CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Added
 - `alpha` extension for feature attribute builder
+- PNG export
 
 ### Changed
 - avoid drawing features with VisibleAttribute false

demo/scheme/src/jvmMain/kotlin/Main.kt

@@ -4,21 +4,20 @@ import androidx.compose.foundation.ContextMenuArea
 import androidx.compose.foundation.ContextMenuItem
 import androidx.compose.material.MaterialTheme
 import androidx.compose.runtime.*
+import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.text.rememberTextMeasurer
 import androidx.compose.ui.window.Window
 import androidx.compose.ui.window.application
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
 import space.kscience.kmath.geometry.Angle
-import space.kscience.maps.features.FeatureStore
-import space.kscience.maps.features.ViewConfig
-import space.kscience.maps.features.ViewPoint
-import space.kscience.maps.features.color
+import space.kscience.maps.features.*
 import space.kscience.maps.scheme.*
+import space.kscience.maps.svg.exportToPng
 import space.kscience.maps.svg.exportToSvg
-import space.kscience.maps.svg.snapshot
 import java.awt.Desktop
 import java.nio.file.Files
 
@@ -57,19 +56,31 @@ fun App() {
 
         var viewPoint: ViewPoint<XY> by remember { mutableStateOf(initialViewPoint) }
 
-        val snapshot = key(features) {
-            features.snapshot()
-        }
+        val painterCache = features.pointerCache()
+
+        val textMeasurer = rememberTextMeasurer()
 
         ContextMenuArea(
             items = {
                 listOf(
                     ContextMenuItem("Export to SVG") {
                         val path = Files.createTempFile("scheme-kt-", ".svg")
-                        snapshot.exportToSvg(viewPoint, 800.0, 800.0, path)
+                        features.exportToSvg(viewPoint, painterCache, Size(800f, 800f), path)
                         println(path.toFile())
                         Desktop.getDesktop().browse(path.toFile().toURI())
                     },
+                    ContextMenuItem("Export to PNG") {
+                        val path = Files.createTempFile("scheme-kt-", ".png")
+                        features.exportToPng(
+                            viewPoint,
+                            painterCache,
+                            textMeasurer,
+                            Size(800f, 800f),
+                            path
+                        )
+                        println(path.toFile())
+                        Desktop.getDesktop().browse(path.toFile().toURI())
+                    }
                 )
             }
         ) {

maps-kt-compose/src/jvmMain/kotlin/space/kscience/maps/compose/mapExport.kt

@@ -0,0 +1,55 @@
+package space.kscience.maps.compose
+
+import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.asSkiaBitmap
+import androidx.compose.ui.graphics.painter.Painter
+import androidx.compose.ui.text.TextMeasurer
+import androidx.compose.ui.unit.DpSize
+import androidx.compose.ui.unit.dp
+import org.jetbrains.skia.Image
+import org.jfree.svg.SVGUtils
+import space.kscience.maps.coordinates.Gmc
+import space.kscience.maps.features.FeatureSet
+import space.kscience.maps.features.PainterFeature
+import space.kscience.maps.features.ViewConfig
+import space.kscience.maps.features.ViewPoint
+import space.kscience.maps.svg.generateBitmap
+import space.kscience.maps.svg.generateSvg
+import java.nio.file.Path
+import kotlin.io.path.writeBytes
+
+public fun FeatureSet<Gmc>.exportToSvg(
+    mapTileProvider: MapTileProvider,
+    viewPoint: ViewPoint<Gmc>,
+    painterCache: Map<PainterFeature<Gmc>, Painter>,
+    size: Size,
+    path: Path,
+) {
+    val mapCanvasState: MapCanvasState = MapCanvasState(mapTileProvider, ViewConfig()).apply {
+        this.viewPoint = viewPoint
+        this.canvasSize = DpSize(size.width.dp, size.height.dp)
+    }
+
+    val svgString: String = generateSvg(mapCanvasState, painterCache)
+    SVGUtils.writeToSVG(path.toFile(), svgString)
+}
+
+public fun FeatureSet<Gmc>.exportToPng(
+    mapTileProvider: MapTileProvider,
+    viewPoint: ViewPoint<Gmc>,
+    painterCache: Map<PainterFeature<Gmc>, Painter>,
+    textMeasurer: TextMeasurer,
+    size: Size,
+    path: Path,
+) {
+    val mapCanvasState: MapCanvasState = MapCanvasState(mapTileProvider, ViewConfig()).apply {
+        this.viewPoint = viewPoint
+        this.canvasSize = DpSize(size.width.dp, size.height.dp)
+    }
+
+    val bitmap = generateBitmap(mapCanvasState, painterCache, textMeasurer, size)
+
+    Image.makeFromBitmap(bitmap.asSkiaBitmap()).encodeToData()?.bytes?.let {
+        path.writeBytes(it)
+    }
+}

maps-kt-compose/src/jvmMain/kotlin/space/kscience/maps/compose/mapExportToSvg.kt

@@ -1,27 +0,0 @@
-package space.kscience.maps.compose
-
-import androidx.compose.ui.unit.DpSize
-import androidx.compose.ui.unit.dp
-import org.jfree.svg.SVGUtils
-import space.kscience.maps.coordinates.Gmc
-import space.kscience.maps.features.ViewConfig
-import space.kscience.maps.features.ViewPoint
-import space.kscience.maps.svg.FeatureSetSnapshot
-import space.kscience.maps.svg.generateSvg
-import java.nio.file.Path
-
-public fun FeatureSetSnapshot<Gmc>.exportToSvg(
-    mapTileProvider: MapTileProvider,
-    viewPoint: ViewPoint<Gmc>,
-    width: Double,
-    height: Double,
-    path: Path,
-) {
-    val mapCanvasState: MapCanvasState = MapCanvasState(mapTileProvider, ViewConfig()).apply {
-        this.viewPoint = viewPoint
-        this.canvasSize = DpSize(width.dp, height.dp)
-    }
-
-    val svgString: String = generateSvg(mapCanvasState)
-    SVGUtils.writeToSVG(path.toFile(), svgString)
-}

maps-kt-features/src/commonMain/kotlin/space/kscience/maps/features/FeatureDrawScope.kt

@@ -4,6 +4,7 @@ import androidx.compose.foundation.Canvas
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
@@ -75,6 +76,11 @@ public class ComposeFeatureDrawScope<T : Any>(
     }
 }
 
+@Composable
+public fun <T: Any> FeatureSet<T>.pointerCache(): Map<PainterFeature<T>, Painter> = key(features) {
+    features.values.filterIsInstance<PainterFeature<T>>().associateWith { it.getPainter() }
+}
+
 
 /**
  * Create a canvas with extended functionality (e.g., drawing text)
@@ -90,7 +96,7 @@ public fun <T : Any> FeatureCanvas(
 ) {
     val textMeasurer = rememberTextMeasurer(0)
 
-    val features by featureFlow.sample(sampleDuration).collectAsState(featureFlow.value)
+    val features: Map<String, Feature<T>> by featureFlow.sample(sampleDuration).collectAsState(featureFlow.value)
 
     val painterCache = features.values
         .filterIsInstance<PainterFeature<T>>()

maps-kt-features/src/jvmMain/kotlin/space/kscience/maps/svg/exportToBitMap.kt

@@ -0,0 +1,34 @@
+package space.kscience.maps.svg
+
+import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.Canvas
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.drawscope.CanvasDrawScope
+import androidx.compose.ui.graphics.painter.Painter
+import androidx.compose.ui.text.TextMeasurer
+import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.LayoutDirection
+import space.kscience.maps.features.CanvasState
+import space.kscience.maps.features.ComposeFeatureDrawScope
+import space.kscience.maps.features.FeatureSet
+import space.kscience.maps.features.PainterFeature
+
+public fun <T : Any> FeatureSet<T>.generateBitmap(
+    canvasState: CanvasState<T>,
+    painterCache: Map<PainterFeature<T>, Painter>,
+    textMeasurer: TextMeasurer,
+    size: Size
+): ImageBitmap {
+
+    val bitmap = ImageBitmap(size.width.toInt(), size.height.toInt())
+
+    CanvasDrawScope().draw(
+        density = Density(1f),
+        layoutDirection = LayoutDirection.Ltr,
+        canvas = Canvas(bitmap),
+        size = size,
+    ) {
+        ComposeFeatureDrawScope(this, canvasState, painterCache, textMeasurer).features(this@generateBitmap)
+    }
+    return bitmap
+}

maps-kt-features/src/jvmMain/kotlin/space/kscience/maps/svg/exportToSvg.kt

@@ -1,6 +1,5 @@
 package space.kscience.maps.svg
 
-import androidx.compose.runtime.Composable
 import androidx.compose.ui.graphics.painter.Painter
 import org.jfree.svg.SVGGraphics2D
 import space.kscience.attributes.Attributes
@@ -8,20 +7,30 @@ import space.kscience.attributes.plus
 import space.kscience.maps.features.*
 
 
-public class FeatureSetSnapshot<T : Any>(
-    public val features: Map<String, Feature<T>>,
-    internal val painterCache: Map<PainterFeature<T>, Painter>,
-)
+public fun <T : Any> FeatureDrawScope<T>.features(featureSet: FeatureSet<T>) {
+    featureSet.features.entries.sortedBy { it.value.z }
+        .filter { state.viewPoint.zoom in it.value.zoomRange }
+        .forEach { (id, feature) ->
+            val attributesCache = mutableMapOf<List<String>, Attributes>()
 
-@Composable
-public fun <T : Any> FeatureSet<T>.snapshot(): FeatureSetSnapshot<T> = FeatureSetSnapshot(
-    features,
-    features.values.filterIsInstance<PainterFeature<T>>().associateWith { it.getPainter() }
-)
+            fun computeGroupAttributes(path: List<String>): Attributes = attributesCache.getOrPut(path) {
+                if (path.isEmpty()) return Attributes.EMPTY
+                else if (path.size == 1) {
+                    featureSet.features[path.first()]?.attributes ?: Attributes.EMPTY
+                } else {
+                    computeGroupAttributes(path.dropLast(1)) +
+                            (featureSet.features[path.first()]?.attributes ?: Attributes.EMPTY)
+                }
+            }
 
+            val path = id.split("/")
+            drawFeature(feature, computeGroupAttributes(path.dropLast(1)))
+        }
+}
 
-public fun <T : Any> FeatureSetSnapshot<T>.generateSvg(
+public fun <T : Any> FeatureSet<T>.generateSvg(
     canvasState: CanvasState<T>,
+    painterCache: Map<PainterFeature<T>, Painter>,
     id: String? = null,
 ): String {
     val svgGraphics2D: SVGGraphics2D = SVGGraphics2D(
@@ -30,25 +39,7 @@ public fun <T : Any> FeatureSetSnapshot<T>.generateSvg(
     )
     val svgScope = SvgDrawScope(canvasState, svgGraphics2D, painterCache)
 
-    svgScope.apply {
-        features.entries.sortedBy { it.value.z }
-            .filter { state.viewPoint.zoom in it.value.zoomRange }
-            .forEach { (id, feature) ->
-                val attributesCache = mutableMapOf<List<String>, Attributes>()
+    svgScope.features(this)
 
-                fun computeGroupAttributes(path: List<String>): Attributes = attributesCache.getOrPut(path) {
-                    if (path.isEmpty()) return Attributes.EMPTY
-                    else if (path.size == 1) {
-                        features[path.first()]?.attributes ?: Attributes.EMPTY
-                    } else {
-                        computeGroupAttributes(path.dropLast(1)) + (features[path.first()]?.attributes
-                            ?: Attributes.EMPTY)
-                    }
-                }
-
-                val path = id.split("/")
-                drawFeature(feature, computeGroupAttributes(path.dropLast(1)))
-            }
-    }
     return svgGraphics2D.getSVGElement(id)
 }

maps-kt-scheme/src/jvmMain/kotlin/space/kscience/maps/svg/schemeExport.kt

@@ -0,0 +1,52 @@
+package space.kscience.maps.svg
+
+import androidx.compose.ui.geometry.Size
+import androidx.compose.ui.graphics.asSkiaBitmap
+import androidx.compose.ui.graphics.painter.Painter
+import androidx.compose.ui.text.TextMeasurer
+import androidx.compose.ui.unit.DpSize
+import androidx.compose.ui.unit.dp
+import org.jetbrains.skia.Image
+import org.jfree.svg.SVGUtils
+import space.kscience.maps.features.FeatureSet
+import space.kscience.maps.features.PainterFeature
+import space.kscience.maps.features.ViewConfig
+import space.kscience.maps.features.ViewPoint
+import space.kscience.maps.scheme.XY
+import space.kscience.maps.scheme.XYCanvasState
+import java.nio.file.Path
+import kotlin.io.path.writeBytes
+
+public fun FeatureSet<XY>.exportToSvg(
+    viewPoint: ViewPoint<XY>,
+    painterCache: Map<PainterFeature<XY>, Painter>,
+    size: Size,
+    path: Path,
+) {
+    val svgCanvasState: XYCanvasState = XYCanvasState(ViewConfig()).apply {
+        this.viewPoint = viewPoint
+        this.canvasSize = DpSize(size.width.dp, size.height.dp)
+    }
+
+    val svgString: String = generateSvg(svgCanvasState, painterCache)
+    SVGUtils.writeToSVG(path.toFile(), svgString)
+}
+
+public fun FeatureSet<XY>.exportToPng(
+    viewPoint: ViewPoint<XY>,
+    painterCache: Map<PainterFeature<XY>, Painter>,
+    textMeasurer: TextMeasurer,
+    size: Size,
+    path: Path,
+) {
+    val svgCanvasState: XYCanvasState = XYCanvasState(ViewConfig()).apply {
+        this.viewPoint = viewPoint
+        this.canvasSize = DpSize(size.width.dp, size.height.dp)
+    }
+
+    val bitmap = generateBitmap(svgCanvasState, painterCache, textMeasurer, size)
+
+    Image.makeFromBitmap(bitmap.asSkiaBitmap()).encodeToData()?.bytes?.let {
+        path.writeBytes(it)
+    }
+}

maps-kt-scheme/src/jvmMain/kotlin/space/kscience/maps/svg/schemeExportToSvg.kt

@@ -1,25 +0,0 @@
-package space.kscience.maps.svg
-
-import androidx.compose.ui.unit.DpSize
-import androidx.compose.ui.unit.dp
-import org.jfree.svg.SVGUtils
-import space.kscience.maps.features.ViewConfig
-import space.kscience.maps.features.ViewPoint
-import space.kscience.maps.scheme.XY
-import space.kscience.maps.scheme.XYCanvasState
-import java.nio.file.Path
-
-public fun FeatureSetSnapshot<XY>.exportToSvg(
-    viewPoint: ViewPoint<XY>,
-    width: Double,
-    height: Double,
-    path: Path,
-) {
-    val svgCanvasState: XYCanvasState = XYCanvasState(ViewConfig()).apply {
-        this.viewPoint = viewPoint
-        this.canvasSize = DpSize(width.dp, height.dp)
-    }
-
-    val svgString: String = generateSvg(svgCanvasState)
-    SVGUtils.writeToSVG(path.toFile(), svgString)
-}