Korner

2.0.0indexed

Smooth iOS-style rounded corners and squircles with per-corner customizable radius and smoothing, type-safe smoothing API, presets (Subtle/Balanced/Smooth/Continuous), lightweight, allocation-friendly, integrates with UI components.

AndroidJSJVMNativeWasm·dev778g-me/Korner

Stars

—

Used by

dependents

—

Health

/ 100

Korner

Smooth rounded corners and squircles for Compose Multiplatform.

Korner Preview

Korner provides beautiful iOS-style smooth corner shapes and superellipses for Compose Multiplatform with fully customizable radius and smoothing values per corner.

Supports:

Android
iOS
Desktop
WASM/Web

Based on the original smooth corner implementation by racra: https://github.com/racra/smooth-corner-rect-android-compose

Features

Smooth iOS-style corners
Superellipse / squircle rendering
Per-corner radius customization
Per-corner smoothing customization
Type-safe smoothing API
Compose Multiplatform support
Works with any Compose UI component
Lightweight and allocation-friendly

Why Korner?

Traditional rounded rectangles use simple circular arcs.

Korner generates smooth superellipse-style curves with more natural transitions and better visual balance — similar to modern design systems used in iOS and contemporary UI frameworks.

Compared to standard rounded corners, smooth corners:

feel more organic
reduce visual sharpness
improve large-radius aesthetics
create cleaner modern UI surfaces

Installation

Gradle

repositories {
    mavenCentral()
}

dependencies {
    implementation("io.github.dev778g-me:korner:2.0.0")
}

Basic Usage

Box(
    modifier = Modifier
        .size(200.dp)
        .background(
            color = Color(0xFFF6EABE),
            shape = AbsoluteSmoothCornerShape(
                cornerRadius = 32.dp,
                cornerSmoothing = CornerSmoothing.Continuous
            )
        )
)

Per-Corner Configuration

Box(
    modifier = Modifier
        .size(200.dp)
        .background(
            color = Color(0xFFF6EABE),
            shape = AbsoluteSmoothCornerShape(
                topLeftRadius = 40.dp,
                topLeftCornerSmoothing = CornerSmoothing.Continuous,

                topRightRadius = 12.dp,
                topRightCornerSmoothing = CornerSmoothing.Balanced,

                bottomRightRadius = 40.dp,
                bottomRightCornerSmoothing = CornerSmoothing.Smooth,

                bottomLeftRadius = 12.dp,
                bottomLeftCornerSmoothing = CornerSmoothing.Subtle
            )
        )
)

Corner Smoothing

Korner uses a type-safe CornerSmoothing API:

@JvmInline
value class CornerSmoothing(val percent: Int) {
    init {
        require(percent in 0..100) {
            "Corner smoothing must be between 0 and 100"
        }
    }

      {
         Subtle = CornerSmoothing()
         Balanced = CornerSmoothing()
         Smooth = CornerSmoothing()
         Continuous = CornerSmoothing()
    }
}