Initial ShadowUI work

src/main/kotlin/net/shadowfacts/asmr/ASMR.kt

@@ -1,11 +1,27 @@
 package net.shadowfacts.asmr
 
 import net.fabricmc.api.ModInitializer
+import net.fabricmc.fabric.api.registry.CommandRegistry
+import net.minecraft.client.MinecraftClient
+import net.minecraft.server.command.CommandManager
 
 object ASMR: ModInitializer {
 
 	override fun onInitialize() {
 		println("hello fabric")
+
+		CommandRegistry.INSTANCE.register(false) { dispatcher ->
+			val command = CommandManager.literal("uitest").executes {
+				try {
+					MinecraftClient.getInstance().openScreen(UITest())
+				} catch (e: Throwable) {
+					e.printStackTrace()
+				}
+				1
+			}
+
+			dispatcher.register(command)
+		}
 	}
 
 }

src/main/kotlin/net/shadowfacts/asmr/UITest.kt

@@ -0,0 +1,54 @@
+package net.shadowfacts.asmr
+
+import net.shadowfacts.kiwidsl.dsl
+import net.shadowfacts.shadowui.UIScreen
+import net.shadowfacts.shadowui.UIView
+import net.shadowfacts.shadowui.util.Color
+
+class UITest: UIScreen() {
+
+	init {
+		val red = UIView().apply {
+			backgroundColor = Color(0xff0000)
+			addView(this)
+		}
+		val green = UIView().apply {
+			backgroundColor = Color(0x00ff00)
+			addView(this)
+		}
+		val blue = UIView().apply {
+			backgroundColor = Color(0x0000ff)
+			addView(this)
+		}
+
+		val purple = UIView().apply {
+			backgroundColor = Color(0x800080)
+			green.addSubview(this)
+		}
+
+		solver.dsl {
+			red.leftAnchor equalTo 0
+			red.widthAnchor equalTo 200
+			red.topAnchor equalTo 0
+			red.heightAnchor equalTo 100
+
+			green.leftAnchor equalTo (red.leftAnchor + red.widthAnchor + 20)
+			green.widthAnchor equalTo red.widthAnchor
+			green.topAnchor equalTo 0
+			green.heightAnchor equalTo (red.heightAnchor + 100)
+
+			blue.leftAnchor equalTo green.leftAnchor
+			blue.widthAnchor equalTo green.widthAnchor
+			blue.topAnchor equalTo (green.topAnchor + green.heightAnchor)
+			blue.heightAnchor equalTo 50
+
+			purple.widthAnchor equalTo 100
+			purple.heightAnchor equalTo 100
+			purple.centerXAnchor equalTo green.centerXAnchor
+			purple.centerYAnchor equalTo green.centerYAnchor
+		}
+
+		layout()
+	}
+
+}

src/main/kotlin/net/shadowfacts/shadowui/LayoutVariable.kt

@@ -0,0 +1,11 @@
+package net.shadowfacts.shadowui
+
+import no.birkett.kiwi.Variable
+
+class LayoutVariable(val owner: UIView, val property: String): Variable("LayoutVariable") {
+
+	override fun getName() = "$owner.$property"
+
+	override fun toString() = "LayoutVariable(name=$name, value=$value)"
+
+}

src/main/kotlin/net/shadowfacts/shadowui/UIScreen.kt

@@ -0,0 +1,28 @@
+package net.shadowfacts.shadowui
+
+import net.minecraft.client.gui.screen.Screen
+import net.minecraft.network.chat.TextComponent
+import no.birkett.kiwi.Solver
+
+open class UIScreen: Screen(TextComponent("UIScreen")) {
+
+	val solver = Solver()
+
+	val views = mutableListOf<UIView>()
+
+	fun addView(view: UIView) {
+		views.add(view)
+		view.solver = solver
+		view.wasAdded()
+	}
+
+	fun layout() {
+		solver.updateVariables()
+		views.forEach(UIView::didLayout)
+	}
+
+	override fun render(mouseX: Int, mouseY: Int, delta: Float) {
+		views.forEach(UIView::draw)
+	}
+
+}

src/main/kotlin/net/shadowfacts/shadowui/UIView.kt

@@ -0,0 +1,79 @@
+package net.shadowfacts.shadowui
+
+import com.mojang.blaze3d.platform.GlStateManager
+import net.shadowfacts.kiwidsl.dsl
+import net.shadowfacts.shadowui.geometry.UIRect
+import net.shadowfacts.shadowui.util.Color
+import net.shadowfacts.shadowui.util.RenderHelper
+import no.birkett.kiwi.Solver
+
+class UIView {
+
+	lateinit var solver: Solver
+
+	// in the coordinate system of the screen
+	val leftAnchor = LayoutVariable(this, "left")
+	val rightAnchor = LayoutVariable(this, "right")
+	val topAnchor = LayoutVariable(this, "top")
+	val bottomAnchor = LayoutVariable(this, "bottom")
+	val widthAnchor = LayoutVariable(this, "width")
+	val heightAnchor = LayoutVariable(this, "height")
+	val centerXAnchor = LayoutVariable(this, "centerX")
+	val centerYAnchor = LayoutVariable(this, "centerY")
+
+	// The rectangle for this view in the coordinate system of the parent view.
+	lateinit var frame: UIRect
+	// The rectangle for this view in its own coordinate system.
+	lateinit var bounds: UIRect
+
+	var backgroundColor = Color(0xff0000)
+
+	var parent: UIView? = null
+	val subviews = mutableListOf<UIView>()
+
+	fun addSubview(view: UIView) {
+		subviews.add(view)
+		view.parent = this
+		view.solver = solver
+
+		view.wasAdded()
+	}
+
+	fun wasAdded() {
+		createInternalConstraints()
+	}
+
+	fun createInternalConstraints() {
+		solver.dsl {
+			rightAnchor equalTo (leftAnchor + widthAnchor)
+			bottomAnchor equalTo (topAnchor + heightAnchor)
+			centerXAnchor equalTo (leftAnchor + widthAnchor / 2)
+			centerYAnchor equalTo (topAnchor + heightAnchor / 2)
+		}
+	}
+
+	fun didLayout() {
+		subviews.forEach(UIView::didLayout)
+
+		val parentLeft = parent?.leftAnchor?.value ?: 0.0
+		val parentTop = parent?.topAnchor?.value ?: 0.0
+		frame = UIRect(leftAnchor.value - parentLeft, topAnchor.value - parentTop, widthAnchor.value, heightAnchor.value)
+		bounds = UIRect(0.0, 0.0, widthAnchor.value, heightAnchor.value)
+	}
+
+	fun draw() {
+		GlStateManager.pushMatrix()
+		GlStateManager.translated(frame.left, frame.top, 0.0)
+
+		RenderHelper.fill(bounds, backgroundColor)
+
+		drawContent()
+
+		subviews.forEach(UIView::draw)
+
+		GlStateManager.popMatrix()
+	}
+
+	fun drawContent() {}
+
+}

src/main/kotlin/net/shadowfacts/shadowui/geometry/UIRect.kt

@@ -0,0 +1,15 @@
+package net.shadowfacts.shadowui.geometry
+
+data class UIRect(val left: Double, val top: Double, val width: Double, val height: Double) {
+
+	val right: Double
+		get() = left + width
+	val bottom: Double
+		get() = top + height
+
+	val midX: Double
+		get() = left + width / 2
+	val midY: Double
+		get() = top + height / 2
+
+}

src/main/kotlin/net/shadowfacts/shadowui/util/Color.kt

@@ -0,0 +1,10 @@
+package net.shadowfacts.shadowui.util
+
+data class Color(val red: Int, val green: Int, val blue: Int, val alpha: Int = 255) {
+
+	constructor(rgb: Int, alpha: Int = 255): this(rgb shr 16, (rgb shr 8) and 255, rgb and 255, alpha)
+
+	val argb: Int
+		get() = ((alpha and 255) shl 24) or ((red and 255) shl 16) or ((green and 255) shl 8) or (blue and 255)
+
+}

src/main/kotlin/net/shadowfacts/shadowui/util/RenderHelper.kt

@@ -0,0 +1,12 @@
+package net.shadowfacts.shadowui.util
+
+import net.minecraft.client.gui.DrawableHelper
+import net.shadowfacts.shadowui.geometry.UIRect
+
+object RenderHelper {
+
+	fun fill(rect: UIRect, color: Color) {
+		DrawableHelper.fill(rect.left.toInt(), rect.top.toInt(), rect.right.toInt(), rect.bottom.toInt(), color.argb)
+	}
+
+}