Add MutableMargin and convert Margin into an interface, MarginInt and MutableMarginInt

korma/src/commonMain/kotlin/com/soywiz/korma/geom/Margin.kt

@@ -1,12 +1,83 @@
 package com.soywiz.korma.geom
 
-data class Margin(val top: Double, val right: Double, val bottom: Double, val left: Double) {
+interface Margin {
+    val top: Double
+    val right: Double
+    val bottom: Double
+    val left: Double
+
+    companion object {
+        operator fun invoke(top: Double, right: Double, bottom: Double, left: Double): Margin = MutableMargin(top, right, bottom, left)
+        operator fun invoke(vertical: Double, horizontal: Double): Margin = MutableMargin(vertical, horizontal)
+        operator fun invoke(margin: Double): Margin = MutableMargin(margin)
+    }
+}
+
+val Margin.leftPlusRight: Double get() = left + right
+val Margin.topPlusBottom: Double get() = top + bottom
+
+val Margin.horizontal: Double get() = (left + right) / 2
+val Margin.vertical: Double get() = (top + bottom) / 2
+
+data class MutableMargin(
+    override var top: Double = 0.0,
+    override var right: Double = 0.0,
+    override var bottom: Double = 0.0,
+    override var left: Double = 0.0
+) : Margin {
     constructor(vertical: Double, horizontal: Double) : this(vertical, horizontal, vertical, horizontal)
     constructor(margin: Double) : this(margin, margin, margin, margin)
 
-    val leftPlusRight get() = left + right
-    val topPlusBottom get() = top + bottom
+    fun setTo(margin: Double): Unit = setTo(margin, margin, margin, margin)
+    fun setTo(vertical: Double, horizontal: Double): Unit = setTo(vertical, horizontal, vertical, horizontal)
+    fun setTo(top: Double, right: Double, bottom: Double, left: Double) {
+        this.top = top
+        this.right = right
+        this.left = left
+        this.bottom = bottom
+    }
+    fun copyFrom(other: Margin) {
+        setTo(other.top, other.right, other.bottom, other.left)
+    }
+}
+
+interface MarginInt {
+    val top: Int
+    val right: Int
+    val bottom: Int
+    val left: Int
+
+    companion object {
+        operator fun invoke(top: Int, right: Int, bottom: Int, left: Int): MarginInt = MutableMarginInt(top, right, bottom, left)
+        operator fun invoke(vertical: Int, horizontal: Int): MarginInt = MutableMarginInt(vertical, horizontal)
+        operator fun invoke(margin: Int): MarginInt = MutableMarginInt(margin)
+    }
+}
+
+val MarginInt.leftPlusRight: Int get() = left + right
+val MarginInt.topPlusBottom: Int get() = top + bottom
+
+val MarginInt.horizontal: Int get() = (left + right) / 2
+val MarginInt.vertical: Int get() = (top + bottom) / 2
+
+data class MutableMarginInt(
+    override var top: Int = 0,
+    override var right: Int = 0,
+    override var bottom: Int = 0,
+    override var left: Int = 0
+) : MarginInt {
+    constructor(vertical: Int, horizontal: Int) : this(vertical, horizontal, vertical, horizontal)
+    constructor(margin: Int) : this(margin, margin, margin, margin)
 
-    val horizontal get() = (left + right) / 2
-    val vertical get() = (top + bottom) / 2
+    fun setTo(margin: Int): Unit = setTo(margin, margin, margin, margin)
+    fun setTo(vertical: Int, horizontal: Int): Unit = setTo(vertical, horizontal, vertical, horizontal)
+    fun setTo(top: Int, right: Int, bottom: Int, left: Int) {
+        this.top = top
+        this.right = right
+        this.left = left
+        this.bottom = bottom
+    }
+    fun copyFrom(other: MarginInt) {
+        setTo(other.top, other.right, other.bottom, other.left)
+    }
 }