()}). They also offer easy access to their various + * components using the following methods:
+ *You can convert colors from one color space to another using
+ * {@link ColorSpace#connect(ColorSpace, ColorSpace)} and its variants. However,
+ * the Color class provides a few convenience methods to simplify
+ * the process. Here is a brief description of some of them:
Please refere to the {@link ColorSpace} documentation for more + * information.
+ * + *The alpha component of a color defines the level of transparency of a + * color. When the alpha component is 0, the color is completely transparent. + * When the alpha is component is 1 (in the \([0..1]\) range) or 255 (in the + * \([0..255]\) range), the color is completely opaque.
+ * + *The color representations described above do not use pre-multiplied
+ * color components (a pre-multiplied color component is a color component
+ * that has been multiplied by the value of the alpha component).
+ * For instance, the color int representation of opaque red is
+ * 0xffff0000. For semi-transparent (50%) red, the
+ * representation becomes 0x80ff0000. The equivalent color
+ * instance representations would be (1.0, 0.0, 0.0, 1.0)
+ * and (1.0, 0.0, 0.0, 0.5).
Returns the value of the red component in the range defined by this + * color's color space (see {@link ColorSpace#getMinValue(int)} and + * {@link ColorSpace#getMaxValue(int)}).
+ * + *If this color's color model is not {@link ColorSpace.Model#RGB RGB},
+ * calling this method is equivalent to getComponent(0).
Returns the value of the green component in the range defined by this + * color's color space (see {@link ColorSpace#getMinValue(int)} and + * {@link ColorSpace#getMaxValue(int)}).
+ * + *If this color's color model is not {@link ColorSpace.Model#RGB RGB},
+ * calling this method is equivalent to getComponent(1).
Returns the value of the blue component in the range defined by this + * color's color space (see {@link ColorSpace#getMinValue(int)} and + * {@link ColorSpace#getMaxValue(int)}).
+ * + *If this color's color model is not {@link ColorSpace.Model#RGB RGB},
+ * calling this method is equivalent to getComponent(2).
getComponent(getComponentCount()).
+ *
+ * @see #red()
+ * @see #green()
+ * @see #blue()
+ * @see #getComponents()
+ * @see #getComponent(int)
+ */
+ public float alpha() {
+ return mComponents[mComponents.length - 1];
+ }
+
+ /**
+ * Returns this color's components as a new array. The last element of the
+ * array is always the alpha component.
+ *
+ * @return A new, non-null array whose size is equal to {@link #getComponentCount()}
+ *
+ * @see #getComponent(int)
+ */
+ @NonNull
+ @Size(min = 4, max = 5)
+ public float[] getComponents() {
+ return Arrays.copyOf(mComponents, mColorSpace.getComponentCount() + 1);
+ }
+
+ /**
+ * Returns the value of the specified component in the range defined by + * this color's color space (see {@link ColorSpace#getMinValue(int)} and + * {@link ColorSpace#getMaxValue(int)}).
+ * + *If the requested component index is {@link #getComponentCount()}, + * this method returns the alpha component, always in the range + * \([0..1\).
+ * + * @see #getComponents() + * + * @throws ArrayIndexOutOfBoundsException If the specified component index + * is < 0 or >= {@link #getComponentCount()} + */ + public float getComponent(@IntRange(from = 0, to = 4) int component) { + return mComponents[component]; + } + + /** + *Returns the relative luminance of this color.
+ * + *Based on the formula for relative luminance defined in WCAG 2.0, + * W3C Recommendation 11 December 2008.
+ * + * @return A value between 0 (darkest black) and 1 (lightest white) + * + * @throws IllegalArgumentException If the this color's color space + * does not use the {@link ColorSpace.Model#RGB RGB} color model + */ + public float luminance() { + if (mColorSpace.getModel() != ColorSpace.Model.RGB) { + throw new IllegalArgumentException("The specified color must be encoded in an RGB " + + "color space. The supplied color space is " + mColorSpace.getModel()); + } + + DoubleUnaryOperator eotf = ((ColorSpace.Rgb) mColorSpace).getEotf(); + double r = eotf.applyAsDouble(mComponents[0]); + double g = eotf.applyAsDouble(mComponents[1]); + double b = eotf.applyAsDouble(mComponents[2]); + + return saturate((float) ((0.2126 * r) + (0.7152 * g) + (0.0722 * b))); + } + + @Override + public boolean equals(Object o) { + if (this == o) return true; + if (o == null || getClass() != o.getClass()) return false; + + Color color = (Color) o; + + //noinspection SimplifiableIfStatement + if (!Arrays.equals(mComponents, color.mComponents)) return false; + return mColorSpace.equals(color.mColorSpace); + } + + @Override + public int hashCode() { + int result = Arrays.hashCode(mComponents); + result = 31 * result + mColorSpace.hashCode(); + return result; + } + + /** + *Returns a string representation of the object. This method returns + * a string equal to the value of:
+ * + *
+ * "Color(" + r + ", " + g + ", " + b + ", " + a +
+ * ", " + getColorSpace().getName + ')'
+ *
+ *
+ * For instance, the string representation of opaque black in the sRGB + * color space is equal to the following value:
+ * + *+ * Color(0.0, 0.0, 0.0, 1.0, sRGB IEC61966-2.1) + *+ * + * @return A non-null string representation of the object + */ + @Override + @NonNull + public String toString() { + StringBuilder b = new StringBuilder("Color("); + for (float c : mComponents) { + b.append(c).append(", "); + } + b.append(mColorSpace.getName()); + b.append(')'); + return b.toString(); + } + + /** + * Returns the color space encoded in the specified color long. + * + * @param color The color long whose color space to extract + * @return A non-null color space instance. If the color long encodes + * an unknown or invalid color space, the {@link ColorSpace.Named#SRGB sRGB} + * color space is returned + * + * @see #red(long) + * @see #green(long) + * @see #blue(long) + * @see #alpha(long) + */ + @NonNull + public static ColorSpace colorSpace(@ColorLong long color) { + return ColorSpace.get((int) (color & 0x3fL)); + } + + /** + * Returns the red component encoded in the specified color long. + * The range of the returned value depends on the color space + * associated with the specified color. The color space can be + * queried by calling {@link #colorSpace(long)}. + * + * @param color The color long whose red channel to extract + * @return A float value with a range defined by the specified color's + * color space + * + * @see #colorSpace(long) + * @see #green(long) + * @see #blue(long) + * @see #alpha(long) + */ + public static float red(@ColorLong long color) { + if ((color & 0x3fL) == 0L) return ((color >> 48) & 0xff) / 255.0f; + return Half.toFloat((short) ((color >> 48) & 0xffff)); + } + + /** + * Returns the green component encoded in the specified color long. + * The range of the returned value depends on the color space + * associated with the specified color. The color space can be + * queried by calling {@link #colorSpace(long)}. + * + * @param color The color long whose green channel to extract + * @return A float value with a range defined by the specified color's + * color space + * + * @see #colorSpace(long) + * @see #red(long) + * @see #blue(long) + * @see #alpha(long) + */ + public static float green(@ColorLong long color) { + if ((color & 0x3fL) == 0L) return ((color >> 40) & 0xff) / 255.0f; + return Half.toFloat((short) ((color >> 32) & 0xffff)); + } + + /** + * Returns the blue component encoded in the specified color long. + * The range of the returned value depends on the color space + * associated with the specified color. The color space can be + * queried by calling {@link #colorSpace(long)}. + * + * @param color The color long whose blue channel to extract + * @return A float value with a range defined by the specified color's + * color space + * + * @see #colorSpace(long) + * @see #red(long) + * @see #green(long) + * @see #alpha(long) + */ + public static float blue(@ColorLong long color) { + if ((color & 0x3fL) == 0L) return ((color >> 32) & 0xff) / 255.0f; + return Half.toFloat((short) ((color >> 16) & 0xffff)); + } + + /** + * Returns the alpha component encoded in the specified color long. + * The returned value is always in the range \([0..1]\). + * + * @param color The color long whose blue channel to extract + * @return A float value in the range \([0..1]\) + * + * @see #colorSpace(long) + * @see #red(long) + * @see #green(long) + * @see #blue(long) + */ + public static float alpha(@ColorLong long color) { + if ((color & 0x3fL) == 0L) return ((color >> 56) & 0xff) / 255.0f; + return ((color >> 6) & 0x3ff) / 1023.0f; + } + + /** + * Indicates whether the specified color is in the + * {@link ColorSpace.Named#SRGB sRGB} color space. + * + * @param color The color to test + * @return True if the color is in the sRGB color space, false otherwise + * + * @see #isInColorSpace(long, ColorSpace) + * @see #isWideGamut(long) + */ + public static boolean isSrgb(@ColorLong long color) { + return colorSpace(color).isSrgb(); + } + + /** + * Indicates whether the specified color is in a wide-gamut color space. + * See {@link ColorSpace#isWideGamut()} for a definition of a wide-gamut + * color space. + * + * @param color The color to test + * @return True if the color is in a wide-gamut color space, false otherwise + * + * @see #isInColorSpace(long, ColorSpace) + * @see #isSrgb(long) + * @see ColorSpace#isWideGamut() + */ + public static boolean isWideGamut(@ColorLong long color) { + return colorSpace(color).isWideGamut(); + } + + /** + * Indicates whether the specified color is in the specified color space. + * + * @param color The color to test + * @param colorSpace The color space to test against + * @return True if the color is in the specified color space, false otherwise + * + * @see #isSrgb(long) + * @see #isWideGamut(long) + */ + public static boolean isInColorSpace(@ColorLong long color, @NonNull ColorSpace colorSpace) { + return (int) (color & 0x3fL) == colorSpace.getId(); + } + + /** + * Converts the specified color long to an ARGB color int. A color int is + * always in the {@link ColorSpace.Named#SRGB sRGB} color space. This implies + * a color space conversion is applied if needed. + * + * @return An ARGB color in the sRGB color space + */ + @ColorInt + public static int toArgb(@ColorLong long color) { + if ((color & 0x3fL) == 0L) return (int) (color >> 32); + + float r = red(color); + float g = green(color); + float b = blue(color); + float a = alpha(color); + + // The transformation saturates the output + float[] c = ColorSpace.connect(colorSpace(color)).transform(r, g, b); + + return ((int) (a * 255.0f + 0.5f) << 24) | + ((int) (c[0] * 255.0f + 0.5f) << 16) | + ((int) (c[1] * 255.0f + 0.5f) << 8) | + (int) (c[2] * 255.0f + 0.5f); + } + + /** + * Creates a new
Color instance from an ARGB color int.
+ * The resulting color is in the {@link ColorSpace.Named#SRGB sRGB}
+ * color space.
+ *
+ * @param color The ARGB color int to create a Color from
+ * @return A non-null instance of {@link Color}
+ */
+ @NonNull
+ public static Color valueOf(@ColorInt int color) {
+ float r = ((color >> 16) & 0xff) / 255.0f;
+ float g = ((color >> 8) & 0xff) / 255.0f;
+ float b = ((color ) & 0xff) / 255.0f;
+ float a = ((color >> 24) & 0xff) / 255.0f;
+ return new Color(r, g, b, a, ColorSpace.get(ColorSpace.Named.SRGB));
+ }
+
+ /**
+ * Creates a new Color instance from a color long.
+ * The resulting color is in the same color space as the specified color long.
+ *
+ * @param color The color long to create a Color from
+ * @return A non-null instance of {@link Color}
+ */
+ @NonNull
+ public static Color valueOf(@ColorLong long color) {
+ return new Color(red(color), green(color), blue(color), alpha(color), colorSpace(color));
+ }
+
+ /**
+ * Creates a new opaque Color in the {@link ColorSpace.Named#SRGB sRGB}
+ * color space with the specified red, green and blue component values. The component
+ * values must be in the range \([0..1]\).
+ *
+ * @param r The red component of the opaque sRGB color to create, in \([0..1]\)
+ * @param g The green component of the opaque sRGB color to create, in \([0..1]\)
+ * @param b The blue component of the opaque sRGB color to create, in \([0..1]\)
+ * @return A non-null instance of {@link Color}
+ */
+ @NonNull
+ public static Color valueOf(float r, float g, float b) {
+ return new Color(r, g, b, 1.0f);
+ }
+
+ /**
+ * Creates a new Color in the {@link ColorSpace.Named#SRGB sRGB}
+ * color space with the specified red, green, blue and alpha component values.
+ * The component values must be in the range \([0..1]\).
+ *
+ * @param r The red component of the sRGB color to create, in \([0..1]\)
+ * @param g The green component of the sRGB color to create, in \([0..1]\)
+ * @param b The blue component of the sRGB color to create, in \([0..1]\)
+ * @param a The alpha component of the sRGB color to create, in \([0..1]\)
+ * @return A non-null instance of {@link Color}
+ */
+ @NonNull
+ public static Color valueOf(float r, float g, float b, float a) {
+ return new Color(saturate(r), saturate(g), saturate(b), saturate(a));
+ }
+
+ /**
+ * Creates a new Color in the specified color space with the
+ * specified red, green, blue and alpha component values. The range of the
+ * components is defined by {@link ColorSpace#getMinValue(int)} and
+ * {@link ColorSpace#getMaxValue(int)}. The values passed to this method
+ * must be in the proper range.
+ *
+ * @param r The red component of the color to create
+ * @param g The green component of the color to create
+ * @param b The blue component of the color to create
+ * @param a The alpha component of the color to create, in \([0..1]\)
+ * @param colorSpace The color space of the color to create
+ * @return A non-null instance of {@link Color}
+ *
+ * @throws IllegalArgumentException If the specified color space uses a
+ * color model with more than 3 components
+ */
+ @NonNull
+ public static Color valueOf(float r, float g, float b, float a, @NonNull ColorSpace colorSpace) {
+ if (colorSpace.getComponentCount() > 3) {
+ throw new IllegalArgumentException("The specified color space must use a color model " +
+ "with at most 3 color components");
+ }
+ return new Color(r, g, b, a, colorSpace);
+ }
+
+ /**
+ * Creates a new Color in the specified color space with the
+ * specified component values. The range of the components is defined by
+ * {@link ColorSpace#getMinValue(int)} and {@link ColorSpace#getMaxValue(int)}.
+ * The values passed to this method must be in the proper range. The alpha
+ * component is always in the range \([0..1]\).
The length of the array of components must be at least
+ * {@link ColorSpace#getComponentCount()} + 1. The component at index
+ * {@link ColorSpace#getComponentCount()} is always alpha.
Packs the 3 component color defined by the specified red, green, blue and + * alpha component values into a color long in the specified color space. See the + * documentation of this class for a description of the color long format.
+ * + *The red, green and blue components must be in the range defined by the + * specified color space. See {@link ColorSpace#getMinValue(int)} and + * {@link ColorSpace#getMaxValue(int)}.
+ * + * @param red The red component of the color to create + * @param green The green component of the color to create + * @param blue The blue component of the color to create + * @param alpha The alpha component of the color to create, in \([0..1]\) + * + * @return A color long + * + * @throws IllegalArgumentException If the color space's id is {@link ColorSpace#MIN_ID} + * or if the color space's color model has more than 3 components + */ + @ColorLong + public static long pack(float red, float green, float blue, float alpha, + @NonNull ColorSpace colorSpace) { + if (colorSpace.isSrgb()) { + int argb = + ((int) (alpha * 255.0f + 0.5f) << 24) | + ((int) (red * 255.0f + 0.5f) << 16) | + ((int) (green * 255.0f + 0.5f) << 8) | + (int) (blue * 255.0f + 0.5f); + return (argb & 0xffffffffL) << 32; + } + + int id = colorSpace.getId(); + if (id == ColorSpace.MIN_ID) { + throw new IllegalArgumentException( + "Unknown color space, please use a color space returned by ColorSpace.get()"); + } + if (colorSpace.getComponentCount() > 3) { + throw new IllegalArgumentException( + "The color space must use a color model with at most 3 components"); + } + + @HalfFloat short r = Half.valueOf(red); + @HalfFloat short g = Half.valueOf(green); + @HalfFloat short b = Half.valueOf(blue); + + int a = (int) (Math.max(0.0f, Math.min(alpha, 1.0f)) * 1023.0f + 0.5f); + + // Suppress sign extension + return (r & 0xffffL) << 48 | + (g & 0xffffL) << 32 | + (b & 0xffffL) << 16 | + (a & 0x3ffL ) << 6 | + id & 0x3fL; + } + + /** + * Converts the specified ARGB color int from the {@link ColorSpace.Named#SRGB sRGB} + * color space into the specified destination color space. The resulting color is + * returned as a color long. See the documentation of this class for a description + * of the color long format. + * + * @param color The sRGB color int to convert + * @param colorSpace The destination color space + * @return A color long in the destination color space + */ + @ColorLong + public static long convert(@ColorInt int color, @NonNull ColorSpace colorSpace) { + float r = ((color >> 16) & 0xff) / 255.0f; + float g = ((color >> 8) & 0xff) / 255.0f; + float b = ((color ) & 0xff) / 255.0f; + float a = ((color >> 24) & 0xff) / 255.0f; + ColorSpace source = ColorSpace.get(ColorSpace.Named.SRGB); + return convert(r, g, b, a, source, colorSpace); + } + + /** + *Converts the specified color long from its color space into the specified + * destination color space. The resulting color is returned as a color long. See + * the documentation of this class for a description of the color long format.
+ * + *When converting several colors in a row, it is recommended to use + * {@link #convert(long, ColorSpace.Connector)} instead to + * avoid the creation of a {@link ColorSpace.Connector} on every invocation.
+ * + * @param color The color long to convert + * @param colorSpace The destination color space + * @return A color long in the destination color space + */ + @ColorLong + public static long convert(@ColorLong long color, @NonNull ColorSpace colorSpace) { + float r = red(color); + float g = green(color); + float b = blue(color); + float a = alpha(color); + ColorSpace source = colorSpace(color); + return convert(r, g, b, a, source, colorSpace); + } + + /** + *Converts the specified 3 component color from the source color space to the + * destination color space. The resulting color is returned as a color long. See + * the documentation of this class for a description of the color long format.
+ * + *When converting multiple colors in a row, it is recommended to use + * {@link #convert(float, float, float, float, ColorSpace.Connector)} instead to + * avoid the creation of a {@link ColorSpace.Connector} on every invocation.
+ * + *The red, green and blue components must be in the range defined by the + * specified color space. See {@link ColorSpace#getMinValue(int)} and + * {@link ColorSpace#getMaxValue(int)}.
+ * + * @param r The red component of the color to convert + * @param g The green component of the color to convert + * @param b The blue component of the color to convert + * @param a The alpha component of the color to convert, in \([0..1]\) + * @param source The source color space, cannot be null + * @param destination The destination color space, cannot be null + * @return A color long in the destination color space + * + * @see #convert(float, float, float, float, ColorSpace.Connector) + */ + @ColorLong + public static long convert(float r, float g, float b, float a, + @NonNull ColorSpace source, @NonNull ColorSpace destination) { + float[] c = ColorSpace.connect(source, destination).transform(r, g, b); + return pack(c[0], c[1], c[2], a, destination); + } + + /** + *Converts the specified color long from a color space to another using the + * specified color space {@link ColorSpace.Connector connector}. The resulting + * color is returned as a color long. See the documentation of this class for a + * description of the color long format.
+ * + *When converting several colors in a row, this method is preferable to + * {@link #convert(long, ColorSpace)} as it prevents a new connector from being + * created on every invocation.
+ * + *The connector's source color space should match the color long's + * color space.
+ * + * @param color The color long to convert + * @param connector A color space connector, cannot be null + * @return A color long in the destination color space of the connector + */ + @ColorLong + public static long convert(@ColorLong long color, @NonNull ColorSpace.Connector connector) { + float r = red(color); + float g = green(color); + float b = blue(color); + float a = alpha(color); + return convert(r, g, b, a, connector); + } + + /** + *Converts the specified 3 component color from a color space to another using + * the specified color space {@link ColorSpace.Connector connector}. The resulting + * color is returned as a color long. See the documentation of this class for a + * description of the color long format.
+ * + *When converting several colors in a row, this method is preferable to + * {@link #convert(float, float, float, float, ColorSpace, ColorSpace)} as + * it prevents a new connector from being created on every invocation.
+ * + *The red, green and blue components must be in the range defined by the + * source color space of the connector. See {@link ColorSpace#getMinValue(int)} + * and {@link ColorSpace#getMaxValue(int)}.
+ * + * @param r The red component of the color to convert + * @param g The green component of the color to convert + * @param b The blue component of the color to convert + * @param a The alpha component of the color to convert, in \([0..1]\) + * @param connector A color space connector, cannot be null + * @return A color long in the destination color space of the connector + * + * @see #convert(float, float, float, float, ColorSpace, ColorSpace) + */ + @ColorLong + public static long convert(float r, float g, float b, float a, + @NonNull ColorSpace.Connector connector) { + float[] c = connector.transform(r, g, b); + return pack(c[0], c[1], c[2], a, connector.getDestination()); + } + + /** + *Returns the relative luminance of a color.
+ * + *Based on the formula for relative luminance defined in WCAG 2.0, + * W3C Recommendation 11 December 2008.
+ * + * @return A value between 0 (darkest black) and 1 (lightest white) + * + * @throws IllegalArgumentException If the specified color's color space + * does not use the {@link ColorSpace.Model#RGB RGB} color model + */ + public static float luminance(@ColorLong long color) { + ColorSpace colorSpace = colorSpace(color); + if (colorSpace.getModel() != ColorSpace.Model.RGB) { + throw new IllegalArgumentException("The specified color must be encoded in an RGB " + + "color space. The supplied color space is " + colorSpace.getModel()); + } + + DoubleUnaryOperator eotf = ((ColorSpace.Rgb) colorSpace).getEotf(); + double r = eotf.applyAsDouble(red(color)); + double g = eotf.applyAsDouble(green(color)); + double b = eotf.applyAsDouble(blue(color)); + + return saturate((float) ((0.2126 * r) + (0.7152 * g) + (0.0722 * b))); + } + + private static float saturate(float v) { + return v <= 0.0f ? 0.0f : (v >= 1.0f ? 1.0f : v); + } + /** * Return the alpha component of a color int. This is the same as saying * color >>> 24 */ + @IntRange(from = 0, to = 255) public static int alpha(int color) { return color >>> 24; } @@ -63,6 +1209,7 @@ public class Color { * Return the red component of a color int. This is the same as saying * (color >> 16) & 0xFF */ + @IntRange(from = 0, to = 255) public static int red(int color) { return (color >> 16) & 0xFF; } @@ -71,6 +1218,7 @@ public class Color { * Return the green component of a color int. This is the same as saying * (color >> 8) & 0xFF */ + @IntRange(from = 0, to = 255) public static int green(int color) { return (color >> 8) & 0xFF; } @@ -79,40 +1227,85 @@ public class Color { * Return the blue component of a color int. This is the same as saying * color & 0xFF */ + @IntRange(from = 0, to = 255) public static int blue(int color) { return color & 0xFF; } /** * Return a color-int from red, green, blue components. - * The alpha component is implicity 255 (fully opaque). - * These component values should be [0..255], but there is no + * The alpha component is implicitly 255 (fully opaque). + * These component values should be \([0..255]\), but there is no * range check performed, so if they are out of range, the * returned color is undefined. - * @param red Red component [0..255] of the color - * @param green Green component [0..255] of the color - * @param blue Blue component [0..255] of the color + * + * @param red Red component \([0..255]\) of the color + * @param green Green component \([0..255]\) of the color + * @param blue Blue component \([0..255]\) of the color */ @ColorInt - public static int rgb(int red, int green, int blue) { + public static int rgb( + @IntRange(from = 0, to = 255) int red, + @IntRange(from = 0, to = 255) int green, + @IntRange(from = 0, to = 255) int blue) { return 0xff000000 | (red << 16) | (green << 8) | blue; } /** - * Return a color-int from alpha, red, green, blue components. - * These component values should be [0..255], but there is no - * range check performed, so if they are out of range, the + * Return a color-int from red, green, blue float components + * in the range \([0..1]\). The alpha component is implicitly + * 1.0 (fully opaque). If the components are out of range, the * returned color is undefined. - * @param alpha Alpha component [0..255] of the color - * @param red Red component [0..255] of the color - * @param green Green component [0..255] of the color - * @param blue Blue component [0..255] of the color + * + * @param red Red component \([0..1]\) of the color + * @param green Green component \([0..1]\) of the color + * @param blue Blue component \([0..1]\) of the color */ @ColorInt - public static int argb(int alpha, int red, int green, int blue) { + public static int rgb(float red, float green, float blue) { + return 0xff000000 | + ((int) (red * 255.0f + 0.5f) << 16) | + ((int) (green * 255.0f + 0.5f) << 8) | + (int) (blue * 255.0f + 0.5f); + } + + /** + * Return a color-int from alpha, red, green, blue components. + * These component values should be \([0..255]\), but there is no + * range check performed, so if they are out of range, the + * returned color is undefined. + * @param alpha Alpha component \([0..255]\) of the color + * @param red Red component \([0..255]\) of the color + * @param green Green component \([0..255]\) of the color + * @param blue Blue component \([0..255]\) of the color + */ + @ColorInt + public static int argb( + @IntRange(from = 0, to = 255) int alpha, + @IntRange(from = 0, to = 255) int red, + @IntRange(from = 0, to = 255) int green, + @IntRange(from = 0, to = 255) int blue) { return (alpha << 24) | (red << 16) | (green << 8) | blue; } + /** + * Return a color-int from alpha, red, green, blue float components + * in the range \([0..1]\). If the components are out of range, the + * returned color is undefined. + * + * @param alpha Alpha component \([0..1]\) of the color + * @param red Red component \([0..1]\) of the color + * @param green Green component \([0..1]\) of the color + * @param blue Blue component \([0..1]\) of the color + */ + @ColorInt + public static int argb(float alpha, float red, float green, float blue) { + return ((int) (alpha * 255.0f + 0.5f) << 24) | + ((int) (red * 255.0f + 0.5f) << 16) | + ((int) (green * 255.0f + 0.5f) << 8) | + (int) (blue * 255.0f + 0.5f); + } + /** * Returns the relative luminance of a color. *@@ -124,23 +1317,31 @@ public class Color { public static float luminance(@ColorInt int color) { ColorSpace.Rgb cs = (ColorSpace.Rgb) ColorSpace.get(ColorSpace.Named.SRGB); DoubleUnaryOperator eotf = cs.getEotf(); - double red = eotf.applyAsDouble(Color.red(color) / 255.0); - double green = eotf.applyAsDouble(Color.green(color) / 255.0); - double blue = eotf.applyAsDouble(Color.blue(color) / 255.0); - return (float) ((0.2126 * red) + (0.7152 * green) + (0.0722 * blue)); + + double r = eotf.applyAsDouble(red(color) / 255.0); + double g = eotf.applyAsDouble(green(color) / 255.0); + double b = eotf.applyAsDouble(blue(color) / 255.0); + + return (float) ((0.2126 * r) + (0.7152 * g) + (0.0722 * b)); } /** - * Parse the color string, and return the corresponding color-int. + *
Parse the color string, and return the corresponding color-int. * If the string cannot be parsed, throws an IllegalArgumentException - * exception. Supported formats are: - * #RRGGBB - * #AARRGGBB - * or one of the following names: - * 'red', 'blue', 'green', 'black', 'white', 'gray', 'cyan', 'magenta', - * 'yellow', 'lightgray', 'darkgray', 'grey', 'lightgrey', 'darkgrey', - * 'aqua', 'fuchsia', 'lime', 'maroon', 'navy', 'olive', 'purple', - * 'silver', 'teal'. + * exception. Supported formats are: + * + *#RRGGBB#AARRGGBBThe following names are also accepted: red, blue,
+ * green, black, white, gray,
+ * cyan, magenta, yellow, lightgray,
+ * darkgray, grey, lightgrey, darkgrey,
+ * aqua, fuchsia, lime, maroon,
+ * navy, olive, purple, silver,
+ * and teal.
hsv[0] is Hue \([0..360[\)hsv[1] is Saturation \([0...1]\)hsv[2] is Value \([0...1]\)hsv[0] is Hue \([0..360[\)hsv[1] is Saturation \([0...1]\)hsv[2] is Value \([0...1]\)hsv[0] is Hue \([0..360[\)hsv[1] is Saturation \([0...1]\)hsv[2] is Value \([0...1]\)hsv[0] is Hue \([0..360[\)hsv[1] is Saturation \([0...1]\)hsv[2] is Value \([0...1]\)To visualize and debug color spaces, you can call {@link #createRenderer()}. * The {@link Renderer} created by calling this method can be used to compare - * color spaces and locate specific colors on a CIE 1931 chromaticity diagram.
+ * color spaces and locate specific colors on a CIE 1931 or CIE 1976 UCS + * chromaticity diagram. * *The following code snippet shows how to render a bitmap that compares * the color gamuts and white points of {@link Named#DCI_P3} and @@ -155,6 +157,7 @@ import java.util.function.DoubleUnaryOperator; * @see Adaptation * @see Renderer */ +@AnyThread @SuppressWarnings("StaticInitializerReferencesSubClass") public abstract class ColorSpace { /** @@ -216,7 +219,7 @@ public abstract class ColorSpace { * * @see #getId() */ - public static final int MAX_ID = 64; // Do not change, used to encode in longs + public static final int MAX_ID = 63; // Do not change, used to encode in longs private static final float[] SRGB_PRIMARIES = { 0.640f, 0.330f, 0.300f, 0.600f, 0.150f, 0.060f }; private static final float[] NTSC_1953_PRIMARIES = { 0.67f, 0.33f, 0.21f, 0.71f, 0.14f, 0.08f }; @@ -341,11 +344,11 @@ public abstract class ColorSpace { * \end{equation}\) * * - *
*
- *
*
- *
The specified array's length must be at least equal to * to the number of color components as returned by * {@link Model#getComponentCount()}, and its first 3 values must * be the XYZ components to convert from.
@@ -1125,6 +1128,7 @@ public abstract class ColorSpace { * @return A string representation of the object */ @Override + @NonNull public String toString() { return mName + " (id=" + mId + ", model=" + mModel + ")"; } @@ -1403,7 +1407,7 @@ public abstract class ColorSpace { ILLUMINANT_D65, x -> absRcpResponse(x, 2.4, 1 / 1.055, 0.055 / 1.055, 1 / 12.92, 0.04045), x -> absResponse(x, 2.4, 1 / 1.055, 0.055 / 1.055, 1 / 12.92, 0.04045), - -0.5f, 7.5f, + -0.799f, 2.399f, Named.EXTENDED_SRGB.ordinal() ); sNamedColorSpaces[Named.LINEAR_EXTENDED_SRGB.ordinal()] = new ColorSpace.Rgb( @@ -1412,7 +1416,7 @@ public abstract class ColorSpace { ILLUMINANT_D65, DoubleUnaryOperator.identity(), DoubleUnaryOperator.identity(), - -0.5f, 7.5f, + -0.5f, 7.499f, Named.LINEAR_EXTENDED_SRGB.ordinal() ); sNamedColorSpaces[Named.BT709.ordinal()] = new ColorSpace.Rgb( @@ -1437,8 +1441,8 @@ public abstract class ColorSpace { "SMPTE RP 431-2-2007 DCI (P3)", new float[] { 0.680f, 0.320f, 0.265f, 0.690f, 0.150f, 0.060f }, new float[] { 0.314f, 0.351f }, - x -> Math.pow(x, 1 / 2.6), - x -> Math.pow(x, 2.6), + x -> Math.pow(x < 0.0f ? 0.0f : x, 1 / 2.6), + x -> Math.pow(x < 0.0f ? 0.0f : x, 2.6), 0.0f, 1.0f, Named.DCI_P3.ordinal() ); @@ -1473,8 +1477,8 @@ public abstract class ColorSpace { "Adobe RGB (1998)", new float[] { 0.64f, 0.33f, 0.21f, 0.71f, 0.15f, 0.06f }, ILLUMINANT_D65, - x -> Math.pow(x, 1 / 2.2), - x -> Math.pow(x, 2.2), + x -> Math.pow(x < 0.0f ? 0.0f : x, 1 / 2.2), + x -> Math.pow(x < 0.0f ? 0.0f : x, 2.2), 0.0f, 1.0f, Named.ADOBE_RGB.ordinal() ); @@ -1720,6 +1724,7 @@ public abstract class ColorSpace { /** * Implementation of the CIE XYZ color space. Assumes the white point is D50. */ + @AnyThread private static final class Xyz extends ColorSpace { private Xyz(@NonNull String name, @IntRange(from = MIN_ID, to = MAX_ID) int id) { super(name, Model.XYZ, id); @@ -1765,6 +1770,7 @@ public abstract class ColorSpace { * Implementation of the CIE L*a*b* color space. Its PCS is CIE XYZ * with a white point of D50. */ + @AnyThread private static final class Lab extends ColorSpace { private static final float A = 216.0f / 24389.0f; private static final float B = 841.0f / 108.0f; @@ -1949,6 +1955,7 @@ public abstract class ColorSpace { *To learn more about the white point adaptation process, refer to the * documentation of {@link Adaptation}.
*/ + @AnyThread public static class Rgb extends ColorSpace { @NonNull private final float[] mWhitePoint; @NonNull private final float[] mPrimaries; @@ -2337,7 +2344,7 @@ public abstract class ColorSpace { * to "gamma space" (gamma encoded). The terms gamma space and gamma encoded * are frequently used because many OETFs can be closely approximated using * a simple power function of the form \(x^{\frac{1}{\gamma}}\) (the - * approximation of the {@link Named#SRGB sRGB} EOTF uses \(\gamma=2.2\) + * approximation of the {@link Named#SRGB sRGB} OETF uses \(\gamma=2.2\) * for instance). * * @return A transfer function that converts from linear space to "gamma space" @@ -2346,7 +2353,7 @@ public abstract class ColorSpace { */ @NonNull public DoubleUnaryOperator getOetf() { - return mOetf; + return mClampedOetf; } /** @@ -2369,7 +2376,7 @@ public abstract class ColorSpace { */ @NonNull public DoubleUnaryOperator getEotf() { - return mEotf; + return mClampedEotf; } @Override @@ -2924,6 +2931,7 @@ public abstract class ColorSpace { * @see ColorSpace#connect(ColorSpace, RenderIntent) * @see ColorSpace#connect(ColorSpace) */ + @AnyThread public static class Connector { @NonNull private final ColorSpace mSource; @NonNull private final ColorSpace mDestination;