From 07ed786ea15b2eb650e230c56b4d143e69e4f3d7 Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Sun, 28 Apr 2019 15:32:37 +0800
Subject: [PATCH] add m_multiply

---
 src/m_multiply.scad | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 src/m_multiply.scad

diff --git a/src/m_multiply.scad b/src/m_multiply.scad
new file mode 100644
index 00000000..fb6f8da1
--- /dev/null
+++ b/src/m_multiply.scad
@@ -0,0 +1,13 @@
+function m_multiply(ma, mb) = 
+    let(
+        c1 = [mb[0][0], mb[1][0], mb[2][0], mb[3][0]],
+        c2 = [mb[0][1], mb[1][1], mb[2][1], mb[3][1]],
+        c3 = [mb[0][2], mb[1][2], mb[2][2], mb[3][2]],
+        c4 = [mb[0][3], mb[1][3], mb[2][3], mb[3][3]]
+    )
+    [
+        [ma[0] * c1, ma[0] * c2, ma[0] * c3, ma[0] * c4],
+        [ma[1] * c1, ma[1] * c2, ma[1] * c3, ma[1] * c4],
+        [ma[2] * c1, ma[2] * c2, ma[2] * c3, ma[2] * c4],
+        [ma[3] * c1, ma[3] * c2, ma[3] * c3, ma[3] * c4]
+    ];
\ No newline at end of file