Modified: trunk/Source/WebCore/ChangeLog (177197 => 177198)
--- trunk/Source/WebCore/ChangeLog 2014-12-12 01:37:07 UTC (rev 177197)
+++ trunk/Source/WebCore/ChangeLog 2014-12-12 01:41:30 UTC (rev 177198)
@@ -1,3 +1,19 @@
+2014-12-11 Rich Tibbett <[email protected]>
+
+ [iOS] Normalize iOS DeviceOrientation beta/gamma per spec.
+ https://bugs.webkit.org/show_bug.cgi?id=137134
+ <radr://problem/9414459>
+
+ Reviewed by Benjamin Poulain.
+
+ Normalize DeviceOrientation beta and gamma on iOS to match the
+ conventions defined in the W3C DeviceOrientation Events specification.
+
+ beta values are returned in the range [-180, 180). gamma values are
+ returned in the range [-90, 90).
+
+ * platform/ios/WebCoreMotionManager.mm:
+
2014-12-11 Commit Queue <[email protected]>
Unreviewed, rolling out r177081.
Modified: trunk/Source/WebCore/platform/ios/WebCoreMotionManager.mm (177197 => 177198)
--- trunk/Source/WebCore/platform/ios/WebCoreMotionManager.mm 2014-12-12 01:37:07 UTC (rev 177197)
+++ trunk/Source/WebCore/platform/ios/WebCoreMotionManager.mm 2014-12-12 01:41:30 UTC (rev 177198)
@@ -252,23 +252,74 @@
Vector<WebCore::DeviceOrientationClientIOS*> orientationClients;
copyToVector(m_deviceOrientationClients, orientationClients);
- // Note that the W3C DeviceOrientation specification labels the X axis
- // as passing between the sides of the device, and the Y axis as passing
- // from top to bottom of the device. Conventional Tait-Bryan Euler angles
- // have the X axis pointing forward (the heading of the aircraft, for
- // example), which is what you would "roll" around, and what the W3C says
- // is the Y axis. Unfortunately CoreMotion doesn't normalize in the
- // same order as the W3C requests, so our beta is [-90, 90] and gamma is
- // [-180, 180]. For most practical uses this is acceptable.
- // See <rdar://problem/9414459> Normalize our DeviceOrientation beta/gamma per spec
+ // Compose the raw motion data to an intermediate ZXY-based 3x3 rotation
+ // matrix (R) where [z=attitude.yaw, x=attitude.pitch, y=attitude.roll]
+ // in the form:
+ //
+ // / R[0] R[1] R[2] \
+ // | R[3] R[4] R[5] |
+ // \ R[6] R[7] R[8] /
- // Rotation around the Z axis (pointing up, normalized to [0, 360] deg).
- double alpha = rad2deg(attitude.yaw > 0 ? attitude.yaw : (M_PI * 2 + attitude.yaw));
- // Rotation around the X axis (side to side).
- double beta = rad2deg(attitude.pitch);
- // Rotation around the Y axis (top to bottom).
- double gamma = rad2deg(attitude.roll);
+ double cX = cos(attitude.pitch);
+ double cY = cos(attitude.roll);
+ double cZ = cos(attitude.yaw);
+ double sX = sin(attitude.pitch);
+ double sY = sin(attitude.roll);
+ double sZ = sin(attitude.yaw);
+ double R[] = {
+ cZ * cY - sZ * sX * sY,
+ - cX * sZ,
+ cY * sZ * sX + cZ * sY,
+ cY * sZ + cZ * sX * sY,
+ cZ * cX,
+ sZ * sY - cZ * cY * sX,
+ - cX * sY,
+ sX,
+ cX * cY
+ };
+
+ // Compute correct, normalized values for DeviceOrientation from
+ // rotation matrix (R) according to the angle conventions defined in the
+ // W3C DeviceOrientation specification.
+
+ double zRot;
+ double xRot;
+ double yRot;
+
+ if (R[8] > 0) {
+ zRot = atan2(-R[1], R[4]);
+ xRot = asin(R[7]);
+ yRot = atan2(-R[6], R[8]);
+ } else if (R[8] < 0) {
+ zRot = atan2(R[1], -R[4]);
+ xRot = -asin(R[7]);
+ xRot += (xRot >= 0) ? -M_PI : M_PI;
+ yRot = atan2(R[6], -R[8]);
+ } else {
+ if (R[6] > 0) {
+ zRot = atan2(-R[1], R[4]);
+ xRot = asin(R[7]);
+ yRot = -M_PI_2;
+ } else if (R[6] < 0) {
+ zRot = atan2(R[1], -R[4]);
+ xRot = -asin(R[7]);
+ xRot += (xRot >= 0) ? -M_PI : M_PI;
+ yRot = -M_PI_2;
+ } else {
+ zRot = atan2(R[3], R[0]);
+ xRot = (R[7] > 0) ? M_PI_2 : -M_PI_2;
+ yRot = 0;
+ }
+ }
+
+ // Rotation around the Z axis (pointing up. normalized to [0, 360] deg).
+ double alpha = rad2deg(zRot > 0 ? zRot : (M_PI * 2 + zRot));
+ // Rotation around the X axis (top to bottom).
+ double beta = rad2deg(xRot);
+ // Rotation around the Y axis (side to side).
+ double gamma = rad2deg(yRot);
+
double heading = (m_headingAvailable && newHeading) ? newHeading.magneticHeading : 0;
double headingAccuracy = (m_headingAvailable && newHeading) ? newHeading.headingAccuracy : -1;
