Proper onLightingInfoChanged tracking

JetBrains · Dec 20, 2024 · 7ab0b32 · 7ab0b32
1 parent 2e92dd8
commit 7ab0b32
Show file tree

Hide file tree

Showing 4 changed files with 107 additions and 53 deletions.
diff --git a/...i-graphics/src/skikoMain/kotlin/androidx/compose/ui/graphics/SkiaGraphicsContext.skiko.kt b/...i-graphics/src/skikoMain/kotlin/androidx/compose/ui/graphics/SkiaGraphicsContext.skiko.kt
@@ -19,14 +19,18 @@ package androidx.compose.ui.graphics
 import androidx.compose.runtime.snapshots.SnapshotStateObserver
 import androidx.compose.ui.InternalComposeUiApi
 import androidx.compose.ui.graphics.layer.GraphicsLayer
+import androidx.compose.ui.unit.Density
 import androidx.compose.ui.unit.IntSize
+import androidx.compose.ui.unit.dp
+import org.jetbrains.skia.Point3
 
 @InternalComposeUiApi
 class SkiaGraphicsContext(
-    var containerSize: () -> IntSize,
-    private val measureDrawBounds: Boolean,
-) : GraphicsContext {
-    private val snapshotObserver = SnapshotStateObserver { command ->
+    internal val measureDrawBounds: Boolean,
+): GraphicsContext {
+    internal val lightGeometry = LightGeometry()
+    internal val lightInfo = LightInfo()
+    internal val snapshotObserver = SnapshotStateObserver { command ->
         command()
     }
 
@@ -39,13 +43,34 @@ class SkiaGraphicsContext(
         snapshotObserver.clear()
     }
 
-    override fun createGraphicsLayer() = GraphicsLayer(
-        snapshotObserver = snapshotObserver,
-        containerSize = containerSize,
-        measureDrawBounds = measureDrawBounds
-    )
+    fun setLightingInfo(
+        centerX: Float = Float.MIN_VALUE,
+        centerY: Float = Float.MIN_VALUE,
+        centerZ: Float = Float.MIN_VALUE,
+        radius: Float = 0f,
+        ambientShadowAlpha: Float = 0f,
+        spotShadowAlpha: Float = 0f
+    ) {
+        lightGeometry.center = Point3(centerX, centerY, centerZ)
+        lightGeometry.radius = radius
+        lightInfo.ambientShadowAlpha = ambientShadowAlpha
+        lightInfo.spotShadowAlpha = spotShadowAlpha
+    }
+
+    override fun createGraphicsLayer() = GraphicsLayer(this)
 
     override fun releaseGraphicsLayer(layer: GraphicsLayer) {
         layer.release()
     }
 }
+
+// Adoption of frameworks/base/libs/hwui/Lighting.h
+internal data class LightGeometry(
+    var center: Point3 = Point3(Float.MIN_VALUE, Float.MIN_VALUE, Float.MIN_VALUE),
+    var radius: Float = 0f
+)
+
+internal data class LightInfo(
+    var ambientShadowAlpha: Float = 0f,
+    var spotShadowAlpha: Float = 0f
+)
diff --git a/...aphics/src/skikoMain/kotlin/androidx/compose/ui/graphics/layer/SkiaGraphicsLayer.skiko.kt b/...aphics/src/skikoMain/kotlin/androidx/compose/ui/graphics/layer/SkiaGraphicsLayer.skiko.kt
@@ -18,7 +18,6 @@ package androidx.compose.ui.graphics.layer
 
 import androidx.compose.runtime.SnapshotMutationPolicy
 import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.snapshots.SnapshotStateObserver
 import androidx.compose.ui.geometry.CornerRadius
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.geometry.Rect
@@ -37,6 +36,7 @@ import androidx.compose.ui.graphics.Paint
 import androidx.compose.ui.graphics.Path
 import androidx.compose.ui.graphics.RenderEffect
 import androidx.compose.ui.graphics.SkiaBackedCanvas
+import androidx.compose.ui.graphics.SkiaGraphicsContext
 import androidx.compose.ui.graphics.asComposeCanvas
 import androidx.compose.ui.graphics.asSkiaColorFilter
 import androidx.compose.ui.graphics.asSkiaPath
@@ -52,9 +52,7 @@ import androidx.compose.ui.unit.Density
 import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.IntSize
 import androidx.compose.ui.unit.LayoutDirection
-import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.toSize
-import kotlin.math.min
 import org.jetbrains.skia.Picture
 import org.jetbrains.skia.PictureRecorder
 import org.jetbrains.skia.Point3
@@ -63,15 +61,13 @@ import org.jetbrains.skia.Rect as SkRect
 import org.jetbrains.skia.ShadowUtils
 
 actual class GraphicsLayer internal constructor(
-    private val snapshotObserver: SnapshotStateObserver,
-    private val containerSize: () -> IntSize,
-    measureDrawBounds: Boolean,
+    private val context: SkiaGraphicsContext,
 ) {
     private val pictureDrawScope = CanvasDrawScope()
     private val pictureRecorder = PictureRecorder()
     private var picture: Picture? = null
     // Use factory for BBoxHierarchy to track real bounds of drawn content
-    private val bbhFactory = if (measureDrawBounds) RTreeFactory() else null
+    private val bbhFactory = if (context.measureDrawBounds) RTreeFactory() else null
 
     // Composable state marker for tracking drawing invalidations.
     private val drawState = mutableStateOf(Unit, object : SnapshotMutationPolicy<Unit> {
@@ -230,7 +226,7 @@ actual class GraphicsLayer internal constructor(
         childDependenciesTracker.withTracking(
             onDependencyRemoved = { it.onRemovedFromParentLayer() }
         ) {
-            snapshotObserver.observeReads(
+            context.snapshotObserver.observeReads(
                 scope = this,
                 onValueChangedForScope = {
                     // Can be called from another thread
@@ -483,7 +479,7 @@ actual class GraphicsLayer internal constructor(
                 it.onRemovedFromParentLayer()
             }
 
-            snapshotObserver.clear(this)
+            context.snapshotObserver.clear(this)
         }
     }
 
@@ -509,26 +505,26 @@ actual class GraphicsLayer internal constructor(
             offscreenBufferRequested
     }
 
-    private fun drawShadow(canvas: Canvas) = with(density) {
+    private fun drawShadow(canvas: Canvas) {
         val path = when (val tmpOutline = internalOutline) {
             is Outline.Rectangle -> Path().apply { addRect(tmpOutline.rect) }
             is Outline.Rounded -> Path().apply { addRoundRect(tmpOutline.roundRect) }
             is Outline.Generic -> tmpOutline.path
             else -> return
         }
 
-        val translationZ = 0f
-        val zParams = Point3(0f, 0f, shadowElevation + translationZ)
-        val lightPos = getLightCenter(containerSize())
-        val ambientColor = ambientShadowColor.copy(alpha = AMBIENT_SHADOW_ALPHA * alpha)
-        val spotColor = spotShadowColor.copy(alpha = SPOT_SHADOW_ALPHA * alpha)
+        val zParams = Point3(0f, 0f, shadowElevation)
+        val ambientAlpha = context.lightInfo.ambientShadowAlpha * alpha
+        val spotAlpha = context.lightInfo.spotShadowAlpha * alpha
+        val ambientColor = ambientShadowColor.copy(alpha = ambientAlpha)
+        val spotColor = spotShadowColor.copy(alpha = spotAlpha)
 
-        ShadowUtils.drawShadow(
+        return ShadowUtils.drawShadow(
             canvas = canvas.nativeCanvas,
             path = path.asSkiaPath(),
             zPlaneParams = zParams,
-            lightPos = lightPos,
-            lightRadius = LIGHT_RADIUS.toPx(),
+            lightPos = context.lightGeometry.center,
+            lightRadius = context.lightGeometry.radius,
             ambientColor = ambientColor.toArgb(),
             spotColor = spotColor.toArgb(),
             transparentOccluder = alpha < 1f,
@@ -557,24 +553,3 @@ private val PICTURE_BOUNDS = SkRect.makeLTRB(
     r = PICTURE_MAX_VALUE,
     b = PICTURE_MAX_VALUE
 )
-
-
-// Adoption of android.view.ThreadedRenderer.setLightCenter
-private fun Density.getLightCenter(containerSize: IntSize): Point3 {
-    val lightX = containerSize.width / 2f
-    val lightY = LIGHT_Y.toPx()
-    // To prevent shadow distortion on larger screens, scale the z position of the light source
-    // relative to the smallest screen dimension.
-    val zRatio = min(containerSize.width, containerSize.height).toFloat() / 450.dp.toPx()
-    val zWeightedAdjustment = (zRatio + 2) / 3f
-    val lightZ = LIGHT_Z.toPx() * zWeightedAdjustment
-
-    return Point3(lightX,lightY, lightZ)
-}
-
-// Values from core/res/res/values/dimens.xml
-private val LIGHT_Y = 0.dp
-private val LIGHT_Z = 500.dp
-private val LIGHT_RADIUS = 800.dp
-private const val AMBIENT_SHADOW_ALPHA = 0.039f
-private const val SPOT_SHADOW_ALPHA = 0.19f
diff --git a/compose/ui/ui/src/skikoMain/kotlin/androidx/compose/ui/node/RootNodeOwner.skiko.kt b/compose/ui/ui/src/skikoMain/kotlin/androidx/compose/ui/node/RootNodeOwner.skiko.kt
@@ -22,6 +22,7 @@ import androidx.compose.runtime.collection.mutableVectorOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
+import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.ExperimentalComposeUiApi
 import androidx.compose.ui.InternalComposeUiApi
 import androidx.compose.ui.Modifier
@@ -65,6 +66,7 @@ import androidx.compose.ui.platform.PlatformClipboardManager
 import androidx.compose.ui.platform.PlatformContext
 import androidx.compose.ui.platform.PlatformRootForTest
 import androidx.compose.ui.platform.PlatformTextInputSessionScope
+import androidx.compose.ui.platform.setLightingInfo
 import androidx.compose.ui.scene.ComposeScene
 import androidx.compose.ui.scene.ComposeSceneInputHandler
 import androidx.compose.ui.scene.ComposeScenePointer
@@ -90,6 +92,10 @@ import androidx.compose.ui.viewinterop.pointerInteropFilter
 import kotlin.coroutines.CoroutineContext
 import kotlin.math.max
 import kotlin.math.min
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.launch
 
 /**
  * Owner of root [LayoutNode].
@@ -126,10 +132,8 @@ internal class RootNodeOwner(
 
     private val rootSemanticsNode = EmptySemanticsModifier()
     private val snapshotObserver = snapshotInvalidationTracker.snapshotObserver()
-    private val graphicsContext = SkiaGraphicsContext(
-        containerSize = { platformContext.windowInfo.containerSize },
-        measureDrawBounds = platformContext.measureDrawLayerBounds,
-    )
+    private val graphicsContext = SkiaGraphicsContext(platformContext.measureDrawLayerBounds)
+    private val coroutineScope = CoroutineScope(coroutineContext + Job(parent = coroutineContext[Job]))
 
     private val rootModifier = EmptySemanticsElement(rootSemanticsNode)
         .focusProperties {
@@ -177,10 +181,18 @@ internal class RootNodeOwner(
         owner.root.attach(owner)
         platformContext.rootForTestListener?.onRootForTestCreated(rootForTest)
         onRootConstrainsChanged(size?.toConstraints())
+        onLightingInfoChanged()
+        coroutineScope.launch {
+            snapshotFlow { platformContext.windowInfo.containerSize }
+                .collect {
+                    onLightingInfoChanged()
+                }
+        }
     }
 
     fun dispose() {
         check(!isDisposed) { "RootNodeOwner is already disposed" }
+        coroutineScope.cancel()
         platformContext.rootForTestListener?.onRootForTestDisposed(rootForTest)
         snapshotObserver.stopObserving()
         graphicsContext.dispose()
@@ -224,6 +236,7 @@ internal class RootNodeOwner(
     fun invalidatePositionInWindow() {
         owner.root.layoutDelegate.measurePassDelegate.notifyChildrenUsingCoordinatesWhilePlacing()
         measureAndLayoutDelegate.dispatchOnPositionedCallbacks(forceDispatch = true)
+        onLightingInfoChanged()
     }
 
     fun draw(canvas: Canvas) = trace("RootNodeOwner:draw") {
@@ -245,6 +258,14 @@ internal class RootNodeOwner(
         }
     }
 
+    private fun onLightingInfoChanged() {
+        graphicsContext.setLightingInfo(
+            canvasOffset = platformContext.convertLocalToWindowPosition(Offset.Zero),
+            density = density,
+            containerSize = platformContext.windowInfo.containerSize
+        )
+    }
+
     @OptIn(InternalCoreApi::class)
     fun onPointerInput(event: PointerInputEvent) {
         if (event.button != null) {

diff --git a/.../ui/ui/src/skikoMain/kotlin/androidx/compose/ui/platform/GraphicsLayerOwnerLayer.skiko.kt b/.../ui/ui/src/skikoMain/kotlin/androidx/compose/ui/platform/GraphicsLayerOwnerLayer.skiko.kt
@@ -26,6 +26,7 @@ import androidx.compose.ui.graphics.GraphicsContext
 import androidx.compose.ui.graphics.Matrix
 import androidx.compose.ui.graphics.Outline
 import androidx.compose.ui.graphics.ReusableGraphicsLayerScope
+import androidx.compose.ui.graphics.SkiaGraphicsContext
 import androidx.compose.ui.graphics.TransformOrigin
 import androidx.compose.ui.graphics.drawscope.CanvasDrawScope
 import androidx.compose.ui.graphics.drawscope.DrawScope
@@ -41,7 +42,8 @@ import androidx.compose.ui.unit.Density
 import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.IntSize
 import androidx.compose.ui.unit.LayoutDirection
-
+import androidx.compose.ui.unit.dp
+import org.jetbrains.skia.Point3
 
 internal class GraphicsLayerOwnerLayer(
     private var graphicsLayer: GraphicsLayer,
@@ -357,3 +359,34 @@ internal class GraphicsLayerOwnerLayer(
         )
     }
 }
+
+internal fun SkiaGraphicsContext.setLightingInfo(
+    canvasOffset: Offset,
+    density: Density,
+    containerSize: IntSize
+) = with(density) {
+    // Adoption of android.view.ThreadedRenderer.setLightCenter
+    val lightX = containerSize.width / 2f - canvasOffset.x
+    val lightY = LIGHT_Y.toPx() - canvasOffset.y
+    // To prevent shadow distortion on larger screens, scale the z position of the light source
+    // relative to the smallest screen dimension.
+    val zRatio = kotlin.math.min(containerSize.width, containerSize.height).toFloat() / 450.dp.toPx()
+    val zWeightedAdjustment = (zRatio + 2) / 3f
+    val lightZ = LIGHT_Z.toPx() * zWeightedAdjustment
+
+    setLightingInfo(
+        centerX = lightX,
+        centerY = lightY,
+        centerZ = lightZ,
+        radius = LIGHT_RADIUS.toPx(),
+        ambientShadowAlpha = AMBIENT_SHADOW_ALPHA,
+        spotShadowAlpha = SPOT_SHADOW_ALPHA
+    )
+}
+
+// Values from core/res/res/values/dimens.xml
+private val LIGHT_Y = 0.dp
+private val LIGHT_Z = 500.dp
+private val LIGHT_RADIUS = 800.dp
+private const val AMBIENT_SHADOW_ALPHA = 0.039f
+private const val SPOT_SHADOW_ALPHA = 0.19f