From 6427edb050b49e6559f6ea69b86aa35a1eab2173 Mon Sep 17 00:00:00 2001
From: drewcassidy <drewcassidy@me.com>
Date: Sun, 21 Feb 2021 16:32:14 -0800
Subject: [PATCH] mark matrix functions as const

---
 src/Matrix4x4.cpp | 4 ++--
 src/Matrix4x4.h   | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/Matrix4x4.cpp b/src/Matrix4x4.cpp
index 8013f50..71d95da 100644
--- a/src/Matrix4x4.cpp
+++ b/src/Matrix4x4.cpp
@@ -21,7 +21,7 @@
 
 namespace rgbcx {
 
-Matrix4x4 operator*(Matrix4x4& lhs, Matrix4x4& rhs) {
+Matrix4x4 operator*(const Matrix4x4& lhs, const Matrix4x4& rhs) {
     Matrix4x4 trans_rhs = rhs.Transpose();  // 🏳️‍⚧️
     Matrix4x4 result;
     for (unsigned r = 0; r < 4; r++) {
@@ -31,7 +31,7 @@ Matrix4x4 operator*(Matrix4x4& lhs, Matrix4x4& rhs) {
     return result;
 }
 
-Vector4 operator*(Matrix4x4& lhs, Vector4& rhs) {
+Vector4 operator*(const Matrix4x4& lhs, const Vector4& rhs) {
     Vector4 result;
 
     for (unsigned r = 0; r < 4; r++) { result[r] = rhs.Dot(lhs[r]); }
diff --git a/src/Matrix4x4.h b/src/Matrix4x4.h
index aa70c32..cb4729c 100644
--- a/src/Matrix4x4.h
+++ b/src/Matrix4x4.h
@@ -34,7 +34,7 @@ class Matrix4x4 {
         return result;
     }
 
-    static Matrix4x4 Transpose(Matrix4x4 &val) {
+    static Matrix4x4 Transpose(const Matrix4x4 &val) {
         Matrix4x4 result;
         for (unsigned r = 0; r < 3; r++) {
             for (unsigned c = 0; c < 3; c++) { result[r][c] = val[c][r]; }
@@ -71,7 +71,7 @@ class Matrix4x4 {
     friend Matrix4x4 &operator*=(Matrix4x4 &lhs, const float &rhs) { return lhs = lhs * rhs; }
     friend Matrix4x4 &operator/=(Matrix4x4 &lhs, const float &rhs) { return lhs = lhs / rhs; }
 
-    Matrix4x4 Transpose() { return Transpose(*this); }
+    Matrix4x4 Transpose() const { return Transpose(*this); }
 
     void Mirror();