From 14a85917477b1351e10adfa85dae7818c7da79c0 Mon Sep 17 00:00:00 2001
From: idontlikegits <zaezae.atto32@gmail.com>
Date: Tue, 10 Mar 2026 16:25:01 +0000
Subject: [PATCH] FIX: matrix3 identity and zero static

---
 G3Dcpp/Matrix4.cpp    | 36 +++++++++++++++++++-----------------
 include/G3D/Matrix3.h | 23 ++++++++++++++++++++---
 2 files changed, 39 insertions(+), 20 deletions(-)

diff --git a/G3Dcpp/Matrix4.cpp b/G3Dcpp/Matrix4.cpp
index 99ba501..c29f93a 100644
--- a/G3Dcpp/Matrix4.cpp
+++ b/G3Dcpp/Matrix4.cpp
@@ -17,23 +17,25 @@
 
 namespace G3D {
 
-const Matrix4& Matrix4::identity() {
-    static Matrix4 m(
-        1, 0, 0, 0,
-        0, 1, 0, 0,
-        0, 0, 1, 0,
-        0, 0, 0, 1);
-    return m;
-}
-
-const Matrix4& Matrix4::zero() {
-    static Matrix4 m(
-        0, 0, 0, 0,
-        0, 0, 0, 0,
-        0, 0, 0, 0,
-        0, 0, 0, 0);
-    return m;
-}
+// *** Read Matrix.h comment regarding identity and zero ***
+
+// const Matrix4& Matrix4::identity() {
+//     static Matrix4 m(
+//         1, 0, 0, 0,
+//         0, 1, 0, 0,
+//         0, 0, 1, 0,
+//         0, 0, 0, 1);
+//     return m;
+// }
+
+// const Matrix4& Matrix4::zero() {
+//     static Matrix4 m(
+//         0, 0, 0, 0,
+//         0, 0, 0, 0,
+//         0, 0, 0, 0,
+//         0, 0, 0, 0);
+//     return m;
+// }
 
 // Deprecated.
 const Matrix4 Matrix4::IDENTITY
diff --git a/include/G3D/Matrix3.h b/include/G3D/Matrix3.h
index 213f752..30b906f 100644
--- a/include/G3D/Matrix3.h
+++ b/include/G3D/Matrix3.h
@@ -246,6 +246,11 @@ class Matrix3 {
 
     static const float EPSILON; 
 
+    // The following comment is wrong. Modern linkers are smart enough to deduplicate
+    // multiple static objects into a single memory address, as long as any function with
+    // a static local variable is marked inline.
+
+    // *** Original G3D comment ***
     // Special values.
     // The unguaranteed order of initialization of static variables across 
     // translation units can be a source of annoying bugs, so now the static
@@ -255,7 +260,7 @@ class Matrix3 {
     // "You might be tempted to write [...] them as inline functions 
     // inside their respective header files, but this is something you 
     // must definitely not do. An inline function can be duplicated 
-    // in every file in which it appears � and this duplication 
+    // in every file in which it appears � and this duplication 
     // includes the static object definition. Because inline functions 
     // automatically default to internal linkage, this would result in 
     // having multiple static objects across the various translation 
@@ -264,8 +269,20 @@ class Matrix3 {
     // function, and this means not making the wrapping functions inline",
     // according to Chapter 10 of "Thinking in C++, 2nd ed. Volume 1" by Bruce Eckel, 
     // http://www.mindview.net/
-    static const Matrix3& zero();
-    static const Matrix3& identity(); 
+    // *** End of G3D comment ***
+
+    static const Matrix3& zero() {
+        static Matrix3 m(0, 0, 0, 0, 0, 0, 0, 0, 0);
+        return m;
+    }
+
+    static const Matrix3& identity() {
+        static Matrix3 m(1, 0, 0, 0, 1, 0, 0, 0, 1);
+        return m;
+    }
+
+    // static const Matrix3& zero();
+    // static const Matrix3& identity(); 
 
     // Deprecated. 
     /** @deprecated Use Matrix3::zero() */