From 57cde916fb7b0794dd44382b0526336c654afddd Mon Sep 17 00:00:00 2001
From: David Thompson <dthompson2@worcester.edu>
Date: Wed, 14 Dec 2022 21:58:03 -0500
Subject: node-2d: Add centering within parent procedures.

---
 catbird/node-2d.scm | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/catbird/node-2d.scm b/catbird/node-2d.scm
index 0a1f683..05393fa 100644
--- a/catbird/node-2d.scm
+++ b/catbird/node-2d.scm
@@ -56,8 +56,11 @@
             align-right
             align-top
             center
+            center-in-parent
             center-horizontal
+            center-horizontal-in-parent
             center-vertical
+            center-vertical-in-parent
             default-height
             default-width
             expire-local-matrix
@@ -726,6 +729,23 @@ A."
   (center-horizontal a b)
   (center-vertical a b))
 
+(define (center-horizontal-in-parent node)
+  "Center x position of NODE within its parent."
+  (set! (position-x node)
+        (+ (/ (- (width (parent node)) (local-width node)) 2.0)
+           (- (local-origin-x node) (local-x node)))))
+
+(define (center-vertical-in-parent node)
+  "Center y position of NODE within its parent."
+  (set! (position-y node)
+        (+ (/ (- (height (parent node)) (local-height node)) 2.0)
+           (- (local-origin-y node) (local-y node)))))
+
+(define (center-in-parent node)
+  "Center NODE within its parent."
+  (center-horizontal-in-parent node)
+  (center-vertical-in-parent node))
+
 
 ;;;
 ;;; Sprite
-- 
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