Update ripple spec

Added new noise function, and general improvements on rendering.

Test: atest RippleDrawableTest
Test: manual
Fixes: 180556929
Fixes: 182172454
Fixes: 182172793
Fixes: 182174746
Change-Id: Ia2701e1438ac17010d5112ed01e296eef3ff4293

3 files changed, 249 insertions, 114 deletions

diff --git a/graphics/java/android/graphics/drawable/RippleAnimationSession.java b/graphics/java/android/graphics/drawable/RippleAnimationSession.java
index 80f65f919fa6..f3bf63bb3660 100644
--- a/graphics/java/android/graphics/drawable/RippleAnimationSession.java
+++ b/graphics/java/android/graphics/drawable/RippleAnimationSession.java
@@ -27,8 +27,9 @@ import android.graphics.Paint;
 import android.graphics.RecordingCanvas;
 import android.graphics.animation.RenderNodeAnimator;
 import android.util.ArraySet;
-import android.view.animation.DecelerateInterpolator;
+import android.view.animation.AnimationUtils;
 import android.view.animation.LinearInterpolator;
+import android.view.animation.PathInterpolator;
 
 import java.util.function.Consumer;
 
@@ -36,32 +37,41 @@ import java.util.function.Consumer;
  * @hide
  */
 public final class RippleAnimationSession {
-    private static final int ENTER_ANIM_DURATION = 350;
-    private static final int EXIT_ANIM_OFFSET = ENTER_ANIM_DURATION;
-    private static final int EXIT_ANIM_DURATION = 350;
+    private static final String TAG = "RippleAnimationSession";
+    private static final int ENTER_ANIM_DURATION = 300;
+    private static final int SLIDE_ANIM_DURATION = 450;
+    private static final int EXIT_ANIM_DURATION = 300;
     private static final TimeInterpolator LINEAR_INTERPOLATOR = new LinearInterpolator();
-    // Matches R.interpolator.fast_out_slow_in but as we have no context we can't just import that
-    private static final TimeInterpolator DECELERATE_INTERPOLATOR = new DecelerateInterpolator();
-
+    private static final TimeInterpolator PATH_INTERPOLATOR =
+            new PathInterpolator(.2f, 0, 0, 1f);
     private Consumer<RippleAnimationSession> mOnSessionEnd;
-    private AnimationProperties<Float, Paint> mProperties;
+    private final AnimationProperties<Float, Paint> mProperties;
     private AnimationProperties<CanvasProperty<Float>, CanvasProperty<Paint>> mCanvasProperties;
     private Runnable mOnUpdate;
     private long mStartTime;
     private boolean mForceSoftware;
-    private ArraySet<Animator> mActiveAnimations = new ArraySet(3);
+    private final float mWidth, mHeight;
+    private final ValueAnimator mSparkle = ValueAnimator.ofFloat(0, 1);
+    private final ArraySet<Animator> mActiveAnimations = new ArraySet<>(3);
 
     RippleAnimationSession(@NonNull AnimationProperties<Float, Paint> properties,
-            boolean forceSoftware) {
+            boolean forceSoftware, float width, float height) {
         mProperties = properties;
         mForceSoftware = forceSoftware;
-    }
-
-    void end() {
-        for (Animator anim: mActiveAnimations) {
-            if (anim != null) anim.end();
-        }
-        mActiveAnimations.clear();
+        mWidth = width;
+        mHeight = height;
+
+        mSparkle.addUpdateListener(anim -> {
+            final long now = AnimationUtils.currentAnimationTimeMillis();
+            final long elapsed = now - mStartTime - ENTER_ANIM_DURATION;
+            final float phase = (float) elapsed / 1000f;
+            mProperties.getShader().setSecondsOffset(phase);
+            notifyUpdate();
+        });
+        mSparkle.setDuration(ENTER_ANIM_DURATION);
+        mSparkle.setStartDelay(ENTER_ANIM_DURATION);
+        mSparkle.setInterpolator(LINEAR_INTERPOLATOR);
+        mSparkle.setRepeatCount(ValueAnimator.INFINITE);
     }
 
     @NonNull RippleAnimationSession enter(Canvas canvas) {
@@ -70,17 +80,19 @@ public final class RippleAnimationSession {
         } else {
             enterSoftware();
         }
-        mStartTime = System.nanoTime();
+        mStartTime = AnimationUtils.currentAnimationTimeMillis();
         return this;
     }
 
     @NonNull RippleAnimationSession exit(Canvas canvas) {
+        mSparkle.end();
         if (isHwAccelerated(canvas)) exitHardware((RecordingCanvas) canvas);
         else exitSoftware();
         return this;
     }
 
     private void onAnimationEnd(Animator anim) {
+        notifyUpdate();
         mActiveAnimations.remove(anim);
     }
 
@@ -92,7 +104,6 @@ public final class RippleAnimationSession {
 
     RippleAnimationSession setOnAnimationUpdated(@Nullable Runnable run) {
         mOnUpdate = run;
-        mProperties.setOnChange(mOnUpdate);
         return this;
     }
 
@@ -122,14 +133,12 @@ public final class RippleAnimationSession {
     }
 
     private long computeDelay() {
-        long currentTime = System.nanoTime();
-        long timePassed =  (currentTime - mStartTime) / 1_000_000;
-        long difference = EXIT_ANIM_OFFSET;
-        return Math.max(difference - timePassed, 0);
+        final long timePassed =  AnimationUtils.currentAnimationTimeMillis() - mStartTime;
+        return Math.max((long) SLIDE_ANIM_DURATION - timePassed, 0);
     }
+
     private void notifyUpdate() {
-        Runnable onUpdate = mOnUpdate;
-        if (onUpdate != null) onUpdate.run();
+        if (mOnUpdate != null) mOnUpdate.run();
     }
 
     RippleAnimationSession setForceSoftwareAnimation(boolean forceSw) {
@@ -153,7 +162,7 @@ public final class RippleAnimationSession {
             }
         });
         exit.setTarget(canvas);
-        exit.setInterpolator(DECELERATE_INTERPOLATOR);
+        exit.setInterpolator(LINEAR_INTERPOLATOR);
 
         long delay = computeDelay();
         exit.setStartDelay(delay);
@@ -161,36 +170,67 @@ public final class RippleAnimationSession {
         mActiveAnimations.add(exit);
     }
 
-    private void enterHardware(RecordingCanvas can) {
+    private void enterHardware(RecordingCanvas canvas) {
         AnimationProperties<CanvasProperty<Float>, CanvasProperty<Paint>>
                 props = getCanvasProperties();
         RenderNodeAnimator expand =
                 new RenderNodeAnimator(props.getProgress(), .5f);
-        expand.setTarget(can);
-        expand.setDuration(ENTER_ANIM_DURATION);
-        expand.addListener(new AnimatorListener(this));
+        RenderNodeAnimator slideX =
+                new RenderNodeAnimator(props.getX(), mWidth / 2);
+        RenderNodeAnimator slideY =
+                new RenderNodeAnimator(props.getY(), mHeight / 2);
+        expand.setTarget(canvas);
+        slideX.setTarget(canvas);
+        slideY.setTarget(canvas);
+        startAnimation(expand, slideX, slideY);
+    }
+
+    private void startAnimation(Animator expand,
+            Animator slideX, Animator slideY) {
+        expand.setDuration(SLIDE_ANIM_DURATION);
+        slideX.setDuration(SLIDE_ANIM_DURATION);
+        slideY.setDuration(SLIDE_ANIM_DURATION);
+        slideX.addListener(new AnimatorListener(this));
         expand.setInterpolator(LINEAR_INTERPOLATOR);
+        slideX.setInterpolator(PATH_INTERPOLATOR);
+        slideY.setInterpolator(PATH_INTERPOLATOR);
         expand.start();
+        slideX.start();
+        slideY.start();
+        if (!mSparkle.isRunning()) {
+            mSparkle.start();
+            mActiveAnimations.add(mSparkle);
+        }
         mActiveAnimations.add(expand);
+        mActiveAnimations.add(slideX);
+        mActiveAnimations.add(slideY);
     }
 
     private void enterSoftware() {
         ValueAnimator expand = ValueAnimator.ofFloat(0f, 0.5f);
+        ValueAnimator slideX = ValueAnimator.ofFloat(
+                mProperties.getX(), mWidth / 2);
+        ValueAnimator slideY = ValueAnimator.ofFloat(
+                mProperties.getY(), mHeight / 2);
         expand.addUpdateListener(updatedAnimation -> {
             notifyUpdate();
             mProperties.getShader().setProgress((Float) expand.getAnimatedValue());
         });
-        expand.addListener(new AnimatorListener(this));
-        expand.setInterpolator(LINEAR_INTERPOLATOR);
-        expand.start();
-        mActiveAnimations.add(expand);
+        slideX.addUpdateListener(anim -> {
+            float x = (float) slideX.getAnimatedValue();
+            float y = (float) slideY.getAnimatedValue();
+            mProperties.setOrigin(x, y);
+            mProperties.getShader().setOrigin(x, y);
+        });
+        startAnimation(expand, slideX, slideY);
     }
 
     @NonNull AnimationProperties<Float, Paint> getProperties() {
         return mProperties;
     }
 
-    @NonNull AnimationProperties getCanvasProperties() {
+    @NonNull
+    AnimationProperties<CanvasProperty<Float>, CanvasProperty<Paint>> getCanvasProperties() {
         if (mCanvasProperties == null) {
             mCanvasProperties = new AnimationProperties<>(
                     CanvasProperty.createFloat(mProperties.getX()),
@@ -209,6 +249,7 @@ public final class RippleAnimationSession {
         AnimatorListener(RippleAnimationSession session) {
             mSession = session;
         }
+
         @Override
         public void onAnimationStart(Animator animation) {
 
@@ -231,21 +272,12 @@ public final class RippleAnimationSession {
     }
 
     static class AnimationProperties<FloatType, PaintType> {
-        private final FloatType mY;
-        private FloatType mProgress;
-        private FloatType mMaxRadius;
+        private final FloatType mProgress;
+        private final FloatType mMaxRadius;
         private final PaintType mPaint;
-        private final FloatType mX;
         private final RippleShader mShader;
-        private Runnable mOnChange;
-
-        private void onChange() {
-            if (mOnChange != null) mOnChange.run();
-        }
-
-        private void setOnChange(Runnable onChange) {
-            mOnChange = onChange;
-        }
+        private FloatType mX;
+        private FloatType mY;
 
         AnimationProperties(FloatType x, FloatType y, FloatType maxRadius,
                 PaintType paint, FloatType progress, RippleShader shader) {
@@ -261,6 +293,11 @@ public final class RippleAnimationSession {
             return mProgress;
         }
 
+        void setOrigin(FloatType x, FloatType y) {
+            mX = x;
+            mY = y;
+        }
+
         FloatType getX() {
             return mX;
         }
diff --git a/graphics/java/android/graphics/drawable/RippleDrawable.java b/graphics/java/android/graphics/drawable/RippleDrawable.java
index 5024875aab3c..7fd3cdc39cc7 100644
--- a/graphics/java/android/graphics/drawable/RippleDrawable.java
+++ b/graphics/java/android/graphics/drawable/RippleDrawable.java
@@ -48,6 +48,7 @@ import android.graphics.RecordingCanvas;
 import android.graphics.Rect;
 import android.graphics.Shader;
 import android.os.Build;
+import android.os.SystemProperties;
 import android.util.AttributeSet;
 import android.view.animation.LinearInterpolator;
 
@@ -159,6 +160,9 @@ public class RippleDrawable extends LayerDrawable {
     /** The maximum number of ripples supported. */
     private static final int MAX_RIPPLES = 10;
     private static final LinearInterpolator LINEAR_INTERPOLATOR = new LinearInterpolator();
+    /** Temporary flag for teamfood. **/
+    private static final boolean FORCE_PATTERNED_STYLE =
+            SystemProperties.getBoolean("persist.material.patternedripple", false);
 
     private final Rect mTempRect = new Rect();
 
@@ -361,7 +365,9 @@ public class RippleDrawable extends LayerDrawable {
             }
         } else {
             if (focused || hovered) {
-                enterPatternedBackgroundAnimation(focused, hovered);
+                if (!pressed) {
+                    enterPatternedBackgroundAnimation(focused, hovered);
+                }
             } else {
                 exitPatternedBackgroundAnimation();
             }
@@ -571,7 +577,10 @@ public class RippleDrawable extends LayerDrawable {
         mState.mMaxRadius = a.getDimensionPixelSize(
                 R.styleable.RippleDrawable_radius, mState.mMaxRadius);
 
-        mState.mRippleStyle = a.getInteger(R.styleable.RippleDrawable_rippleStyle, STYLE_SOLID);
+        if (!FORCE_PATTERNED_STYLE) {
+            mState.mRippleStyle = a.getInteger(R.styleable.RippleDrawable_rippleStyle,
+                    mState.mRippleStyle);
+        }
     }
 
     private void verifyRequiredAttributes(@NonNull TypedArray a) throws XmlPullParserException {
@@ -812,21 +821,25 @@ public class RippleDrawable extends LayerDrawable {
     }
 
     private void drawPatterned(@NonNull Canvas canvas) {
-        final Rect bounds = getBounds();
+        final Rect bounds = getDirtyBounds();
         final int saveCount = canvas.save(Canvas.CLIP_SAVE_FLAG);
         boolean useCanvasProps = shouldUseCanvasProps(canvas);
         boolean changedHotspotBounds = !bounds.equals(mHotspotBounds);
         if (isBounded()) {
-            canvas.clipRect(mHotspotBounds);
+            canvas.clipRect(bounds);
         }
-        float x, y;
+        float x, y, w, h;
         if (changedHotspotBounds) {
             x = mHotspotBounds.exactCenterX();
             y = mHotspotBounds.exactCenterY();
+            w = mHotspotBounds.width();
+            h = mHotspotBounds.height();
             useCanvasProps = false;
         } else {
             x = mPendingX;
             y = mPendingY;
+            w = bounds.width();
+            h = bounds.height();
         }
         boolean shouldAnimate = mRippleActive;
         boolean shouldExit = mExitingAnimation;
@@ -837,9 +850,9 @@ public class RippleDrawable extends LayerDrawable {
         drawPatternedBackground(canvas);
         if (shouldAnimate && mRunningAnimations.size() <= MAX_RIPPLES) {
             RippleAnimationSession.AnimationProperties<Float, Paint> properties =
-                    createAnimationProperties(x, y);
-            mRunningAnimations.add(new RippleAnimationSession(properties, !useCanvasProps)
-                    .setOnAnimationUpdated(useCanvasProps ? null : () -> invalidateSelf(false))
+                    createAnimationProperties(x, y, w, h);
+            mRunningAnimations.add(new RippleAnimationSession(properties, !useCanvasProps, w, h)
+                    .setOnAnimationUpdated(() -> invalidateSelf(false))
                     .setOnSessionEnd(session -> {
                         mRunningAnimations.remove(session);
                     })
@@ -864,20 +877,8 @@ public class RippleDrawable extends LayerDrawable {
             } else {
                 RippleAnimationSession.AnimationProperties<Float, Paint> p =
                         s.getProperties();
-                float posX, posY;
-                if (changedHotspotBounds) {
-                    posX = x;
-                    posY = y;
-                    if (p.getPaint().getShader() instanceof RippleShader) {
-                        RippleShader shader = (RippleShader) p.getPaint().getShader();
-                        shader.setOrigin(posX, posY);
-                    }
-                } else {
-                    posX = p.getX();
-                    posY = p.getY();
-                }
                 float radius = p.getMaxRadius();
-                canvas.drawCircle(posX, posY, radius, p.getPaint());
+                canvas.drawCircle(p.getX(), p.getY(), radius, p.getPaint());
             }
         }
         canvas.restoreToCount(saveCount);
@@ -905,14 +906,13 @@ public class RippleDrawable extends LayerDrawable {
 
     private float computeRadius() {
         Rect b = getDirtyBounds();
-        float gap = 0;
-        float radius = (float) Math.sqrt(b.width() * b.width() + b.height() * b.height()) / 2 + gap;
+        float radius = (float) Math.sqrt(b.width() * b.width() + b.height() * b.height()) / 2;
         return radius;
     }
 
     @NonNull
     private RippleAnimationSession.AnimationProperties<Float, Paint> createAnimationProperties(
-            float x, float y) {
+            float x, float y, float w, float h) {
         Paint p = new Paint(mRipplePaint);
         float radius = mState.mMaxRadius;
         RippleAnimationSession.AnimationProperties<Float, Paint> properties;
@@ -920,19 +920,19 @@ public class RippleDrawable extends LayerDrawable {
         int color = mMaskColorFilter == null
                 ? mState.mColor.getColorForState(getState(), Color.BLACK)
                 : mMaskColorFilter.getColor();
-        color = color | 0xFF000000;
         shader.setColor(color);
         shader.setOrigin(x, y);
+        shader.setResolution(w, h);
+        shader.setSecondsOffset(0);
         shader.setRadius(radius);
         shader.setProgress(.0f);
         properties = new RippleAnimationSession.AnimationProperties<>(
                 x, y, radius, p, 0f,
                 shader);
         if (mMaskShader == null) {
-            shader.setHasMask(false);
+            shader.setShader(null);
         } else {
             shader.setShader(mMaskShader);
-            shader.setHasMask(true);
         }
         p.setShader(shader);
         p.setColorFilter(null);
@@ -1160,7 +1160,7 @@ public class RippleDrawable extends LayerDrawable {
             // The ripple timing depends on the paint's alpha value, so we need
             // to push just the alpha channel into the paint and let the filter
             // handle the full-alpha color.
-            int maskColor = color | 0xFF000000;
+            int maskColor = mState.mRippleStyle == STYLE_PATTERNED ? color : color | 0xFF000000;
             if (mMaskColorFilter.getColor() != maskColor) {
                 mMaskColorFilter = new PorterDuffColorFilter(maskColor, mMaskColorFilter.getMode());
             }
@@ -1276,7 +1276,7 @@ public class RippleDrawable extends LayerDrawable {
         @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
         ColorStateList mColor = ColorStateList.valueOf(Color.MAGENTA);
         int mMaxRadius = RADIUS_AUTO;
-        int mRippleStyle = STYLE_SOLID;
+        int mRippleStyle = FORCE_PATTERNED_STYLE ? STYLE_PATTERNED : STYLE_SOLID;
 
         public RippleState(LayerState orig, RippleDrawable owner, Resources res) {
             super(orig, owner, res);
diff --git a/graphics/java/android/graphics/drawable/RippleShader.java b/graphics/java/android/graphics/drawable/RippleShader.java
index 500efdd84854..25492779e6e9 100644
--- a/graphics/java/android/graphics/drawable/RippleShader.java
+++ b/graphics/java/android/graphics/drawable/RippleShader.java
@@ -17,58 +17,153 @@
 package android.graphics.drawable;
 
 import android.annotation.ColorInt;
-import android.annotation.NonNull;
 import android.graphics.Color;
 import android.graphics.RuntimeShader;
 import android.graphics.Shader;
 
 final class RippleShader extends RuntimeShader {
-    private static final String SHADER = "uniform float2 in_origin;\n"
-            + "uniform float in_maxRadius;\n"
+    private static final String SHADER_UNIFORMS =  "uniform vec2 in_origin;\n"
             + "uniform float in_progress;\n"
+            + "uniform float in_maxRadius;\n"
+            + "uniform vec2 in_resolution;\n"
             + "uniform float in_hasMask;\n"
-            + "uniform float4 in_color;\n"
-            + "uniform shader in_shader;\n"
-            + "float dist2(float2 p0, float2 pf) { return sqrt((pf.x - p0.x) * (pf.x - p0.x) + "
-            + "(pf.y - p0.y) * (pf.y - p0.y)); }\n"
-            + "float mod2(float a, float b) { return a - (b * floor(a / b)); }\n"
-            + "float rand(float2 src) { return fract(sin(dot(src.xy, float2(12.9898, 78.233))) * "
-            + "43758.5453123); }\n"
-            + "float4 main(float2 p)\n"
-            + "{\n"
-            + "    float fraction = in_progress;\n"
-            + "    float2 fragCoord = p;//sk_FragCoord.xy;\n"
-            + "    float maxDist = in_maxRadius;\n"
-            + "    float fragDist = dist2(in_origin, fragCoord.xy);\n"
-            + "    float circleRadius = maxDist * fraction;\n"
-            + "    float colorVal = (fragDist - circleRadius) / maxDist;\n"
-            + "    float d = fragDist < circleRadius \n"
-            + "        ? 1. - abs(colorVal * 3. * smoothstep(0., 1., fraction)) \n"
-            + "        : 1. - abs(colorVal * 5.);\n"
-            + "    d = smoothstep(0., 1., d);\n"
-            + "    float divider = 2.;\n"
-            + "    float x = floor(fragCoord.x / divider);\n"
-            + "    float y = floor(fragCoord.y / divider);\n"
-            + "    float density = .95;\n"
-            + "    d = rand(float2(x, y)) > density ? d : d * .2;\n"
-            + "    d = d * rand(float2(fraction, x * y));\n"
-            + "    float alpha = 1. - pow(fraction, 2.);\n"
-            + "    if (in_hasMask != 0.) {return sample(in_shader).a * in_color * d * alpha;}\n"
-            + "    return in_color * d * alpha;\n"
+            + "uniform float in_secondsOffset;\n"
+            + "uniform vec4 in_color;\n"
+            + "uniform shader in_shader;\n";
+    private static final String SHADER_LIB =
+            "float triangleNoise(vec2 n) {\n"
+            + "    n  = fract(n * vec2(5.3987, 5.4421));\n"
+            + "    n += dot(n.yx, n.xy + vec2(21.5351, 14.3137));\n"
+            + "    float xy = n.x * n.y;\n"
+            + "    return fract(xy * 95.4307) + fract(xy * 75.04961) - 1.0;\n"
+            + "}"
+            + "const float PI = 3.1415926535897932384626;\n"
+            + "\n"
+            + "float threshold(float v, float l, float h) {\n"
+            + "  return step(l, v) * (1.0 - step(h, v));\n"
+            + "}\n"
+            + "\n"
+            + "float sparkles(vec2 uv, float t) {\n"
+            + "  float n = triangleNoise(uv);\n"
+            + "  float s = 0.0;\n"
+            + "  for (float i = 0; i < 4; i += 1) {\n"
+            + "    float l = i * 0.25;\n"
+            + "    float h = l + 0.025;\n"
+            + "    float o = abs(sin(0.1 * PI * (t + i)));\n"
+            + "    s += threshold(n + o, l, h);\n"
+            + "  }\n"
+            + "  return saturate(s);\n"
+            + "}\n"
+            + "\n"
+            + "float softCircle(vec2 uv, vec2 xy, float radius, float blur) {\n"
+            + "  float blurHalf = blur * 0.5;\n"
+            + "  float d = distance(uv, xy);\n"
+            + "  return 1. - smoothstep(1. - blurHalf, 1. + blurHalf, d / radius);\n"
+            + "}\n"
+            + "\n"
+            + "float softRing(vec2 uv, vec2 xy, float radius, float blur) {\n"
+            + "  float thickness = 0.4;\n"
+            + "  float circle_outer = softCircle(uv, xy, radius + thickness * 0.5, blur);\n"
+            + "  float circle_inner = softCircle(uv, xy, radius - thickness * 0.5, blur);\n"
+            + "  return circle_outer - circle_inner;\n"
+            + "}\n"
+            + "\n"
+            + "struct Viewport {\n"
+            + "  float aspect;\n"
+            + "  vec2 uv;\n"
+            + "  vec2 resolution_pixels;\n"
+            + "};\n"
+            + "\n"
+            + "Viewport getViewport(vec2 frag_coord, vec2 resolution_pixels) {\n"
+            + "  Viewport v;\n"
+            + "  v.aspect = resolution_pixels.y / resolution_pixels.x;\n"
+            + "  v.uv = frag_coord / resolution_pixels;\n"
+            + "  v.uv.y = (1.0 - v.uv.y) * v.aspect;\n"
+            + "  v.resolution_pixels = resolution_pixels;\n"
+            + "  return v;\n"
+            + "}\n"
+            + "\n"
+            + "vec2 getTouch(vec2 touch_position_pixels, Viewport viewport) {\n"
+            + "  vec2 touch = touch_position_pixels / viewport.resolution_pixels;\n"
+            + "  touch.y *= viewport.aspect;\n"
+            + "  return touch;\n"
+            + "}\n"
+            + "\n"
+            + "struct Wave {\n"
+            + "  float ring;\n"
+            + "  float circle;\n"
+            + "};\n"
+            + "\n"
+            + "Wave getWave(Viewport viewport, vec2 touch, float progress) {\n"
+            + "  float fade = pow((clamp(progress, 0.8, 1.0)), 8.);\n"
+            + "  Wave w;\n"
+            + "  w.ring = max(softRing(viewport.uv, touch, progress, 0.45) - fade, 0.);\n"
+            + "  w.circle = softCircle(viewport.uv, touch, 2.0 * progress, 0.2) - progress;\n"
+            + "  return w;\n"
+            + "}\n"
+            + "\n"
+            + "vec4 getRipple(vec4 color, float loudness, float sparkle, Wave wave) {\n"
+            + "  float alpha = wave.ring * sparkle * loudness\n"
+            + "        + wave.circle * color.a;\n"
+            + "  return vec4(color.rgb, saturate(alpha));\n"
+            + "}\n"
+            + "\n"
+            + "float getRingMask(vec2 frag, vec2 center, float r, float progress) {\n"
+            + "      float dist = distance(frag, center);\n"
+            + "      float expansion = r * .6;\n"
+            + "      r = r * min(1.,progress);\n"
+            + "      float minD = max(r - expansion, 0.);\n"
+            + "      float maxD = r + expansion;\n"
+            + "      if (dist > maxD || dist < minD) return .0;\n"
+            + "      return min(maxD - dist, dist - minD) / expansion;    \n"
+            + "}\n"
+            + "\n"
+            + "float subProgress(float start, float end, float progress) {\n"
+            + "    float sub = clamp(progress, start, end);\n"
+            + "    return (sub - start) / (end - start); \n"
             + "}\n";
+    private static final String SHADER_MAIN = "vec4 main(vec2 p) {\n"
+            + "    float fadeIn = subProgress(0., 0.175, in_progress);\n"
+            + "    float fadeOutNoise = subProgress(0.375, 1., in_progress);\n"
+            + "    float fadeOutRipple = subProgress(0.375, 0.75, in_progress);\n"
+            + "    Viewport vp = getViewport(p, in_resolution);\n"
+            + "    vec2 touch = getTouch(in_origin, vp);\n"
+            + "    Wave w = getWave(vp, touch, in_progress * 0.25);\n"
+            + "    float ring = getRingMask(p, in_origin, in_maxRadius, fadeIn);\n"
+            + "    float alpha = min(fadeIn, 1. - fadeOutNoise);\n"
+            + "    float sparkle = sparkles(p, in_progress * 0.25 + in_secondsOffset)\n"
+            + "        * ring * alpha;\n"
+            + "    vec4 r = getRipple(in_color, 1., sparkle, w);\n"
+            + "    float fade = min(fadeIn, 1.-fadeOutRipple);\n"
+            + "    vec4 circle = vec4(in_color.rgb, softCircle(p, in_origin, in_maxRadius "
+            + "      * fadeIn, 0.2) * fade * in_color.a);\n"
+            + "    float mask = in_hasMask == 1. ? sample(in_shader).a > 0. ? 1. : 0. : 1.;\n"
+            + "    return mix(circle, vec4(1.), sparkle * mask);\n"
+            + "}";
+    private static final String SHADER = SHADER_UNIFORMS + SHADER_LIB + SHADER_MAIN;
 
     RippleShader() {
         super(SHADER, false);
     }
 
-    public void setShader(@NonNull Shader s) {
-        setInputShader("in_shader", s);
+    public void setShader(Shader shader) {
+        if (shader != null) {
+            setInputShader("in_shader", shader);
+        }
+        setUniform("in_hasMask", shader == null ? 0 : 1);
     }
 
     public void setRadius(float radius) {
         setUniform("in_maxRadius", radius);
     }
 
+    /**
+     * Continuous offset used as noise phase.
+     */
+    public void setSecondsOffset(float t) {
+        setUniform("in_secondsOffset", t);
+    }
+
     public void setOrigin(float x, float y) {
         setUniform("in_origin", new float[] {x, y});
     }
@@ -77,13 +172,16 @@ final class RippleShader extends RuntimeShader {
         setUniform("in_progress", progress);
     }
 
-    public void setHasMask(boolean hasMask) {
-        setUniform("in_hasMask", hasMask ? 1 : 0);
-    }
-
+    /**
+     * Color of the circle that's under the sparkles. Sparkles will always be white.
+     */
     public void setColor(@ColorInt int colorIn) {
         Color color = Color.valueOf(colorIn);
         this.setUniform("in_color", new float[] {color.red(),
                 color.green(), color.blue(), color.alpha()});
     }
+
+    public void setResolution(float w, float h) {
+        setUniform("in_resolution", w, h);
+    }
 }