private static bool TryGetLastFrameFromExtensions(out XRCameraFrame frame)
{
ARCoreExtensions extensions = ARCoreExtensions._instance;
ARCameraManager cameraManager = extensions.CameraManager;
var cameraParams = new XRCameraParams
{
zNear = cameraManager.GetComponent <Camera>().nearClipPlane,
zFar = cameraManager.GetComponent <Camera>().farClipPlane,
screenWidth = Screen.width,
screenHeight = Screen.height,
screenOrientation = Screen.orientation
};
if (!cameraManager.subsystem.TryGetLatestFrame(
cameraParams, out frame))
{
Debug.LogWarning(
"The current XRCameraFrame is not available, try again later.");
return(false);
}
if (frame.timestampNs == 0 || frame.FrameHandle() == IntPtr.Zero)
{
Debug.LogWarning(
"The current XRCameraFrame is not ready, try again later.");
return(false);
}
return(true);
}
/// <summary>
/// Get the 4x4 image display matrix for the camera frame. This is used by the texture
/// populated based on CPU images
/// to calculate the display coordinates.
/// </summary>
/// <param name="frame">The XRCameraFrame instance.</param>
/// <returns>The 4x4 image display matrix.</returns>
public static Matrix4x4 GetImageDisplayMatrix(this XRCameraFrame frame)
{
// Unity Screen Coordinate: Android Screen Coordinate (flipped Y-Axis):
// (0, 1) (1, 1) (0, 0) (1, 0)
// |----------------| |----------------|
// | | | |
// | | | |
// | | | |
// | | | |
// | | | |
// | | | |
// | | | |
// |----------------| |----------------|
// (0, 0) (1, 0) (0, 1) (1, 1)
IntPtr sessionHandle = ARCoreExtensions._instance.currentARCoreSessionHandle;
// X-Axis (1, 0) in Unity view maps to (1, 1) on Android screen.
Vector2 affineBasisX = new Vector2(1.0f, 1.0f);
// Y-Axis (0, 1) in Unity view maps to (0, 0) on Android screen.
Vector2 affineBasisY = new Vector2(0.0f, 0.0f);
// Origin (0, 0) in Unity view maps to (0, 1) on Android screen.
Vector2 affineOrigin = new Vector2(0.0f, 1.0f);
Vector2 transformedX = FrameApi.TransformCoordinates2d(
sessionHandle, frame.FrameHandle(), ApiCoordinates2dType.ViewNormalized,
ApiCoordinates2dType.ImageNormalized, ref affineBasisX);
Vector2 transformedY = FrameApi.TransformCoordinates2d(
sessionHandle, frame.FrameHandle(), ApiCoordinates2dType.ViewNormalized,
ApiCoordinates2dType.ImageNormalized, ref affineBasisY);
Vector2 transformedOrigin = FrameApi.TransformCoordinates2d(
sessionHandle, frame.FrameHandle(), ApiCoordinates2dType.ViewNormalized,
ApiCoordinates2dType.ImageNormalized, ref affineOrigin);
Matrix4x4 imageMatrix = Matrix4x4.identity;
imageMatrix[0, 0] = transformedX.x - transformedOrigin.x;
imageMatrix[0, 1] = transformedX.y - transformedOrigin.y;
imageMatrix[1, 0] = transformedY.x - transformedOrigin.x;
imageMatrix[1, 1] = transformedY.y - transformedOrigin.y;
imageMatrix[2, 0] = transformedOrigin.x;
imageMatrix[2, 1] = transformedOrigin.y;
return(imageMatrix);
}