Refactor Sk2x<T> + Sk4x<T> into SkNf<N,T> and SkNi<N,T>

tests/SkNxTest.cpp

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkNx.h"
+#include "Test.h"
+
+template <int N, typename T>
+static void test_Nf(skiatest::Reporter* r) {
+
+    auto assert_nearly_eq = [&](double eps, const SkNf<N,T>& v, T a, T b, T c, T d) {
+        auto close = [=](T a, T b) { return fabs(a-b) <= eps; };
+        T vals[4];
+        v.store(vals);
+        REPORTER_ASSERT(r, close(vals[0], a) && close(vals[1], b));
+        REPORTER_ASSERT(r, close(   v[0], a) && close(   v[1], b));
+
+        if (N == 4) {
+            REPORTER_ASSERT(r, close(vals[2], c) && close(vals[3], d));
+            REPORTER_ASSERT(r, close(   v[2], c) && close(   v[3], d));
+        }
+    };
+    auto assert_eq = [&](const SkNf<N,T>& v, T a, T b, T c, T d) {
+        return assert_nearly_eq(0, v, a,b,c,d);
+    };
+
+    T vals[] = {3, 4, 5, 6};
+    SkNf<N,T> a = SkNf<N,T>::Load(vals),
+              b(a),
+              c = a;
+    SkNf<N,T> d;
+    d = a;
+
+    assert_eq(a, 3, 4, 5, 6);
+    assert_eq(b, 3, 4, 5, 6);
+    assert_eq(c, 3, 4, 5, 6);
+    assert_eq(d, 3, 4, 5, 6);
+
+    assert_eq(a+b, 6, 8, 10, 12);
+    assert_eq(a*b, 9, 16, 25, 36);
+    assert_eq(a*b-b, 6, 12, 20, 30);
+    assert_eq((a*b).sqrt(), 3, 4, 5, 6);
+    assert_eq(a/b, 1, 1, 1, 1);
+    assert_eq(-a, -3, -4, -5, -6);
+
+    SkNf<N,T> fours(4);
+
+    assert_eq(fours.sqrt(), 2,2,2,2);
+    assert_nearly_eq(0.001, fours.rsqrt(), 0.5, 0.5, 0.5, 0.5);
+
+    assert_eq(              fours.      invert(), 0.25, 0.25, 0.25, 0.25);
+    assert_nearly_eq(0.001, fours.approxInvert(), 0.25, 0.25, 0.25, 0.25);
+
+    assert_eq(SkNf<N,T>::Min(a, fours), 3, 4, 4, 4);
+    assert_eq(SkNf<N,T>::Max(a, fours), 4, 4, 5, 6);
+
+    // Test some comparisons.  This is not exhaustive.
+    REPORTER_ASSERT(r, (a == b).allTrue());
+    REPORTER_ASSERT(r, (a+b == a*b-b).anyTrue());
+    REPORTER_ASSERT(r, !(a+b == a*b-b).allTrue());
+    REPORTER_ASSERT(r, !(a+b == a*b).anyTrue());
+    REPORTER_ASSERT(r, !(a != b).anyTrue());
+    REPORTER_ASSERT(r, (a < fours).anyTrue());
+    REPORTER_ASSERT(r, (a <= fours).anyTrue());
+    REPORTER_ASSERT(r, !(a > fours).allTrue());
+    REPORTER_ASSERT(r, !(a >= fours).allTrue());
+}
+
+DEF_TEST(SkNf, r) {
+    test_Nf<2, float>(r);
+    test_Nf<2, double>(r);
+
+    test_Nf<4, float>(r);
+    test_Nf<4, double>(r);
+}