Fix infinite matrix during an invert.
This patch ensures that when inverting a SkMatrix44, we handle small
floats properly. When inverted these can cause infinite values, but
still evaluate to true in an if condition.
BUG=chromium:498516
Review URL: https://codereview.chromium.org/1209763002
diff --git a/tests/Matrix44Test.cpp b/tests/Matrix44Test.cpp
index cd11a7d..9208ed1 100644
--- a/tests/Matrix44Test.cpp
+++ b/tests/Matrix44Test.cpp
@@ -426,6 +426,31 @@
0, 0, -1, 1};
expected.setRowMajord(expectedInverseAffineAndPerspective);
REPORTER_ASSERT(reporter, nearly_equal(expected, inverse));
+
+ SkMatrix44 tinyScale(SkMatrix44::kIdentity_Constructor);
+ tinyScale.setDouble(0, 0, 1e-39);
+ REPORTER_ASSERT(reporter, tinyScale.getType() == SkMatrix44::kScale_Mask);
+ REPORTER_ASSERT(reporter, !tinyScale.invert(NULL));
+ REPORTER_ASSERT(reporter, !tinyScale.invert(&inverse));
+
+ SkMatrix44 tinyScaleTranslate(SkMatrix44::kIdentity_Constructor);
+ tinyScaleTranslate.setDouble(0, 0, 1e-38);
+ REPORTER_ASSERT(reporter, tinyScaleTranslate.invert(NULL));
+ tinyScaleTranslate.setDouble(0, 3, 10);
+ REPORTER_ASSERT(
+ reporter, tinyScaleTranslate.getType() ==
+ (SkMatrix44::kScale_Mask | SkMatrix44::kTranslate_Mask));
+ REPORTER_ASSERT(reporter, !tinyScaleTranslate.invert(NULL));
+ REPORTER_ASSERT(reporter, !tinyScaleTranslate.invert(&inverse));
+
+ SkMatrix44 tinyScalePerspective(SkMatrix44::kIdentity_Constructor);
+ tinyScalePerspective.setDouble(0, 0, 1e-39);
+ tinyScalePerspective.setDouble(3, 2, -1);
+ REPORTER_ASSERT(reporter, (tinyScalePerspective.getType() &
+ SkMatrix44::kPerspective_Mask) ==
+ SkMatrix44::kPerspective_Mask);
+ REPORTER_ASSERT(reporter, !tinyScalePerspective.invert(NULL));
+ REPORTER_ASSERT(reporter, !tinyScalePerspective.invert(&inverse));
}
static void test_transpose(skiatest::Reporter* reporter) {