[orx-mesh, orx-mesh-generator, orx-obj-loader] Add decal and tangent tools

orx-mesh/src/commonMain/kotlin/VertexData.kt

@@ -13,11 +13,6 @@ interface IVertexData {
      */
     val positions: List<Vector3>
 
-    /**
-     * Vertex normals
-     */
-    val normals: List<Vector3>
-
     /**
      * Vertex texture coordinates
      */
@@ -28,6 +23,11 @@ interface IVertexData {
      */
     val colors: List<ColorRGBa>
 
+    /**
+     * Vertex normals
+     */
+    val normals: List<Vector3>
+
     /**
      * Vertex tangents
      */
@@ -37,6 +37,16 @@ interface IVertexData {
      * Vertex bitangents
      */
     val bitangents: List<Vector3>
+
+    /**
+     * Convert to [VertexData]
+     */
+    fun toVertexData() : VertexData
+
+    /**
+     * Convert to [MutableVertexData]
+     */
+    fun toMutableVertexData() : MutableVertexData
 }
 
 /**
@@ -44,26 +54,23 @@ interface IVertexData {
  */
 class VertexData(
     override val positions: List<Vector3> = emptyList(),
-    override val normals: List<Vector3> = emptyList(),
     override val textureCoords: List<Vector2> = emptyList(),
     override val colors: List<ColorRGBa> = emptyList(),
+    override val normals: List<Vector3> = emptyList(),
     override val tangents: List<Vector3> = emptyList(),
     override val bitangents: List<Vector3> = emptyList()
 ) : IVertexData {
 
-    /**
-     * Convert to [MutableVertexData]
-     */
-    fun toMutableVertexData(): MutableVertexData {
-        return MutableVertexData(
-            positions.toMutableList(),
-            normals.toMutableList(),
-            textureCoords.toMutableList(),
-            colors.toMutableList(),
-            tangents.toMutableList(),
-            bitangents.toMutableList()
-        )
-    }
+    override fun toVertexData(): VertexData = this
+
+    override fun toMutableVertexData(): MutableVertexData = MutableVertexData(
+        positions.toMutableList(),
+        textureCoords.toMutableList(),
+        colors.toMutableList(),
+        normals.toMutableList(),
+        tangents.toMutableList(),
+        bitangents.toMutableList()
+    )
 }
 
 
@@ -72,24 +79,54 @@ class VertexData(
  */
 class MutableVertexData(
     override val positions: MutableList<Vector3> = mutableListOf(),
-    override val normals: MutableList<Vector3> = mutableListOf(),
     override val textureCoords: MutableList<Vector2> = mutableListOf(),
     override val colors: MutableList<ColorRGBa> = mutableListOf(),
+    override val normals: MutableList<Vector3> = mutableListOf(),
     override val tangents: MutableList<Vector3> = mutableListOf(),
     override val bitangents: MutableList<Vector3> = mutableListOf()
 ) : IVertexData {
 
-    /**
-     * Convert to [VertexData]
-     */
-    fun toVertexData(): VertexData {
-        return VertexData(
-            positions.toList(),
-            normals.toList(),
-            textureCoords.toList(),
-            colors.toList(),
-            tangents.toList(),
-            bitangents.toList()
-        )
-    }
+    override fun toVertexData(): VertexData = VertexData(
+        positions.toList(),
+        textureCoords.toList(),
+        colors.toList(),
+        normals.toList(),
+        tangents.toList(),
+        bitangents.toList()
+    )
+
+    override fun toMutableVertexData(): MutableVertexData = this
+}
+
+/**
+ * Add [point] to vertex data
+ */
+fun MutableVertexData.add(point: Point) {
+    positions.add(point.position)
+    point.color?.let { colors.add(it) }
+    point.textureCoord?.let { textureCoords.add(it) }
+    point.normal?.let { normals.add(it) }
+    point.tangent?.let { tangents.add(it) }
+    point.bitangent?.let { bitangents.add(it) }
+}
+
+/**
+ * Retrieve [Point] from vertex data
+ */
+operator fun IVertexData.get(
+    index: Int,
+    textureCoordsIndex: Int = index,
+    colorsIndex: Int = index,
+    normalsIndex: Int = index,
+    tangentsIndex: Int = index,
+    bitangentsIndex: Int = index
+): Point {
+    return Point(
+        positions[index],
+        textureCoords.getOrNull(textureCoordsIndex),
+        colors.getOrNull(colorsIndex),
+        normals.getOrNull(normalsIndex),
+        tangents.getOrNull(tangentsIndex),
+        bitangents.getOrNull(bitangentsIndex)
+    )
 }