From 46fdcfb171fa639565e02ae9562ffbf05a40b5e6 Mon Sep 17 00:00:00 2001
From: Kyle De'Vir <kyle.devir@mykolab.com>
Date: Sun, 29 May 2016 02:58:27 +1000
Subject: [PATCH 1/3] Added HMM_MultiplyMat4ByVec4 function

Multiplies a 4x4 matrix by a 4x4 vector and
returns it.
---
 HandmadeMath.h | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/HandmadeMath.h b/HandmadeMath.h
index 97899d0..53efc77 100644
--- a/HandmadeMath.h
+++ b/HandmadeMath.h
@@ -257,6 +257,7 @@ HMMDEF hmm_vec4 HMM_DivideVec4(hmm_vec4 Left, hmm_vec4 Right);
 HMMDEF hmm_mat4 HMM_Mat4(void);
 HMMDEF hmm_mat4 HMM_Mat4d(float Diagonal);
 HMMDEF hmm_mat4 HMM_MultiplyMat4(hmm_mat4 Left, hmm_mat4 Right);
+HMMDEF hmm_vec4 HMM_MultiplyMat4ByVec4(hmm_mat4 Matrix, hmm_vec4 Vector);
 
 HMMDEF hmm_mat4 HMM_Orthographic(float Left, float Right, float Bottom, float Top, float Near, float Far);
 HMMDEF hmm_mat4 HMM_Perspective(float FOV, float AspectRatio, float Near, float Far);
@@ -708,6 +709,26 @@ HMM_MultiplyMat4(hmm_mat4 Left, hmm_mat4 Right)
     return (Result);
 }
 
+hmm_vec4
+HMM_MultiplyMat4ByVec4(hmm_mat4 Matrix, hmm_vec4 Vector)
+{
+    hmm_vec4 Result = HMM_Vec4(0.0f, 0.0f, 0.0f, 0.0f);
+    
+    int Rows, Columns;
+    for(Rows = 0; Rows < 4; ++Rows)
+    {
+        float Sum = 0;
+        for(Columns = 0; Columns < 4; ++Columns)
+        {
+            Sum += Matrix.Elements[Rows][Columns] * Vector.Elements[Columns];
+        }
+        
+        Result.Elements[Rows] = Sum;
+    }
+    
+    return (Result);
+}
+
 hmm_mat4
 HMM_Orthographic(float Left, float Right, float Bottom, float Top, float Near, float Far)
 {

From a72ff828a6103e2f707b6d6f78371c749efd0f42 Mon Sep 17 00:00:00 2001
From: Kyle De'Vir <kyle.devir@mykolab.com>
Date: Sun, 29 May 2016 03:29:29 +1000
Subject: [PATCH 2/3] Added C++ HMM_MultiplyMat4ByVec4 functionality

Added operator overloaded HMM_MultiplyMat4ByVec4
functionality.
---
 HandmadeMath.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/HandmadeMath.h b/HandmadeMath.h
index 53efc77..9856715 100644
--- a/HandmadeMath.h
+++ b/HandmadeMath.h
@@ -917,6 +917,14 @@ Multiply(hmm_mat4 Left, hmm_mat4 Right)
     return (Result);
 }
 
+HINLINE hmm_vec4
+Multiply(hmm_mat4 Matrix, hmm_vec4 Vector)
+{
+    hmm_vec4 Result = HMM_MultiplyMat4ByVec4(Matrix, Vector);
+    
+    return (Result);
+}
+
 HINLINE hmm_vec2
 Divide(hmm_vec2 Left, hmm_vec2 Right)
 {
@@ -1036,6 +1044,14 @@ operator*(hmm_vec4 Left, hmm_vec4 Right)
     return (Result);
 }
 
+HINLINE hmm_vec4
+operator*(hmm_mat4 Matrix, hmm_vec4 Vector)
+{
+    hmm_vec4 Result = Multiply(Matrix, Vector);
+    
+    return (Result);
+}
+
 HINLINE hmm_mat4
 operator*(hmm_mat4 Left, hmm_mat4 Right)
 {

From 9b2c7bf3012d1116cfb90453601e5673937bee15 Mon Sep 17 00:00:00 2001
From: Kyle De'Vir <kyle.devir@mykolab.com>
Date: Sun, 29 May 2016 03:39:08 +1000
Subject: [PATCH 3/3] Added C++ HMM_MultiplyMat4ByVec4 functionality

Added missing prototypes
---
 HandmadeMath.h | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/HandmadeMath.h b/HandmadeMath.h
index 9856715..8db5f05 100644
--- a/HandmadeMath.h
+++ b/HandmadeMath.h
@@ -285,6 +285,7 @@ HMMDEF hmm_vec2 HMM_Multiply(int X, int Y);
 HMMDEF hmm_vec3 HMM_Multiply(int X, int Y, int Z);
 HMMDEF hmm_vec4 HMM_Multiply(int X, int Y, int Z, int W);
 HMMDEF hmm_mat4 HMM_Multiply(hmm_mat4 Left, hmm_mat4 Right);
+HMMDEF hmm_vec4 HMM_Multiply(hmm_mat4 Matrix, hmm_vec4 Vector);
 
 HMMDEF hmm_vec2 HMM_Divide(int X, int Y);
 HMMDEF hmm_vec3 HMM_Divide(int X, int Y, int Z);
@@ -306,6 +307,8 @@ HMMDEF hmm_mat4 operator*(hmm_mat4 Left, hmm_mat4 Right);
 HMMDEF hmm_vec3 operator*(hmm_vec3 Left, float Right);
 HMMDEF hmm_vec2 operator*(hmm_vec2 Left, float Right);
 
+HMMDEF hmm_vec4 operator*(hmm_mat4 Matrix, hmm_vec4 Vector);
+
 HMMDEF hmm_vec2 operator/(hmm_vec2 Left, hmm_vec2 Right);
 HMMDEF hmm_vec3 operator/(hmm_vec3 Left, hmm_vec3 Right);
 HMMDEF hmm_vec4 operator/(hmm_vec4 Left, hmm_vec4 Right);
@@ -1044,14 +1047,6 @@ operator*(hmm_vec4 Left, hmm_vec4 Right)
     return (Result);
 }
 
-HINLINE hmm_vec4
-operator*(hmm_mat4 Matrix, hmm_vec4 Vector)
-{
-    hmm_vec4 Result = Multiply(Matrix, Vector);
-    
-    return (Result);
-}
-
 HINLINE hmm_mat4
 operator*(hmm_mat4 Left, hmm_mat4 Right)
 {
@@ -1060,6 +1055,14 @@ operator*(hmm_mat4 Left, hmm_mat4 Right)
     return (Result);
 }
 
+HINLINE hmm_vec4
+operator*(hmm_mat4 Matrix, hmm_vec4 Vector)
+{
+    hmm_vec4 Result = Multiply(Matrix, Vector);
+    
+    return (Result);
+}
+
 HINLINE hmm_vec2
 operator/(hmm_vec2 Left, hmm_vec2 Right)
 {