add asScalars() to document when we want to treat SkPoint or SkRect as an array

trunk/tests/PointTest.cpp

 
 /*
  * Copyright 2011 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/SkPoint.cpp and its header
 
 #include "SkPoint.h"
+#include "SkRect.h"
 #include "Test.h"
 
+static void test_casts(skiatest::Reporter* reporter) {
+    SkPoint p = { 0, 0 };
+    SkRect  r = { 0, 0, 0, 0 };
+
+    const SkScalar* pPtr = SkTCast<const SkScalar*>(&p);
+    const SkScalar* rPtr = SkTCast<const SkScalar*>(&r);
+
+    REPORTER_ASSERT(reporter, p.asScalars() == pPtr);
+    REPORTER_ASSERT(reporter, r.asScalars() == rPtr);
+}
+
 // Tests that SkPoint::length() and SkPoint::Length() both return
 // approximately expectedLength for this (x,y).
 static void test_length(skiatest::Reporter* reporter, SkScalar x, SkScalar y,
                         SkScalar expectedLength) {
     SkPoint point;
     point.set(x, y);
     SkScalar s1 = point.length();
     SkScalar s2 = SkPoint::Length(x, y);
     //The following should be exactly the same, but need not be.
     //See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=323
     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(s1, s2));
     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(s1, expectedLength));
 }
 
 // Tests SkPoint::Normalize() for this (x,y)
 static void test_Normalize(skiatest::Reporter* reporter,
                            SkScalar x, SkScalar y) {
     SkPoint point;
     point.set(x, y);
     SkScalar oldLength = point.length();
     SkScalar returned = SkPoint::Normalize(&point);
     SkScalar newLength = point.length();
     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(returned, oldLength));
     REPORTER_ASSERT(reporter, SkScalarNearlyEqual(newLength, SK_Scalar1));
 }
 
 static void PointTest(skiatest::Reporter* reporter) {
+    test_casts(reporter);
+
     test_length(reporter, SkIntToScalar(3), SkIntToScalar(4), SkIntToScalar(5));
     test_length(reporter, SkFloatToScalar(0.6f), SkFloatToScalar(0.8f),
                 SK_Scalar1);
     test_Normalize(reporter, SkIntToScalar(3), SkIntToScalar(4));
     test_Normalize(reporter, SkFloatToScalar(0.6f), SkFloatToScalar(0.8f));
 }
 
 #include "TestClassDef.h"
 DEFINE_TESTCLASS("Point", PointTestClass, PointTest)