/// <inheritdoc />
private void OnPreCull()
{
if (!ReadingModeEnabled)
{
return;
}
const float ResolutionScale = 45.0f / 33.0f;
StartCoroutine(ResetViewMatricesOnFrameEnd());
Matrix4x4 leftProj = CameraCache.Main.GetStereoProjectionMatrix(Camera.StereoscopicEye.Left);
Matrix4x4 rightProj = CameraCache.Main.GetStereoProjectionMatrix(Camera.StereoscopicEye.Right);
leftProj.m00 *= ResolutionScale;
leftProj.m11 *= ResolutionScale;
rightProj.m00 *= ResolutionScale;
rightProj.m11 *= ResolutionScale;
CameraCache.Main.SetStereoProjectionMatrix(Camera.StereoscopicEye.Left, leftProj);
CameraCache.Main.SetStereoProjectionMatrix(Camera.StereoscopicEye.Right, rightProj);
HolographicFrame holographicFrame = WindowsMixedRealityUtilities.CurrentWindowsHolographicFrame;
if (holographicFrame != null)
{
HolographicFramePrediction prediction = holographicFrame.CurrentPrediction;
for (int i = 0; i < prediction.CameraPoses.Count; ++i)
{
HolographicCameraPose cameraPose = prediction.CameraPoses[i];
if (cameraPose.HolographicCamera.CanOverrideViewport)
{
HolographicStereoTransform stereoProjection = cameraPose.ProjectionTransform;
stereoProjection.Left.M11 *= ResolutionScale;
stereoProjection.Left.M22 *= ResolutionScale;
stereoProjection.Right.M11 *= ResolutionScale;
stereoProjection.Right.M22 *= ResolutionScale;
cameraPose.OverrideProjectionTransform(stereoProjection);
}
}
}
}
/// <summary>
/// Updates the constant buffer for the display with view and projection
/// matrices for the current frame.
/// </summary>
public void UpdateViewProjectionBuffer(
DeviceResources deviceResources,
HolographicCameraPose cameraPose,
SpatialCoordinateSystem coordinateSystem
)
{
// The system changes the viewport on a per-frame basis for system optimizations.
d3dViewport.X = (float)cameraPose.Viewport.Left;
d3dViewport.Y = (float)cameraPose.Viewport.Top;
d3dViewport.Width = (float)cameraPose.Viewport.Width;
d3dViewport.Height = (float)cameraPose.Viewport.Height;
d3dViewport.MinDepth = 0;
d3dViewport.MaxDepth = 1;
// The projection transform for each frame is provided by the HolographicCameraPose.
HolographicStereoTransform cameraProjectionTransform = cameraPose.ProjectionTransform;
// Get a container object with the view and projection matrices for the given
// pose in the given coordinate system.
HolographicStereoTransform?viewTransformContainer = cameraPose.TryGetViewTransform(coordinateSystem);
// If TryGetViewTransform returns null, that means the pose and coordinate system
// cannot be understood relative to one another; content cannot be rendered in this
// coordinate system for the duration of the current frame.
// This usually means that positional tracking is not active for the current frame, in
// which case it is possible to use a SpatialLocatorAttachedFrameOfReference to render
// content that is not world-locked instead.
ViewProjectionConstantBuffer viewProjectionConstantBufferData = new ViewProjectionConstantBuffer();
bool viewTransformAcquired = viewTransformContainer.HasValue;
if (viewTransformAcquired)
{
// Otherwise, the set of view transforms can be retrieved.
HolographicStereoTransform viewCoordinateSystemTransform = viewTransformContainer.Value;
// Update the view matrices. Holographic cameras (such as Microsoft HoloLens) are
// constantly moving relative to the world. The view matrices need to be updated
// every frame.
viewProjectionConstantBufferData.viewProjectionLeft = Matrix4x4.Transpose(
viewCoordinateSystemTransform.Left * cameraProjectionTransform.Left
);
viewProjectionConstantBufferData.viewProjectionRight = Matrix4x4.Transpose(
viewCoordinateSystemTransform.Right * cameraProjectionTransform.Right
);
}
// Use the D3D device context to update Direct3D device-based resources.
var context = deviceResources.D3DDeviceContext;
// Loading is asynchronous. Resources must be created before they can be updated.
if (context == null || viewProjectionConstantBuffer == null || !viewTransformAcquired)
{
framePending = false;
}
else
{
// Update the view and projection matrices.
context.UpdateSubresource(ref viewProjectionConstantBufferData, viewProjectionConstantBuffer);
framePending = true;
}
}
