public void onFovChanged(
final HeadMountedDisplay hmd,
final FieldOfView leftFov,
final FieldOfView rightFov,
final float virtualEyeToScreenDistance) {
if (this.mDrawingFrame) {
throw new IllegalStateException("Cannot change FOV while rendering a frame.");
}
this.mHmd = new HeadMountedDisplay(hmd);
this.mLeftEyeViewport = this.initViewportForEye(leftFov, 0.0f);
this.mRightEyeViewport = this.initViewportForEye(rightFov, this.mLeftEyeViewport.width);
this.mMetersPerTanAngle = virtualEyeToScreenDistance;
final ScreenParams screen = this.mHmd.getScreenParams();
this.mXPxPerTanAngle = screen.getWidth() / (screen.getWidthMeters() / this.mMetersPerTanAngle);
this.mYPxPerTanAngle =
screen.getHeight() / (screen.getHeightMeters() / this.mMetersPerTanAngle);
this.mFovsChanged = true;
this.mViewportsChanged = true;
}
