Addy

core/java/android/hardware/display/ColorDisplayManager.java

@@ -437,6 +437,30 @@ public boolean setAppSaturationLevel(@NonNull String packageName,
         return mManager.setAppSaturationLevel(packageName, saturationLevel);
     }
 
+    /**
+     * Set the global color balance for a specific RGB channel.
+     *
+     * @param channel RGB (0,1,2) channel to change
+     * @param value 0-255 (inclusive), where 255 is default balance
+     * @return whether the change was successful
+     * @hide
+     */
+    @RequiresPermission(android.Manifest.permission.CONTROL_DISPLAY_COLOR_TRANSFORMS)
+    public boolean setColorBalanceChannel(int channel, int value) {
+        return mManager.setColorBalanceChannel(channel, value);
+    }
+
+    /**
+     * Get the current global color balance for a specific RGB channel.
+     *
+     * @param channel RGB (0,1,2) channel to get the balance of
+     * @return weight of the channel, 0-255 (inclusive) where 255 is the default
+     * @hide
+     */
+    public int getColorBalanceChannel(int channel) {
+        return mManager.getColorBalanceChannel(channel);
+    }
+
     /**
      * Enables or disables display white balance.
      *
@@ -682,6 +706,22 @@ boolean setAppSaturationLevel(String packageName, int saturationLevel) {
             }
         }
 
+        boolean setColorBalanceChannel(int channel, int value) {
+            try {
+                return mCdm.setColorBalanceChannel(channel, value);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+        }
+
+        int getColorBalanceChannel(int channel) {
+            try {
+                return mCdm.getColorBalanceChannel(channel);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+        }
+
         boolean isDisplayWhiteBalanceEnabled() {
             try {
                 return mCdm.isDisplayWhiteBalanceEnabled();

core/java/android/hardware/display/IColorDisplayManager.aidl

@@ -43,6 +43,9 @@ interface IColorDisplayManager {
     int getColorMode();
     void setColorMode(int colorMode);
 
+    int getColorBalanceChannel(int channel);
+    boolean setColorBalanceChannel(int channel, int value);
+
     boolean isDisplayWhiteBalanceEnabled();
     boolean setDisplayWhiteBalanceEnabled(boolean enabled);
     Time getNightDisplayAutoStartTime();

core/java/android/provider/Settings.java

@@ -10386,6 +10386,24 @@ public static boolean putFloatForUser(ContentResolver cr, String name, float val
         public static final String NIGHT_DISPLAY_LAST_ACTIVATED_TIME =
                 "night_display_last_activated_time";
 
+        /**
+         * Display color balance for the red channel, from 0 to 255.
+         * @hide
+         */
+        public static final String DISPLAY_COLOR_BALANCE_RED = "display_color_balance_red";
+
+        /**
+         * Display color balance for the green channel, from 0 to 255.
+         * @hide
+         */
+        public static final String DISPLAY_COLOR_BALANCE_GREEN = "display_color_balance_green";
+
+        /**
+         * Display color balance for the blue channel, from 0 to 255.
+         * @hide
+         */
+        public static final String DISPLAY_COLOR_BALANCE_BLUE = "display_color_balance_blue";
+
         /**
          * Control whether display white balance is currently enabled.
          * @hide

core/res/res/raw/color_fade_frag.frag

@@ -3,12 +3,26 @@
 precision mediump float;
 uniform samplerExternalOES texUnit;
 uniform float opacity;
-uniform float gamma;
 varying vec2 UV;
 
-void main()
-{
-    vec4 color = texture2D(texUnit, UV);
-    vec3 rgb = pow(color.rgb * opacity, vec3(gamma));
-    gl_FragColor = vec4(rgb, 1.0);
+vec3 srgbTransfer(vec3 c) {
+    vec3 gamma = 1.055 * pow(c, vec3(1.0/2.4)) - 0.055;
+    vec3 linear = 12.92 * c;
+    bvec3 selectParts = lessThan(c, vec3(0.0031308));
+    return mix(gamma, linear, selectParts);
+}
+
+vec3 srgbTransferInv(vec3 c) {
+    vec3 gamma = pow((c + 0.055)/1.055, vec3(2.4));
+    vec3 linear = c / 12.92;
+    bvec3 selectParts = lessThan(c, vec3(0.04045));
+    return mix(gamma, linear, selectParts);
+}
+
+void main() {
+    vec3 inRgb = srgbTransferInv(texture2D(texUnit, UV).rgb);
+    vec3 fade = inRgb * opacity * opacity;
+    vec3 outRgb = srgbTransfer(fade);
+
+    gl_FragColor = vec4(outRgb, 1.0);
 }

graphics/java/android/graphics/ColorSpace.java

@@ -813,6 +813,18 @@ public enum Adaptation {
                  0.7328f, -0.7036f,  0.0030f,
                  0.4296f,  1.6975f,  0.0136f,
                 -0.1624f,  0.0061f,  0.9834f
+        }),
+        /**
+         * CAT16 chromatic adaptation transform, as defined in the
+         * CAM16 color appearance model.
+         *
+         * @see <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/col.22131">Comprehensive color solutions: CAM16, CAT16, and CAM16-UCS</a>
+         * @hide
+        */
+        CAT16(new float[] {
+                 0.401288f, -0.250268f, -0.002079f,
+                 0.650173f,  1.204414f,  0.048952f,
+                -0.051461f,  0.045854f,  0.953127f,
         });
 
         final float[] mTransform;

services/core/java/com/android/server/display/ColorFade.java

@@ -106,7 +106,7 @@ final class ColorFade implements ScreenStateAnimator {
     private final float mProjMatrix[] = new float[16];
     private final int[] mGLBuffers = new int[2];
     private int mTexCoordLoc, mVertexLoc, mTexUnitLoc, mProjMatrixLoc, mTexMatrixLoc;
-    private int mOpacityLoc, mGammaLoc;
+    private int mOpacityLoc;
     private int mProgram;
 
     // Vertex and corresponding texture coordinates.
@@ -253,7 +253,6 @@ private boolean initGLShaders(Context context) {
         mTexMatrixLoc = GLES20.glGetUniformLocation(mProgram, "tex_matrix");
 
         mOpacityLoc = GLES20.glGetUniformLocation(mProgram, "opacity");
-        mGammaLoc = GLES20.glGetUniformLocation(mProgram, "gamma");
         mTexUnitLoc = GLES20.glGetUniformLocation(mProgram, "texUnit");
 
         GLES20.glUseProgram(mProgram);
@@ -397,12 +396,7 @@ public boolean draw(float level) {
             GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
 
             // Draw the frame.
-            double one_minus_level = 1 - level;
-            double cos = Math.cos(Math.PI * one_minus_level);
-            double sign = cos < 0 ? -1 : 1;
-            float opacity = (float) -Math.pow(one_minus_level, 2) + 1;
-            float gamma = (float) ((0.5d * sign * Math.pow(cos, 2) + 0.5d) * 0.9d + 0.1d);
-            drawFaded(opacity, 1.f / gamma);
+            drawFaded(level);
             if (checkGlErrors("drawFrame")) {
                 return false;
             }
@@ -414,9 +408,9 @@ public boolean draw(float level) {
         return showSurface(1.0f);
     }
 
-    private void drawFaded(float opacity, float gamma) {
+    private void drawFaded(float opacity) {
         if (DEBUG) {
-            Slog.d(TAG, "drawFaded: opacity=" + opacity + ", gamma=" + gamma);
+            Slog.d(TAG, "drawFaded: opacity=" + opacity);
         }
         // Use shaders
         GLES20.glUseProgram(mProgram);
@@ -425,7 +419,6 @@ private void drawFaded(float opacity, float gamma) {
         GLES20.glUniformMatrix4fv(mProjMatrixLoc, 1, false, mProjMatrix, 0);
         GLES20.glUniformMatrix4fv(mTexMatrixLoc, 1, false, mTexMatrix, 0);
         GLES20.glUniform1f(mOpacityLoc, opacity);
-        GLES20.glUniform1f(mGammaLoc, gamma);
 
         // Use textures
         GLES20.glActiveTexture(GLES20.GL_TEXTURE0);