UX feedback for ripple

- Updated easings
- Made sparkles larger
- Made sparkles density independent
- Modified sparkle animation speed

Fixes: 182173639
Test: visual
Change-Id: I91b9f2dc9ffa19ce7b960129256be86eee217e8a

graphics/java/android/graphics/drawable/RippleAnimationSession.java

@@ -26,8 +26,8 @@ import android.graphics.CanvasProperty;
 import android.graphics.Paint;
 import android.graphics.RecordingCanvas;
 import android.graphics.animation.RenderNodeAnimator;
-import android.util.ArraySet;
 import android.view.animation.AnimationUtils;
+import android.view.animation.Interpolator;
 import android.view.animation.LinearInterpolator;
 import android.view.animation.PathInterpolator;
 
@@ -41,8 +41,8 @@ public final class RippleAnimationSession {
     private static final int ENTER_ANIM_DURATION = 450;
     private static final int EXIT_ANIM_DURATION = 300;
     private static final TimeInterpolator LINEAR_INTERPOLATOR = new LinearInterpolator();
-    private static final TimeInterpolator PATH_INTERPOLATOR =
-            new PathInterpolator(.2f, 0, 0, 1f);
+    private static final Interpolator FAST_OUT_LINEAR_IN =
+            new PathInterpolator(0.4f, 0f, 1f, 1f);
     private Consumer<RippleAnimationSession> mOnSessionEnd;
     private final AnimationProperties<Float, Paint> mProperties;
     private AnimationProperties<CanvasProperty<Float>, CanvasProperty<Paint>> mCanvasProperties;
@@ -59,7 +59,7 @@ public final class RippleAnimationSession {
         mSparkle.addUpdateListener(anim -> {
             final long now = AnimationUtils.currentAnimationTimeMillis();
             final long elapsed = now - mStartTime - ENTER_ANIM_DURATION;
-            final float phase = (float) elapsed / 30000f;
+            final float phase = (float) elapsed / 800;
             mProperties.getShader().setNoisePhase(phase);
             notifyUpdate();
         });
@@ -174,7 +174,7 @@ public final class RippleAnimationSession {
     private void startAnimation(Animator expand) {
         expand.setDuration(ENTER_ANIM_DURATION);
         expand.addListener(new AnimatorListener(this));
-        expand.setInterpolator(LINEAR_INTERPOLATOR);
+        expand.setInterpolator(FAST_OUT_LINEAR_IN);
         expand.start();
         if (!mSparkle.isRunning()) {
             mSparkle.start();

graphics/java/android/graphics/drawable/RippleDrawable.java

@@ -914,7 +914,7 @@ public class RippleDrawable extends LayerDrawable {
         shader.setColor(color);
         shader.setOrigin(w / 2, y / 2);
         shader.setTouch(x, y);
-        shader.setResolution(w, h);
+        shader.setResolution(w, h, mState.mDensity);
         shader.setNoisePhase(0);
         shader.setRadius(radius);
         shader.setProgress(.0f);

graphics/java/android/graphics/drawable/RippleShader.java

@@ -20,13 +20,15 @@ import android.annotation.ColorInt;
 import android.graphics.Color;
 import android.graphics.RuntimeShader;
 import android.graphics.Shader;
+import android.util.DisplayMetrics;
 
 final class RippleShader extends RuntimeShader {
     private static final String SHADER_UNIFORMS =  "uniform vec2 in_origin;\n"
             + "uniform vec2 in_touch;\n"
             + "uniform float in_progress;\n"
             + "uniform float in_maxRadius;\n"
-            + "uniform vec2 in_resolution;\n"
+            + "uniform vec2 in_resolutionScale;\n"
+            + "uniform vec2 in_noiseScale;\n"
             + "uniform float in_hasMask;\n"
             + "uniform float in_noisePhase;\n"
             + "uniform vec4 in_color;\n"
@@ -40,18 +42,15 @@ final class RippleShader extends RuntimeShader {
             + "}"
             + "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 + 0.005;\n"
-            + "    float o = abs(sin(0.1 * PI * (t + i)));\n"
-            + "    s += threshold(n + o, l, h);\n"
+            + "    float l = i * 0.01;\n"
+            + "    float h = l + 0.1;\n"
+            + "    float o = smoothstep(n - l, h, n);\n"
+            + "    o *= abs(sin(PI * o * (t + 0.55 * i)));\n"
+            + "    s += o;\n"
             + "  }\n"
             + "  return saturate(s);\n"
             + "}\n"
@@ -83,7 +82,9 @@ final class RippleShader extends RuntimeShader {
             + "    vec2 center = mix(in_touch, in_origin, fadeIn);\n"
             + "    float ring = getRingMask(p, center, in_maxRadius, fadeIn);\n"
             + "    float alpha = min(fadeIn, 1. - fadeOutNoise);\n"
-            + "    float sparkle = sparkles(p, in_noisePhase) * ring * alpha;\n"
+            + "    vec2 uv = p * in_resolutionScale;\n"
+            + "    vec2 densityUv = uv - mod(uv, in_noiseScale);\n"
+            + "    float sparkle = sparkles(densityUv, in_noisePhase) * ring * alpha;\n"
             + "    float fade = min(fadeIn, 1. - fadeOutRipple);\n"
             + "    vec4 circle = in_color * (softCircle(p, center, in_maxRadius "
             + "      * fadeIn, 0.2) * fade);\n"
@@ -135,7 +136,10 @@ final class RippleShader extends RuntimeShader {
                 color.green(), color.blue(), color.alpha()});
     }
 
-    public void setResolution(float w, float h) {
-        setUniform("in_resolution", w, h);
+    public void setResolution(float w, float h, int density) {
+        float noiseScale = 0.8f;
+        float densityScale = density * DisplayMetrics.DENSITY_DEFAULT_SCALE * 0.5f * noiseScale;
+        setUniform("in_resolutionScale", new float[] {1f / w, 1f / h});
+        setUniform("in_noiseScale", new float[] {densityScale / w, densityScale / h});
     }
 }