A (very) minimal SVG DSL for Jetpack Compose on Android (inspired by https://twitter.com/alexstyl/status/1659043650238844928).

MainActivity.kt

package com.amarland.simplesvgdsl

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Box
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.darkColorScheme
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.PathFillType
import androidx.compose.ui.graphics.SolidColor
import androidx.compose.ui.unit.DpSize
import androidx.compose.ui.unit.dp

class MainActivity : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContent {
            MaterialTheme(colorScheme = darkColorScheme()) {
                Box(
                    modifier = Modifier
                        .fillMaxSize()
                        .background(MaterialTheme.colorScheme.background)
                ) {
                    Svg(
                        contentDescription = "",
                        viewBox = ViewBox(0F, 0F, 100F, 100F),
                        modifier = Modifier.align(Alignment.Center),
                        size = DpSize(64.dp, 64.dp)
                    ) {
                        val onBackgroundColorAsBrush =
                            SolidColor(MaterialTheme.colorScheme.onBackground)
                        path {
                            d = "M0 50a50 50 0 1 0 100 0a50 50 0 1 0 -100 0"
                            fill = onBackgroundColorAsBrush
                        }

                        val primaryColorAsBrush = SolidColor(MaterialTheme.colorScheme.primary)
                        path {
                            d = "M50 0L21 90L98 35L2 35L79 90z"
                            fill = primaryColorAsBrush
                            fillType = PathFillType.EvenOdd
                        }
                    }
                }
            }
        }
    }
}

SvgDsl.kt

package com.amarland.simplesvgdsl

import androidx.compose.foundation.Image
import androidx.compose.runtime.Composable
import androidx.compose.runtime.Immutable
import androidx.compose.ui.Modifier
import androidx.compose.ui.geometry.Offset
import androidx.compose.ui.geometry.Size
import androidx.compose.ui.graphics.Brush
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.graphics.PathFillType
import androidx.compose.ui.graphics.SolidColor
import androidx.compose.ui.graphics.vector.DefaultFillType
import androidx.compose.ui.graphics.vector.ImageVector
import androidx.compose.ui.graphics.vector.PathNode
import androidx.compose.ui.graphics.vector.addPathNodes
import androidx.compose.ui.unit.DpSize
import androidx.compose.ui.unit.dp

@Immutable
class ViewBox(val min: Offset, val size: Size) {

    constructor(size: Size) : this(Offset.Zero, size)

    constructor(
        minX: Float = 0F,
        minY: Float = 0F,
        width: Float,
        height: Float
    ) : this(Offset(minX, minY), Size(width, height))

    fun copy(min: Offset = this.min, size: Size = this.size) = ViewBox(min, size)

    operator fun component1() = min.x
    operator fun component2() = min.y
    operator fun component3() = size.width
    operator fun component4() = size.height
}

interface SvgPathScope {

    var d: String
    var fill: Brush
    var fillType: PathFillType
}

interface SvgScope {

    var tint: Color

    fun path(block: SvgPathScope.() -> Unit)
}

@Composable
fun Svg(
    contentDescription: String,
    viewBox: ViewBox,
    modifier: Modifier = Modifier,
    size: DpSize = DpSize(viewBox.size.width.dp, viewBox.size.height.dp),
    block: @Composable SvgScope.() -> Unit
) {
    SvgScopeInstance.block()

    val (width, height) = size
    val (viewBoxWidth, viewBoxHeight) = viewBox.size
    val imageVector = ImageVector.Builder(
        defaultWidth = width,
        defaultHeight = height,
        viewportWidth = viewBoxWidth,
        viewportHeight = viewBoxHeight,
        tintColor = SvgScopeInstance.tint
    ).apply {
        val (minX, minY) = viewBox.min
        if (minX != 0F || minY != 0F) {
            addGroup(translationX = -minX, translationY = -minY)
        }

        for ((pathNodes, fill, fillType) in SvgScopeInstance.paths) {
            addPath(
                pathData = pathNodes,
                pathFillType = fillType,
                fill = fill
            )
        }
    }.build()

    Image(
        imageVector = imageVector,
        contentDescription = contentDescription,
        modifier = modifier
    )
}

private object SvgPathScopeInstance : SvgPathScope {

    override var d: String = ""
    override var fill: Brush = SolidColor(Color.Black)
    override var fillType: PathFillType = DefaultFillType
}

@Immutable
private data class Path(
    val nodes: List<PathNode>,
    val fill: Brush,
    val fillType: PathFillType
)

private object SvgScopeInstance : SvgScope {

    override var tint: Color = Color.Unspecified

    private val _paths = mutableListOf<Path>()
    val paths: Iterable<Path> = _paths

    override fun path(block: SvgPathScope.() -> Unit) {
        SvgPathScopeInstance.block()

        val pathNodes = addPathNodes(SvgPathScopeInstance.d.takeUnless(String::isBlank))
        _paths += Path(
            pathNodes,
            SvgPathScopeInstance.fill,
            SvgPathScopeInstance.fillType
        )
    }
}