diff --git a/include/utils/SkMatrix44.h b/include/utils/SkMatrix44.h index af61a11c68..4789e7e209 100644 --- a/include/utils/SkMatrix44.h +++ b/include/utils/SkMatrix44.h @@ -103,6 +103,17 @@ struct SkVector4 { class SK_API SkMatrix44 { public: + + enum Uninitialized_Constructor { + kUninitialized_Constructor + }; + enum Identity_Constructor { + kIdentity_Constructor + }; + + SkMatrix44(Uninitialized_Constructor) { } + SkMatrix44(Identity_Constructor) { this->setIdentity(); } + SkMatrix44() { this->setIdentity(); } SkMatrix44(const SkMatrix44&); SkMatrix44(const SkMatrix44& a, const SkMatrix44& b); diff --git a/tests/Matrix44Test.cpp b/tests/Matrix44Test.cpp index 9dc77c2b5d..794c935ac9 100644 --- a/tests/Matrix44Test.cpp +++ b/tests/Matrix44Test.cpp @@ -77,6 +77,35 @@ static bool bits_isonly(int value, int mask) { return 0 == (value & ~mask); } +static void test_constructor(skiatest::Reporter* reporter) { + // Allocate a matrix on the heap + SkMatrix44* placeholderMatrix = new SkMatrix44(); + for (int row = 0; row < 4; ++row) { + for (int col = 0; col < 4; ++col) { + placeholderMatrix->setDouble(row, col, row * col); + } + } + + // Use placement-new syntax to trigger the constructor on top of the heap + // address we already initialized. This allows us to check that the + // constructor did avoid initializing the matrix contents. + SkMatrix44* testMatrix = new(placeholderMatrix) SkMatrix44(SkMatrix44::kUninitialized_Constructor); + REPORTER_ASSERT(reporter, testMatrix == placeholderMatrix); + REPORTER_ASSERT(reporter, !testMatrix->isIdentity()); + for (int row = 0; row < 4; ++row) { + for (int col = 0; col < 4; ++col) { + REPORTER_ASSERT(reporter, nearly_equal_double(row * col, testMatrix->getDouble(row, col))); + } + } + + // Verify that kIdentity_Constructor really does initialize to an identity matrix. + testMatrix = 0; + testMatrix = new(placeholderMatrix) SkMatrix44(SkMatrix44::kIdentity_Constructor); + REPORTER_ASSERT(reporter, testMatrix == placeholderMatrix); + REPORTER_ASSERT(reporter, testMatrix->isIdentity()); + REPORTER_ASSERT(reporter, *testMatrix == SkMatrix44::I()); +} + static void test_translate(skiatest::Reporter* reporter) { SkMatrix44 mat, inverse; @@ -396,6 +425,7 @@ static void TestMatrix44(skiatest::Reporter* reporter) { test_common_angles(reporter); } + test_constructor(reporter); test_gettype(reporter); test_determinant(reporter); test_transpose(reporter);