1 files changed, 40 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/utils/SkMatrix22.cpp b/gfx/skia/skia/src/utils/SkMatrix22.cpp
new file mode 100644
index 000000000..a13b72939
--- /dev/null
+++ b/gfx/skia/skia/src/utils/SkMatrix22.cpp
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkMatrix.h"
+#include "SkMatrix22.h"
+#include "SkPoint.h"
+#include "SkScalar.h"
+
+void SkComputeGivensRotation(const SkVector& h, SkMatrix* G) {
+    const SkScalar& a = h.fX;
+    const SkScalar& b = h.fY;
+    SkScalar c, s;
+    if (0 == b) {
+        c = SkScalarCopySign(SK_Scalar1, a);
+        s = 0;
+        //r = SkScalarAbs(a);
+    } else if (0 == a) {
+        c = 0;
+        s = -SkScalarCopySign(SK_Scalar1, b);
+        //r = SkScalarAbs(b);
+    } else if (SkScalarAbs(b) > SkScalarAbs(a)) {
+        SkScalar t = a / b;
+        SkScalar u = SkScalarCopySign(SkScalarSqrt(SK_Scalar1 + t*t), b);
+        s = -SK_Scalar1 / u;
+        c = -s * t;
+        //r = b * u;
+    } else {
+        SkScalar t = b / a;
+        SkScalar u = SkScalarCopySign(SkScalarSqrt(SK_Scalar1 + t*t), a);
+        c = SK_Scalar1 / u;
+        s = -c * t;
+        //r = a * u;
+    }
+
+    G->setSinCos(s, c);
+}