Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge changes from topic "themesMay2322" into tm-dev

Browse Source 
* changes:
  Update ColorScheme.toString() formatting
  Match latest variant spec; update hue rotation logic
  Match Android's colors to design intent
This commit is contained in:
James O'Leary
2022-05-27 16:40:18 +00:00
committed by Android (Google) Code Review
parent 999a0666ac c4e3d76a03
commit f5fff77bf8
7 changed files with 956 additions and 80 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
core/java/com/android/internal/graphics/cam/Cam.java
View File

@@ -386,6 +386,13 @@ public class Cam {
// Yellows are very chromatic at L = 100, and blues are very chromatic at L = 0. All the
// other hues are white at L = 100, and black at L = 0. To preserve consistency for users of
// this system, it is better to simply return white at L* > 99, and black and L* < 0.
if (frame == Frame.DEFAULT) {
// If the viewing conditions are the same as the default sRGB-like viewing conditions,
// skip to using HctSolver: it uses geometrical insights to find the closest in-gamut
// match to hue/chroma/lstar.
return HctSolver.solveToInt(hue, chroma, lstar);
}
if (chroma < 1.0 || Math.round(lstar) <= 0.0 || Math.round(lstar) >= 100.0) {
return CamUtils.intFromLstar(lstar);
}

157
core/java/com/android/internal/graphics/cam/CamUtils.java
View File

@@ -73,11 +73,123 @@ public final class CamUtils {
// used. It was derived using Schlomer's technique of transforming the xyY
// primaries to XYZ, then applying a correction to ensure mapping from sRGB
// 1, 1, 1 to the reference white point, D65.
static final float[][] SRGB_TO_XYZ = {
{0.41233895f, 0.35762064f, 0.18051042f},
{0.2126f, 0.7152f, 0.0722f},
{0.01932141f, 0.11916382f, 0.95034478f}
};
static final double[][] SRGB_TO_XYZ =
new double[][] {
new double[] {0.41233895, 0.35762064, 0.18051042},
new double[] {0.2126, 0.7152, 0.0722},
new double[] {0.01932141, 0.11916382, 0.95034478},
};
static final double[][] XYZ_TO_SRGB =
new double[][] {
new double[] {
3.2413774792388685, -1.5376652402851851, -0.49885366846268053,
},
new double[] {
-0.9691452513005321, 1.8758853451067872, 0.04156585616912061,
},
new double[] {
0.05562093689691305, -0.20395524564742123, 1.0571799111220335,
},
};
/**
* The signum function.
*
* @return 1 if num > 0, -1 if num < 0, and 0 if num = 0
*/
public static int signum(double num) {
if (num < 0) {
return -1;
} else if (num == 0) {
return 0;
} else {
return 1;
}
}
/**
* Converts an L* value to an ARGB representation.
*
* @param lstar L* in L*a*b*
* @return ARGB representation of grayscale color with lightness matching L*
*/
public static int argbFromLstar(double lstar) {
double fy = (lstar + 16.0) / 116.0;
double fz = fy;
double fx = fy;
double kappa = 24389.0 / 27.0;
double epsilon = 216.0 / 24389.0;
boolean lExceedsEpsilonKappa = lstar > 8.0;
double y = lExceedsEpsilonKappa ? fy * fy * fy : lstar / kappa;
boolean cubeExceedEpsilon = fy * fy * fy > epsilon;
double x = cubeExceedEpsilon ? fx * fx * fx : lstar / kappa;
double z = cubeExceedEpsilon ? fz * fz * fz : lstar / kappa;
float[] whitePoint = WHITE_POINT_D65;
return argbFromXyz(x * whitePoint[0], y * whitePoint[1], z * whitePoint[2]);
}
/** Converts a color from ARGB to XYZ. */
public static int argbFromXyz(double x, double y, double z) {
double[][] matrix = XYZ_TO_SRGB;
double linearR = matrix[0][0] * x + matrix[0][1] * y + matrix[0][2] * z;
double linearG = matrix[1][0] * x + matrix[1][1] * y + matrix[1][2] * z;
double linearB = matrix[2][0] * x + matrix[2][1] * y + matrix[2][2] * z;
int r = delinearized(linearR);
int g = delinearized(linearG);
int b = delinearized(linearB);
return argbFromRgb(r, g, b);
}
/** Converts a color from linear RGB components to ARGB format. */
public static int argbFromLinrgb(double[] linrgb) {
int r = delinearized(linrgb[0]);
int g = delinearized(linrgb[1]);
int b = delinearized(linrgb[2]);
return argbFromRgb(r, g, b);
}
/** Converts a color from linear RGB components to ARGB format. */
public static int argbFromLinrgbComponents(double r, double g, double b) {
return argbFromRgb(delinearized(r), delinearized(g), delinearized(b));
}
/**
* Delinearizes an RGB component.
*
* @param rgbComponent 0.0 <= rgb_component <= 100.0, represents linear R/G/B channel
* @return 0 <= output <= 255, color channel converted to regular RGB space
*/
public static int delinearized(double rgbComponent) {
double normalized = rgbComponent / 100.0;
double delinearized = 0.0;
if (normalized <= 0.0031308) {
delinearized = normalized * 12.92;
} else {
delinearized = 1.055 * Math.pow(normalized, 1.0 / 2.4) - 0.055;
}
return clampInt(0, 255, (int) Math.round(delinearized * 255.0));
}
/**
* Clamps an integer between two integers.
*
* @return input when min <= input <= max, and either min or max otherwise.
*/
public static int clampInt(int min, int max, int input) {
if (input < min) {
return min;
} else if (input > max) {
return max;
}
return input;
}
/** Converts a color from RGB components to ARGB format. */
public static int argbFromRgb(int red, int green, int blue) {
return (255 << 24) | ((red & 255) << 16) | ((green & 255) << 8) | (blue & 255);
}
static int intFromLstar(float lstar) {
if (lstar < 1) {
@@ -126,9 +238,9 @@ public final class CamUtils {
final float r = linearized(Color.red(argb));
final float g = linearized(Color.green(argb));
final float b = linearized(Color.blue(argb));
float[][] matrix = SRGB_TO_XYZ;
float y = (r * matrix[1][0]) + (g * matrix[1][1]) + (b * matrix[1][2]);
return y;
double[][] matrix = SRGB_TO_XYZ;
double y = (r * matrix[1][0]) + (g * matrix[1][1]) + (b * matrix[1][2]);
return (float) y;
}
@NonNull
@@ -137,19 +249,30 @@ public final class CamUtils {
final float g = linearized(Color.green(argb));
final float b = linearized(Color.blue(argb));
float[][] matrix = SRGB_TO_XYZ;
float x = (r * matrix[0][0]) + (g * matrix[0][1]) + (b * matrix[0][2]);
float y = (r * matrix[1][0]) + (g * matrix[1][1]) + (b * matrix[1][2]);
float z = (r * matrix[2][0]) + (g * matrix[2][1]) + (b * matrix[2][2]);
return new float[]{x, y, z};
double[][] matrix = SRGB_TO_XYZ;
double x = (r * matrix[0][0]) + (g * matrix[0][1]) + (b * matrix[0][2]);
double y = (r * matrix[1][0]) + (g * matrix[1][1]) + (b * matrix[1][2]);
double z = (r * matrix[2][0]) + (g * matrix[2][1]) + (b * matrix[2][2]);
return new float[]{(float) x, (float) y, (float) z};
}
static float yFromLstar(float lstar) {
float ke = 8.0f;
/**
* Converts an L* value to a Y value.
*
* <p>L* in L*a*b* and Y in XYZ measure the same quantity, luminance.
*
* <p>L* measures perceptual luminance, a linear scale. Y in XYZ measures relative luminance, a
* logarithmic scale.
*
* @param lstar L* in L*a*b*
* @return Y in XYZ
*/
public static double yFromLstar(double lstar) {
double ke = 8.0;
if (lstar > ke) {
return (float) Math.pow(((lstar + 16.0) / 116.0), 3) * 100f;
return Math.pow((lstar + 16.0) / 116.0, 3.0) * 100.0;
} else {
return lstar / (24389f / 27f) * 100f;
return lstar / (24389.0 / 27.0) * 100.0;
}
}

20
core/java/com/android/internal/graphics/cam/Frame.java
View File

@@ -19,6 +19,8 @@ package com.android.internal.graphics.cam;
import android.annotation.NonNull;
import android.util.MathUtils;
import com.android.internal.annotations.VisibleForTesting;
/**
* The frame, or viewing conditions, where a color was seen. Used, along with a color, to create a
* color appearance model representing the color.
@@ -68,15 +70,18 @@ public final class Frame {
private final float mFlRoot;
private final float mZ;
float getAw() {
@VisibleForTesting
public float getAw() {
return mAw;
}
float getN() {
@VisibleForTesting
public float getN() {
return mN;
}
float getNbb() {
@VisibleForTesting
public float getNbb() {
return mNbb;
}
@@ -92,8 +97,9 @@ public final class Frame {
return mNc;
}
@VisibleForTesting
@NonNull
float[] getRgbD() {
public float[] getRgbD() {
return mRgbD;
}
@@ -101,7 +107,9 @@ public final class Frame {
return mFl;
}
float getFlRoot() {
@VisibleForTesting
@NonNull
public float getFlRoot() {
return mFlRoot;
}
@@ -167,7 +175,7 @@ public final class Frame {
5.0 * adaptingLuminance));
// Intermediate factor, ratio of background relative luminance to white relative luminance
float n = CamUtils.yFromLstar(backgroundLstar) / whitepoint[1];
float n = (float) CamUtils.yFromLstar(backgroundLstar) / whitepoint[1];
// Base exponential nonlinearity
// note Schlomer 2018 has a typo and uses 1.58, the correct factor is 1.48

721
core/java/com/android/internal/graphics/cam/HctSolver.java Normal file
View File

@@ -0,0 +1,721 @@
/*
* Copyright (C) 2022 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.internal.graphics.cam;
/**
* An efficient algorithm for determining the closest sRGB color to a set of HCT coordinates,
* based on geometrical insights for finding intersections in linear RGB, CAM16, and L*a*b*.
*
* Algorithm identified and implemented by Tianguang Zhang.
* Copied from //java/com/google/ux/material/libmonet/hct on May 22 2022.
* ColorUtils/MathUtils functions that were required were added to CamUtils.
*/
public class HctSolver {
private HctSolver() {}
// Matrix used when converting from linear RGB to CAM16.
static final double[][] SCALED_DISCOUNT_FROM_LINRGB =
new double[][] {
new double[] {
0.001200833568784504, 0.002389694492170889, 0.0002795742885861124,
},
new double[] {
0.0005891086651375999, 0.0029785502573438758, 0.0003270666104008398,
},
new double[] {
0.00010146692491640572, 0.0005364214359186694, 0.0032979401770712076,
},
};
// Matrix used when converting from CAM16 to linear RGB.
static final double[][] LINRGB_FROM_SCALED_DISCOUNT =
new double[][] {
new double[] {
1373.2198709594231, -1100.4251190754821, -7.278681089101213,
},
new double[] {
-271.815969077903, 559.6580465940733, -32.46047482791194,
},
new double[] {
1.9622899599665666, -57.173814538844006, 308.7233197812385,
},
};
// Weights for transforming a set of linear RGB coordinates to Y in XYZ.
static final double[] Y_FROM_LINRGB = new double[] {0.2126, 0.7152, 0.0722};
// Lookup table for plane in XYZ's Y axis (relative luminance) that corresponds to a given
// L* in L*a*b*. HCT's T is L*, and XYZ's Y is directly correlated to linear RGB, this table
// allows us to thus find the intersection between HCT and RGB, giving a solution to the
// RGB coordinates that correspond to a given set of HCT coordinates.
static final double[] CRITICAL_PLANES =
new double[] {
0.015176349177441876,
0.045529047532325624,
0.07588174588720938,
0.10623444424209313,
0.13658714259697685,
0.16693984095186062,
0.19729253930674434,
0.2276452376616281,
0.2579979360165119,
0.28835063437139563,
0.3188300904430532,
0.350925934958123,
0.3848314933096426,
0.42057480301049466,
0.458183274052838,
0.4976837250274023,
0.5391024159806381,
0.5824650784040898,
0.6277969426914107,
0.6751227633498623,
0.7244668422128921,
0.775853049866786,
0.829304845476233,
0.8848452951698498,
0.942497089126609,
1.0022825574869039,
1.0642236851973577,
1.1283421258858297,
1.1946592148522128,
1.2631959812511864,
1.3339731595349034,
1.407011200216447,
1.4823302800086415,
1.5599503113873272,
1.6398909516233677,
1.7221716113234105,
1.8068114625156377,
1.8938294463134073,
1.9832442801866852,
2.075074464868551,
2.1693382909216234,
2.2660538449872063,
2.36523901573795,
2.4669114995532007,
2.5710888059345764,
2.6777882626779785,
2.7870270208169257,
2.898822059350997,
3.0131901897720907,
3.1301480604002863,
3.2497121605402226,
3.3718988244681087,
3.4967242352587946,
3.624204428461639,
3.754355295633311,
3.887192587735158,
4.022731918402185,
4.160988767090289,
4.301978482107941,
4.445716283538092,
4.592217266055746,
4.741496401646282,
4.893568542229298,
5.048448422192488,
5.20615066083972,
5.3666897647573375,
5.5300801301023865,
5.696336044816294,
5.865471690767354,
6.037501145825082,
6.212438385869475,
6.390297286737924,
6.571091626112461,
6.7548350853498045,
6.941541251256611,
7.131223617812143,
7.323895587840543,
7.5195704746346665,
7.7182615035334345,
7.919981813454504,
8.124744458384042,
8.332562408825165,
8.543448553206703,
8.757415699253682,
8.974476575321063,
9.194643831691977,
9.417930041841839,
9.644347703669503,
9.873909240696694,
10.106627003236781,
10.342513269534024,
10.58158024687427,
10.8238400726681,
11.069304815507364,
11.317986476196008,
11.569896988756009,
11.825048221409341,
12.083451977536606,
12.345119996613247,
12.610063955123938,
12.878295467455942,
13.149826086772048,
13.42466730586372,
13.702830557985108,
13.984327217668513,
14.269168601521828,
14.55736596900856,
14.848930523210871,
15.143873411576273,
15.44220572664832,
15.743938506781891,
16.04908273684337,
16.35764934889634,
16.66964922287304,
16.985093187232053,
17.30399201960269,
17.62635644741625,
17.95219714852476,
18.281524751807332,
18.614349837764564,
18.95068293910138,
19.290534541298456,
19.633915083172692,
19.98083495742689,
20.331304511189067,
20.685334046541502,
21.042933821039977,
21.404114048223256,
21.76888489811322,
22.137256497705877,
22.50923893145328,
22.884842241736916,
23.264076429332462,
23.6469514538663,
24.033477234264016,
24.42366364919083,
24.817520537484558,
25.21505769858089,
25.61628489293138,
26.021211842414342,
26.429848230738664,
26.842203703840827,
27.258287870275353,
27.678110301598522,
28.10168053274597,
28.529008062403893,
28.96010235337422,
29.39497283293396,
29.83362889318845,
30.276079891419332,
30.722335150426627,
31.172403958865512,
31.62629557157785,
32.08401920991837,
32.54558406207592,
33.010999283389665,
33.4802739966603,
33.953417292456834,
34.430438229418264,
34.911345834551085,
35.39614910352207,
35.88485700094671,
36.37747846067349,
36.87402238606382,
37.37449765026789,
37.87891309649659,
38.38727753828926,
38.89959975977785,
39.41588851594697,
39.93615253289054,
40.460400508064545,
40.98864111053629,
41.520882981230194,
42.05713473317016,
42.597404951718396,
43.141702194811224,
43.6900349931913,
44.24241185063697,
44.798841244188324,
45.35933162437017,
45.92389141541209,
46.49252901546552,
47.065252796817916,
47.64207110610409,
48.22299226451468,
48.808024568002054,
49.3971762874833,
49.9904556690408,
50.587870934119984,
51.189430279724725,
51.79514187861014,
52.40501387947288,
53.0190544071392,
53.637271562750364,
54.259673423945976,
54.88626804504493,
55.517063457223934,
56.15206766869424,
56.79128866487574,
57.43473440856916,
58.08241284012621,
58.734331877617365,
59.39049941699807,
60.05092333227251,
60.715611475655585,
61.38457167773311,
62.057811747619894,
62.7353394731159,
63.417162620860914,
64.10328893648692,
64.79372614476921,
65.48848194977529,
66.18756403501224,
66.89098006357258,
67.59873767827808,
68.31084450182222,
69.02730813691093,
69.74813616640164,
70.47333615344107,
71.20291564160104,
71.93688215501312,
72.67524319850172,
73.41800625771542,
74.16517879925733,
74.9167682708136,
75.67278210128072,
76.43322770089146,
77.1981124613393,
77.96744375590167,
78.74122893956174,
79.51947534912904,
80.30219030335869,
81.08938110306934,
81.88105503125999,
82.67721935322541,
83.4778813166706,
84.28304815182372,
85.09272707154808,
85.90692527145302,
86.72564993000343,
87.54890820862819,
88.3767072518277,
89.2090541872801,
90.04595612594655,
90.88742016217518,
91.73345337380438,
92.58406282226491,
93.43925555268066,
94.29903859396902,
95.16341895893969,
96.03240364439274,
96.9059996312159,
97.78421388448044,
98.6670533535366,
99.55452497210776,
};
/**
* Sanitizes a small enough angle in radians.
*
* @param angle An angle in radians; must not deviate too much from 0.
* @return A coterminal angle between 0 and 2pi.
*/
static double sanitizeRadians(double angle) {
return (angle + Math.PI * 8) % (Math.PI * 2);
}
/**
* Delinearizes an RGB component, returning a floating-point number.
*
* @param rgbComponent 0.0 <= rgb_component <= 100.0, represents linear R/G/B channel
* @return 0.0 <= output <= 255.0, color channel converted to regular RGB space
*/
static double trueDelinearized(double rgbComponent) {
double normalized = rgbComponent / 100.0;
double delinearized;
if (normalized <= 0.0031308) {
delinearized = normalized * 12.92;
} else {
delinearized = 1.055 * Math.pow(normalized, 1.0 / 2.4) - 0.055;
}
return delinearized * 255.0;
}
static double chromaticAdaptation(double component) {
double af = Math.pow(Math.abs(component), 0.42);
return CamUtils.signum(component) * 400.0 * af / (af + 27.13);
}
/**
* Returns the hue of a linear RGB color in CAM16.
*
* @param linrgb The linear RGB coordinates of a color.
* @return The hue of the color in CAM16, in radians.
*/
static double hueOf(double[] linrgb) {
// Calculate scaled discount components using in-lined matrix multiplication to avoid
// an array allocation.
double[][] matrix = SCALED_DISCOUNT_FROM_LINRGB;
double[] row = linrgb;
double rD = linrgb[0] * matrix[0][0] + row[1] * matrix[0][1] + row[2] * matrix[0][2];
double gD = linrgb[0] * matrix[1][0] + row[1] * matrix[1][1] + row[2] * matrix[1][2];
double bD = linrgb[0] * matrix[2][0] + row[1] * matrix[2][1] + row[2] * matrix[2][2];
double rA = chromaticAdaptation(rD);
double gA = chromaticAdaptation(gD);
double bA = chromaticAdaptation(bD);
// redness-greenness
double a = (11.0 * rA + -12.0 * gA + bA) / 11.0;
// yellowness-blueness
double b = (rA + gA - 2.0 * bA) / 9.0;
return Math.atan2(b, a);
}
/**
* Cyclic order is the idea that 330° → 5° → 200° is in order, but, 180° → 270° → 210° is not.
* Visually, A B and C are angles, and they are in cyclic order if travelling from A to C
* in a way that increases angle (ex. counter-clockwise if +x axis = 0 degrees and +y = 90)
* means you must cross B.
* @param a first angle in possibly cyclic triplet
* @param b second angle in possibly cyclic triplet
* @param c third angle in possibly cyclic triplet
* @return true if B is between A and C
*/
static boolean areInCyclicOrder(double a, double b, double c) {
double deltaAB = sanitizeRadians(b - a);
double deltaAC = sanitizeRadians(c - a);
return deltaAB < deltaAC;
}
/**
* Find an intercept using linear interpolation.
*
* @param source The starting number.
* @param mid The number in the middle.
* @param target The ending number.
* @return A number t such that lerp(source, target, t) = mid.
*/
static double intercept(double source, double mid, double target) {
if (target == source) {
return target;
}
return (mid - source) / (target - source);
}
/**
* Linearly interpolate between two points in three dimensions.
*
* @param source three dimensions representing the starting point
* @param t the percentage to travel between source and target, from 0 to 1
* @param target three dimensions representing the end point
* @return three dimensions representing the point t percent from source to target.
*/
static double[] lerpPoint(double[] source, double t, double[] target) {
return new double[] {
source[0] + (target[0] - source[0]) * t,
source[1] + (target[1] - source[1]) * t,
source[2] + (target[2] - source[2]) * t,
};
}
/**
* Intersects a segment with a plane.
*
* @param source The coordinates of point A.
* @param coordinate The R-, G-, or B-coordinate of the plane.
* @param target The coordinates of point B.
* @param axis The axis the plane is perpendicular with. (0: R, 1: G, 2: B)
* @return The intersection point of the segment AB with the plane R=coordinate, G=coordinate,
* or B=coordinate
*/
static double[] setCoordinate(double[] source, double coordinate, double[] target, int axis) {
double t = intercept(source[axis], coordinate, target[axis]);
return lerpPoint(source, t, target);
}
/** Ensure X is between 0 and 100. */
static boolean isBounded(double x) {
return 0.0 <= x && x <= 100.0;
}
/**
* Returns the nth possible vertex of the polygonal intersection.
*
* @param y The Y value of the plane.
* @param n The zero-based index of the point. 0 <= n <= 11.
* @return The nth possible vertex of the polygonal intersection of the y plane and the RGB cube
* in linear RGB coordinates, if it exists. If the possible vertex lies outside of the cube,
* [-1.0, -1.0, -1.0] is returned.
*/
static double[] nthVertex(double y, int n) {
double kR = Y_FROM_LINRGB[0];
double kG = Y_FROM_LINRGB[1];
double kB = Y_FROM_LINRGB[2];
double coordA = n % 4 <= 1 ? 0.0 : 100.0;
double coordB = n % 2 == 0 ? 0.0 : 100.0;
if (n < 4) {
double g = coordA;
double b = coordB;
double r = (y - g * kG - b * kB) / kR;
if (isBounded(r)) {
return new double[] {r, g, b};
} else {
return new double[] {-1.0, -1.0, -1.0};
}
} else if (n < 8) {
double b = coordA;
double r = coordB;
double g = (y - r * kR - b * kB) / kG;
if (isBounded(g)) {
return new double[] {r, g, b};
} else {
return new double[] {-1.0, -1.0, -1.0};
}
} else {
double r = coordA;
double g = coordB;
double b = (y - r * kR - g * kG) / kB;
if (isBounded(b)) {
return new double[] {r, g, b};
} else {
return new double[] {-1.0, -1.0, -1.0};
}
}
}
/**
* Finds the segment containing the desired color.
*
* @param y The Y value of the color.
* @param targetHue The hue of the color.
* @return A list of two sets of linear RGB coordinates, each corresponding to an endpoint of
* the segment containing the desired color.
*/
static double[][] bisectToSegment(double y, double targetHue) {
double[] left = new double[] {-1.0, -1.0, -1.0};
double[] right = left;
double leftHue = 0.0;
double rightHue = 0.0;
boolean initialized = false;
boolean uncut = true;
for (int n = 0; n < 12; n++) {
double[] mid = nthVertex(y, n);
if (mid[0] < 0) {
continue;
}
double midHue = hueOf(mid);
if (!initialized) {
left = mid;
right = mid;
leftHue = midHue;
rightHue = midHue;
initialized = true;
continue;
}
if (uncut || areInCyclicOrder(leftHue, midHue, rightHue)) {
uncut = false;
if (areInCyclicOrder(leftHue, targetHue, midHue)) {
right = mid;
rightHue = midHue;
} else {
left = mid;
leftHue = midHue;
}
}
}
return new double[][] {left, right};
}
static int criticalPlaneBelow(double x) {
return (int) Math.floor(x - 0.5);
}
static int criticalPlaneAbove(double x) {
return (int) Math.ceil(x - 0.5);
}
/**
* Finds a color with the given Y and hue on the boundary of the cube.
*
* @param y The Y value of the color.
* @param targetHue The hue of the color.
* @return The desired color, in linear RGB coordinates.
*/
static int bisectToLimit(double y, double targetHue) {
double[][] segment = bisectToSegment(y, targetHue);
double[] left = segment[0];
double leftHue = hueOf(left);
double[] right = segment[1];
for (int axis = 0; axis < 3; axis++) {
if (left[axis] != right[axis]) {
int lPlane = -1;
int rPlane = 255;
if (left[axis] < right[axis]) {
lPlane = criticalPlaneBelow(trueDelinearized(left[axis]));
rPlane = criticalPlaneAbove(trueDelinearized(right[axis]));
} else {
lPlane = criticalPlaneAbove(trueDelinearized(left[axis]));
rPlane = criticalPlaneBelow(trueDelinearized(right[axis]));
}
for (int i = 0; i < 8; i++) {
if (Math.abs(rPlane - lPlane) <= 1) {
break;
} else {
int mPlane = (int) Math.floor((lPlane + rPlane) / 2.0);
double midPlaneCoordinate = CRITICAL_PLANES[mPlane];
double[] mid = setCoordinate(left, midPlaneCoordinate, right, axis);
double midHue = hueOf(mid);
if (areInCyclicOrder(leftHue, targetHue, midHue)) {
right = mid;
rPlane = mPlane;
} else {
left = mid;
leftHue = midHue;
lPlane = mPlane;
}
}
}
}
}
return CamUtils.argbFromLinrgbComponents((left[0] + right[0]) / 2,
(left[1] + right[1]) / 2, (left[2] + right[2]) / 2);
}
/** Equation used in CAM16 conversion that removes the effect of chromatic adaptation. */
static double inverseChromaticAdaptation(double adapted) {
double adaptedAbs = Math.abs(adapted);
double base = Math.max(0, 27.13 * adaptedAbs / (400.0 - adaptedAbs));
return CamUtils.signum(adapted) * Math.pow(base, 1.0 / 0.42);
}
/**
* Finds a color with the given hue, chroma, and Y.
*
* @param hueRadians The desired hue in radians.
* @param chroma The desired chroma.
* @param y The desired Y.
* @return The desired color as a hexadecimal integer, if found; 0 otherwise.
*/
static int findResultByJ(double hueRadians, double chroma, double y) {
// Initial estimate of j.
double j = Math.sqrt(y) * 11.0;
// ===========================================================
// Operations inlined from Cam16 to avoid repeated calculation
// ===========================================================
Frame viewingConditions = Frame.DEFAULT;
double tInnerCoeff = 1 / Math.pow(1.64 - Math.pow(0.29, viewingConditions.getN()), 0.73);
double eHue = 0.25 * (Math.cos(hueRadians + 2.0) + 3.8);
double p1 = eHue * (50000.0 / 13.0) * viewingConditions.getNc()
* viewingConditions.getNcb();
double hSin = Math.sin(hueRadians);
double hCos = Math.cos(hueRadians);
for (int iterationRound = 0; iterationRound < 5; iterationRound++) {
// ===========================================================
// Operations inlined from Cam16 to avoid repeated calculation
// ===========================================================
double jNormalized = j / 100.0;
double alpha = chroma == 0.0 || j == 0.0 ? 0.0 : chroma / Math.sqrt(jNormalized);
double t = Math.pow(alpha * tInnerCoeff, 1.0 / 0.9);
double acExponent = 1.0 / viewingConditions.getC() / viewingConditions.getZ();
double ac = viewingConditions.getAw() * Math.pow(jNormalized, acExponent);
double p2 = ac / viewingConditions.getNbb();
double gamma = 23.0 * (p2 + 0.305) * t / (23.0 * p1 + 11 * t * hCos + 108.0 * t * hSin);
double a = gamma * hCos;
double b = gamma * hSin;
double rA = (460.0 * p2 + 451.0 * a + 288.0 * b) / 1403.0;
double gA = (460.0 * p2 - 891.0 * a - 261.0 * b) / 1403.0;
double bA = (460.0 * p2 - 220.0 * a - 6300.0 * b) / 1403.0;
double rCScaled = inverseChromaticAdaptation(rA);
double gCScaled = inverseChromaticAdaptation(gA);
double bCScaled = inverseChromaticAdaptation(bA);
double[][] matrix = LINRGB_FROM_SCALED_DISCOUNT;
double linrgbR = rCScaled * matrix[0][0] + gCScaled * matrix[0][1]
+ bCScaled * matrix[0][2];
double linrgbG = rCScaled * matrix[1][0] + gCScaled * matrix[1][1]
+ bCScaled * matrix[1][2];
double linrgbB = rCScaled * matrix[2][0] + gCScaled * matrix[2][1]
+ bCScaled * matrix[2][2];
// ===========================================================
// Operations inlined from Cam16 to avoid repeated calculation
// ===========================================================
if (linrgbR < 0 || linrgbG < 0 || linrgbB < 0) {
return 0;
}
double kR = Y_FROM_LINRGB[0];
double kG = Y_FROM_LINRGB[1];
double kB = Y_FROM_LINRGB[2];
double fnj = kR * linrgbR + kG * linrgbG + kB * linrgbB;
if (fnj <= 0) {
return 0;
}
if (iterationRound == 4 || Math.abs(fnj - y) < 0.002) {
if (linrgbR > 100.01 || linrgbG > 100.01 || linrgbB > 100.01) {
return 0;
}
return CamUtils.argbFromLinrgbComponents(linrgbR, linrgbG, linrgbB);
}
// Iterates with Newton method,
// Using 2 * fn(j) / j as the approximation of fn'(j)
j = j - (fnj - y) * j / (2 * fnj);
}
return 0;
}
/**
* Finds an sRGB color with the given hue, chroma, and L*, if possible.
*
* @param hueDegrees The desired hue, in degrees.
* @param chroma The desired chroma.
* @param lstar The desired L*.
* @return A hexadecimal representing the sRGB color. The color has sufficiently close hue,
* chroma, and L* to the desired values, if possible; otherwise, the hue and L* will be
* sufficiently close, and chroma will be maximized.
*/
public static int solveToInt(double hueDegrees, double chroma, double lstar) {
if (chroma < 0.0001 || lstar < 0.0001 || lstar > 99.9999) {
return CamUtils.argbFromLstar(lstar);
}
hueDegrees = sanitizeDegreesDouble(hueDegrees);
double hueRadians = Math.toRadians(hueDegrees);
double y = CamUtils.yFromLstar(lstar);
int exactAnswer = findResultByJ(hueRadians, chroma, y);
if (exactAnswer != 0) {
return exactAnswer;
}
return bisectToLimit(y, hueRadians);
}
/**
* Sanitizes a degree measure as a floating-point number.
*
* @return a degree measure between 0.0 (inclusive) and 360.0 (exclusive).
*/
public static double sanitizeDegreesDouble(double degrees) {
degrees = degrees % 360.0;
if (degrees < 0) {
degrees = degrees + 360.0;
}
return degrees;
}
/**
* Finds an sRGB color with the given hue, chroma, and L*, if possible.
*
* @param hueDegrees The desired hue, in degrees.
* @param chroma The desired chroma.
* @param lstar The desired L*.
* @return An CAM16 object representing the sRGB color. The color has sufficiently close hue,
* chroma, and L* to the desired values, if possible; otherwise, the hue and L* will be
* sufficiently close, and chroma will be maximized.
*/
public static Cam solveToCam(double hueDegrees, double chroma, double lstar) {
return Cam.fromInt(solveToInt(hueDegrees, chroma, lstar));
}
}

33
core/tests/coretests/src/android/colormodel/CamTest.java
View File

@@ -18,6 +18,9 @@ package com.android.internal.graphics.cam;
import static org.junit.Assert.assertEquals;
import android.platform.test.annotations.LargeTest;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
@@ -69,7 +72,7 @@ public final class CamTest {
public void camFromGreen() {
Cam cam = Cam.fromInt(GREEN);
assertEquals(79.331f, cam.getJ(), 0.001f);
assertEquals(108.409f, cam.getChroma(), 0.001f);
assertEquals(108.410f, cam.getChroma(), 0.001f);
assertEquals(142.139f, cam.getHue(), 0.001f);
assertEquals(85.587f, cam.getM(), 0.001f);
assertEquals(78.604f, cam.getS(), 0.001f);
@@ -193,4 +196,32 @@ public final class CamTest {
public void deltaERedToBlue() {
assertEquals(21.415f, Cam.fromInt(RED).distance(Cam.fromInt(BLUE)), 0.001f);
}
@Test
public void viewingConditions_default() {
Frame vc = Frame.DEFAULT;
Assert.assertEquals(0.184, vc.getN(), 0.001);
Assert.assertEquals(29.981, vc.getAw(), 0.001);
Assert.assertEquals(1.016, vc.getNbb(), 0.001);
Assert.assertEquals(1.021, vc.getRgbD()[0], 0.001);
Assert.assertEquals(0.986, vc.getRgbD()[1], 0.001);
Assert.assertEquals(0.933, vc.getRgbD()[2], 0.001);
Assert.assertEquals(0.789, vc.getFlRoot(), 0.001);
}
@LargeTest
@Test
public void testHctReflexivity() {
for (int i = 0; i <= 0x00ffffff; i++) {
int color = 0xFF000000 | i;
Cam hct = Cam.fromInt(color);
int reconstructedFromHct = Cam.getInt(hct.getHue(), hct.getChroma(),
CamUtils.lstarFromInt(color));
Assert.assertEquals("input was " + Integer.toHexString(color)
+ "; output was " + Integer.toHexString(reconstructedFromHct),
reconstructedFromHct, reconstructedFromHct);
}
}
}

96
packages/SystemUI/monet/src/com/android/systemui/monet/ColorScheme.kt
View File

@@ -21,8 +21,8 @@ import android.app.WallpaperColors
import android.graphics.Color
import com.android.internal.graphics.ColorUtils
import com.android.internal.graphics.cam.Cam
import com.android.internal.graphics.cam.CamUtils
import kotlin.math.absoluteValue
import kotlin.math.max
import kotlin.math.roundToInt
const val TAG = "ColorScheme"
@@ -43,13 +43,13 @@ internal interface Hue {
* second item in the pair is a hue rotation that should be applied
*/
fun getHueRotation(sourceHue: Float, hueAndRotations: List<Pair<Int, Int>>): Double {
for (i in 0..hueAndRotations.size) {
val previousIndex = if (i == 0) hueAndRotations.size - 1 else i - 1
val thisHue = hueAndRotations[i].first
val previousHue = hueAndRotations[previousIndex].first
if (ColorScheme.angleIsBetween(sourceHue, thisHue, previousHue)) {
return ColorScheme.wrapDegreesDouble(sourceHue.toDouble() +
hueAndRotations[previousIndex].second)
val sanitizedSourceHue = (if (sourceHue < 0 || sourceHue >= 360) 0 else sourceHue).toFloat()
for (i in 0..hueAndRotations.size - 2) {
val thisHue = hueAndRotations[i].first.toFloat()
val nextHue = hueAndRotations[i + 1].first.toFloat()
if (thisHue <= sanitizedSourceHue && sanitizedSourceHue < nextHue) {
return ColorScheme.wrapDegreesDouble(sanitizedSourceHue.toDouble() +
hueAndRotations[i].second)
}
}
@@ -79,7 +79,7 @@ internal class HueSubtract(val amountDegrees: Double) : Hue {
internal class HueVibrantSecondary() : Hue {
val hueToRotations = listOf(Pair(0, 18), Pair(41, 15), Pair(61, 10), Pair(101, 12),
Pair(131, 15), Pair(181, 18), Pair(251, 15), Pair(301, 12))
Pair(131, 15), Pair(181, 18), Pair(251, 15), Pair(301, 12), Pair(360, 12))
override fun get(sourceColor: Cam): Double {
return getHueRotation(sourceColor.hue, hueToRotations)
}
@@ -87,7 +87,7 @@ internal class HueVibrantSecondary() : Hue {
internal class HueVibrantTertiary() : Hue {
val hueToRotations = listOf(Pair(0, 35), Pair(41, 30), Pair(61, 20), Pair(101, 25),
Pair(131, 30), Pair(181, 35), Pair(251, 30), Pair(301, 25))
Pair(131, 30), Pair(181, 35), Pair(251, 30), Pair(301, 25), Pair(360, 25))
override fun get(sourceColor: Cam): Double {
return getHueRotation(sourceColor.hue, hueToRotations)
}
@@ -95,7 +95,7 @@ internal class HueVibrantTertiary() : Hue {
internal class HueExpressiveSecondary() : Hue {
val hueToRotations = listOf(Pair(0, 45), Pair(21, 95), Pair(51, 45), Pair(121, 20),
Pair(141, 45), Pair(191, 90), Pair(271, 45), Pair(321, 45))
Pair(151, 45), Pair(191, 90), Pair(271, 45), Pair(321, 45), Pair(360, 45))
override fun get(sourceColor: Cam): Double {
return getHueRotation(sourceColor.hue, hueToRotations)
}
@@ -103,7 +103,7 @@ internal class HueExpressiveSecondary() : Hue {
internal class HueExpressiveTertiary() : Hue {
val hueToRotations = listOf(Pair(0, 120), Pair(21, 120), Pair(51, 20), Pair(121, 45),
Pair(141, 20), Pair(191, 15), Pair(271, 20), Pair(321, 120))
Pair(151, 20), Pair(191, 15), Pair(271, 20), Pair(321, 120), Pair(360, 120))
override fun get(sourceColor: Cam): Double {
return getHueRotation(sourceColor.hue, hueToRotations)
}
@@ -111,34 +111,13 @@ internal class HueExpressiveTertiary() : Hue {
internal interface Chroma {
fun get(sourceColor: Cam): Double
/**
* Given a hue, and a mapping of hues to hue rotations, find which hues in the mapping the
* hue fall betweens, and use the hue rotation of the lower hue.
*
* @param sourceHue hue of source color
* @param hueAndChromas list of pairs, where the first item in a pair is a hue, and the
* second item in the pair is a chroma that should be applied
*/
fun getSpecifiedChroma(sourceHue: Float, hueAndChromas: List<Pair<Int, Int>>): Double {
for (i in 0..hueAndChromas.size) {
val previousIndex = if (i == 0) hueAndChromas.size - 1 else i - 1
val thisHue = hueAndChromas[i].first
val previousHue = hueAndChromas[previousIndex].first
if (ColorScheme.angleIsBetween(sourceHue, thisHue, previousHue)) {
return hueAndChromas[i].second.toDouble()
}
}
// If this statement executes, something is wrong, there should have been a rotation
// found using the arrays.
return sourceHue.toDouble()
}
}
internal class ChromaMinimum(val chroma: Double) : Chroma {
internal class ChromaMaxOut : Chroma {
override fun get(sourceColor: Cam): Double {
return max(sourceColor.chroma.toDouble(), chroma)
// Intentionally high. Gamut mapping from impossible HCT to sRGB will ensure that
// the maximum chroma is reached, even if lower than this constant.
return 130.0
}
}
@@ -192,11 +171,11 @@ enum class Style(internal val coreSpec: CoreSpec) {
n2 = TonalSpec(HueSource(), ChromaConstant(8.0))
)),
VIBRANT(CoreSpec(
a1 = TonalSpec(HueSource(), ChromaMinimum(48.0)),
a1 = TonalSpec(HueSource(), ChromaMaxOut()),
a2 = TonalSpec(HueVibrantSecondary(), ChromaConstant(24.0)),
a3 = TonalSpec(HueVibrantTertiary(), ChromaConstant(32.0)),
n1 = TonalSpec(HueSource(), ChromaConstant(12.0)),
n2 = TonalSpec(HueSource(), ChromaConstant(14.0))
n1 = TonalSpec(HueSource(), ChromaConstant(8.0)),
n2 = TonalSpec(HueSource(), ChromaConstant(12.0))
)),
EXPRESSIVE(CoreSpec(
a1 = TonalSpec(HueAdd(240.0), ChromaConstant(40.0)),
@@ -229,7 +208,7 @@ enum class Style(internal val coreSpec: CoreSpec) {
}
class ColorScheme(
@ColorInt seed: Int,
@ColorInt val seed: Int,
val darkTheme: Boolean,
val style: Style = Style.TONAL_SPOT
) {
@@ -293,12 +272,14 @@ class ColorScheme(
override fun toString(): String {
return "ColorScheme {\n" +
" neutral1: ${humanReadable(neutral1)}\n" +
" neutral2: ${humanReadable(neutral2)}\n" +
" accent1: ${humanReadable(accent1)}\n" +
" accent2: ${humanReadable(accent2)}\n" +
" accent3: ${humanReadable(accent3)}\n" +
" seed color: ${stringForColor(seed)}\n" +
" style: $style\n" +
" palettes: \n" +
" ${humanReadable("PRIMARY", accent1)}\n" +
" ${humanReadable("SECONDARY", accent2)}\n" +
" ${humanReadable("TERTIARY", accent3)}\n" +
" ${humanReadable("NEUTRAL", neutral1)}\n" +
" ${humanReadable("NEUTRAL VARIANT", neutral2)}\n" +
"}"
}
@@ -416,13 +397,6 @@ class ColorScheme(
return seeds
}
internal fun angleIsBetween(angle: Float, a: Int, b: Int): Boolean {
if (a < b) {
return a <= angle && angle <= b
}
return a <= angle || angle <= b
}
private fun wrapDegrees(degrees: Int): Int {
return when {
degrees < 0 -> {
@@ -455,8 +429,20 @@ class ColorScheme(
return 180f - ((a - b).absoluteValue - 180f).absoluteValue
}
private fun humanReadable(colors: List<Int>): String {
return colors.joinToString { "#" + Integer.toHexString(it) }
private fun stringForColor(color: Int): String {
val width = 4
val hct = Cam.fromInt(color)
val h = "H${hct.hue.roundToInt().toString().padEnd(width)}"
val c = "C${hct.chroma.roundToInt().toString().padEnd(width)}"
val t = "T${CamUtils.lstarFromInt(color).roundToInt().toString().padEnd(width)}"
val hex = Integer.toHexString(color).replaceRange(0, 2, "").uppercase()
return "$h$c$t = #$hex"
}
private fun humanReadable(paletteName: String, colors: List<Int>): String {
return "$paletteName\n" + colors.map {
stringForColor(it)
}.joinToString(separator = "\n") { it }
}
private fun score(cam: Cam, proportion: Double): Double {

2
packages/SystemUI/tests/src/com/android/systemui/monet/ColorSchemeTest.java
View File

@@ -69,7 +69,7 @@ public class ColorSchemeTest extends SysuiTestCase {
// Expressive applies hue rotations to the theme color. The input theme color has hue
// 117, ensuring the hue changed significantly is a strong signal styles are being applied.
ColorScheme colorScheme = new ColorScheme(wallpaperColors, false, Style.EXPRESSIVE);
Assert.assertEquals(Cam.fromInt(colorScheme.getAccent1().get(6)).getHue(), 357.46, 0.1);
Assert.assertEquals(357.77, Cam.fromInt(colorScheme.getAccent1().get(6)).getHue(), 0.1);
}