From 969fb17f34a28374201b755d9f4cd3023825c40c Mon Sep 17 00:00:00 2001
From: Lanius Trolling <lanius@laniustrolling.dev>
Date: Sun, 14 Apr 2024 08:39:19 -0400
Subject: [PATCH] Improve SVG-handling code

---
 .../mechyrdia/lore/{fonts.kt => Fonts.kt}     | 93 +++++++++++++------
 1 file changed, 63 insertions(+), 30 deletions(-)
 rename src/jvmMain/kotlin/info/mechyrdia/lore/{fonts.kt => Fonts.kt} (85%)

diff --git a/src/jvmMain/kotlin/info/mechyrdia/lore/fonts.kt b/src/jvmMain/kotlin/info/mechyrdia/lore/Fonts.kt
similarity index 85%
rename from src/jvmMain/kotlin/info/mechyrdia/lore/fonts.kt
rename to src/jvmMain/kotlin/info/mechyrdia/lore/Fonts.kt
index ac5411e..9c36df5 100644
--- a/src/jvmMain/kotlin/info/mechyrdia/lore/fonts.kt
+++ b/src/jvmMain/kotlin/info/mechyrdia/lore/Fonts.kt
@@ -3,8 +3,7 @@ package info.mechyrdia.lore
 import com.jaredrummler.fontreader.truetype.FontFileReader
 import com.jaredrummler.fontreader.truetype.TTFFile
 import com.jaredrummler.fontreader.util.GlyphSequence
-import info.mechyrdia.data.FileStorage
-import info.mechyrdia.data.StoragePath
+import info.mechyrdia.data.*
 import info.mechyrdia.route.KeyedEnumSerializer
 import info.mechyrdia.yieldThread
 import kotlinx.coroutines.Dispatchers
@@ -46,12 +45,44 @@ enum class TextAlignment {
 
 object TextAlignmentSerializer : KeyedEnumSerializer<TextAlignment>(TextAlignment.entries)
 
+data class SvgDoc(
+	val width: Double,
+	val height: Double,
+	val viewBoxX: Double,
+	val viewBoxY: Double,
+	val viewBoxW: Double,
+	val viewBoxH: Double,
+	val path: SvgPath
+)
+
+data class SvgPath(
+	val d: String,
+	val fillRule: String
+)
+
+fun <T, C : XmlTagConsumer<T>> C.svg(svgDoc: SvgDoc) = declaration(standalone = false)
+	.defaultXmlns("http://www.w3.org/2000/svg")
+	.root(
+		"svg",
+		attributes = mapOf(
+			"width" to svgDoc.width.xmlValue,
+			"height" to svgDoc.height.xmlValue,
+			"viewBox" to listOf(
+				svgDoc.viewBoxX,
+				svgDoc.viewBoxY,
+				svgDoc.viewBoxW,
+				svgDoc.viewBoxH,
+			).joinToString(separator = " ") { it.xmlValue }
+		)
+	) { "path"(attributes = mapOf("d" to svgDoc.path.d, "fill-rule" to svgDoc.path.fillRule)) }
+
 object MechyrdiaSansFont {
 	private val logger: Logger = LoggerFactory.getLogger(MechyrdiaSansFont::class.java)
 	
-	suspend fun renderTextToSvg(text: String, bold: Boolean, italic: Boolean, align: TextAlignment): String {
+	suspend fun renderTextToSvg(text: String, bold: Boolean, italic: Boolean, align: TextAlignment): SvgDoc {
 		val (file, font) = getFont(bold, italic)
-		return layoutText(text, file, font, align).toSvgDocument(80.0 / file.unitsPerEm, 12.0)
+		val shape = layoutText(text, file, font, align)
+		return createSvgDocument(shape, 80.0 / file.unitsPerEm, 12.0)
 	}
 	
 	private val fontsRoot = StoragePath("fonts")
@@ -209,27 +240,30 @@ object MechyrdiaSansFont {
 		}
 	}
 	
-	private fun Shape.toSvgDocument(scale: Double, padding: Double = 0.0): String {
-		return buildString {
-			appendLine("<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\"?>")
-			
-			val viewBox = bounds2D
-			val vBoxPad = padding / scale
-			val sizePad = padding * 2
-			
-			appendLine("<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"${(viewBox.width * scale) + sizePad}\" height=\"${(viewBox.height * scale) + sizePad}\" viewBox=\"${viewBox.minX - vBoxPad} ${viewBox.minY - vBoxPad} ${viewBox.width + (vBoxPad * 2)} ${viewBox.height + (vBoxPad * 2)}\">")
-			appendLine(toSvgPath())
-			appendLine("</svg>")
-		}
+	private fun createSvgDocument(shape: Shape, scale: Double, padding: Double = 0.0): SvgDoc {
+		val viewBox = shape.bounds2D
+		val vBoxPad = padding / scale
+		val sizePad = padding * 2
+		
+		val path = shape.calculateSvgPath()
+		
+		return SvgDoc(
+			width = (viewBox.width * scale) + sizePad,
+			height = (viewBox.height * scale) + sizePad,
+			viewBoxX = viewBox.minX - vBoxPad,
+			viewBoxY = viewBox.minY - vBoxPad,
+			viewBoxW = viewBox.width + (vBoxPad * 2),
+			viewBoxH = viewBox.height + (vBoxPad * 2),
+			path = path
+		)
 	}
 	
-	private fun Shape.toSvgPath(): String {
-		return buildString {
-			append("<path d=\"")
-			
-			val iterator = getPathIterator(null)
+	private fun Shape.calculateSvgPath(): SvgPath {
+		val iterator = getPathIterator(null)
+		val d = buildString {
 			val coords = DoubleArray(6)
 			var isFirst = true
+			
 			while (!iterator.isDone) {
 				if (isFirst)
 					isFirst = false
@@ -264,16 +298,15 @@ object MechyrdiaSansFont {
 				
 				yieldThread()
 			}
-			
-			append("\" fill-rule=\"")
-			when (val winding = iterator.windingRule) {
-				PathIterator.WIND_EVEN_ODD -> append("evenodd")
-				PathIterator.WIND_NON_ZERO -> append("nonzero")
-				else -> error("Invalid winding rule $winding")
-			}
-			
-			append("\" />")
 		}
+		
+		val fillRule = when (val winding = iterator.windingRule) {
+			PathIterator.WIND_EVEN_ODD -> "evenodd"
+			PathIterator.WIND_NON_ZERO -> "nonzero"
+			else -> error("Invalid winding rule $winding")
+		}
+		
+		return SvgPath(d, fillRule)
 	}
 }
 
-- 
2.25.1