fix(math): correct select logic in quaternion and svd

Fixed conditional selection logic in quaternion and SVD math functions by swapping select argument order for correctness. Fixed LookRotationSafe and normalizesafe to return valid quaternions. Corrected SVD helper functions for proper value swapping and safe reciprocal. Added unit tests for matrix, reflection, projection, refraction, quaternion normalization, LookRotationSafe, and SVD operations. Incremented project version to 1.3.3. Minor formatting and using directive updates.

Misaki.HighPerformance.Test/UnitTest/Mathematics/TestMathFunctions.cs

@@ -1,4 +1,5 @@
 using Misaki.HighPerformance.Mathematics;
+using System.Numerics;
 
 namespace Misaki.HighPerformance.Test.UnitTest.Mathematics;
 
@@ -288,4 +289,64 @@ public class TestMathFunctions
         Assert.AreEqual(5f, result.y, 1e-6f); // condition is false, so select b.y
         Assert.AreEqual(3f, result.z, 1e-6f); // condition is true, so select a.z
     }
+
+    [TestMethod]
+    public void TestMatrixFunctions()
+    {
+        // Test determinant and inverse of a 2x2 matrix
+        var m = new float2x2(new float2(1f, 2f), new float2(3f, 4f));
+        var det = math.determinant(m);
+
+        Assert.AreEqual(-2f, det, 1e-6f);
+
+        var inv = math.inverse(m);
+        var expectedInv = new float2x2(new float2(-2f, 1f), new float2(1.5f, -0.5f));
+        Assert.AreEqual(expectedInv.c0.x, inv.c0.x, 1e-6f);
+        Assert.AreEqual(expectedInv.c0.y, inv.c0.y, 1e-6f);
+        Assert.AreEqual(expectedInv.c1.x, inv.c1.x, 1e-6f);
+        Assert.AreEqual(expectedInv.c1.y, inv.c1.y, 1e-6f);
+    }
+
+    [TestMethod]
+    public void TestRflections()
+    {
+        // Test reflect function
+        var incident = new float3(1f, -1f, 0f);
+        var normal = math.normalize(new float3(0f, 1f, 0f));
+        var reflected = math.reflect(incident, normal);
+
+        // The reflected vector should be (1, 1, 0)
+        Assert.AreEqual(1f, reflected.x, 1e-6f);
+        Assert.AreEqual(1f, reflected.y, 1e-6f);
+        Assert.AreEqual(0f, reflected.z, 1e-6f);
+    }
+
+    [TestMethod]
+    public void TestProjections()
+    {
+        // Test project function
+        var vector = new float3(1f, 2f, 3f);
+        var onNormal = math.normalize(new float3(0f, 1f, 0f));
+        var projected = math.project(vector, onNormal);
+
+        // The projection of (1,2,3) onto the Y-axis should be (0,2,0)
+        Assert.AreEqual(0f, projected.x, 1e-6f);
+        Assert.AreEqual(2f, projected.y, 1e-6f);
+        Assert.AreEqual(0f, projected.z, 1e-6f);
+    }
+
+    [TestMethod]
+    public void TestRefraction()
+    {
+        // Test refract function
+        var incident = math.normalize(new float3(1f, -1f, 0f));
+        var normal = math.normalize(new float3(0f, 1f, 0f));
+        var eta = 0.5f; // Refractive index ratio
+        var refracted = math.refract(incident, normal, eta);
+        
+        // The refracted vector should be approximately (0.707, -0.707, 0)
+        Assert.AreEqual(0.3535534f, refracted.x, 1e-6f);
+        Assert.AreEqual(-0.9354144f, refracted.y, 1e-6f);
+        Assert.AreEqual(0f, refracted.z, 1e-6f);
+    }
 }