Implement unit tests and temporary MathUtil wrappers for transform functionality

cc/math_util.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_MATH_UTIL_H_
 #define CC_MATH_UTIL_H_
 
 #include "base/logging.h"
 #include "cc/cc_export.h"
 #include "ui/gfx/point_f.h"
 #include "ui/gfx/point3_f.h"
+#include "ui/gfx/transform.h"
 
 namespace WebKit {
 class WebTransformationMatrix;
 }
 
 namespace gfx {
 class QuadF;
 class Rect;
 class RectF;
 class Vector2dF;
@@ skipping 40 matching lines @@
     double x;
     double y;
     double z;
     double w;
 };
 
 class CC_EXPORT MathUtil {
 public:
     static const double PI_DOUBLE;
     static const float PI_FLOAT;
+    static const double EPSILON;
 
     static double Deg2Rad(double deg)  { return deg * PI_DOUBLE / 180; }
     static double Rad2Deg(double rad)  { return rad * 180 / PI_DOUBLE; }
 
     static float Deg2Rad(float deg)  { return deg * PI_FLOAT / 180; }
     static float Rad2Deg(float rad)  { return rad * 180 / PI_FLOAT; }
 
     // Background: WebTransformationMatrix code in WebCore does not do the right thing in
     // mapRect / mapQuad / projectQuad when there is a perspective projection that causes
     // one of the transformed vertices to go to w < 0. In those cases, it is necessary to
@@ skipping 26 matching lines @@
     static void flattenTransformTo2d(WebKit::WebTransformationMatrix&);
 
     static gfx::Vector2dF computeTransform2dScaleComponents(const WebKit::WebTransformationMatrix&);
 
     // Returns the smallest angle between the given two vectors in degrees. Neither vector is
     // assumed to be normalized.
     static float smallestAngleBetweenVectors(gfx::Vector2dF, gfx::Vector2dF);
 
     // Projects the |source| vector onto |destination|. Neither vector is assumed to be normalized.
     static gfx::Vector2dF projectVector(gfx::Vector2dF source, gfx::Vector2dF destination);
+
+    // Temporary API to ease migration from WebKit::WebTransformationMatrix
+    // to gfx::Transform.
+    //
+    // TODO(shawnsingh, vollick) we should phase out as much as possible of
+    // these temporary functions, putting functionality into gfx::Transform.
+    static bool isInvertible(const gfx::Transform&);
+    static bool isBackFaceVisible(const gfx::Transform&);
+    static bool isIdentity(const gfx::Transform&);
+    static bool isIdentityOrTranslation(const gfx::Transform&);
+    static bool hasPerspective(const gfx::Transform&);
+    static void makeIdentity(gfx::Transform*);
+    static void rotateEulerAngles(gfx::Transform*, double eulerX, double eulerY, double eulerZ);
+    static void rotateAxisAngle(gfx::Transform*, double i, double j, double k, double degrees);
+    static gfx::Transform inverse(const gfx::Transform&);
+    static gfx::Transform to2dTransform(const gfx::Transform&);
+    // Note carefully: the args here are labeled as per Webcore indexing conventions.
+    static gfx::Transform createGfxTransform(double m11, double m12, double m13, double m14,
+                                             double m21, double m22, double m23, double m24,
+                                             double m31, double m32, double m33, double m34,
+                                             double m41, double m42, double m43, double m44);
+
+    static gfx::Transform createGfxTransform(double a, double b, double c,
+                                             double d, double e, double f);
 };
 
+// TODO(shawnsingh, vollick) this is a temporary home, should eventually
+// be phased out in favor of gfx::Transform API.
+gfx::Transform CC_EXPORT operator*(const gfx::Transform&, const gfx::Transform&);
+
 } // namespace cc
 
 #endif  // CC_MATH_UTIL_H_