Add new SkPoint3 class

tests/Point3Test.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.
+ */
+
+// Unit tests for src/core/SkPoint3.cpp and its header
+
+#include "SkPoint3.h"
+#include "Test.h"
+
+static void test_eq_ops(skiatest::Reporter* reporter) {
+    const SkPoint3 p0 = SkPoint3::Make(0, 0, 0);
+    const SkPoint3 p1 = SkPoint3::Make(1, 1, 1);
+    const SkPoint3 p2 = SkPoint3::Make(1, 1, 1);
+
+    REPORTER_ASSERT(reporter, p0 != p1);
+    REPORTER_ASSERT(reporter, p1 == p2);
+}
+
+static void test_ops(skiatest::Reporter* reporter) {
+    SkPoint3 v = SkPoint3::Make(1, 1, 1);
+    v.normalize();
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(v.length(), SK_Scalar1));
+
+    // scale
+    SkPoint3 p;
+    v.scale(3.0f, &p);
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(p.length(), 3.0f));
+
+    p.scale(1.0f/3.0f);
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(p.length(), SK_Scalar1));
+
+    SkPoint3 p1 = SkPoint3::Make(20.0f, 2.0f, 10.0f);
+    SkPoint3 p2 = -p1;
+
+    // -
+    p = p1 - p1;
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(p.x(), 0.0f));
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(p.y(), 0.0f));
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(p.z(), 0.0f));
+
+    // +
+    p = p1 + p2;
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(p.x(), 0.0f));
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(p.y(), 0.0f));
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(p.z(), 0.0f));
+}
+
+static void test_dot(skiatest::Reporter* reporter) {
+    const SkPoint3 xAxis = SkPoint3::Make(1.0f, 0.0f, 0.0f);
+    const SkPoint3 yAxis = SkPoint3::Make(0.0f, 1.0f, 0.0f);
+    const SkPoint3 zAxis = SkPoint3::Make(0.0f, 0.0f, 1.0f);
+
+    SkScalar dot = xAxis.dot(yAxis);
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dot, 0.0f));
+
+    dot = yAxis.dot(zAxis);
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dot, 0.0f));
+
+    dot = zAxis.dot(xAxis);
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dot, 0.0f));
+
+    SkPoint3 v = SkPoint3::Make(13.0f, 2.0f, 7.0f);
+    v.normalize();
+
+    dot = v.dot(v);
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dot, 1.0f));
+
+    v = SkPoint3::Make(SK_ScalarRoot2Over2, SK_ScalarRoot2Over2, 0.0f);
+
+    dot = xAxis.dot(v);
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dot, SK_ScalarRoot2Over2));
+
+    dot = yAxis.dot(v);
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(dot, SK_ScalarRoot2Over2));
+}
+
+static void test_length(skiatest::Reporter* reporter, 
+                        SkScalar x, SkScalar y, SkScalar z, SkScalar expectedLen) {
+    SkPoint3 point = SkPoint3::Make(x, y, z);
+
+    SkScalar s1 = point.length();
+    SkScalar s2 = SkPoint3::Length(x, y, z);
+
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(s1, s2));
+    REPORTER_ASSERT(reporter, SkScalarNearlyEqual(s1, expectedLen));
+}
+
+static void test_normalize(skiatest::Reporter* reporter,
+                           SkScalar x, SkScalar y, SkScalar z, SkScalar expectedLen) {
+    SkPoint3 point = SkPoint3::Make(x, y, z);
+
+    bool result = point.normalize();
+    SkScalar newLength = point.length();
+
+    if (0 == expectedLen) {
+        const SkPoint3 empty = SkPoint3::Make(0.0f, 0.0f, 0.0f);
+
+        REPORTER_ASSERT(reporter, SkScalarNearlyEqual(newLength, 0));
+        REPORTER_ASSERT(reporter, !result);
+        REPORTER_ASSERT(reporter, point == empty);
+    } else {
+        REPORTER_ASSERT(reporter, SkScalarNearlyEqual(newLength, SK_Scalar1));
+        REPORTER_ASSERT(reporter, result);
+    }
+}
+
+DEF_TEST(Point3, reporter) {
+    test_eq_ops(reporter);
+    test_ops(reporter);
+    test_dot(reporter);
+
+    static const struct {
+        SkScalar fX;
+        SkScalar fY;
+        SkScalar fZ;
+        SkScalar fLength;    
+    } gRec[] = {
+        { 0.0f, 0.0f, 0.0f, 0.0f },
+        { 0.3f, 0.4f, 0.5f, SK_ScalarRoot2Over2 },
+        { 1.0e-37f, 1.0e-37f, 1.0e-37f, 0.0f },  // underflows
+        { 3.4e38f, 0.0f, 0.0f, 3.4e38f }         // overflows
+    };
+
+    for (size_t i = 0; i < SK_ARRAY_COUNT(gRec); ++i) {
+        test_length(reporter, gRec[i].fX, gRec[i].fY, gRec[i].fZ, gRec[i].fLength);
+        test_normalize(reporter, gRec[i].fX, gRec[i].fY, gRec[i].fZ, gRec[i].fLength);
+    }
+}