Added new and improved floating-point equality tester.

tests/OpenTK.Tests/Assertions.fs

@@ -9,9 +9,19 @@ open OpenTK
 [<AutoOpen>]
 module private AssertHelpers =
     [<Literal>]
-    let private BitAccuracy = 13
+    let private BitAccuracy = 16
 
-    let approxEq a b = MathHelper.ApproximatelyEqual(a,b,BitAccuracy)
+    //let approxEq a b = MathHelper.ApproximatelyEqual(a,b,BitAccuracy)
+    let approxEq a b = MathHelper.ApproximatelyEqualEpsilon(a,b,0.0001f)
+    let approxEqSingleEpsilon a b = MathHelper.ApproximatelyEqualEpsilon(a, b, 0.00001f)
+    let approxEqDoubleEpsilon a b = MathHelper.ApproximatelyEqualEpsilon(a, b, 0.00001)
+
+    let approxEqSingleEpsilonWithError (a, b, c : float32) = MathHelper.ApproximatelyEqualEpsilon(a, b, c)
+    let approxEqDoubleEpsilonWithError (a, b, c : float) = MathHelper.ApproximatelyEqualEpsilon(a, b, c)
+
+    let anyZero2 (a : Vector2) = (approxEq a.X 0.0f || approxEq a.Y 0.0f)
+    let anyZero3 (a : Vector3) = (approxEq a.X 0.0f || approxEq a.Y 0.0f || approxEq a.Z 0.0f)
+    let anyZero4 (a : Vector4) = (approxEq a.X 0.0f || approxEq a.Y 0.0f || approxEq a.Z 0.0f || approxEq a.W 0.0f)
 
 /// We use a full type here instead of a module, as the overloading semantics are more suitable for our desired goal.
 [<Sealed>]
@@ -31,4 +41,31 @@ type internal Assert =
         if not <| approxEq a b then raise <| new Xunit.Sdk.EqualException(a,b)
 
 
+    static member ApproximatelyEqualEpsilon(a : float32, b : float32) =
+        if not <| approxEqSingleEpsilon a b then raise <| new Xunit.Sdk.EqualException(a,b)
+
+    static member ApproximatelyEqualEpsilon(a : float32, b : float32, c : float32) =
+        if not <| approxEqSingleEpsilonWithError(a, b, c) then raise <| new Xunit.Sdk.EqualException(a,b)
+
+
+    static member ApproximatelyEqualEpsilon(a : float, b : float) =
+        if not <| approxEqDoubleEpsilon a b then raise <| new Xunit.Sdk.EqualException(a,b)
+
+    static member ApproximatelyEqualEpsilon(a : float, b : float, c : float) =
+        if not <| approxEqDoubleEpsilonWithError(a, b, c) then raise <| new Xunit.Sdk.EqualException(a,b)
+
+
+    static member NotApproximatelyEqualEpsilon(a : float32, b : float32) =
+        if approxEqSingleEpsilon a b then raise <| new Xunit.Sdk.EqualException(a,b)
+
+    static member NotApproximatelyEqualEpsilon(a : float32, b : float32, c : float32) =
+        if approxEqSingleEpsilonWithError(a, b, c) then raise <| new Xunit.Sdk.EqualException(a,b)
+
+
+    static member NotApproximatelyEqualEpsilon(a : float, b : float) =
+        if approxEqDoubleEpsilon a b then raise <| new Xunit.Sdk.EqualException(a,b)
+
+    static member NotApproximatelyEqualEpsilon(a : float, b : float, c : float) =
+        if approxEqDoubleEpsilonWithError(a, b, c) then raise <| new Xunit.Sdk.EqualException(a,b)
+
     static member ThrowsIndexExn(f:unit -> unit) = Assert.Throws<IndexOutOfRangeException>(f) |> ignore

tests/OpenTK.Tests/MathHelperTests.fs

@@ -6,50 +6,303 @@ open FsCheck.Xunit
 open System
 open OpenTK
 
-[<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
 module MathHelper =
-    /// This test ensures that approximately equal can never get it 'wrong' about the values.
-    [<Property>]
-    let ``ApproximatelyEqual is never incorrect`` (a : float32,b : float32,bits : int32) =
-        let clamped = max 0 (min bits 24)
-        let areApproxEqual = MathHelper.ApproximatelyEqual(a,b,clamped)
-        let areExactlyEqual = a = b
-        let isWrong = areExactlyEqual && not areApproxEqual
-        Assert.False(isWrong)
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
+    module ``ApproximatelyEqual (delta)`` =
+        /// This test ensures that approximately equal can never get it 'wrong' about the values.
+        [<Property>]
+        let ``ApproximatelyEqual is never incorrect`` (a : float32,b : float32,bits : int32) =
+            let clamped = max 0 (min bits 24)
+            let areApproxEqual = MathHelper.ApproximatelyEqual(a,b,clamped)
+            let areExactlyEqual = a = b
+            let isWrong = areExactlyEqual && not areApproxEqual
+            Assert.False(isWrong)
 
-    [<Property>]
-    let ``ApproximatelyEqual can return true if some values are not exactly equal`` (a : float32,b : float32,bits : int32) =
-        let clamped = max 0 (min bits 24)
-        let areApproxEqual = MathHelper.ApproximatelyEqual(a,b,clamped)
-        let areExactlyEqual = a = b
-        let isWrong = areExactlyEqual && not areApproxEqual
-        let p = new PropertyAttribute()
-        Assert.False(isWrong)
+        [<Property>]
+        let ``ApproximatelyEqual can return true if some values are not exactly equal`` (a : float32,b : float32,bits : int32) =
+            let clamped = max 0 (min bits 24)
+            let areApproxEqual = MathHelper.ApproximatelyEqual(a,b,clamped)
+            let areExactlyEqual = a = b
+            let isWrong = areExactlyEqual && not areApproxEqual
+            let p = new PropertyAttribute()
+            Assert.False(isWrong)
 
-    [<Fact>]
-    let ``ApproximatelyEqual correctly approximates equality``() =
-        let a = 0.000000001f
-        let b = 0.0000000010000001f
-        Assert.NotEqual(a,b)
-        [ 1..24 ] |> List.iter (fun i -> Assert.True(MathHelper.ApproximatelyEqual(a,b,i)))
+        [<Fact>]
+        let ``ApproximatelyEqual correctly approximates equality``() =
+            let a = 0.000000001f
+            let b = 0.0000000010000001f
+            Assert.NotEqual(a,b)
+            [ 1..24 ] |> List.iter (fun i -> Assert.True(MathHelper.ApproximatelyEqual(a,b,i)))
 
-    [<Fact>]
-    let ``ApproximatelyEqual reports very different values as non-equal even with high bit count``() =
-        let a = 2.0f
-        let b = 1.0f
-        Assert.NotEqual(a,b)
-        Assert.False(MathHelper.ApproximatelyEqual(a,b,10))
+        [<Fact>]
+        let ``ApproximatelyEqual reports very different values as non-equal even with high bit count``() =
+            let a = 2.0f
+            let b = 1.0f
+            Assert.NotEqual(a,b)
+            Assert.False(MathHelper.ApproximatelyEqual(a,b,10))
 
-    [<Fact>]
-    let ``ApproximatelyEqual works with single zero value``() =
-        let a = 1.0f
-        let b = 0.0f
-        Assert.NotEqual(a,b)
-        Assert.False(MathHelper.ApproximatelyEqual(a,b,0))
+        [<Fact>]
+        let ``ApproximatelyEqual works with single zero value``() =
+            let a = 1.0f
+            let b = 0.0f
+            Assert.NotEqual(a,b)
+            Assert.False(MathHelper.ApproximatelyEqual(a,b,0))
 
-    [<Fact>]
-    let ``ApproximatelyEqual works with both zero values``() =
-        let a = 0.0f
-        let b = 0.0f
-        Assert.Equal(a,b)
-        Assert.True(MathHelper.ApproximatelyEqual(a,b,0))
+        [<Fact>]
+        let ``ApproximatelyEqual works with both zero values``() =
+            let a = 0.0f
+            let b = 0.0f
+            Assert.Equal(a,b)
+            Assert.True(MathHelper.ApproximatelyEqual(a,b,0))
+
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
+    module ``ApproximatelyEqual (single-precision epsilon)`` =
+        //
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for large positive values``() =
+            Assert.ApproximatelyEqualEpsilon(1000000.0f, 1000001.0f);
+            Assert.ApproximatelyEqualEpsilon(1000001.0f, 1000000.0f);
+            Assert.NotApproximatelyEqualEpsilon(10000.0f, 10001.0f);
+            Assert.NotApproximatelyEqualEpsilon(10001.0f, 10000.0f);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for large negative values``() =
+            Assert.ApproximatelyEqualEpsilon(-1000000.0f, -1000001.0f);
+            Assert.ApproximatelyEqualEpsilon(-1000001.0f, -1000000.0f);
+            Assert.NotApproximatelyEqualEpsilon(-10000.0f, -10001.0f);
+            Assert.NotApproximatelyEqualEpsilon(-10001.0f, -10000.0f);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for positive values around 1``() =
+            Assert.ApproximatelyEqualEpsilon(1.0000001f, 1.0000002f);
+            Assert.ApproximatelyEqualEpsilon(1.0000002f, 1.0000001f);
+            Assert.NotApproximatelyEqualEpsilon(1.0002f, 1.0001f);
+            Assert.NotApproximatelyEqualEpsilon(1.0001f, 1.0002f);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for negative values around -1``() =
+            Assert.ApproximatelyEqualEpsilon(-1.000001f, -1.000002f);
+            Assert.ApproximatelyEqualEpsilon(-1.000002f, -1.000001f);
+            Assert.NotApproximatelyEqualEpsilon(-1.0001f, -1.0002f);
+            Assert.NotApproximatelyEqualEpsilon(-1.0002f, -1.0001f);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for values between 1 and 0``() =
+            Assert.ApproximatelyEqualEpsilon(0.000000001000001f, 0.000000001000002f);
+            Assert.ApproximatelyEqualEpsilon(0.000000001000002f, 0.000000001000001f);
+            Assert.NotApproximatelyEqualEpsilon(0.000000000001002f, 0.000000000001001f);
+            Assert.NotApproximatelyEqualEpsilon(0.000000000001001f, 0.000000000001002f);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for values between -1 and 0``() =
+            Assert.ApproximatelyEqualEpsilon(-0.000000001000001f, -0.000000001000002f);
+            Assert.ApproximatelyEqualEpsilon(-0.000000001000002f, -0.000000001000001f);
+            Assert.NotApproximatelyEqualEpsilon(-0.000000000001002f, -0.000000000001001f);
+            Assert.NotApproximatelyEqualEpsilon(-0.000000000001001f, -0.000000000001002f);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for comparisons involving 0``() =
+            Assert.ApproximatelyEqualEpsilon(0.0f, 0.0f);
+            Assert.ApproximatelyEqualEpsilon(0.0f, -0.0f);
+            Assert.ApproximatelyEqualEpsilon(-0.0f, -0.0f);
+            Assert.NotApproximatelyEqualEpsilon(0.00000001f, 0.0f);
+            Assert.NotApproximatelyEqualEpsilon(0.0f, 0.00000001f);
+            Assert.NotApproximatelyEqualEpsilon(-0.00000001f, 0.0f);
+            Assert.NotApproximatelyEqualEpsilon(0.0f, -0.00000001f);
+
+            Assert.ApproximatelyEqualEpsilon(0.0f, 1e-40f, 0.01f);
+            Assert.ApproximatelyEqualEpsilon(1e-40f, 0.0f, 0.01f);
+            Assert.NotApproximatelyEqualEpsilon(1e-40f, 0.0f, 0.000001f);
+            Assert.NotApproximatelyEqualEpsilon(0.0f, 1e-40f, 0.000001f);
+
+            Assert.ApproximatelyEqualEpsilon(0.0f, -1e-40f, 0.1f);
+            Assert.ApproximatelyEqualEpsilon(-1e-40f, 0.0f, 0.1f);
+            Assert.NotApproximatelyEqualEpsilon(-1e-40f, 0.0f, 0.00000001f);
+            Assert.NotApproximatelyEqualEpsilon(0.0f, -1e-40f, 0.00000001f);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for extreme values with overflow potential``() =
+            Assert.ApproximatelyEqualEpsilon(System.Single.MaxValue, System.Single.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.MaxValue, -System.Single.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(-System.Single.MaxValue, System.Single.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.MaxValue, System.Single.MaxValue / 2.0f);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.MaxValue, -System.Single.MaxValue / 2.0f);
+            Assert.NotApproximatelyEqualEpsilon(-System.Single.MaxValue, System.Single.MaxValue / 2.0f);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for values involving infinities``() =
+            Assert.ApproximatelyEqualEpsilon(System.Single.PositiveInfinity, System.Single.PositiveInfinity);
+            Assert.ApproximatelyEqualEpsilon(System.Single.NegativeInfinity, System.Single.NegativeInfinity);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NegativeInfinity, System.Single.PositiveInfinity);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.PositiveInfinity, System.Single.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NegativeInfinity, -System.Single.MaxValue);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for values involving NaN``() =
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NaN, System.Single.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NaN, 0.0f);
+            Assert.NotApproximatelyEqualEpsilon(-0.0f, System.Single.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NaN, -0.0f);
+            Assert.NotApproximatelyEqualEpsilon(0.0f, System.Single.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NaN, System.Single.PositiveInfinity);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.PositiveInfinity, System.Single.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NaN, System.Single.NegativeInfinity);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NegativeInfinity, System.Single.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NaN, System.Single.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.MaxValue, System.Single.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NaN, -System.Single.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(-System.Single.MaxValue, System.Single.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NaN, System.Single.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.Epsilon, System.Single.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.NaN, -System.Single.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(-System.Single.Epsilon, System.Single.NaN);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for values on opposite sides of 0``() =
+            Assert.NotApproximatelyEqualEpsilon(1.000000001f, -1.0f);
+            Assert.NotApproximatelyEqualEpsilon(-1.0f, 1.000000001f);
+            Assert.NotApproximatelyEqualEpsilon(-1.000000001f, 1.0f);
+            Assert.NotApproximatelyEqualEpsilon(1.0f, -1.000000001f);
+            Assert.ApproximatelyEqualEpsilon(10.0f * System.Single.Epsilon, 10.0f * -System.Single.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(10000.0f * System.Single.Epsilon, 10000.0f * -System.Single.Epsilon);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (single precision) is correct for values very close to 0``() =
+            Assert.ApproximatelyEqualEpsilon(System.Single.Epsilon, System.Single.Epsilon);
+            Assert.ApproximatelyEqualEpsilon(System.Single.Epsilon, -System.Single.Epsilon);
+            Assert.ApproximatelyEqualEpsilon(-System.Single.Epsilon, System.Single.Epsilon);
+            Assert.ApproximatelyEqualEpsilon(System.Single.Epsilon, 0.0f);
+            Assert.ApproximatelyEqualEpsilon(0.0f, System.Single.Epsilon);
+            Assert.ApproximatelyEqualEpsilon(-System.Single.Epsilon, 0.0f);
+            Assert.ApproximatelyEqualEpsilon(0.0f, -System.Single.Epsilon);
+
+            Assert.NotApproximatelyEqualEpsilon(0.000000001f, -System.Single.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(0.000000001f, System.Single.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(System.Single.Epsilon, 0.000000001f);
+            Assert.NotApproximatelyEqualEpsilon(-System.Single.Epsilon, 0.000000001f);
+
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
+    module ``ApproximatelyEqual (double-precision epsilon)`` =
+        //
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for large positive values``() =
+            Assert.ApproximatelyEqualEpsilon(1000000.0, 1000001.0);
+            Assert.ApproximatelyEqualEpsilon(1000001.0, 1000000.0);
+            Assert.NotApproximatelyEqualEpsilon(10000.0, 10001.0);
+            Assert.NotApproximatelyEqualEpsilon(10001.0, 10000.0);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for large negative values``() =
+            Assert.ApproximatelyEqualEpsilon(-1000000.0, -1000001.0);
+            Assert.ApproximatelyEqualEpsilon(-1000001.0, -1000000.0);
+            Assert.NotApproximatelyEqualEpsilon(-10000.0, -10001.0);
+            Assert.NotApproximatelyEqualEpsilon(-10001.0, -10000.0);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for positive values around 1``() =
+            Assert.ApproximatelyEqualEpsilon(1.0000001, 1.0000002);
+            Assert.ApproximatelyEqualEpsilon(1.0000002, 1.0000001);
+            Assert.NotApproximatelyEqualEpsilon(1.0002, 1.0001);
+            Assert.NotApproximatelyEqualEpsilon(1.0001, 1.0002);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for negative values around -1``() =
+            Assert.ApproximatelyEqualEpsilon(-1.000001, -1.000002);
+            Assert.ApproximatelyEqualEpsilon(-1.000002, -1.000001);
+            Assert.NotApproximatelyEqualEpsilon(-1.0001, -1.0002);
+            Assert.NotApproximatelyEqualEpsilon(-1.0002, -1.0001);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for values between 1 and 0``() =
+            Assert.ApproximatelyEqualEpsilon(0.000000001000001, 0.000000001000002);
+            Assert.ApproximatelyEqualEpsilon(0.000000001000002, 0.000000001000001);
+            Assert.NotApproximatelyEqualEpsilon(0.000000000001002, 0.000000000001001);
+            Assert.NotApproximatelyEqualEpsilon(0.000000000001001, 0.000000000001002);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for values between -1 and 0``() =
+            Assert.ApproximatelyEqualEpsilon(-0.000000001000001, -0.000000001000002);
+            Assert.ApproximatelyEqualEpsilon(-0.000000001000002, -0.000000001000001);
+            Assert.NotApproximatelyEqualEpsilon(-0.000000000001002, -0.000000000001001);
+            Assert.NotApproximatelyEqualEpsilon(-0.000000000001001, -0.000000000001002);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for comparisons involving 0``() =
+            Assert.ApproximatelyEqualEpsilon(0.0, 0.0);
+            Assert.ApproximatelyEqualEpsilon(0.0, -0.0);
+            Assert.ApproximatelyEqualEpsilon(-0.0, -0.0);
+            Assert.NotApproximatelyEqualEpsilon(0.00000001, 0.0);
+            Assert.NotApproximatelyEqualEpsilon(0.0, 0.00000001);
+            Assert.NotApproximatelyEqualEpsilon(-0.00000001, 0.0);
+            Assert.NotApproximatelyEqualEpsilon(0.0, -0.00000001);
+
+            Assert.ApproximatelyEqualEpsilon(0.0, 1e-310, 0.01);
+            Assert.ApproximatelyEqualEpsilon(1e-310, 0.0, 0.01);
+            Assert.NotApproximatelyEqualEpsilon(1e-310, 0.0, 0.000001);
+            Assert.NotApproximatelyEqualEpsilon(0.0, 1e-310, 0.000001);
+
+            Assert.ApproximatelyEqualEpsilon(0.0, -1e-310, 0.1);
+            Assert.ApproximatelyEqualEpsilon(-1e-310, 0.0, 0.1);
+            Assert.NotApproximatelyEqualEpsilon(-1e-310, 0.0, 0.00000001);
+            Assert.NotApproximatelyEqualEpsilon(0.0, -1e-310, 0.00000001);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for extreme values with overflow potential``() =
+            Assert.ApproximatelyEqualEpsilon(System.Double.MaxValue, System.Double.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.MaxValue, -System.Double.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(-System.Double.MaxValue, System.Double.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.MaxValue, System.Double.MaxValue / 2.0);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.MaxValue, -System.Double.MaxValue / 2.0);
+            Assert.NotApproximatelyEqualEpsilon(-System.Double.MaxValue, System.Double.MaxValue / 2.0);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for values involving infinities``() =
+            Assert.ApproximatelyEqualEpsilon(System.Double.PositiveInfinity, System.Double.PositiveInfinity);
+            Assert.ApproximatelyEqualEpsilon(System.Double.NegativeInfinity, System.Double.NegativeInfinity);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NegativeInfinity, System.Double.PositiveInfinity);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.PositiveInfinity, System.Double.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NegativeInfinity, -System.Double.MaxValue);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for values involving NaN``() =
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NaN, System.Double.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NaN, 0.0);
+            Assert.NotApproximatelyEqualEpsilon(-0.0, System.Double.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NaN, -0.0);
+            Assert.NotApproximatelyEqualEpsilon(0.0, System.Double.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NaN, System.Double.PositiveInfinity);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.PositiveInfinity, System.Double.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NaN, System.Double.NegativeInfinity);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NegativeInfinity, System.Double.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NaN, System.Double.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.MaxValue, System.Double.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NaN, -System.Double.MaxValue);
+            Assert.NotApproximatelyEqualEpsilon(-System.Double.MaxValue, System.Double.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NaN, System.Double.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.Epsilon, System.Double.NaN);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.NaN, -System.Double.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(-System.Double.Epsilon, System.Double.NaN);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for values on opposite sides of 0``() =
+            Assert.NotApproximatelyEqualEpsilon(1.000000001, -1.0);
+            Assert.NotApproximatelyEqualEpsilon(-1.0, 1.000000001);
+            Assert.NotApproximatelyEqualEpsilon(-1.000000001, 1.0);
+            Assert.NotApproximatelyEqualEpsilon(1.0, -1.000000001);
+            Assert.ApproximatelyEqualEpsilon(10.0 * System.Double.Epsilon, 10.0 * -System.Double.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(100000000000.0 * System.Double.Epsilon, 100000000000.0 * -System.Double.Epsilon);
+
+        [<Fact>]
+        let ``ApproximatelyEqual (double precision) is correct for values very close to 0``() =
+            Assert.ApproximatelyEqualEpsilon(System.Double.Epsilon, System.Double.Epsilon);
+            Assert.ApproximatelyEqualEpsilon(System.Double.Epsilon, -System.Double.Epsilon);
+            Assert.ApproximatelyEqualEpsilon(-System.Double.Epsilon, System.Double.Epsilon);
+            Assert.ApproximatelyEqualEpsilon(System.Double.Epsilon, 0.0);
+            Assert.ApproximatelyEqualEpsilon(0.0, System.Double.Epsilon);
+            Assert.ApproximatelyEqualEpsilon(-System.Double.Epsilon, 0.0);
+            Assert.ApproximatelyEqualEpsilon(0.0, -System.Double.Epsilon);
+
+            Assert.NotApproximatelyEqualEpsilon(0.000000001, -System.Double.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(0.000000001, System.Double.Epsilon);
+            Assert.NotApproximatelyEqualEpsilon(System.Double.Epsilon, 0.000000001);
+            Assert.NotApproximatelyEqualEpsilon(-System.Double.Epsilon, 0.000000001);

tests/OpenTK.Tests/Matrix4Tests.fs

@@ -7,7 +7,7 @@ open System
 open OpenTK
 
 module Matrix4 =
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Constructors =
         //
         [<Property>]
@@ -88,7 +88,7 @@ module Matrix4 =
             Assert.Equal(o, A.M43)
             Assert.Equal(p, A.M44)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Equality =
         //
         [<Property>]
@@ -103,7 +103,7 @@ module Matrix4 =
         let ``A matrix is not equal to an object which is not a matrix`` (a : Matrix4, b : Vector3) =
             Assert.False(a.Equals(b))
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Multiplication =
         //
         [<Property>]
@@ -202,7 +202,7 @@ module Matrix4 =
             Assert.Equal(R4, AScaled.Row3)
 
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Addition =
         //
         [<Property>]
@@ -232,7 +232,7 @@ module Matrix4 =
             Assert.Equal(o + o, sum.M43)
             Assert.Equal(p + p, sum.M44)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Subtraction =
         //
         [<Property>]
@@ -262,7 +262,7 @@ module Matrix4 =
             Assert.Equal(o - o, sub.M43)
             Assert.Equal(p - p, sub.M44)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Indexing =
         //
         [<Property>]
@@ -338,7 +338,7 @@ module Matrix4 =
         let ``Indexed set operator throws exception for negative indices`` (b : Matrix4, x : float32) =
             let mutable a = b
 
-            
+
 
             (fun() -> a.[-1, 2] <- x) |> Assert.ThrowsIndexExn
             (fun() -> a.[1, -2] <- x) |> Assert.ThrowsIndexExn
@@ -363,7 +363,7 @@ module Matrix4 =
             (fun() -> a.[1, 6] |> ignore) |> Assert.ThrowsIndexExn
             (fun() -> a.[7, 12] |> ignore) |> Assert.ThrowsIndexExn
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Row and column properties`` =
         //
         [<Property>]

tests/OpenTK.Tests/Vector2Tests.fs

@@ -8,7 +8,7 @@ open System.Runtime.InteropServices
 open OpenTK
 
 module Vector2 =
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Constructors =
         //
         [<Property>]
@@ -23,7 +23,7 @@ module Vector2 =
             Assert.Equal(x,v.X)
             Assert.Equal(y,v.Y)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Clamping =
         //
         [<Property>]
@@ -46,7 +46,7 @@ module Vector2 =
             Assert.Equal(expX, res.X)
             Assert.Equal(expY, res.Y)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Length =
         //
         [<Property>]
@@ -75,7 +75,7 @@ module Vector2 =
 
             Assert.Equal(lsq, v.LengthSquared)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Unit vectors and perpendicularity`` =
         //
         [<Property>]
@@ -92,7 +92,7 @@ module Vector2 =
 
             Assert.Equal(perp, v.PerpendicularLeft)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Indexing =
         //
         [<Property>]
@@ -126,7 +126,7 @@ module Vector2 =
 
             (fun() -> v.[2] |> ignore) |> Assert.ThrowsIndexExn
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Simple Properties`` =
         //
         [<Property>]
@@ -139,7 +139,7 @@ module Vector2 =
             //
             Assert.True(a.Length >= 0.0f)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Addition =
         //
         [<Property>]
@@ -176,7 +176,7 @@ module Vector2 =
 
             Assert.ApproximatelyEqual(v1, sum)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Multiplication =
         //
         [<Property>]
@@ -227,7 +227,7 @@ module Vector2 =
             Assert.Equal(a.X * f,r.X)
             Assert.Equal(a.Y * f,r.Y)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Subtraction =
         //
         [<Property>]
@@ -252,49 +252,50 @@ module Vector2 =
 
             Assert.ApproximatelyEqual(v1, sum)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Division =
         //
         [<Property>]
         let ``Vector2-float division is the same as component-float division`` (a : Vector2, f : float32) =
-            let r = a / f
+            if not (approxEq f 0.0f) then
+                let r = a / f
 
-            Assert.ApproximatelyEqual(a.X / f,r.X)
-            Assert.ApproximatelyEqual(a.Y / f,r.Y)
+                Assert.ApproximatelyEqual(a.X / f,r.X)
+                Assert.ApproximatelyEqual(a.Y / f,r.Y)
 
         [<Property>]
         let ``Static Vector2-Vector2 division method is the same as component division`` (a : Vector2, b : Vector2) =
+            if not (anyZero2 a || anyZero2 b) then
+                let v1 = Vector2(a.X / b.X, a.Y / b.Y)
+                let sum = Vector2.Divide(a, b)
 
-            let v1 = Vector2(a.X / b.X, a.Y / b.Y)
-            let sum = Vector2.Divide(a, b)
-
-            Assert.ApproximatelyEqual(v1, sum)
+                Assert.ApproximatelyEqual(v1, sum)
 
         [<Property>]
         let ``Static Vector2-Vector2 divison method by reference `` (a : Vector2, b : Vector2) =
+            if not (anyZero2 a || anyZero2 b) then
+                let v1 = Vector2(a.X / b.X, a.Y / b.Y)
+                let sum = Vector2.Divide(ref a, ref b)
 
-            let v1 = Vector2(a.X / b.X, a.Y / b.Y)
-            let sum = Vector2.Divide(ref a, ref b)
-
-            Assert.ApproximatelyEqual(v1, sum)
+                Assert.ApproximatelyEqual(v1, sum)
 
         [<Property>]
         let ``Static Vector2-scalar division method is the same as component division`` (a : Vector2, b : float32) =
+            if not (approxEq b 0.0f) then
+                let v1 = Vector2(a.X / b, a.Y / b)
+                let sum = Vector2.Divide(a, b)
 
-            let v1 = Vector2(a.X / b, a.Y / b)
-            let sum = Vector2.Divide(a, b)
-
-            Assert.ApproximatelyEqual(v1, sum)
+                Assert.ApproximatelyEqual(v1, sum)
 
         [<Property>]
         let ``Static Vector2-scalar divison method by reference is the same as component division`` (a : Vector2, b : float32) =
+            if not (approxEq b 0.0f) then
+                let v1 = Vector2(a.X / b, a.Y / b)
+                let sum = Vector2.Divide(ref a, b)
 
-            let v1 = Vector2(a.X / b, a.Y / b)
-            let sum = Vector2.Divide(ref a, b)
+                Assert.ApproximatelyEqual(v1, sum)
 
-            Assert.ApproximatelyEqual(v1, sum)
-
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Negation =
         //
         [<Property>]
@@ -304,7 +305,7 @@ module Vector2 =
             Assert.Equal(-x, vNeg.X)
             Assert.Equal(-y, vNeg.Y)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Equality =
         //
         [<Property>]
@@ -335,7 +336,7 @@ module Vector2 =
             Assert.True(equality)
             Assert.False(inequalityByOtherType)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Swizzling =
         //
         [<Property>]
@@ -346,7 +347,7 @@ module Vector2 =
             let v1yx = v1.Yx;
             Assert.Equal(v2, v1yx);
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Interpolation =
         //
         [<Property>]
@@ -373,7 +374,7 @@ module Vector2 =
             let vRes = Vector2.BaryCentric(ref a, ref b, ref c, u, v)
             Assert.Equal(r, vRes)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Vector products`` =
         //
         [<Property>]
@@ -394,7 +395,7 @@ module Vector2 =
             let vRes = Vector2.PerpDot(ref a, ref b)
             Assert.Equal(perpDot, vRes)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Normalization =
         //
         [<Property>]
@@ -434,16 +435,20 @@ module Vector2 =
 
         [<Property>]
         let ``Normalization by reference is the same as division by magnitude`` (a : Vector2) =
-            let norm = a / a.Length
-            let vRes = Vector2.Normalize(ref a)
+            // Zero-length vectors can't be normalized
+            if not (approxEq a.Length 0.0f) then
+                let norm = a / a.Length
+                let vRes = Vector2.Normalize(ref a)
 
-            Assert.ApproximatelyEqual(norm, vRes)
+                Assert.ApproximatelyEqual(norm, vRes)
 
         [<Property>]
         let ``Normalization is the same as division by magnitude`` (a : Vector2) =
-            let norm = a / a.Length
+            // Zero-length vectors can't be normalized
+            if not (approxEq a.Length 0.0f) then
+                let norm = a / a.Length
 
-            Assert.ApproximatelyEqual(norm, Vector2.Normalize(a));
+                Assert.ApproximatelyEqual(norm, Vector2.Normalize(a));
 
         [<Property>]
         let ``Fast approximate normalization by reference is the same as multiplication by the fast inverse square`` (a : Vector2) =
@@ -462,66 +467,74 @@ module Vector2 =
 
             Assert.ApproximatelyEqual(norm, Vector2.NormalizeFast(a));
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Magnitude min and max`` =
         //
         [<Property>]
         let ``MagnitudeMin selects the vector with equal or lesser magnitude given two vectors`` (v1 : Vector2, v2: Vector2) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector2.MagnitudeMin(v1, v2)
+                let vMin = Vector2.MagnitudeMin(v1, v2)
 
-            if vMin = v1 then
-                let v1ShorterThanv2 = l1 < l2
-                Assert.True(v1ShorterThanv2)
-            else
-                let v2ShorterThanOrEqualTov1 = l2 <= l1
-                Assert.True(v2ShorterThanOrEqualTov1)
+                if vMin = v1 then
+                    let v1ShorterThanv2 = l1 < l2
+                    Assert.True(v1ShorterThanv2)
+                else
+                    let v2ShorterThanOrEqualTov1 = l2 <= l1
+                    Assert.True(v2ShorterThanOrEqualTov1)
 
         [<Property>]
         let ``MagnitudeMax selects the vector with equal or greater magnitude given two vectors`` (v1 : Vector2, v2: Vector2) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector2.MagnitudeMax(v1, v2)
+                let vMin = Vector2.MagnitudeMax(v1, v2)
 
-            if vMin = v1 then
-                let v1LongerThanOrEqualTov2 = l1 >= l2
-                Assert.True(v1LongerThanOrEqualTov2)
-            else
-                let v2LongerThanv1 = l2 > l1
-                Assert.True(v2LongerThanv1)
+                if vMin = v1 then
+                    let v1LongerThanOrEqualTov2 = l1 >= l2
+                    Assert.True(v1LongerThanOrEqualTov2)
+                else
+                    let v2LongerThanv1 = l2 > l1
+                    Assert.True(v2LongerThanv1)
 
         [<Property>]
         let ``MagnitudeMin by reference selects the vector with equal or lesser magnitude given two vectors`` (v1 : Vector2, v2: Vector2) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector2.MagnitudeMin(ref v1, ref v2)
+                let vMin = Vector2.MagnitudeMin(ref v1, ref v2)
 
-            if vMin = v1 then
-                let v1ShorterThanv2 = l1 < l2
-                Assert.True(v1ShorterThanv2)
-            else
-                let v2ShorterThanOrEqualTov1 = l2 <= l1
-                Assert.True(v2ShorterThanOrEqualTov1)
+                if vMin = v1 then
+                    let v1ShorterThanv2 = l1 < l2
+                    Assert.True(v1ShorterThanv2)
+                else
+                    let v2ShorterThanOrEqualTov1 = l2 <= l1
+                    Assert.True(v2ShorterThanOrEqualTov1)
 
         [<Property>]
         let ``MagnitudeMax by reference selects the vector with equal greater magnitude given two vectors`` (v1 : Vector2, v2: Vector2) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector2.MagnitudeMax(ref v1, ref v2)
+                let vMin = Vector2.MagnitudeMax(ref v1, ref v2)
 
-            if vMin = v1 then
-                let v1LongerThanOrEqualTov2 = l1 >= l2
-                Assert.True(v1LongerThanOrEqualTov2)
-            else
-                let v2LongerThanv1 = l2 > l1
-                Assert.True(v2LongerThanv1)
+                if vMin = v1 then
+                    let v1LongerThanOrEqualTov2 = l1 >= l2
+                    Assert.True(v1LongerThanOrEqualTov2)
+                else
+                    let v2LongerThanv1 = l2 > l1
+                    Assert.True(v2LongerThanv1)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Component min and max`` =
         //
         [<Property>]
@@ -556,7 +569,7 @@ module Vector2 =
             Assert.True(isComponentLargest vMax.X v1.X v2.X)
             Assert.True(isComponentLargest vMax.Y v1.Y v2.Y)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Transformation =
         //
         [<Property>]
@@ -579,7 +592,7 @@ module Vector2 =
 
             Assert.ApproximatelyEqual(transformedVector, Vector2.Transform(ref v, ref q))
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Serialization =
         //
         [<Property>]

tests/OpenTK.Tests/Vector3Tests.fs

@@ -8,7 +8,7 @@ open System.Runtime.InteropServices
 open OpenTK
 
 module Vector3 =
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Constructors =
         //
         [<Property>]
@@ -65,7 +65,7 @@ module Vector3 =
             Assert.Equal(b, v2.Y)
             Assert.Equal(c, v2.Z)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Indexing =
         //
         [<Property>]
@@ -100,7 +100,7 @@ module Vector3 =
 
             (fun() -> v.[4] |> ignore) |> Assert.ThrowsIndexExn
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Length =
         //
         [<Property>]
@@ -124,7 +124,7 @@ module Vector3 =
 
             Assert.Equal(lsq, v.LengthSquared)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Normalization =
         //
         [<Property>]
@@ -167,16 +167,20 @@ module Vector3 =
 
         [<Property>]
         let ``Normalization by reference is the same as division by magnitude`` (a : Vector3) =
-            let norm = a / a.Length
-            let vRes = Vector3.Normalize(ref a)
+            // Zero-length vectors can't be normalized
+            if not (approxEq a.Length 0.0f) then
+                let norm = a / a.Length
+                let vRes = Vector3.Normalize(ref a)
 
-            Assert.ApproximatelyEqual(norm, vRes)
+                Assert.ApproximatelyEqual(norm, vRes)
 
         [<Property>]
         let ``Normalization is the same as division by magnitude`` (a : Vector3) =
-            let norm = a / a.Length
+            // Zero-length vectors can't be normalized
+            if not (approxEq a.Length 0.0f) then
+                let norm = a / a.Length
 
-            Assert.ApproximatelyEqual(norm, Vector3.Normalize(a));
+                Assert.ApproximatelyEqual(norm, Vector3.Normalize(a));
 
         [<Property>]
         let ``Fast approximate normalization by reference is the same as multiplication by the fast inverse square`` (a : Vector3) =
@@ -195,7 +199,7 @@ module Vector3 =
 
             Assert.ApproximatelyEqual(norm, Vector3.NormalizeFast(a));
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Addition =
         //
         [<Property>]
@@ -236,7 +240,7 @@ module Vector3 =
 
             Assert.ApproximatelyEqual(v1, sum)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Subtraction =
         //
         [<Property>]
@@ -263,7 +267,7 @@ module Vector3 =
 
             Assert.ApproximatelyEqual(v1, sum)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Multiplication =
         //
         [<Property>]
@@ -344,7 +348,7 @@ module Vector3 =
 
             Assert.ApproximatelyEqual(v1, sum)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Division =
         //
         [<Property>]
@@ -358,37 +362,37 @@ module Vector3 =
 
         [<Property>]
         let ``Static Vector3-Vector3 division method is the same as component division`` (a : Vector3, b : Vector3) =
+            if not (anyZero3 a || anyZero3 b) then
+                let v1 = Vector3(a.X / b.X, a.Y / b.Y, a.Z / b.Z)
+                let sum = Vector3.Divide(a, b)
 
-            let v1 = Vector3(a.X / b.X, a.Y / b.Y, a.Z / b.Z)
-            let sum = Vector3.Divide(a, b)
-
-            Assert.ApproximatelyEqual(v1, sum)
+                Assert.ApproximatelyEqual(v1, sum)
 
         [<Property>]
         let ``Static Vector3-Vector3 divison method by reference is the same as component division`` (a : Vector3, b : Vector3) =
+            if not (anyZero3 a || anyZero3 b) then
+                let v1 = Vector3(a.X / b.X, a.Y / b.Y, a.Z / b.Z)
+                let sum = Vector3.Divide(ref a, ref b)
 
-            let v1 = Vector3(a.X / b.X, a.Y / b.Y, a.Z / b.Z)
-            let sum = Vector3.Divide(ref a, ref b)
-
-            Assert.ApproximatelyEqual(v1, sum)
+                Assert.ApproximatelyEqual(v1, sum)
 
         [<Property>]
         let ``Static Vector3-scalar division method is the same as component division`` (a : Vector3, b : float32) =
+            if not (approxEq b 0.0f) then // we don't support diving by zero.
+                let v1 = Vector3(a.X / b, a.Y / b, a.Z / b)
+                let sum = Vector3.Divide(a, b)
 
-            let v1 = Vector3(a.X / b, a.Y / b, a.Z / b)
-            let sum = Vector3.Divide(a, b)
-
-            Assert.ApproximatelyEqual(v1, sum)
+                Assert.ApproximatelyEqual(v1, sum)
 
         [<Property>]
         let ``Static Vector3-scalar divison method by reference is the same as component division`` (a : Vector3, b : float32) =
+            if not (approxEq b 0.0f) then // we don't support diving by zero.
+                let v1 = Vector3(a.X / b, a.Y / b, a.Z / b)
+                let sum = Vector3.Divide(ref a, b)
 
-            let v1 = Vector3(a.X / b, a.Y / b, a.Z / b)
-            let sum = Vector3.Divide(ref a, b)
+                Assert.ApproximatelyEqual(v1, sum)
 
-            Assert.ApproximatelyEqual(v1, sum)
-
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Negation =
         //
         [<Property>]
@@ -399,7 +403,7 @@ module Vector3 =
             Assert.Equal(-y, vNeg.Y)
             Assert.Equal(-z, vNeg.Z)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Equality =
         //
         [<Property>]
@@ -430,7 +434,7 @@ module Vector3 =
             Assert.True(equality)
             Assert.False(inequalityByOtherType)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Swizzling =
         //
         [<Property>]
@@ -475,7 +479,7 @@ module Vector3 =
             Assert.Equal(zx, v.Zx);
             Assert.Equal(zy, v.Zy);
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Interpolation =
         //
         [<Property>]
@@ -503,7 +507,7 @@ module Vector3 =
             let vRes = Vector3.BaryCentric(ref a, ref b, ref c, u, v)
             Assert.Equal(r, vRes)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Vector products`` =
         //
         [<Property>]
@@ -527,66 +531,74 @@ module Vector3 =
             let vRes = Vector3.Cross(ref a, ref b)
             Assert.Equal(cross, vRes)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Magnitude min and max`` =
         //
         [<Property>]
         let ``MagnitudeMin selects the vector with equal or lesser magnitude given two vectors`` (v1 : Vector3, v2: Vector3) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector3.MagnitudeMin(v1, v2)
+                let vMin = Vector3.MagnitudeMin(v1, v2)
 
-            if vMin = v1 then
-                let v1ShorterThanv2 = l1 < l2
-                Assert.True(v1ShorterThanv2)
-            else
-                let v2ShorterThanOrEqualTov1 = l2 <= l1
-                Assert.True(v2ShorterThanOrEqualTov1)
+                if vMin = v1 then
+                    let v1ShorterThanv2 = l1 < l2
+                    Assert.True(v1ShorterThanv2)
+                else
+                    let v2ShorterThanOrEqualTov1 = l2 <= l1
+                    Assert.True(v2ShorterThanOrEqualTov1)
 
         [<Property>]
         let ``MagnitudeMax selects the vector with equal or greater magnitude given two vectors`` (v1 : Vector3, v2: Vector3) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector3.MagnitudeMax(v1, v2)
+                let vMin = Vector3.MagnitudeMax(v1, v2)
 
-            if vMin = v1 then
-                let v1LongerThanOrEqualTov2 = l1 >= l2
-                Assert.True(v1LongerThanOrEqualTov2)
-            else
-                let v2LongerThanv1 = l2 > l1
-                Assert.True(v2LongerThanv1)
+                if vMin = v1 then
+                    let v1LongerThanOrEqualTov2 = l1 >= l2
+                    Assert.True(v1LongerThanOrEqualTov2)
+                else
+                    let v2LongerThanv1 = l2 > l1
+                    Assert.True(v2LongerThanv1)
 
         [<Property>]
         let ``MagnitudeMin by reference selects the vector with equal or lesser magnitude given two vectors`` (v1 : Vector3, v2: Vector3) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector3.MagnitudeMin(ref v1, ref v2)
+                let vMin = Vector3.MagnitudeMin(ref v1, ref v2)
 
-            if vMin = v1 then
-                let v1ShorterThanv2 = l1 < l2
-                Assert.True(v1ShorterThanv2)
-            else
-                let v2ShorterThanOrEqualTov1 = l2 <= l1
-                Assert.True(v2ShorterThanOrEqualTov1)
+                if vMin = v1 then
+                    let v1ShorterThanv2 = l1 < l2
+                    Assert.True(v1ShorterThanv2)
+                else
+                    let v2ShorterThanOrEqualTov1 = l2 <= l1
+                    Assert.True(v2ShorterThanOrEqualTov1)
 
         [<Property>]
         let ``MagnitudeMax by reference selects the vector with equal or greater magnitude given two vectors`` (v1 : Vector3, v2: Vector3) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector3.MagnitudeMax(ref v1, ref v2)
+                let vMin = Vector3.MagnitudeMax(ref v1, ref v2)
 
-            if vMin = v1 then
-                let v1LongerThanOrEqualTov2 = l1 >= l2
-                Assert.True(v1LongerThanOrEqualTov2)
-            else
-                let v2LongerThanv1 = l2 > l1
-                Assert.True(v2LongerThanv1)
+                if vMin = v1 then
+                    let v1LongerThanOrEqualTov2 = l1 >= l2
+                    Assert.True(v1LongerThanOrEqualTov2)
+                else
+                    let v2LongerThanv1 = l2 > l1
+                    Assert.True(v2LongerThanv1)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Component min and max`` =
         //
         [<Property>]
@@ -625,7 +637,7 @@ module Vector3 =
             Assert.True(isComponentLargest vMax.Y v1.Y v2.Y)
             Assert.True(isComponentLargest vMax.Z v1.Z v2.Z)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Clamping =
         //
         [<Property>]
@@ -652,7 +664,7 @@ module Vector3 =
             Assert.Equal(expY, res.Y)
             Assert.Equal(expZ, res.Z)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Unit vectors``=
         //
         [<Property>]
@@ -685,7 +697,7 @@ module Vector3 =
 
             Assert.Equal(Vector3.One, unitOne)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Serialization =
         //
         [<Property>]
@@ -695,7 +707,7 @@ module Vector3 =
             Assert.Equal(expectedSize, Vector3.SizeInBytes)
             Assert.Equal(expectedSize, Marshal.SizeOf(Vector3()))
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Transformation =
         //
         [<Property>]

tests/OpenTK.Tests/Vector4Tests.fs

@@ -8,7 +8,7 @@ open System.Runtime.InteropServices
 open OpenTK
 
 module Vector4 =
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Constructors =
         //
         [<Property>]
@@ -85,7 +85,7 @@ module Vector4 =
             Assert.Equal(z, v2.Z)
             Assert.Equal(w, v2.W)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Indexing =
         //
         [<Property>]
@@ -121,7 +121,7 @@ module Vector4 =
 
             (fun() -> v.[4] |> ignore) |> Assert.ThrowsIndexExn
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Length =
         //
         [<Property>]
@@ -145,7 +145,7 @@ module Vector4 =
 
             Assert.Equal(lsq, v.LengthSquared)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Normalization =
         //
         [<Property>]
@@ -153,25 +153,29 @@ module Vector4 =
             let v = Vector4(x, y, z, w)
             let l = v.Length
 
-            let norm = v.Normalized()
+            // Zero-length vectors can't be normalized
+            if not (approxEq l 0.0f) then
+                let norm = v.Normalized()
 
-            Assert.ApproximatelyEqual(v.X / l, norm.X)
-            Assert.ApproximatelyEqual(v.Y / l, norm.Y)
-            Assert.ApproximatelyEqual(v.Z / l, norm.Z)
-            Assert.ApproximatelyEqual(v.W / l, norm.W)
+                Assert.ApproximatelyEqual(v.X / l, norm.X)
+                Assert.ApproximatelyEqual(v.Y / l, norm.Y)
+                Assert.ApproximatelyEqual(v.Z / l, norm.Z)
+                Assert.ApproximatelyEqual(v.W / l, norm.W)
 
         [<Property>]
         let ``Normalization of instance transforms the instance into a unit length vector with the correct components`` (x, y, z, w) =
             let v = Vector4(x, y, z, w)
             let l = v.Length
 
-            let norm = Vector4(x, y, z, w)
-            norm.Normalize()
+            // Zero-length vectors can't be normalized
+            if not (approxEq l 0.0f) then
+                let norm = Vector4(x, y, z, w)
+                norm.Normalize()
 
-            Assert.ApproximatelyEqual(v.X / l, norm.X)
-            Assert.ApproximatelyEqual(v.Y / l, norm.Y)
-            Assert.ApproximatelyEqual(v.Z / l, norm.Z)
-            Assert.ApproximatelyEqual(v.W / l, norm.W)
+                Assert.ApproximatelyEqual(v.X / l, norm.X)
+                Assert.ApproximatelyEqual(v.Y / l, norm.Y)
+                Assert.ApproximatelyEqual(v.Z / l, norm.Z)
+                Assert.ApproximatelyEqual(v.W / l, norm.W)
 
         [<Property>]
         let ``Fast approximate normalization of instance transforms the instance into a unit length vector with the correct components`` (x, y, z, w) =
@@ -188,16 +192,20 @@ module Vector4 =
 
         [<Property>]
         let ``Normalization by reference is the same as division by magnitude`` (a : Vector4) =
-            let norm = a / a.Length
-            let vRes = Vector4.Normalize(ref a)
+            // Zero-length vectors can't be normalized
+            if not (approxEq a.Length 0.0f) then
+                let norm = a / a.Length
+                let vRes = Vector4.Normalize(ref a)
 
-            Assert.ApproximatelyEqual(norm, vRes)
+                Assert.ApproximatelyEqual(norm, vRes)
 
         [<Property>]
         let ``Normalization is the same as division by magnitude`` (a : Vector4) =
-            let norm = a / a.Length
+            // Zero-length vectors can't be normalized
+            if not (approxEq a.Length 0.0f) then
+                let norm = a / a.Length
 
-            Assert.ApproximatelyEqual(norm, Vector4.Normalize(a));
+                Assert.ApproximatelyEqual(norm, Vector4.Normalize(a));
 
         [<Property>]
         let ``Fast approximate normalization by reference is the same as multiplication by the fast inverse square`` (a : Vector4) =
@@ -211,12 +219,11 @@ module Vector4 =
         [<Property>]
         let ``Fast approximate normalization is the same as multiplication by the fast inverse square`` (a : Vector4) =
             let scale = MathHelper.InverseSqrtFast(a.X * a.X + a.Y * a.Y + a.Z * a.Z + a.W * a.W)
-
             let norm = a * scale
 
             Assert.ApproximatelyEqual(norm, Vector4.NormalizeFast(a));
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Addition =
         //
         [<Property>]
@@ -258,7 +265,7 @@ module Vector4 =
 
             Assert.ApproximatelyEqual(v1, sum)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Subtraction =
         //
         [<Property>]
@@ -286,7 +293,7 @@ module Vector4 =
 
             Assert.ApproximatelyEqual(v1, sum)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Multiplication =
         //
         [<Property>]
@@ -374,7 +381,7 @@ module Vector4 =
 
             Assert.ApproximatelyEqual(v1, sum)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Division =
         //
         [<Property>]
@@ -389,37 +396,37 @@ module Vector4 =
 
         [<Property>]
         let ``Static Vector4-Vector4 division method is the same as component division`` (a : Vector4, b : Vector4) =
+            if not (anyZero4 a || anyZero4 b) then
+                let v1 = Vector4(a.X / b.X, a.Y / b.Y, a.Z / b.Z, a.W / b.W)
+                let sum = Vector4.Divide(a, b)
 
-            let v1 = Vector4(a.X / b.X, a.Y / b.Y, a.Z / b.Z, a.W / b.W)
-            let sum = Vector4.Divide(a, b)
-
-            Assert.ApproximatelyEqual(v1, sum)
+                Assert.ApproximatelyEqual(v1, sum)
 
         [<Property>]
         let ``Static Vector4-Vector4 divison method by reference is the same as component division`` (a : Vector4, b : Vector4) =
+            if not (anyZero4 a || anyZero4 b) then
+                let v1 = Vector4(a.X / b.X, a.Y / b.Y, a.Z / b.Z, a.W / b.W)
+                let sum = Vector4.Divide(ref a, ref b)
 
-            let v1 = Vector4(a.X / b.X, a.Y / b.Y, a.Z / b.Z, a.W / b.W)
-            let sum = Vector4.Divide(ref a, ref b)
-
-            Assert.ApproximatelyEqual(v1, sum)
+                Assert.ApproximatelyEqual(v1, sum)
 
         [<Property>]
         let ``Static Vector4-scalar division method is the same as component division`` (a : Vector4, b : float32) =
+            if not (approxEq b 0.0f) then // we don't support diving by zero.
+                let v1 = Vector4(a.X / b, a.Y / b, a.Z / b, a.W / b)
+                let sum = Vector4.Divide(a, b)
 
-            let v1 = Vector4(a.X / b, a.Y / b, a.Z / b, a.W / b)
-            let sum = Vector4.Divide(a, b)
-
-            Assert.ApproximatelyEqual(v1, sum)
+                Assert.ApproximatelyEqual(v1, sum)
 
         [<Property>]
         let ``Static Vector4-scalar divison method by reference is the same as component division`` (a : Vector4, b : float32) =
+            if not (approxEq b 0.0f) then // we don't support diving by zero.
+                let v1 = Vector4(a.X / b, a.Y / b, a.Z / b, a.W / b)
+                let sum = Vector4.Divide(ref a, b)
 
-            let v1 = Vector4(a.X / b, a.Y / b, a.Z / b, a.W / b)
-            let sum = Vector4.Divide(ref a, b)
+                Assert.ApproximatelyEqual(v1, sum)
 
-            Assert.ApproximatelyEqual(v1, sum)
-
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Negation =
         //
         [<Property>]
@@ -431,7 +438,7 @@ module Vector4 =
             Assert.Equal(-z, vNeg.Z)
             Assert.Equal(-w, vNeg.W)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Equality =
         //
         [<Property>]
@@ -471,7 +478,7 @@ module Vector4 =
 
             Assert.False(inequalityByOtherType)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Swizzling =
         //
         [<Property>]
@@ -650,7 +657,7 @@ module Vector4 =
             Assert.Equal(wy, v.Wy)
             Assert.Equal(wz, v.Wz)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Interpolation =
         //
         [<Property>]
@@ -679,7 +686,7 @@ module Vector4 =
             let vRes = Vector4.BaryCentric(ref a, ref b, ref c, u, v)
             Assert.Equal(r, vRes)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Vector products`` =
         //
         [<Property>]
@@ -691,66 +698,74 @@ module Vector4 =
             let vRes = Vector4.Dot(ref a, ref b)
             Assert.Equal(dot, vRes)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Magnitude min and max`` =
         //
         [<Property>]
         let ``MagnitudeMin selects the vector with equal or lesser magnitude given two vectors`` (v1 : Vector4, v2: Vector4) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector4.MagnitudeMin(v1, v2)
+                let vMin = Vector4.MagnitudeMin(v1, v2)
 
-            if vMin = v1 then
-                let v1ShorterThanv2 = l1 < l2
-                Assert.True(v1ShorterThanv2)
-            else
-                let v2ShorterThanOrEqualTov1 = l2 <= l1
-                Assert.True(v2ShorterThanOrEqualTov1)
+                if vMin = v1 then
+                    let v1ShorterThanv2 = l1 < l2
+                    Assert.True(v1ShorterThanv2)
+                else
+                    let v2ShorterThanOrEqualTov1 = l2 <= l1
+                    Assert.True(v2ShorterThanOrEqualTov1)
 
         [<Property>]
         let ``MagnitudeMax selects the vector with equal or greater magnitude given two vectors`` (v1 : Vector4, v2: Vector4) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector4.MagnitudeMax(v1, v2)
+                let vMin = Vector4.MagnitudeMax(v1, v2)
 
-            if vMin = v1 then
-                let v1LongerThanOrEqualTov2 = l1 >= l2
-                Assert.True(v1LongerThanOrEqualTov2)
-            else
-                let v2LongerThanv1 = l2 > l1
-                Assert.True(v2LongerThanv1)
+                if vMin = v1 then
+                    let v1LongerThanOrEqualTov2 = l1 >= l2
+                    Assert.True(v1LongerThanOrEqualTov2)
+                else
+                    let v2LongerThanv1 = l2 > l1
+                    Assert.True(v2LongerThanv1)
 
         [<Property>]
         let ``MagnitudeMin by reference selects the vector with equal or lesser magnitude given two vectors`` (v1 : Vector4, v2: Vector4) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector4.MagnitudeMin(ref v1, ref v2)
+                let vMin = Vector4.MagnitudeMin(ref v1, ref v2)
 
-            if vMin = v1 then
-                let v1ShorterThanv2 = l1 < l2
-                Assert.True(v1ShorterThanv2)
-            else
-                let v2ShorterThanOrEqualTov1 = l2 <= l1
-                Assert.True(v2ShorterThanOrEqualTov1)
+                if vMin = v1 then
+                    let v1ShorterThanv2 = l1 < l2
+                    Assert.True(v1ShorterThanv2)
+                else
+                    let v2ShorterThanOrEqualTov1 = l2 <= l1
+                    Assert.True(v2ShorterThanOrEqualTov1)
 
         [<Property>]
         let ``MagnitudeMax by reference selects the vector with equal or greater magnitude given two vectors`` (v1 : Vector4, v2: Vector4) =
-            let l1 = v1.LengthSquared
-            let l2 = v2.LengthSquared
+            // Results do not matter for equal vectors
+            if not (v1 = v2) then
+                let l1 = v1.LengthSquared
+                let l2 = v2.LengthSquared
 
-            let vMin = Vector4.MagnitudeMax(ref v1, ref v2)
+                let vMin = Vector4.MagnitudeMax(ref v1, ref v2)
 
-            if vMin = v1 then
-                let v1LongerThanOrEqualTov2 = l1 >= l2
-                Assert.True(v1LongerThanOrEqualTov2)
-            else
-                let v2LongerThanv1 = l2 > l1
-                Assert.True(v2LongerThanv1)
+                if vMin = v1 then
+                    let v1LongerThanOrEqualTov2 = l1 >= l2
+                    Assert.True(v1LongerThanOrEqualTov2)
+                else
+                    let v2LongerThanv1 = l2 > l1
+                    Assert.True(v2LongerThanv1)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Component min and max`` =
         //
         [<Property>]
@@ -794,7 +809,7 @@ module Vector4 =
             Assert.True(isComponentLargest vMax.W v1.W v2.W)
 
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Clamping =
         //
         [<Property>]
@@ -825,7 +840,7 @@ module Vector4 =
             Assert.Equal(expZ, res.Z)
             Assert.Equal(expW, res.W)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module ``Unit vectors``=
         //
         [<Property>]
@@ -864,7 +879,7 @@ module Vector4 =
 
             Assert.Equal(Vector4.One, unitOne)
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Serialization =
         //
         [<Property>]
@@ -874,7 +889,7 @@ module Vector4 =
             Assert.Equal(expectedSize, Vector4.SizeInBytes)
             Assert.Equal(expectedSize, Marshal.SizeOf(Vector4()))
 
-    [<Properties(Arbitrary = [| typeof<OpenTKGen> |])>]
+    [<Properties(Arbitrary = [| typeof<OpenTKGen> |], MaxTest = 10000)>]
     module Transformation =
         //
         [<Property>]