From 40a66f2e11d4a180554845312684299c2c2cbd43 Mon Sep 17 00:00:00 2001
From: David Thompson <dthompson2@worcester.edu>
Date: Sun, 13 Aug 2017 13:54:17 -0400
Subject: math: matrix: Add custom record type printer.

* chickadee/math/matrix.scm (display-matrix4): New procedure.
---
 chickadee/math/matrix.scm | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/chickadee/math/matrix.scm b/chickadee/math/matrix.scm
index 26b70fe..2e94233 100644
--- a/chickadee/math/matrix.scm
+++ b/chickadee/math/matrix.scm
@@ -16,6 +16,7 @@
 ;;; <http://www.gnu.org/licenses/>.
 
 (define-module (chickadee math matrix)
+  #:use-module (ice-9 format)
   #:use-module (ice-9 match)
   #:use-module (rnrs bytevectors)
   #:use-module (srfi srfi-9)
@@ -52,6 +53,29 @@
 (define-inlinable (matrix-ref matrix row column)
   (f32vector-ref matrix (+ (* row 4) column)))
 
+(define (display-matrix4 matrix port)
+  (let ((m (matrix4-bv matrix)))
+    (format port
+            "#<matrix4 [[~f ~f ~f ~f] [~f ~f ~f ~f] [~f ~f ~f ~f] [~f ~f ~f ~f]]>"
+            (matrix-ref m 0 0)
+            (matrix-ref m 0 1)
+            (matrix-ref m 0 2)
+            (matrix-ref m 0 3)
+            (matrix-ref m 1 0)
+            (matrix-ref m 1 1)
+            (matrix-ref m 1 2)
+            (matrix-ref m 1 3)
+            (matrix-ref m 2 0)
+            (matrix-ref m 2 1)
+            (matrix-ref m 2 2)
+            (matrix-ref m 2 3)
+            (matrix-ref m 3 0)
+            (matrix-ref m 3 1)
+            (matrix-ref m 3 2)
+            (matrix-ref m 3 3))))
+
+(set-record-type-printer! <matrix4> display-matrix4)
+
 (define (init-matrix4 matrix
                       aa ab ac ad
                       ba bb bc bd
-- 
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