--- title: "PolygonShapeGeometry" description: "Geometry describing a polygon's [vertices], [center], and [rounding]." type: "class" lastmod: "2026-09-24" --- ## API Reference > Source set: Common ```kotlin public class PolygonShapeGeometry internal constructor( public val vertices: List, public val center: Offset, public val rounding: CornerRounding, @get:Suppress("NullableCollection") public val perVertexRounding: List?, internal val roundingReference: Size? = null, ) ``` Geometry describing a polygon's `vertices`, `center`, and `rounding`. The consumer defines the coordinate space. [PolygonShapeScope](/jetpack-compose/androidx.compose.foundation/foundation/interfaces/PolygonShapeScope/api) factories create geometry in pixels in the layout's coordinate space, while geometry passed directly to [PolygonShape](/jetpack-compose/androidx.compose.foundation/foundation/functions/PolygonShape/api) uses an author-chosen space and is scaled into the layout bounds at resolution time. Rounding resolves in the vertex coordinate space. A float radius is a length in that space, and a percent radius resolves against the smaller dimension of the vertex bounds. ## Functions ### equals > Source set: Common ```kotlin override fun equals(other: Any?): Boolean ``` ### hashCode > Source set: Common ```kotlin override fun hashCode(): Int ``` ### toString > Source set: Common ```kotlin override fun toString(): String ``` ## Members ### CornerRounding > Source set: Common ```kotlin public class CornerRounding internal constructor( internal val value: Float, internal val unit: Int, internal val smoothing: Float, ) ``` Amount and quality of rounding around a polygon vertex. A corner takes one of three forms: - unrounded, with a radius of 0, keeping the sharp vertex; - rounded with a circular arc, with a `smoothing` of 0, following an approximated circular arc between adjacent edges; - rounded with continuous curvature, with `smoothing` > 0, where two symmetric cubic Bézier flanking curves connect the circular arc to the edges. A `smoothing` of 0 keeps a purely circular arc and 1 maximizes the flanking curves so they meet in the middle. ## Functions ### equals > Source set: Common ```kotlin override fun equals(other: Any?): Boolean ``` ### hashCode > Source set: Common ```kotlin override fun hashCode(): Int ``` ### toString > Source set: Common ```kotlin override fun toString(): String ``` ## Members ### Companion > Source set: Common ```kotlin public companion object ``` ## Properties ### Unrounded > Source set: Common ```kotlin public val Unrounded: CornerRounding = CornerRounding(0f, UnitLength, 0f) ``` Rounding with a radius of zero, producing a sharp corner at the vertex. ### Companion > Source set: Common ```kotlin public companion object ``` ## Functions ### CornerRounding > Source set: Common ```kotlin public fun CornerRounding(radius: Float, smoothing: Float = 0f): CornerRounding ``` Creates a `CornerRounding` with a `radius` in the same coordinate space as the vertices. #### Parameters | | | | --- | --- | | radius | rounding radius in the vertex coordinate space, at least 0 | | smoothing | the amount by which the arc is "smoothed" by extending the curve from the inner circular arc to the edge between vertices. A value of 0 (no smoothing) indicates that the corner is rounded by only a circular arc; there are no flanking curves. A value of 1 indicates that there is no circular arc in the center; the flanking curves on either side meet at the middle. | #### Throws: IllegalArgumentException if `radius` is negative or [smoothing](#smoothing) is outside the range 0 to 1 ### CornerRounding > Source set: Common ```kotlin public fun CornerRounding(radius: Dp, smoothing: Float = 0f): CornerRounding ``` Creates a `CornerRounding` with a `radius` in `Dp`, resolved with the shape's density. #### Parameters | | | | --- | --- | | radius | rounding radius of the corner, at least 0 | | smoothing | the amount by which the arc is "smoothed" by extending the curve from the inner circular arc to the edge between vertices. A value of 0 (no smoothing) indicates that the corner is rounded by only a circular arc; there are no flanking curves. A value of 1 indicates that there is no circular arc in the center; the flanking curves on either side meet at the middle. | #### Throws: IllegalArgumentException if `radius` is negative or unspecified, or [smoothing](#smoothing) is outside the range 0 to 1 ### CornerRounding > Source set: Common ```kotlin public fun CornerRounding( @IntRange(from = 0, to = 100) percent: Int, smoothing: Float = 0f, ): CornerRounding ``` Creates a `CornerRounding` with a radius as a `percent` of the geometry it applies to. The reference is the generating radius for regular polygons and stars, or the smaller dimension of the vertex bounds for vertex-list geometry, so the radius scales with the shape rather than with the layout container. #### Parameters | | | | --- | --- | | percent | rounding radius as a percentage of the geometry, in the range 0 to 100 | | smoothing | the amount by which the arc is "smoothed" by extending the curve from the inner circular arc to the edge between vertices. A value of 0 (no smoothing) indicates that the corner is rounded by only a circular arc; there are no flanking curves. A value of 1 indicates that there is no circular arc in the center; the flanking curves on either side meet at the middle. | #### Throws: IllegalArgumentException if `percent` is outside the range 0 to 100 or [smoothing](#smoothing) is outside the range 0 to 1 ## Code Examples ### UnitSpacePolygonShapeSample ```kotlin @Sampled @Composable fun UnitSpacePolygonShapeSample() { // A kite authored in the unit square [0..1] with per-vertex rounding in the same coordinate // space. The shape scales and centers into any container preserving its aspect ratio. val kite = remember { PolygonShape( PolygonShapeGeometry( vertices = listOf(Offset(0.5f, 0f), Offset(1f, 0.4f), Offset(0.5f, 1f), Offset(0f, 0.4f)), perVertexRounding = listOf( CornerRounding(0.1f), CornerRounding(0.15f), CornerRounding(0.05f), CornerRounding(0.15f), ), ) ) } Box(Modifier.size(width = 120.dp, height = 84.dp).clip(kite).background(Color(0xFF673AB7))) } ```