[orx-shapes] convert to MPP

orx-shapes/src/commonMain/kotlin/RectangleGrid.kt

@@ -0,0 +1,43 @@
+package org.openrndr.extra.shapes
+
+import org.openrndr.shape.Rectangle
+
+/**
+ * Splits [Rectangle] into a grid of [Rectangle]s
+ * @param columns the number of columns in the resulting grid
+ * @param rows the number of rows in the resulting grid
+ * @param marginX the unitless margin width
+ * @param marginY the unitless margin height
+ * @param gutterX the unitless gutter width, the horizontal space between grid cells
+ * @param gutterY the unitless gutter height, the vertical space between grid cells
+ */
+fun Rectangle.grid(
+    columns: Int,
+    rows: Int,
+    marginX: Double = 0.0,
+    marginY: Double = 0.0,
+    gutterX: Double = 0.0,
+    gutterY: Double = 0.0
+): List<List<Rectangle>> {
+
+    val totalWidth = width - marginX * 2.0
+    val totalHeight = height - marginY * 2.0
+
+    val totalGutterWidth = gutterX * (columns - 1).coerceAtLeast(0)
+    val totalGutterHeight = gutterY * (rows - 1).coerceAtLeast(0)
+
+    val cellWidth = ((totalWidth - totalGutterWidth) / columns).coerceAtLeast(0.0)
+    val cellHeight = ((totalHeight - totalGutterHeight) / rows).coerceAtLeast(0.0)
+
+    val cellSpaceX = cellWidth + gutterX
+    val cellSpaceY = cellHeight + gutterY
+
+    val x0 = x + marginX
+    val y0 = y + marginY
+
+    return (0 until rows).map { row ->
+        (0 until columns).map { column ->
+            Rectangle(x0 + column * cellSpaceX, y0 + row * cellSpaceY, cellWidth, cellHeight)
+        }
+    }
+}