From 68b5d1385689bd4b2f619f73be9f0191c95c39d4 Mon Sep 17 00:00:00 2001
From: Juan Sebastian Martinez <juansmartinez@google.com>
Date: Tue, 8 Sep 2026 08:57:10 -0700
Subject: [PATCH] Making LavaBeats shader time relative to the STARTED
 lifecycle state

This makes sure that the shader time is always relative to the lifecycle
of the app, avoiding the storage of very large numbers over time as the
device is left on for a long period of time. The latter makes the effect
laggy and janky due to computations with large numbers
---
 .../ui/haptics/lavabeats/LavaBeatsGraphics.kt | 27 +++++++++++--------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/samples/user-interface/haptics/src/main/java/com/example/platform/ui/haptics/lavabeats/LavaBeatsGraphics.kt b/samples/user-interface/haptics/src/main/java/com/example/platform/ui/haptics/lavabeats/LavaBeatsGraphics.kt
index 1f899a27..8f80bc33 100644
--- a/samples/user-interface/haptics/src/main/java/com/example/platform/ui/haptics/lavabeats/LavaBeatsGraphics.kt
+++ b/samples/user-interface/haptics/src/main/java/com/example/platform/ui/haptics/lavabeats/LavaBeatsGraphics.kt
@@ -27,12 +27,16 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableFloatStateOf
+import androidx.compose.runtime.mutableLongStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.drawWithCache
 import androidx.compose.ui.graphics.ShaderBrush
 import androidx.compose.ui.platform.LocalDensity
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.compose.LocalLifecycleOwner
+import androidx.lifecycle.repeatOnLifecycle
 
 @Composable
 fun LavaBeatsGraphics(
@@ -47,21 +51,22 @@ fun LavaBeatsGraphics(
         val density = LocalDensity.current
         val width = with(density) { constraints.maxWidth.toPx() }
         val height = with(density) { constraints.maxHeight.toPx() }
-        var firstTime by remember { mutableFloatStateOf(-1f) }
+        var startTimeMillis by remember { mutableLongStateOf(-1L) }
         var time by remember { mutableFloatStateOf(0f) }
+
+        val lifecycleOwner = LocalLifecycleOwner.current
         val isInDarkMode = isSystemInDarkTheme()
         val surfaceColor = MaterialTheme.colorScheme.background
 
-        LaunchedEffect(Unit) {
-            // Use withInfiniteAnimationFrameMillis to update the time uniform per frame.
-            // This is a more efficient approach than passing a new shader instance
-            // or re-creating the RenderEffect on every frame.
-            while (true) {
-                withInfiniteAnimationFrameMillis { frameTime ->
-                    if (firstTime == -1f) {
-                        firstTime = frameTime / 1000f
-                    } else {
-                        time = frameTime / 1000f - firstTime
+        LaunchedEffect(lifecycleOwner) {
+            lifecycleOwner.lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {
+                startTimeMillis = -1L
+                while (true) {
+                    withInfiniteAnimationFrameMillis { frameTime ->
+                        if (startTimeMillis == -1L) {
+                            startTimeMillis = frameTime
+                        }
+                        time = (frameTime - startTimeMillis) / 1000f
                     }
                 }
             }