Unary minus vectors (#130)

* Unary Minus operator for vec2, vec3, and vec4

* Update README.md

Co-authored-by: zak <zak@DESKTOP-V1AQ0IT>

HandmadeMath.h

@@ -2795,6 +2795,46 @@ HMM_INLINE hmm_bool operator!=(hmm_vec4 Left, hmm_vec4 Right)
     return !HMM_PREFIX(EqualsVec4)(Left, Right);
 }
 
+COVERAGE(HMM_UnaryMinusVec2, 1)
+HMM_INLINE hmm_vec2 operator-(hmm_vec2 In)
+{
+    ASSERT_COVERED(HMM_UnaryMinusVec2);
+    
+    hmm_vec2 Result;
+    Result.X = -In.X;
+    Result.Y = -In.Y;
+    return(Result);
+}
+
+COVERAGE(HMM_UnaryMinusVec3, 1)
+HMM_INLINE hmm_vec3 operator-(hmm_vec3 In)
+{
+    ASSERT_COVERED(HMM_UnaryMinusVec3);
+
+    hmm_vec3 Result;
+    Result.X = -In.X;
+    Result.Y = -In.Y;
+    Result.Z = -In.Z;
+    return(Result);
+}
+
+COVERAGE(HMM_UnaryMinusVec4, 1)
+HMM_INLINE hmm_vec4 operator-(hmm_vec4 In)
+{
+    ASSERT_COVERED(HMM_UnaryMinusVec4);
+    
+    hmm_vec4 Result;
+#if HANDMADE_MATH__USE_SSE
+    Result.InternalElementsSSE = _mm_xor_ps(In.InternalElementsSSE, _mm_set1_ps(-0.0f));
+#else
+    Result.X = -In.X;
+    Result.Y = -In.Y;
+    Result.Z = -In.Z;
+    Result.W = -In.W;
+#endif
+    return(Result);
+}
+
 #endif /* __cplusplus */
 
 #if defined(__GNUC__) || defined(__clang__)

README.md

@@ -10,6 +10,7 @@ To get started, go download [the latest release](https://github.com/HandmadeMath
 
 Version         | Changes        |
 ----------------|----------------|
+**1.12.0** | Added Unary Minus operator for `HMM_Vec2`, `HMM_Vec3`, and `HMM_Vec4`. |
 **1.11.1** | Added HMM_PREFIX macro to a few functions that were missing it. |
 **1.11.0** | Added ability to customize or remove the default `HMM_` prefix on function names by defining a macro called `HMM_PREFIX(name)`. |
 **1.10.1** | Removed stdint.h, this doesn't exist on some really old compilers and we didn't really use it anyways. |

test/categories/Subtraction.h

@@ -199,3 +199,32 @@ TEST(Subtraction, Quaternion)
     EXPECT_FLOAT_EQ(q1.W, -4.0f);
 #endif
 }
+
+#ifdef __cplusplus
+TEST(UnaryMinus, Vec2)
+{
+    hmm_vec2 VectorOne = {1.0f, 2.0f};
+    hmm_vec2 Result = -VectorOne;
+    EXPECT_FLOAT_EQ(Result.X, -1.0f);
+    EXPECT_FLOAT_EQ(Result.Y, -2.0f);
+}
+
+TEST(UnaryMinus, Vec3)
+{
+    hmm_vec3 VectorOne = {1.0f, 2.0f, 3.0f};
+    hmm_vec3 Result = -VectorOne;
+    EXPECT_FLOAT_EQ(Result.X, -1.0f);
+    EXPECT_FLOAT_EQ(Result.Y, -2.0f);
+    EXPECT_FLOAT_EQ(Result.Z, -3.0f);
+}
+
+TEST(UnaryMinus, Vec4)
+{
+    hmm_vec4 VectorOne = {1.0f, 2.0f, 3.0f, 4.0f};
+    hmm_vec4 Result = -VectorOne;
+    EXPECT_FLOAT_EQ(Result.X, -1.0f);
+    EXPECT_FLOAT_EQ(Result.Y, -2.0f);
+    EXPECT_FLOAT_EQ(Result.Z, -3.0f);
+    EXPECT_FLOAT_EQ(Result.W, -4.0f);
+}
+#endif