[orx-math] Make Matrix and SparseMatrix serializable with kotlinx.serialization

orx-math/src/commonMain/kotlin/matrix/Matrix.kt

@@ -1,5 +1,7 @@
 package org.openrndr.extra.math.matrix
 
+import kotlinx.serialization.Serializable
+
 /**
  * Represents a two-dimensional matrix with support for basic operations such as indexing,
  * copying, and mathematical computations.
@@ -7,6 +9,7 @@ package org.openrndr.extra.math.matrix
  * @property rows The number of rows in the matrix.
  * @property cols The number of columns in the matrix.
  */
+@Serializable
 class Matrix(val rows: Int, val cols: Int) {
     val data = Array(rows) { DoubleArray(cols) }
 

orx-math/src/commonMain/kotlin/matrix/SparseMatrix.kt

@@ -1,5 +1,6 @@
 package org.openrndr.extra.math.matrix
 
+import kotlinx.serialization.Serializable
 import kotlin.math.abs
 import kotlin.math.sqrt
 
@@ -37,6 +38,7 @@ private fun countNonZeroElements(matrix: Matrix): Int {
  * @property columnIndices Array containing the column indices of the non-zero values.
  * @property rowPointers Array containing the starting position of each row in the values array.
  */
+@Serializable
 class SparseMatrix(
     val rows: Int,
     val cols: Int,