Geometry API
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最后更新时间 (UTC)：2025-07-27。
[null,null,["最后更新时间 (UTC)：2025-07-27。"],[],[],null,["# Geometry APIs\n\nThe Geometry APIs allow you to create interactive tools such as erasers and\nselection mechanisms.\n\nTo illustrate practical application of the Geometry APIs, explore the following\neraser implementation example.\n\n### Whole stroke eraser\n\n fun eraseWholeStrokes(\n eraserBox: ImmutableBox,\n finishedStrokesState: MutableState\u003cSet\u003cStroke\u003e\u003e,\n ) {\n val threshold = 0.1f\n\n val strokesToErase = finishedStrokesState.value.filter { stroke -\u003e\n stroke.shape.computeCoverageIsGreaterThan(\n box = eraserBox,\n coverageThreshold = threshold,\n )\n }\n if (strokesToErase.isNotEmpty()) {\n Snapshot.withMutableSnapshot {\n finishedStrokesState.value -= strokesToErase\n }\n }\n }\n\nFor a Compose implementation, make sure to trigger a recomposition, so the\nstrokes are effectively removed. For example, an approach would be to use\n`rememberCoroutineScope` in your composable and pass the coroutine scope to your\ntouch listener, allowing you to modify `finishedStrokesState` within the scope\nof Compose.\n| **Note:** An eraser that only removes the parts of the strokes it touches can be implemented by seeing if a stroke intersects with individual line segments of a [`StrokeInputBatch`](/reference/kotlin/androidx/ink/strokes/StrokeInputBatch) and creating new [`StrokeInputBatch`](/reference/kotlin/androidx/ink/strokes/StrokeInputBatch) and [`Stroke`](/reference/kotlin/androidx/ink/strokes/Stroke) objects out of the line segments that aren't intersected."]]