Pass MotionEvent tilt angles to Blink on Android.

content/browser/renderer_host/input/motion_event_web_unittest.cc

+// Copyright 2015 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.
+
+// MSVC++ requires this to be set before any other includes to get M_PI.
+#define _USE_MATH_DEFINES
+
+#include <cmath>
+
+#include "content/browser/renderer_host/input/motion_event_web.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/events/blink/blink_event_util.h"
+#include "ui/events/gesture_detection/motion_event_generic.h"
+#include "ui/events/test/motion_event_test_utils.h"
+
+using ui::MotionEvent;
+using ui::MotionEventGeneric;
+using ui::PointerProperties;
+
+namespace content {
+
+TEST(MotionEventWebTest, Constructor) {
+  const float pi = static_cast<float>(M_PI);
+  const float orientations[] = {
+      -pi, -2.f * pi / 3, -pi / 3, 0.f, pi / 3, 2.f * pi / 3};
+  const float tilts[] = {0.f, pi / 4, pi / 3};
+  const MotionEvent::ToolType tool_types[] = {MotionEvent::TOOL_TYPE_FINGER,
+                                              MotionEvent::TOOL_TYPE_STYLUS,
+                                              MotionEvent::TOOL_TYPE_MOUSE};
+
+  base::TimeTicks event_time = base::TimeTicks::Now();
+  PointerProperties pp;
+  MotionEventGeneric generic_event(MotionEvent::ACTION_MOVE, event_time, pp);
+
+  for (MotionEvent::ToolType tool_type : tool_types) {
+    for (float orientation : orientations) {
+      for (float tilt : tilts) {
+        PointerProperties pp2;
+        pp2.orientation = orientation;
+        pp2.tilt = tilt;
+        pp2.tool_type = tool_type;
+        size_t pointer_index = generic_event.PushPointer(pp2);
+        EXPECT_GT(pointer_index, 0u);
+
+        blink::WebTouchEvent web_touch_event =
+            CreateWebTouchEventFromMotionEvent(generic_event, true);
+
+        MotionEventWeb event(web_touch_event);
+        EXPECT_EQ(tool_type, event.GetToolType(pointer_index));
+        if (tool_type == MotionEvent::TOOL_TYPE_STYLUS) {
+          // Web touch event touch point tilt plane angles are stored as ints,
+          // thus the tilt precision is 1 degree and the error should not be
+          // greater than 0.5 degrees.
+          EXPECT_NEAR(tilt, event.GetTilt(pointer_index), 0.5f * M_PI / 180.f)
+              << " orientation=" << orientation;
+        } else {
+          EXPECT_EQ(0.f, event.GetTilt(pointer_index));
+        }
+        if (tool_type == MotionEvent::TOOL_TYPE_STYLUS && tilt > 0.f) {
+          // Full stylus tilt orientation information survives above event
+          // conversions only if there is a non-zero stylus tilt angle.

[mustaq, 2015/10/30 14:58:14]

Please add a ref to crbug.com/493728 here. I think your tiltx/y calculation now
fully captures the stylus info in ME, nothing is lost really.

Let's discuss it in the bug, this shouldn't block the CL.

[e_hakkinen, 2015/10/30 15:45:24]

Done.

+          EXPECT_NEAR(orientation, event.GetOrientation(pointer_index), 1e-4)
+              << " tilt=" << tilt;
+        } else {
+          // For non-stylus pointers and for styluses with a zero tilt angle,
+          // orientation quadrant information is lost.
+          EXPECT_NEAR(fmod(orientation + M_PI, M_PI_2),
+                      event.GetOrientation(pointer_index), 1e-4);
+        }
+
+        generic_event.RemovePointerAt(pointer_index);
+      }
+    }
+  }
+}
+
+}  // namespace content