Completed webkit radiusX, radiusY and rotationAngle handling.

content/browser/renderer_host/input/motion_event_web.cc

Index: content/browser/renderer_host/input/motion_event_web.cc
diff --git a/content/browser/renderer_host/input/motion_event_web.cc b/content/browser/renderer_host/input/motion_event_web.cc
index 6e53773a68e8c14f28d79d1a43e9cca1bab1a7d5..f20d70c730163bb340cfceae1d2db1a0d2215a28 100644
--- a/content/browser/renderer_host/input/motion_event_web.cc
+++ b/content/browser/renderer_host/input/motion_event_web.cc
@@ -2,8 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// MSVC++ requires this to be set before any other includes to get M_PI.
+#define _USE_MATH_DEFINES
+
 #include "content/browser/renderer_host/input/motion_event_web.h"
 
+#include <cmath>
+
 #include "base/logging.h"
 #include "content/common/input/web_touch_event_traits.h"
 
@@ -102,11 +107,32 @@ float MotionEventWeb::GetRawY(size_t pointer_index) const {
 
 float MotionEventWeb::GetTouchMajor(size_t pointer_index) const {
   DCHECK_LT(pointer_index, GetPointerCount());
-  // TODO(jdduke): We should be a bit more careful about axes here.
   return 2.f * std::max(event_.touches[pointer_index].radiusX,
                         event_.touches[pointer_index].radiusY);
 }
 
+float MotionEventWeb::GetTouchMinor(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, GetPointerCount());
+  return 2.f * std::min(event_.touches[pointer_index].radiusX,
+                        event_.touches[pointer_index].radiusY);
+}
+
+float MotionEventWeb::GetOrientation(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, GetPointerCount());
+
+  float rotation_angle_rad = event_.touches[pointer_index].rotationAngle
+      * M_PI / 180.f;
+  DCHECK(0 <= rotation_angle_rad && rotation_angle_rad <= M_PI_2)
+      << "Unexpected touch rotation angle";
+
+  if (event_.touches[pointer_index].radiusX
+      >= event_.touches[pointer_index].radiusY) {

[jdduke (slow), 2014/08/29 16:45:08]

Nit: I would make this a strict inequality, that way, if radiusX==radiusY and
rotationAngle is 0 (probably a very common case), you get a returned orientation
of 0 (although I suppose the rotation doesn't matter much when the two are
equal).

[mustaq, 2014/08/29 16:53:00]

Yeah, just discovered the default=90 value an hour ago. Trying to fix such
corner cases now. See the current patch.

On 2014/08/29 16:45:08, jdduke wrote:

+    rotation_angle_rad -= (float) M_PI_2;
+  }
+
+  return rotation_angle_rad;
+}
+
 float MotionEventWeb::GetPressure(size_t pointer_index) const {
   return 0.f;
 }