Improve grammar/spelling

* Removed copy in operator[]

* Updated version info

HandmadeMath.h

@@ -1,5 +1,5 @@
 /*
-  HandmadeMath.h v1.5.0
+  HandmadeMath.h v1.7.1
   
   This is a single header file with a bunch of useful functions for game and
   graphics math operations.
@@ -166,8 +166,19 @@
           (*) Changed internal structure for better performance and inlining.
           (*) As a result, HANDMADE_MATH_NO_INLINE has been removed and no
               longer has any effect.
-          
+     1.5.1
-          
+          (*) Fixed a bug with uninitialized elements in HMM_LookAt.
+     1.6.0
+          (*) Added array subscript operators for vector and matrix types in
+              C++. This is provided as a convenience, but be aware that it may
+              incur an extra function call in unoptimized builds.
+     1.7.0
+          (*) Renamed the 'Rows' member of hmm_mat4 to 'Columns'. Since our
+              matrices are column-major, this should have been named 'Columns'
+              from the start. 'Rows' is still present, but has been deprecated.
+     1.7.1
+          (*) Changed operator[] to take a const ref int instead of an int. 
+
   LICENSE
   
   This software is in the public domain. Where that dedication is not
@@ -312,6 +323,13 @@ typedef union hmm_vec2
     };
 
     float Elements[2];
+
+#ifdef __cplusplus
+    inline float &operator[](const int &Index)
+    {
+        return Elements[Index];
+    }
+#endif
 } hmm_vec2;
 
 typedef union hmm_vec3
@@ -356,6 +374,13 @@ typedef union hmm_vec3
     };
 
     float Elements[3];
+
+#ifdef __cplusplus
+    inline float &operator[](const int &Index)
+    {
+        return Elements[Index];
+    }
+#endif
 } hmm_vec3;
 
 typedef union hmm_vec4
@@ -413,6 +438,13 @@ typedef union hmm_vec4
 #ifdef HANDMADE_MATH__USE_SSE    
     __m128 InternalElementsSSE;
 #endif
+
+#ifdef __cplusplus
+    inline float &operator[](const int &Index)
+    {
+        return Elements[Index];
+    }
+#endif
 } hmm_vec4;
 
 typedef union hmm_mat4
@@ -420,8 +452,27 @@ typedef union hmm_mat4
     float Elements[4][4];
         
 #ifdef HANDMADE_MATH__USE_SSE
+    __m128 Columns[4];
+
+    // DEPRECATED. Our matrices are column-major, so this was named
+    // incorrectly. Use Columns instead.
     __m128 Rows[4];
 #endif
+
+#ifdef __cplusplus
+    inline hmm_vec4 operator[](const int &Index)
+    {
+        float* col = Elements[Index];
+
+        hmm_vec4 result;
+        result.Elements[0] = col[0];
+        result.Elements[1] = col[1];
+        result.Elements[2] = col[2];
+        result.Elements[3] = col[3];
+
+        return result;
+    }
+#endif
 } hmm_mat4;
 
 typedef union hmm_quaternion
@@ -1087,10 +1138,10 @@ HMM_INLINE hmm_vec4 HMM_NormalizeVec4(hmm_vec4 A)
 HMM_INLINE __m128 HMM_LinearCombineSSE(__m128 Left, hmm_mat4 Right)
 {
     __m128 Result;
-    Result = _mm_mul_ps(_mm_shuffle_ps(Left, Left, 0x00), Right.Rows[0]);
+    Result = _mm_mul_ps(_mm_shuffle_ps(Left, Left, 0x00), Right.Columns[0]);
-    Result = _mm_add_ps(Result, _mm_mul_ps(_mm_shuffle_ps(Left, Left, 0x55), Right.Rows[1]));
+    Result = _mm_add_ps(Result, _mm_mul_ps(_mm_shuffle_ps(Left, Left, 0x55), Right.Columns[1]));
-    Result = _mm_add_ps(Result, _mm_mul_ps(_mm_shuffle_ps(Left, Left, 0xaa), Right.Rows[2]));
+    Result = _mm_add_ps(Result, _mm_mul_ps(_mm_shuffle_ps(Left, Left, 0xaa), Right.Columns[2]));
-    Result = _mm_add_ps(Result, _mm_mul_ps(_mm_shuffle_ps(Left, Left, 0xff), Right.Rows[3]));
+    Result = _mm_add_ps(Result, _mm_mul_ps(_mm_shuffle_ps(Left, Left, 0xff), Right.Columns[3]));
     
     return (Result);
 }
@@ -1125,7 +1176,7 @@ HMM_INLINE hmm_mat4 HMM_Transpose(hmm_mat4 Matrix)
 {
     hmm_mat4 Result = Matrix;
     
-    _MM_TRANSPOSE4_PS(Result.Rows[0], Result.Rows[1], Result.Rows[2], Result.Rows[3]);
+    _MM_TRANSPOSE4_PS(Result.Columns[0], Result.Columns[1], Result.Columns[2], Result.Columns[3]);
 
     return (Result);
 }
@@ -1138,10 +1189,10 @@ HMM_INLINE hmm_mat4 HMM_AddMat4(hmm_mat4 Left, hmm_mat4 Right)
 {
     hmm_mat4 Result;
 
-    Result.Rows[0] = _mm_add_ps(Left.Rows[0], Right.Rows[0]);
+    Result.Columns[0] = _mm_add_ps(Left.Columns[0], Right.Columns[0]);
-    Result.Rows[1] = _mm_add_ps(Left.Rows[1], Right.Rows[1]);
+    Result.Columns[1] = _mm_add_ps(Left.Columns[1], Right.Columns[1]);
-    Result.Rows[2] = _mm_add_ps(Left.Rows[2], Right.Rows[2]);
+    Result.Columns[2] = _mm_add_ps(Left.Columns[2], Right.Columns[2]);
-    Result.Rows[3] = _mm_add_ps(Left.Rows[3], Right.Rows[3]);    
+    Result.Columns[3] = _mm_add_ps(Left.Columns[3], Right.Columns[3]);    
 
     return (Result);
 }
@@ -1154,10 +1205,10 @@ HMM_INLINE hmm_mat4 HMM_SubtractMat4(hmm_mat4 Left, hmm_mat4 Right)
 {
     hmm_mat4 Result;
 
-    Result.Rows[0] = _mm_sub_ps(Left.Rows[0], Right.Rows[0]);
+    Result.Columns[0] = _mm_sub_ps(Left.Columns[0], Right.Columns[0]);
-    Result.Rows[1] = _mm_sub_ps(Left.Rows[1], Right.Rows[1]);
+    Result.Columns[1] = _mm_sub_ps(Left.Columns[1], Right.Columns[1]);
-    Result.Rows[2] = _mm_sub_ps(Left.Rows[2], Right.Rows[2]);
+    Result.Columns[2] = _mm_sub_ps(Left.Columns[2], Right.Columns[2]);
-    Result.Rows[3] = _mm_sub_ps(Left.Rows[3], Right.Rows[3]);
+    Result.Columns[3] = _mm_sub_ps(Left.Columns[3], Right.Columns[3]);
 
     return (Result);
 }
@@ -1173,10 +1224,10 @@ HMM_INLINE hmm_mat4 HMM_MultiplyMat4f(hmm_mat4 Matrix, float Scalar)
     hmm_mat4 Result;
 
     __m128 SSEScalar = _mm_set1_ps(Scalar);
-    Result.Rows[0] = _mm_mul_ps(Matrix.Rows[0], SSEScalar);
+    Result.Columns[0] = _mm_mul_ps(Matrix.Columns[0], SSEScalar);
-    Result.Rows[1] = _mm_mul_ps(Matrix.Rows[1], SSEScalar);
+    Result.Columns[1] = _mm_mul_ps(Matrix.Columns[1], SSEScalar);
-    Result.Rows[2] = _mm_mul_ps(Matrix.Rows[2], SSEScalar);
+    Result.Columns[2] = _mm_mul_ps(Matrix.Columns[2], SSEScalar);
-    Result.Rows[3] = _mm_mul_ps(Matrix.Rows[3], SSEScalar);
+    Result.Columns[3] = _mm_mul_ps(Matrix.Columns[3], SSEScalar);
 
     return (Result);
 }
@@ -1192,10 +1243,10 @@ HMM_INLINE hmm_mat4 HMM_DivideMat4f(hmm_mat4 Matrix, float Scalar)
     hmm_mat4 Result;
     
     __m128 SSEScalar = _mm_set1_ps(Scalar);
-    Result.Rows[0] = _mm_div_ps(Matrix.Rows[0], SSEScalar);
+    Result.Columns[0] = _mm_div_ps(Matrix.Columns[0], SSEScalar);
-    Result.Rows[1] = _mm_div_ps(Matrix.Rows[1], SSEScalar);
+    Result.Columns[1] = _mm_div_ps(Matrix.Columns[1], SSEScalar);
-    Result.Rows[2] = _mm_div_ps(Matrix.Rows[2], SSEScalar);
+    Result.Columns[2] = _mm_div_ps(Matrix.Columns[2], SSEScalar);
-    Result.Rows[3] = _mm_div_ps(Matrix.Rows[3], SSEScalar);    
+    Result.Columns[3] = _mm_div_ps(Matrix.Columns[3], SSEScalar);    
 
     return (Result);
 }
@@ -2210,10 +2261,10 @@ hmm_mat4 HMM_MultiplyMat4(hmm_mat4 Left, hmm_mat4 Right)
 
 #ifdef HANDMADE_MATH__USE_SSE
 
-    Result.Rows[0] = HMM_LinearCombineSSE(Right.Rows[0], Left);
+    Result.Columns[0] = HMM_LinearCombineSSE(Right.Columns[0], Left);
-    Result.Rows[1] = HMM_LinearCombineSSE(Right.Rows[1], Left);
+    Result.Columns[1] = HMM_LinearCombineSSE(Right.Columns[1], Left);
-    Result.Rows[2] = HMM_LinearCombineSSE(Right.Rows[2], Left);
+    Result.Columns[2] = HMM_LinearCombineSSE(Right.Columns[2], Left);
-    Result.Rows[3] = HMM_LinearCombineSSE(Right.Rows[3], Left);     
+    Result.Columns[3] = HMM_LinearCombineSSE(Right.Columns[3], Left);     
     
 #else
     int Columns;
@@ -2334,14 +2385,17 @@ hmm_mat4 HMM_LookAt(hmm_vec3 Eye, hmm_vec3 Center, hmm_vec3 Up)
     Result.Elements[0][0] = S.X;
     Result.Elements[0][1] = U.X;
     Result.Elements[0][2] = -F.X;
+    Result.Elements[0][3] = 0.0f;
 
     Result.Elements[1][0] = S.Y;
     Result.Elements[1][1] = U.Y;
     Result.Elements[1][2] = -F.Y;
+    Result.Elements[1][3] = 0.0f;
 
     Result.Elements[2][0] = S.Z;
     Result.Elements[2][1] = U.Z;
     Result.Elements[2][2] = -F.Z;
+    Result.Elements[2][3] = 0.0f;
 
     Result.Elements[3][0] = -HMM_DotVec3(S, Eye);
     Result.Elements[3][1] = -HMM_DotVec3(U, Eye);

README.md

@@ -8,8 +8,12 @@ To get started, go download [the latest release](https://github.com/HandmadeMath
 
 -----
 
-Version         | Changes        | 
+Version         | Changes        |
 ----------------|----------------|
+**1.7.1** | Changed operator[] to take a const ref int instead of an int.
+**1.7.0** | Renamed the 'Rows' member of hmm_mat4 to 'Columns'. Since our matrices are column-major, this should have been named 'Columns' from the start. 'Rows' is still present, but has been deprecated.
+**1.6.0** | Added array subscript operators for vector and matrix types in C++. This is provided as a convenience, but be aware that it may incur an extra function call in unoptimized builds.
+**1.5.1** | Fixed a bug with uninitialized elements in HMM_LookAt.
 **1.5.0** | Changed internal structure for better performance and inlining. As a result, `HANDMADE_MATH_NO_INLINE` has been removed and no longer has any effect.
 **1.4.0** | Fixed bug when using C mode. SSE'd all vec4 operations. Removed zeroing for better performance.
 **1.3.0** | Removed need to `#define HANDMADE_MATH_CPP_MODE`. C++ definitions are now included automatically in C++ environments.

test/categories/Initialization.h

@@ -18,6 +18,10 @@ TEST(Initialization, Vectors)
     EXPECT_FLOAT_EQ(v2.Height, 2.0f);
     EXPECT_FLOAT_EQ(v2.Elements[0], 1.0f);
     EXPECT_FLOAT_EQ(v2.Elements[1], 2.0f);
+#ifdef __cplusplus
+    EXPECT_FLOAT_EQ(v2[0], 1.0f);
+    EXPECT_FLOAT_EQ(v2[1], 2.0f);
+#endif
 
     EXPECT_FLOAT_EQ(v2i.X, 1.0f);
     EXPECT_FLOAT_EQ(v2i.Y, 2.0f);
@@ -29,6 +33,10 @@ TEST(Initialization, Vectors)
     EXPECT_FLOAT_EQ(v2i.Height, 2.0f);
     EXPECT_FLOAT_EQ(v2i.Elements[0], 1.0f);
     EXPECT_FLOAT_EQ(v2i.Elements[1], 2.0f);
+#ifdef __cplusplus
+    EXPECT_FLOAT_EQ(v2i[0], 1.0f);
+    EXPECT_FLOAT_EQ(v2i[1], 2.0f);
+#endif
 
     //
     // Test vec3
@@ -56,6 +64,11 @@ TEST(Initialization, Vectors)
     EXPECT_FLOAT_EQ(v3.UV.Elements[1], 2.0f);
     EXPECT_FLOAT_EQ(v3.VW.Elements[0], 2.0f);
     EXPECT_FLOAT_EQ(v3.VW.Elements[1], 3.0f);
+#ifdef __cplusplus
+    EXPECT_FLOAT_EQ(v3[0], 1.0f);
+    EXPECT_FLOAT_EQ(v3[1], 2.0f);
+    EXPECT_FLOAT_EQ(v3[2], 3.0f);
+#endif
 
     EXPECT_FLOAT_EQ(v3i.X, 1.0f);
     EXPECT_FLOAT_EQ(v3i.Y, 2.0f);
@@ -77,6 +90,11 @@ TEST(Initialization, Vectors)
     EXPECT_FLOAT_EQ(v3i.UV.Elements[1], 2.0f);
     EXPECT_FLOAT_EQ(v3i.VW.Elements[0], 2.0f);
     EXPECT_FLOAT_EQ(v3i.VW.Elements[1], 3.0f);
+#ifdef __cplusplus
+    EXPECT_FLOAT_EQ(v3i[0], 1.0f);
+    EXPECT_FLOAT_EQ(v3i[1], 2.0f);
+    EXPECT_FLOAT_EQ(v3i[2], 3.0f);
+#endif
 
     //
     // Test vec4
@@ -107,6 +125,12 @@ TEST(Initialization, Vectors)
     EXPECT_FLOAT_EQ(v4.RGB.Elements[0], 1.0f);
     EXPECT_FLOAT_EQ(v4.RGB.Elements[1], 2.0f);
     EXPECT_FLOAT_EQ(v4.RGB.Elements[2], 3.0f);
+#ifdef __cplusplus
+    EXPECT_FLOAT_EQ(v4[0], 1.0f);
+    EXPECT_FLOAT_EQ(v4[1], 2.0f);
+    EXPECT_FLOAT_EQ(v4[2], 3.0f);
+    EXPECT_FLOAT_EQ(v4[3], 4.0f);
+#endif
 
     EXPECT_FLOAT_EQ(v4i.X, 1.0f);
     EXPECT_FLOAT_EQ(v4i.Y, 2.0f);
@@ -130,6 +154,12 @@ TEST(Initialization, Vectors)
     EXPECT_FLOAT_EQ(v4i.RGB.Elements[0], 1.0f);
     EXPECT_FLOAT_EQ(v4i.RGB.Elements[1], 2.0f);
     EXPECT_FLOAT_EQ(v4i.RGB.Elements[2], 3.0f);
+#ifdef __cplusplus
+    EXPECT_FLOAT_EQ(v4i[0], 1.0f);
+    EXPECT_FLOAT_EQ(v4i[1], 2.0f);
+    EXPECT_FLOAT_EQ(v4i[2], 3.0f);
+    EXPECT_FLOAT_EQ(v4i[3], 4.0f);
+#endif
 
     EXPECT_FLOAT_EQ(v4v.X, 1.0f);
     EXPECT_FLOAT_EQ(v4v.Y, 2.0f);
@@ -153,6 +183,12 @@ TEST(Initialization, Vectors)
     EXPECT_FLOAT_EQ(v4v.RGB.Elements[0], 1.0f);
     EXPECT_FLOAT_EQ(v4v.RGB.Elements[1], 2.0f);
     EXPECT_FLOAT_EQ(v4v.RGB.Elements[2], 3.0f);
+#ifdef __cplusplus
+    EXPECT_FLOAT_EQ(v4v[0], 1.0f);
+    EXPECT_FLOAT_EQ(v4v[1], 2.0f);
+    EXPECT_FLOAT_EQ(v4v[2], 3.0f);
+    EXPECT_FLOAT_EQ(v4v[3], 4.0f);
+#endif
 }
 
 TEST(Initialization, MatrixEmpty)
@@ -163,6 +199,9 @@ TEST(Initialization, MatrixEmpty)
         for (int Row = 0; Row < 4; ++Row)
         {
             EXPECT_FLOAT_EQ(m4.Elements[Column][Row], 0.0f);
+#ifdef __cplusplus
+            EXPECT_FLOAT_EQ(m4[Column][Row], 0.0f);
+#endif
         }
     }
 }

test/categories/SSE.h

@@ -8,10 +8,10 @@ TEST(SSE, LinearCombine)
     hmm_mat4 MatrixTwo = HMM_Mat4d(4.0f);
     hmm_mat4 Result;
     
-    Result.Rows[0] = HMM_LinearCombineSSE(MatrixOne.Rows[0], MatrixTwo);
+    Result.Columns[0] = HMM_LinearCombineSSE(MatrixOne.Columns[0], MatrixTwo);
-    Result.Rows[1] = HMM_LinearCombineSSE(MatrixOne.Rows[1], MatrixTwo);
+    Result.Columns[1] = HMM_LinearCombineSSE(MatrixOne.Columns[1], MatrixTwo);
-    Result.Rows[2] = HMM_LinearCombineSSE(MatrixOne.Rows[2], MatrixTwo);
+    Result.Columns[2] = HMM_LinearCombineSSE(MatrixOne.Columns[2], MatrixTwo);
-    Result.Rows[3] = HMM_LinearCombineSSE(MatrixOne.Rows[3], MatrixTwo);
+    Result.Columns[3] = HMM_LinearCombineSSE(MatrixOne.Columns[3], MatrixTwo);
     
     {
         EXPECT_FLOAT_EQ(Result.Elements[0][0], 8.0f);
@@ -23,14 +23,12 @@ TEST(SSE, LinearCombine)
         EXPECT_FLOAT_EQ(Result.Elements[1][1], 8.0f);                
         EXPECT_FLOAT_EQ(Result.Elements[1][2], 0.0f);
         EXPECT_FLOAT_EQ(Result.Elements[1][3], 0.0f);
-
                         
         EXPECT_FLOAT_EQ(Result.Elements[2][0], 0.0f);
         EXPECT_FLOAT_EQ(Result.Elements[2][1], 0.0f);                
         EXPECT_FLOAT_EQ(Result.Elements[2][2], 8.0f);
         EXPECT_FLOAT_EQ(Result.Elements[2][3], 0.0f);
 
-        
         EXPECT_FLOAT_EQ(Result.Elements[3][0], 0.0f);
         EXPECT_FLOAT_EQ(Result.Elements[3][1], 0.0f);                
         EXPECT_FLOAT_EQ(Result.Elements[3][2], 0.0f);

test/categories/Transformation.h

@@ -51,3 +51,27 @@ TEST(Transformations, Scale)
     EXPECT_FLOAT_EQ(scaled.Z, 1.5f);
     EXPECT_FLOAT_EQ(scaled.W, 1.0f);
 }
+
+TEST(Transformations, LookAt)
+{
+    const float abs_error = 0.0001f;
+
+    hmm_mat4 result = HMM_LookAt(HMM_Vec3(1.0f, 0.0f, 0.0f), HMM_Vec3(0.0f, 2.0f, 1.0f), HMM_Vec3(2.0f, 1.0f, 1.0f));
+
+    EXPECT_NEAR(result.Elements[0][0], 0.169031f, abs_error);
+    EXPECT_NEAR(result.Elements[0][1], 0.897085f, abs_error);
+    EXPECT_NEAR(result.Elements[0][2], 0.408248f, abs_error);
+    EXPECT_FLOAT_EQ(result.Elements[0][3], 0.0f);
+    EXPECT_NEAR(result.Elements[1][0], 0.507093f, abs_error);
+    EXPECT_NEAR(result.Elements[1][1], 0.276026f, abs_error);
+    EXPECT_NEAR(result.Elements[1][2], -0.816497f, abs_error);
+    EXPECT_FLOAT_EQ(result.Elements[1][3], 0.0f);
+    EXPECT_NEAR(result.Elements[2][0], -0.845154f, abs_error);
+    EXPECT_NEAR(result.Elements[2][1], 0.345033f, abs_error);
+    EXPECT_NEAR(result.Elements[2][2], -0.408248f, abs_error);
+    EXPECT_FLOAT_EQ(result.Elements[2][3], 0.0f);
+    EXPECT_NEAR(result.Elements[3][0], -0.169031f, abs_error);
+    EXPECT_NEAR(result.Elements[3][1], -0.897085f, abs_error);
+    EXPECT_NEAR(result.Elements[3][2], -0.408248f, abs_error);
+    EXPECT_FLOAT_EQ(result.Elements[3][3], 1.0f);
+}