fuchsia.ui.gfx

PROTOCOLS

SnapshotCallbackDEPRECATED

Defined in fuchsia.ui.gfx/commands.fidl

OnData

Request

Name	Type
data	fuchsia.mem/Buffer

STRUCTS

AddChildCmd

Defined in fuchsia.ui.gfx/commands.fidl

Add a node as a child to another node.

Constraints:

• id refs a Node with the has_children characteristic.
• child_id refs any Node.

Discussion: The child node is first removed from its existing parent, as if DetachCmd was applied first.

Field	Type	Description	Default
node_id	uint32		No default
child_id	uint32		No default

AddLayerCmd

Defined in fuchsia.ui.gfx/commands.fidl

Add a layer to a layer stack. Constraints:

• layer_stack_id refs a LayerStack.
• layer_id refs a Layer.
• The layer must not already belong to a different stack; it must first be detached.

Field	Type	Description	Default
layer_stack_id	uint32		No default
layer_id	uint32		No default

AddLightCmd

Defined in fuchsia.ui.gfx/commands.fidl

Adds the light specified by light_id specified by light_id to the scene identified by scene_id.

Field	Type	Description	Default
scene_id	uint32		No default
light_id	uint32		No default

AddPartCmd

Defined in fuchsia.ui.gfx/commands.fidl

Add a node as a part of another node. The implications of being a part rather than a child differ based on the type of the part. However, one implication is constant: removing all of a node's children (e.g. via DetachChildrenCmd) does not affect its parts. This is similar to the "shadow DOM" in a web browser: the controls of a

Constraints:

• id refs a Node with the has_parts characteristic.
• part_id refs any Node.

Discussion: The part node is first removed from its existing parent, as if DetachCmd was applied first.

Field	Type	Description	Default
node_id	uint32		No default
part_id	uint32		No default

AmbientLightArgs

Defined in fuchsia.ui.gfx/resources.fidl

An AmbientLight is a Light that is is assumed to be everywhere in the scene, in all directions.

Supported commands:

• SetLightColor

Field	Type	Description	Default
dummy	uint32		0

BindMeshBuffersCmd

Defined in fuchsia.ui.gfx/commands.fidl

Field	Type	Description	Default
mesh_id	uint32		No default
index_buffer_id	uint32		No default
index_format	MeshIndexFormat		No default
index_offset	uint64		No default
index_count	uint32		No default
vertex_buffer_id	uint32		No default
vertex_format	MeshVertexFormat		No default
vertex_offset	uint64		No default
vertex_count	uint32		No default
bounding_box	BoundingBox		No default

BoundingBox

Defined in fuchsia.ui.gfx/types.fidl

Represents an axis-aligned bounding box.

If any of the dimensions has a negative extent (e.g. max.x < min.x) then the bounding box is treated as empty. It is valid for a client to define an empty bounding box.

An "empty bounding box" is one that does not admit a point inhabitant. Note that a zero-volume, zero-area bounding box (e.g., a point like (0,0,0)-(0,0,0), or a line like (0,0,0)-(1,0,0)) is thus not empty.

Field	Type	Description	Default
min	vec3		No default
max	vec3		No default

BufferArgs

Defined in fuchsia.ui.gfx/resources.fidl

A buffer mapped to a range of Memory.

Field	Type	Description	Default
memory_id	uint32		No default
memory_offset	uint32		No default
num_bytes	uint32		No default

CameraArgs

Defined in fuchsia.ui.gfx/resources.fidl

A Camera is used to render a Scene from a particular viewpoint. This is achieved by setting a Renderer to use the camera.

The following commands may be applied to a Camera:

• SetCameraTransform
• SetCameraProjection
• SetCameraPoseBuffer

Field	Type	Description	Default
scene_id	uint32	The scene that the camera is viewing.	No default

CircleArgs

Defined in fuchsia.ui.gfx/shapes.fidl

Field	Type	Description	Default
radius	Value		No default

ClipNodeArgs

Defined in fuchsia.ui.gfx/nodes.fidl

Characteristics:

• has_parent
• is_clip
• has_parts

Field	Type	Description	Default
unused	uint32		0

ColorRgb

Defined in fuchsia.ui.gfx/types.fidl

Field	Type	Description	Default
red	float32		No default
green	float32		No default
blue	float32		No default

ColorRgbValue

Defined in fuchsia.ui.gfx/types.fidl

A value that is specified explicitly by value if variable_id is zero, or is the value produced by the resource identified by variable_id, e.g. an animation or expression. In the latter case, the value produced by the resource must be a ColorRgb, and value is ignored.

Field	Type	Description	Default
value	ColorRgb		No default
variable_id	uint32		No default

ColorRgba

Defined in fuchsia.ui.gfx/types.fidl

sRGB color space and nonlinear transfer function.

Field	Type	Description	Default
red	uint8		No default
green	uint8		No default
blue	uint8		No default
alpha	uint8		No default

ColorRgbaValue

Defined in fuchsia.ui.gfx/types.fidl

A value that is specified explicitly by value if variable_id is zero, or is the value produced by the resource identified by variable_id, e.g. an animation or expression. In the latter case, the value produced by the resource must be a ColorRgba, and value is ignored.

Field	Type	Description	Default
value	ColorRgba		No default
variable_id	uint32		No default

CompositorArgs

Defined in fuchsia.ui.gfx/resources.fidl

A Compositor draws its LayerStack into a framebuffer provided by its attached Display, if any. If no display is attached, nothing is rendered.

Field	Type	Description	Default
dummy	uint32		0

CreateResourceCmd resource

Defined in fuchsia.ui.gfx/commands.fidl

Instructs the compositor to create the specified Resource, and to register it in a table so that it can be referenced by subsequent commands.

Field	Type	Description	Default
id	uint32	An ID that is currently not used within the session.	No default
resource	ResourceArgs		No default

DetachChildrenCmd

Defined in fuchsia.ui.gfx/commands.fidl

Detaches all of a node's children (but not its parts).

Field	Type	Description	Default
node_id	uint32		No default

DetachCmd

Defined in fuchsia.ui.gfx/commands.fidl

Detaches a parentable object from its parent (e.g. a node from a parent node, or a layer from a layer stack). It is illegal to apply this command to a non-parentable object. No-op if the target object currently has no parent.

Constraints:

• id refs a parentable object

Discussion: For nodes, this command will detach a node from its parent, regardless of whether it is a part or a child of its parent.

Field	Type	Description	Default
id	uint32		No default

DetachLightCmd

Defined in fuchsia.ui.gfx/commands.fidl

Detach the light specified by light_id from the scene that it is attached to, if any.

Field	Type	Description	Default
light_id	uint32		No default

DetachLightsCmd

Defined in fuchsia.ui.gfx/commands.fidl

Detach all lights from the scene specified by scene_id.

Field	Type	Description	Default
scene_id	uint32		No default

DirectionalLightArgs

Defined in fuchsia.ui.gfx/resources.fidl

A DirectionalLight is a Light that is emitted from a point at infinity.

Although the light is directional, the light has some amount of angular dispersion (i.e., the light is not fully columnated). For simplicity, we assume the dispersion of the light source is symmetric about the light's primary direction.

Supported commands:

• SetLightColor
• SetLightDirection

Field	Type	Description	Default
dummy	uint32		0

DisplayCompositorArgs

Defined in fuchsia.ui.gfx/resources.fidl

A DisplayCompositor draws its attached LayerStack into an image that is presented on a display.

Field	Type	Description	Default
dummy	uint32		0

DisplayInfo

Defined in fuchsia.ui.gfx/display_info.fidl

Provides information about a display.

Field	Type	Description	Default
width_in_px	uint32	The size of the display, in physical pixels.	No default
height_in_px	uint32		No default

EntityNodeArgs

Defined in fuchsia.ui.gfx/nodes.fidl

Characteristics:

• has_transform
• has_children
• has_parent
• has_parts
• has_clip

Field	Type	Description	Default
unused	uint32		0

ExportResourceCmdDeprecated resource

Defined in fuchsia.ui.gfx/commands.fidl

Create an external reference to the specified resource, which can then be imported into another Session by passing a handle to token's peer to ImportResourceCmd; see that comment for more details.

The importing client is typically in a different process than the exporter. No specific mechanism is provided for transferring a token from an exporter to an importer; collaborators may choose any out-of-band API they wish to do so.

Field	Type	Description	Default
id	uint32		No default
token	handle<eventpair>		No default

ExportToken resource

Defined in fuchsia.ui.gfx/tokens.fidl

Token that uniquely identifies a root point for a subgraph in the global scene graph. Each ExportToken has exactly one corresponding ImportToken.

A Scenic client can have its contents referenced from another client by creating a typed resource using this token. The other client must also create a correspondingly typed resource using the corresponding ImportToken.

The exact nature of the inter-client reference depends on the specific resources created from the tokens. For example, creating a View resource from this token allows everything attached to the View to be embedded in another clients ViewHolder.

Field	Type	Description	Default
value	handle<eventpair>		No default

FactoredTransform

Defined in fuchsia.ui.gfx/types.fidl

Field	Type	Description	Default
translation	vec3		No default
scale	vec3		No default
anchor	vec3	Point around which rotation and scaling occur.	No default
rotation	Quaternion		No default

FloatValue

Defined in fuchsia.ui.gfx/types.fidl

A value that is specified explicitly by value if variable_id is zero, or is the value produced by the resource identified by variable_id, e.g. an animation or expression. In the latter case, the value produced by the resource must be a float32, and value is ignored.

Field	Type	Description	Default
value	float32		No default
variable_id	uint32		No default

ImageArgs

Defined in fuchsia.ui.gfx/resources.fidl

An image mapped to a range of a Memory resource.

Field	Type	Description	Default
info	fuchsia.images/ImageInfo		No default
memory_id	uint32		No default
memory_offset	uint32		No default

ImageArgs2

Defined in fuchsia.ui.gfx/resources.fidl

An image mapped to a range of a Memory resource.

Field	Type	Description	Default
width	uint32		No default
height	uint32		No default
buffer_collection_id	uint32	The id of a BufferCollection. Before creating this resource, the buffer collection should be registered on the same Session with RegisterBufferCollection and it should have its contraints set. Once the buffers are allocated successfully (e.g. after calling WaitForBuffersAllocated), the collection's id can be used to create the image resource.	No default
buffer_collection_index	uint32	The index of the VMO from the BufferCollection that backs this image.	No default

ImageArgs3 resource

Defined in fuchsia.ui.gfx/resources.fidl

An image that is backed by a BufferCollection registered with Allocator.

Field	Type	Description	Default
width	uint32		No default
height	uint32		No default
import_token	fuchsia.ui.composition/BufferCollectionImportToken	Image creation requires an allocated BufferCollection registered with Allocator. import_token should be the other end of a BufferCollectionExportToken that is successfully registered. All clients of the specified BufferCollection must have set their constraints and buffers should be allocated before calling.	No default
buffer_collection_index	uint32	The index of the VMO from the BufferCollection that backs this image.	No default

ImagePipe2Args resource

Defined in fuchsia.ui.gfx/resources.fidl

ImagePipe2 is a Resource that can be used as a Texture for a Material.

Field	Type	Description	Default
image_pipe_request	server_end<fuchsia.images/ImagePipe2>		No default

ImportResourceCmdDeprecated resource

Defined in fuchsia.ui.gfx/commands.fidl

Import a resource that was exported via ExportResourceCmd(). token is a handle to the eventpair peer that was used to export the resource, and spec describes the type of the imported resource, and the commands which can legally be applied to it. Afterward, id can be used to refer to the resource in an Command, similarly (but not identically: see below) to a resource that was created in the session. For example, you can add children to an imported EntityNode via AddChildCmd.

However, note that the importer does not gain full access to the imported resource, but rather to an attenuated subset of its capabilities. For example, you cannot use a DetachCmd to detach an imported EntityNode from its parent.

Unlike ExportResourceCmd, there is no configurable timeout. There is an expectation that the exported resource will become available in a short amount of time. TODO: this needs elaboration... e.g. we might notify via the SessionListener when we know that the link will never be made (e.g. if the peer of the import token is destroyed).

Field	Type	Description	Default
id	uint32		No default
token	handle<eventpair>		No default
spec	ImportSpec		No default

ImportToken resource

Defined in fuchsia.ui.gfx/tokens.fidl

Token that uniquely identifies an attachment point for a subgraph in the global scene graph. Each ImportToken has exactly one corresponding ExportToken.

A Scenic client can reference contents from another client by creating a typed resource using this token. The other client must also create a correspondingly typed resource using the corresponding ExportToken.

The exact nature of the inter-client reference depends on the specific resources created from the tokens. For example, creating a ViewHolder resource from this token allows a client to embed another client's View.

Field	Type	Description	Default
value	handle<eventpair>		No default

ImportUnboundEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered when the imported resource with the given ID is no longer bound to its host resource, or if the imported resource can not be bound because the host resource is not available.

Field	Type	Description	Default
resource_id	uint32		No default

LayerArgs

Defined in fuchsia.ui.gfx/resources.fidl

A Layer is a 2-dimensional image that is drawn by a Compositor. The contents of each Layer in a Layerstack are independent of each other. A layer is not drawn unless it has a camera, texture, or color.

Supported commands:

• Detach
• SetCamera
• SetColor
• SetTexture
• SetSize (depth must be zero)
• SetSize
• SetTranslation (z component determines the relative Z-ordering of layers)
• SetRotation (must rotate around Z-axis)
• SetScale

Field	Type	Description	Default
dummy	uint32		0

LayerStackArgs

Defined in fuchsia.ui.gfx/resources.fidl

A LayerStack is a stack of layers that are attached to a Compositor, which draws them in order of increasing Z-order (or rather, presents the illusion of drawing them in that order: it may apply any optimizations that don't affect the output).

Supported commands:

• AddLayer

Field	Type	Description	Default
dummy	uint32		0

MaterialArgs

Defined in fuchsia.ui.gfx/resources.fidl

Simple texture-mapped material.

Supported commands:

• SetTextureCmd: sets the texture, or it can be left as zero (no texture). The texture can be an Image or ImagePipe2.
• SetColorCmd: sets the color.

Field	Type	Description	Default
dummy	uint32		0

Matrix4Value

Defined in fuchsia.ui.gfx/types.fidl

A value that is specified explicitly by value if variable_id is zero, or is the value produced by the resource identified by variable_id, e.g. an animation or expression. In the latter case, the value produced by the resource must be a vec4, and value is ignored.

Field	Type	Description	Default
value	mat4		No default
variable_id	uint32		No default

MemoryArgs resource

Defined in fuchsia.ui.gfx/resources.fidl

Memory is a Resource that wraps a client-provided Zircon vmo to register it with Scenic.

Field	Type	Description	Default
vmo	handle<vmo>	The VMO which backs this memory.	No default
allocation_size	uint64	The amount of memory from vmo that should be utilized.	No default
memory_type	fuchsia.images/MemoryType	The type of memory stored in the VMO, namely whether it's GPU memory or host memory.	No default

MeshArgs

Defined in fuchsia.ui.gfx/shapes.fidl

A Mesh cannot be rendered until it has been bound to vertex/index buffers; see BindMeshBuffersCmd.

<EMPTY>

MeshVertexFormat

Defined in fuchsia.ui.gfx/commands.fidl

Field	Type	Description	Default
position_type	ValueType	kVector2 or kVector3.	No default
normal_type	ValueType	kVector2 or kVector3 (must match position_type), or kNone.	No default
tex_coord_type	ValueType	kVector2 or kNone.	No default

Metrics

Defined in fuchsia.ui.gfx/types.fidl

Rendering target metrics associated with a node. See also MetricsEvent.

Field	Type	Description	Default
scale_x	float32	The ratio between the size of one logical pixel within the node's local coordinate system and the size of one physical pixel of the rendering target. This scale factors change in relation to the resolution of the rendering target and the scale transformations applied by containing nodes. They are always strictly positive and non-zero. For example, suppose the rendering target is a high resolution display with a device pixel ratio of 2.0 meaning that each logical pixel within the model corresponds to two physical pixels of the display. Assuming no scale transformations affect the node, then its metrics event will report a scale factor of 2.0. Building on this example, if instead the node's parent applies a scale transformation of 0.25 to the node, then the node's metrics event will report a scale factor of 0.5 indicating that the node should render its content at a reduced resolution and level of detail since a smaller area of physical pixels (half the size in each dimension) will be rendered.	No default
scale_y	float32		No default
scale_z	float32		No default

MetricsEvent

Defined in fuchsia.ui.gfx/events.fidl

Provides rendering target metrics information about the specified node.

This event is delivered when the following conditions are true:

• The node is a descendant of a Scene.
• The node has kMetricsEventMask set to an enabled state.
• The node's metrics have changed since they were last delivered, or since kMetricsEventMask transitioned from a disabled state to an enabled state.

Subscribe to this event to receive information about the scale factors you should apply when generating textures for your nodes.

Field	Type	Description	Default
node_id	uint32		No default
metrics	Metrics		No default

OpacityNodeArgsHACK

Defined in fuchsia.ui.gfx/nodes.fidl

Characteristics:

• has_transform
• has_parent
• has_children
• has_parts
• has_opacity

Field	Type	Description	Default
unused	uint32		0

Plane3

Defined in fuchsia.ui.gfx/types.fidl

Oriented plane described by a normal vector and a distance from the origin along that vector.

Field	Type	Description	Default
dir	vec3		No default
dist	float32		No default

PointLightArgs

Defined in fuchsia.ui.gfx/resources.fidl

A PointLight is a Light that emits light in all directions. By default, the intensity of the light falls off according to the physically based "inverse-square law" (see Wikipedia), although it can be adjusted to other values for artistic effect.

Supported commands:

• SetLightColor
• SetPointLightPosition
• SetPointLightFalloff

Field	Type	Description	Default
dummy	uint32		0

Quaternion

Defined in fuchsia.ui.gfx/types.fidl

Field	Type	Description	Default
x	float32		No default
y	float32		No default
z	float32		No default
w	float32		No default

QuaternionValue

Defined in fuchsia.ui.gfx/types.fidl

A value that is specified explicitly by value if variable_id is zero, or is the value produced by the resource identified by variable_id, e.g. an animation or expression. In the latter case, the value produced by the resource must be a Quaternion, and value is ignored.

Field	Type	Description	Default
value	Quaternion		No default
variable_id	uint32		No default

RectangleArgs

Defined in fuchsia.ui.gfx/shapes.fidl

Rectangle centered at (0,0).

Field	Type	Description	Default
width	Value		No default
height	Value		No default

ReleaseResourceCmd

Defined in fuchsia.ui.gfx/commands.fidl

Releases the client's reference to the resource; it is then illegal to use the ID in subsequent Commands. Other references to the resource may exist, so releasing the resource does not result in its immediate destruction; it is only destroyed once the last reference is released. For example, the resource may be required to render an in-progress frame, or it may be referred to by another resource). However, the ID will be immediately unregistered, and may be reused to create a new resource.

Field	Type	Description	Default
id	uint32	ID of the resource to be dereferenced.	No default

RemoveAllLayersCmd

Defined in fuchsia.ui.gfx/commands.fidl

Remove all layers from a layer stack. Constraints

• layer_stack_id refs a LayerStack.

Field	Type	Description	Default
layer_stack_id	uint32		No default

RemoveLayerCmd

Defined in fuchsia.ui.gfx/commands.fidl

Remove a layer from a layer stack. Constraints:

• layer_stack_id refs a LayerStack.
• layer_id refs a Layer.
• The layer must belong to this stack.

Field	Type	Description	Default
layer_stack_id	uint32		No default
layer_id	uint32		No default

RendererArgs

Defined in fuchsia.ui.gfx/resources.fidl

A Renderer renders a Scene via a Camera.

Supported commands:

• SetCamera
• SetRendererParam

Field	Type	Description	Default
dummy	uint32		0

RoundedRectangleArgs

Defined in fuchsia.ui.gfx/shapes.fidl

RoundedRectangle centered at (0,0). Legal parameter values must satisfy the constraint that the flat sides of the rectangle have non-negative length. In other words, the following constraints must hold:

• top_left_radius + top_right_radius <= width
• bottom_left_radius + bottom_right_radius <= width
• top_left_radius + bottom_left_radius <= height
• top_right_radius + bottom_right_radius <= height

Field	Type	Description	Default
width	Value		No default
height	Value		No default
top_left_radius	Value		No default
top_right_radius	Value		No default
bottom_right_radius	Value		No default
bottom_left_radius	Value		No default

SceneAddAmbientLightCmd

Defined in fuchsia.ui.gfx/commands.fidl

Adds the light specified by light_id specified by light_id to the scene identified by scene_id.

Field	Type	Description	Default
scene_id	uint32		No default
light_id	uint32		No default

SceneAddDirectionalLightCmd

Defined in fuchsia.ui.gfx/commands.fidl

Adds the light specified by light_id specified by light_id to the scene identified by scene_id.

Field	Type	Description	Default
scene_id	uint32		No default
light_id	uint32		No default

SceneAddPointLightCmd

Defined in fuchsia.ui.gfx/commands.fidl

Adds the light specified by light_id specified by light_id to the scene identified by scene_id.

Field	Type	Description	Default
scene_id	uint32		No default
light_id	uint32		No default

SceneArgs

Defined in fuchsia.ui.gfx/resources.fidl

A Scene is the root of a scene-graph, and defines the rendering environment (lighting, etc.) for the tree of nodes beneath it.

Supported commands:

• Add/RemoveLight
• AddChild

Field	Type	Description	Default
dummy	uint32		0

SendSizeChangeHintCmdHACK

Defined in fuchsia.ui.gfx/commands.fidl

Sends a hint about a pending size change to the given node and all nodes below. This is generally sent before an animation.

width_change_factor and height_change_factor is how much bigger or smaller the item is expected to be in the near future. This one number encapsulate both changes in scale, as well as changes to layout width and height.

Field	Type	Description	Default
node_id	uint32		No default
width_change_factor	float32		No default
height_change_factor	float32		No default

SetAnchorCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a Resource's (typically a Node's) anchor point.

Constraints:

• id refs a Resource with the has_transform characteristic.

Field	Type	Description	Default
id	uint32		No default
value	Vector3Value		No default

SetCameraClipSpaceTransformCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a camera's 2D clip-space transform.

Constraints:

• camera_id refs a Camera.
• translation is the desired translation, in Vulkan NDC.
• scale is the scale factor to apply on the x/y plane before translation.

Field	Type	Description	Default
camera_id	uint32		No default
translation	vec2		No default
scale	float32		No default

SetCameraCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a renderer's camera.

Constraints:

• renderer_id refs a Renderer.
• camera_id refs a Camera, or stops rendering by passing zero.
• matrix is a value or variable of type kMatrix4x4.

Field	Type	Description	Default
renderer_id	uint32		No default
camera_id	uint32		No default

SetCameraPoseBufferCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets the "pose buffer" for the camera identified by camera_id. This operation can be applied to both Cameras and StereoCameras.

This will override any position and rotation set for the camera and will make it take its position and rotation from the pose buffer each frame based on the presentation time for that frame.

A pose buffer represents a ring buffer of poses for a fixed number of time points in the future. Each entry in the buffer identified by buffer_id is a quaternion and a position layed out as follows:

struct Pose { // Quaternion float32 a; float32 b; float32 c; float32 d;

// Position float32 x; float32 y; float32 z;

// Reserved/Padding byte[4] reserved; }

The buffer can be thought of as a packed array of num_entries Pose structs and is required to be at least num_entries * sizeof(Pose) bytes.

The quaternions and positions are specified in the space of the camera's parent node.

base_time is a base time point expressed in nanoseconds in the CLOCK_MONOTONIC timebase and time_interval is the time in nanoseconds between entries in the buffer. base_time must be in the past.

For a given point in time t expressed in nanoseconds in the CLOCK_MONOTONIC timebase the index of the corresponding pose in the pose buffer can be computed as follows:

index(t) = ((t - base_time) / time_interval) % num_entries

poses[index(t)] is valid for t over the time interval (t - time_interval, t] and should be expected to updated continuously without synchronization for the duration of that interval. If a single pose value is needed for multiple non-atomic operations a value should be latched and stored outside the pose buffer.

Because the poses are not protected by any synchronization primitives it is possible that when a pose is latched it will be only partially updated, and the pose being read will contain some components from the pose before it is updated and some components from the updated pose. The safety of using these "torn" poses relies on two things:

1. Sequential poses written to poses[index(t)] are very similar to each other numerically, so that if some components are taken from the first and some are taken from another the result is numerically similar to both

2. The space of positions and quaternions is locally flat at the scale of changes between sequential updates, which guarantees that two poses which are numerically similar also represent semantically similar poses (i.e. there are no discontinuities which will cause a small numerical change in the position or quaterninon to cause a large change in the encoded pose) For positions this is guaranteed because Scenic uses a Euclidean 3-space which is globally flat and for quaternions this is guaranteed because quaternions encode rotation as points on a unit 4-sphere, and spheres are locally flat. For more details on the encoding of rotations in quaterions see https://en.wikipedia.org/wiki/Quaternions_and_spatial_rotation

This commanderation is intended for late latching camera pose to support low-latency motion-tracked rendering.

Field	Type	Description	Default
camera_id	uint32		No default
buffer_id	uint32		No default
num_entries	uint32		No default
base_time	int64		No default
time_interval	uint64		No default

SetCameraProjectionCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a camera's projection matrix. This operation cannot be applied to a StereoCamera.

Constraints:

• camera_id refs a Camera that is not a StereoCamera.
• fovy is the Y-axis field of view, in radians.

NOTE: A default orthographic projection is specified by setting fovy to zero. In this case, the camera transform is ignored.

Field	Type	Description	Default
camera_id	uint32		No default
fovy	FloatValue		No default

SetCameraTransformCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a camera's view matrix. This operation can be applied to both Cameras and StereoCameras.

Constraints:

• camera_id refs a Camera.
• eye_position is the position of the eye.
• eye_look_at is the point is the scene the that eye is pointed at.
• eye_up defines the camera's "up" vector.

Field	Type	Description	Default
camera_id	uint32		No default
eye_position	Vector3Value		No default
eye_look_at	Vector3Value		No default
eye_up	Vector3Value		No default

SetClipCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets/clears a node's clip. DEPRECATED: use SetClipPlanesCmd.

Constraints:

• node_id refs a Node with the has_clip characteristic.
• clip_id a Node with the is_clip characteristic, or nothing. If the referenced node is not rooted, then it will have no effect (since its full world-transform cannot be determined).
• clip_to_self If false, children are only clipped to the region specified by clip_id. If true, children are additionally clipped to the node's shape (as determined by its ShapeNode parts).

Discussion: If a node has a clip, it will be applied to both the parts and the children of the node. Under some circumstances (TBD), a clip will not be applicable to a node; in such cases it will be as though no clip has been specified for the node.

Field	Type	Description	Default
node_id	uint32		No default
clip_id	uint32		No default
clip_to_self	bool		No default

SetClipPlanesCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets the list of clip planes that apply to a Node and all of its children. Replaces the list set by any previous SetClipPlanesCmd.

• node_id refs a Node with the has_clip characteristic.
• clip_planes is the new list of oriented clip planes.

Field	Type	Description	Default
node_id	uint32		No default
clip_planes	vector<Plane3>		No default

SetColorCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a material's color.

Constraints:

• material_id refs a Material.

If a texture is set on the material, then the value sampled from the texture is multiplied by the color.

Field	Type	Description	Default
material_id	uint32		No default
color	ColorRgbaValue		No default

SetDisableClippingCmd

Defined in fuchsia.ui.gfx/commands.fidl

Set whether clipping should be disabled for the specified renderer. For a newly-created renderer, clipping will NOT be disabled (i.e. it will be enabled).

NOTE: this disables visual clipping only; objects are still clipped for the purposes of hit-testing.

renderer_id refs the target renderer. disable_clipping specifies whether the clipping should be disabled.

Field	Type	Description	Default
renderer_id	uint32		No default
disable_clipping	bool		No default

SetDisplayColorConversionCmdHACK

Defined in fuchsia.ui.gfx/commands.fidl

Set the color conversion applied to the compositor's display. The conversion is applied to to each pixel according to the formula:

(matrix * (pixel + preoffsets)) + postoffsets

where pixel is a column vector consisting of the pixel's 3 components.

matrix is passed in row-major order. Clients will be responsible for passing default values, when needed. Default values are not currently supported in fidl. Default Values: preoffsets = [0 0 0] matrix = [1 0 0 0 1 0 0 0 1] postoffsets = [0 0 0]

Field	Type	Description	Default
compositor_id	uint32		No default
preoffsets	float32[3]		No default
matrix	float32[9]		No default
postoffsets	float32[3]		No default

SetDisplayMinimumRgbCmdHACK

Defined in fuchsia.ui.gfx/commands.fidl

Field	Type	Description	Default
min_value	uint8		No default

SetDisplayRotationCmdHACK

Defined in fuchsia.ui.gfx/commands.fidl

Depending on the device, the display might be rotated with respect to what the lower level device controller considers the physical orientation of pixels. The compositors and layers must be in alignment with the underlying physical orientation which means that for certain operations like screenshotting, they cannot provide results with the accurate orientation unless they have information about how the higher-level display is orienting the screen. The only legal values for the rotation are 0, 90, 180, and 270, which are each applied counterclockwise.

Field	Type	Description	Default
compositor_id	uint32		No default
rotation_degrees	uint32		No default

SetEnableDebugViewBoundsCmd

Defined in fuchsia.ui.gfx/commands.fidl

Field	Type	Description	Default
view_id	uint32		No default
enable	bool		No default

SetEventMaskCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets which events a resource should deliver to the session listener. This command replaces any prior event mask for the resource.

The initial event mask for a resource is zero, meaning no events are reported.

Constraints:

• resource_id is a valid resource id
• event_mask is zero or a combination of k*EventMask bits OR'ed together.

Field	Type	Description	Default
id	uint32		No default
event_mask	uint32		No default

SetHitTestBehaviorCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a node's hit test behavior.

Discussion: By default, hit testing is performed on the node's content, its parts, and its children.

Field	Type	Description	Default
node_id	uint32		No default
hit_test_behavior	HitTestBehavior		No default

SetImportFocusCmdDEPRECATED

Defined in fuchsia.ui.gfx/commands.fidl

<EMPTY>

SetLabelCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets/clears a label to help developers identify the purpose of the resource when using diagnostic tools.

The label serves no functional purpose in the scene graph. It exists only to help developers understand its structure. The scene manager may truncate or discard labels at will.

Constraints:

• The label's maximum length is kLabelMaxLength characters.
• Setting the label to an empty string clears it.

Field	Type	Description	Default
id	uint32		No default
label	string		No default

SetLayerStackCmd

Defined in fuchsia.ui.gfx/commands.fidl

Set a compositor's layer stack, replacing the current stack (if any). Constraints:

• compositor_id refs a DisplayCompositor.
• layer_stack_id refs a LayerStack.

Field	Type	Description	Default
compositor_id	uint32		No default
layer_stack_id	uint32		No default

SetLightColorCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets the color of the Light identified by light_id.

Field	Type	Description	Default
light_id	uint32		No default
color	ColorRgbValue		No default

SetLightDirectionCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets the direction of the DirectionalLight identified by light_id.

Field	Type	Description	Default
light_id	uint32		No default
direction	Vector3Value		No default

SetMaterialCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets/clears a node's material.

Constraints:

• node_id refs a Node with the has_material characteristic.
• material_id refs a Material, or nothing.
• if this command causes the target to have both a Shape and a Material, then these must be compatible with each other (see README.md regarding "Shape/Material Compatibility").

Discussion: In order to be painted, a node requires both a Shape and a Material. Without a material, a node can still participate in hit-testing and clipping. Without a shape, a node cannot do any of the above.

Field	Type	Description	Default
node_id	uint32		No default
material_id	uint32		No default

SetOpacityCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a node's opacity.

Constraints:

• node_id refs a Node with the has_opacity characteristic.
• opacity is in the range [0, 1].

Field	Type	Description	Default
node_id	uint32		No default
opacity	float32		No default

SetPointLightFalloffCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets the falloff factor of the PointLight identified by light_id. A value of 1.0 corresponds to the physically-based "inverse-square law" (see Wikipedia). Other values can be used for artistic effect, e.g. a value of 0.0 means that the radiance of a surface is not dependant on its distance from the light.

Field	Type	Description	Default
light_id	uint32		No default
falloff	FloatValue		No default

SetPointLightPositionCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets the position of the PointLight identified by light_id.

Field	Type	Description	Default
light_id	uint32		No default
position	Vector3Value		No default

SetRendererCmd

Defined in fuchsia.ui.gfx/commands.fidl

Set a layer's renderer, replacing the current renderer (if any). Constraints:

• layer_id refs a Layer.
• renderer_id refs a Renderer.

Field	Type	Description	Default
layer_id	uint32		No default
renderer_id	uint32		No default

SetRendererParamCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a parameter that affects how a renderer renders a scene.

renderer_id refs the Renderer that is being modified. param describes the parameter that should be set, and to what.

Field	Type	Description	Default
renderer_id	uint32		No default
param	RendererParam		No default

SetRotationCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a Resource's (typically a Node's) rotation.

Constraints:

• id refs a Resource with the has_transform characteristic.

Discussion: Quaternions represent any rotation in a 3D coordinate system. Consisting of [a,b,c,d], [a] represents the amount of rotation that should be applied and [b,c,d] represents the vector around which the rotation is applied. This conforms to the semantics of glm::quat.

Field	Type	Description	Default
id	uint32		No default
value	QuaternionValue		No default

SetScaleCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a Resource's (typically a Node's) scale.

Constraints:

• id refs a Resource with the has_transform characteristic.

Field	Type	Description	Default
id	uint32		No default
value	Vector3Value		No default

SetSemanticVisibilityCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a node's semantic visibility.

Discussion: By default, all nodes are semantically visible. Semantically invisible nodes and their children are ignored by hit tests performed for accessibility.

Field	Type	Description	Default
node_id	uint32		No default
visible	bool		true

SetShapeCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets/clears a node's shape.

Constraints:

• node_id refs a Node with the has_shape characteristic.
• shape_id refs a Shape, or nothing.
• if this command causes the target to have both a Shape and a Material, then these must be compatible with each other (see README.md regarding "Shape/Material Compatibility").

Discussion: In order to be painted, a node requires both a Shape and a Material. Without a material, a node can still participate in hit-testing and clipping. Without a shape, a node cannot do any of the above.

Field	Type	Description	Default
node_id	uint32		No default
shape_id	uint32		No default

SetSizeCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets an object's size.

Constraints:

• id refs a resizeable object.
• some objects that support this command may have additional constraints (e.g. in some cases depth must be zero).

Field	Type	Description	Default
id	uint32		No default
value	Vector2Value		No default

SetStereoCameraProjectionCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a StereoCamera's projection matrices. This operation can only be applied to a StereoCamera.

Constraints:

• camera_id refs a StereoCamera.
• left_projection is the projection matrix for the left eye.
• right_projection is the projection matrix for the right eye.

These projection matrices may also contain a transform in camera space for their eye if needed.

Field	Type	Description	Default
camera_id	uint32		No default
left_projection	Matrix4Value		No default
right_projection	Matrix4Value		No default

SetTagCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets/clears a node's tag value.

A session can apply a tag value to any node to which it has access, including imported nodes. These tags are private to the session and cannot be read or modified by other sessions. When multiple sessions import the same node, each session will only observe its own tag values.

Hit test results for a session only include nodes which the session has tagged with a non-zero value. Therefore a session can use tag values to associate nodes with their functional purpose when picked.

Constraints:

• node_id refs a Node.
• tag_value is the tag value to assign, or 0 to remove the tag.

Field	Type	Description	Default
node_id	uint32		No default
tag_value	uint32		No default

SetTextureCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets/clears a material's texture.

Constraints:

• material_id refs a Material.
• texture_id refs a Image, ImagePipe2, or nothing.

If no texture is provided (i.e. texture_id is zero), a solid color is used. If a texture is provided, then the value sampled from the texture is multiplied by the color.

Field	Type	Description	Default
material_id	uint32		No default
texture_id	uint32		No default

SetTranslationCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets a Resource's (typically a Node's) translation.

Constraints:

• id refs a Resource with the has_transform characteristic.

Field	Type	Description	Default
id	uint32		No default
value	Vector3Value		No default

SetViewHolderBoundsColorCmd

Defined in fuchsia.ui.gfx/commands.fidl

Field	Type	Description	Default
view_holder_id	uint32		No default
color	ColorRgbValue		No default

SetViewPropertiesCmd

Defined in fuchsia.ui.gfx/commands.fidl

Sets the properties for a ViewHolder's attached View.

Constraints:

• view_holder_id refs a ViewHolder.

Field	Type	Description	Default
view_holder_id	uint32		No default
properties	ViewProperties		No default

ShapeNodeArgs

Defined in fuchsia.ui.gfx/nodes.fidl

Characteristics:

• has_parent
• has_shape
• has_material

Field	Type	Description	Default
unused	uint32		0

SizeChangeHintEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered in response to a size change hint from a parent node (SendSizeChangeHintCmd).

This event is delivered when the following conditions are true:

• The node has kSizeChangeEventMask set to an enabled state.
• A parent node has sent a SendSizeChangeHintCmd.

Subscribe to this event to receive information about how large textures you will need in the near future for your nodes. The canonical use case is to pre-allocate memory to avoid repeated re-allocations.

Field	Type	Description	Default
node_id	uint32		No default
width_change_factor	float32		No default
height_change_factor	float32		No default

StereoCameraArgs

Defined in fuchsia.ui.gfx/resources.fidl

A StereoCamera is a Camera that renders the scene in side-by-side stereo.

Any command which can be applied to a Camera can also be applied to a StereoCamera. Additional supported commands:

• SetStereoCameraProjection

Field	Type	Description	Default
scene_id	uint32	The scene that the camera is viewing.	No default

TakeSnapshotCmdDEPRECATED resource

Defined in fuchsia.ui.gfx/commands.fidl

Field	Type	Description	Default
node_id	uint32		No default
callback	SnapshotCallbackDEPRECATED		No default

VariableArgs

Defined in fuchsia.ui.gfx/resources.fidl

Describes a typed, client-modifiable value.

Field	Type	Description	Default
type	ValueType		No default
initial_value	Value		No default

Vector2Value

Defined in fuchsia.ui.gfx/types.fidl

A value that is specified explicitly by value if variable_id is zero, or is the value produced by the resource identified by variable_id, e.g. an animation or expression. In the latter case, the value produced by the resource must be a vec2, and value is ignored.

Field	Type	Description	Default
value	vec2		No default
variable_id	uint32		No default

Vector3Value

Defined in fuchsia.ui.gfx/types.fidl

A value that is specified explicitly by value if variable_id is zero, or is the value produced by the resource identified by variable_id, e.g. an animation or expression. In the latter case, the value produced by the resource must be a vec3, and value is ignored.

Field	Type	Description	Default
value	vec3		No default
variable_id	uint32		No default

Vector4Value

Defined in fuchsia.ui.gfx/types.fidl

A value that is specified explicitly by value if variable_id is zero, or is the value produced by the resource identified by variable_id, e.g. an animation or expression. In the latter case, the value produced by the resource must be a vec4, and value is ignored.

Field	Type	Description	Default
value	vec4		No default
variable_id	uint32		No default

ViewArgs resource

Defined in fuchsia.ui.gfx/resources.fidl

Represents the root of a subgraph within a larger scene graph. Nodes can be attached to the View as children, and these Nodes will have the Views' coordinate transform applied to their own, in addition to being clipped to the Views' bounding box. See ViewProperties.

Each View is linked to a paired ViewHolder via a shared token pair.

Usually the View and its associated ViewHolder exist in separate processes. By combining them, the UI for an entire system can be built using content contributed from many different processes.

Field	Type	Description	Default
token	fuchsia.ui.views/ViewToken		No default
debug_name	string?		No default

ViewArgs3 resource

Defined in fuchsia.ui.gfx/resources.fidl

Represents the root of a subgraph within a larger scene graph. Nodes can be attached to the View as children, and these Nodes will have the Views' coordinate transform applied to their own, in addition to being clipped to the Views' bounding box. See ViewProperties.

Each View is linked to a paired ViewHolder via a shared token pair.

Usually the View and its associated ViewHolder exist in separate processes. By combining them, the UI for an entire system can be built using content contributed from many different processes.

Clients self-identify their View with a ViewRef, which is a stable identifier that may be cloned and passed to other components in a feed-forward style. It is accompanied by a ViewRefControl, which Scenic uses to signal View destruction across the system; the ViewRefControl must be unique - do not clone it.

Field	Type	Description	Default
token	fuchsia.ui.views/ViewToken		No default
control_ref	fuchsia.ui.views/ViewRefControl	control_ref.reference must have default eventpair rights (i.e., with signaling), minus ZX_RIGHT_DUPLICATE.	No default
view_ref	fuchsia.ui.views/ViewRef	view_ref.reference must have basic rights (i.e., no signaling).	No default
debug_name	string?		No default

ViewAttachedToSceneEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered to a View's Session when the parent ViewHolder for the given View becomes a part of a Scene.

A ViewHolder is considered to be part of a Scene if there is an unbroken chain of parent-child relationships between the Scene node and the ViewHolder node.

Field	Type	Description	Default
view_id	uint32		No default
properties	ViewProperties		No default

ViewConnectedEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered to a ViewHolder's Session when its peer View is connected.

Field	Type	Description	Default
view_holder_id	uint32		No default

ViewDetachedFromSceneEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered to a View's Session when the parent ViewHolder for the given View is no longer part of a scene.

This can happen if the ViewHolder is detached directly from the scene, or if one of its parent nodes is.

A ViewHolder is considered to be part of a Scene if there is an unbroken chain of parent-child relationships between the Scene node and the ViewHolder node.

Field	Type	Description	Default
view_id	uint32		No default

ViewDisconnectedEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered to a ViewHolder's Session when its peer View is disconnected or destroyed.

If the View is destroyed before the connection is established, then this event will be delivered immediately when the ViewHolder attempts to connect.

Field	Type	Description	Default
view_holder_id	uint32		No default

ViewHolderArgs resource

Defined in fuchsia.ui.gfx/resources.fidl

Represents an attachment point for a subgraph within a larger scene graph. The ViewHolder can be attached to a Node as a child, and the contents of the linked View will become a child of the Node as well.

Each ViewHolder is linked to a paired View via a shared token pair.

Usually the ViewHolder and its associated View exist in separate processes. By combining them, the UI for an entire system can be built using content contributed from many different processes.

Field	Type	Description	Default
token	fuchsia.ui.views/ViewHolderToken		No default
debug_name	string?		No default

ViewHolderConnectedEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered to a View's Session when its peer ViewHolder is connected.

If the ViewHolder is destroyed before the connection is established, then this event will not be delivered.

Field	Type	Description	Default
view_id	uint32		No default

ViewHolderDisconnectedEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered to a View's Session when its peer ViewHolder is disconnected or destroyed.

If the ViewHolder is destroyed before the connection is established, then this event will be delivered immediately when the View attempts to connect.

Field	Type	Description	Default
view_id	uint32		No default

ViewProperties

Defined in fuchsia.ui.gfx/types.fidl

Represents the properties for a View.

Field	Type	Description	Default
bounding_box	BoundingBox	The View's bounding box extents can be defined as: { bounding_box.min, bounding_box.max } Content contained within the View is clipped to this bounding box.	No default
inset_from_min	vec3	insets_from_min and insets_from_max specify the distances between the view's bounding box and that of its parent. These properties are not strictly enforced by Scenic, but only used as hints for clients and other components that receives ViewProperties: View clients can assume that anything drawn outside of { bounding_box.min + inset_from_min, bounding_box.max - inset_from_max } may be obscured by an ancestor view. The reason for obscuring, and the rules surrounding it, is specific to each product.	No default
inset_from_max	vec3		No default
focus_change	bool	Whether the View can receive a focus event; default is true. When false, and this View is eligible to receive a focus event, no focus/unfocus event is actually sent to any View.	true
downward_input	bool	Whether the View allows geometrically underlying Views to receive input; default is true. When false, Scenic does not send input events to underlying Views.	true

ViewPropertiesChangedEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered when the parent ViewHolder for the given View makes a change to the View's properties.

Field	Type	Description	Default
view_id	uint32		No default
properties	ViewProperties		No default

ViewState

Defined in fuchsia.ui.gfx/types.fidl

Represents the state of a View in Scenic.

Field	Type	Description	Default
is_rendering	bool	Whether the View is rendering. Default is false. Delivered to the View's corresponding ViewHolder after the View's first frame render request.	No default

ViewStateChangedEvent

Defined in fuchsia.ui.gfx/events.fidl

Delivered to a ViewHolder's Session when its peer View's state has changed.

Field	Type	Description	Default
view_holder_id	uint32		No default
state	ViewState		No default

mat4

Defined in fuchsia.ui.gfx/types.fidl

Field	Type	Description	Default
matrix	float32[16]	Column major order.	No default

vec2

Defined in fuchsia.ui.gfx/types.fidl

Field	Type	Description	Default
x	float32		No default
y	float32		No default

vec3

Defined in fuchsia.ui.gfx/types.fidl

Field	Type	Description	Default
x	float32		No default
y	float32		No default
z	float32		No default

vec4

Defined in fuchsia.ui.gfx/types.fidl

Field	Type	Description	Default
x	float32		No default
y	float32		No default
z	float32		No default
w	float32		No default

ENUMS

HitTestBehavior strict

Type: uint32

Defined in fuchsia.ui.gfx/types.fidl

Describes how nodes interact with hit testings.

Name	Value	Description
kDefault	0	Apply hit testing to the node's content, its parts, and its children.
kSuppress	1	Suppress hit testing of the node and everything it contains.

ImportSpec strict

Type: uint32

Defined in fuchsia.ui.gfx/resources.fidl

Describes an exported resource that is to be imported by an ImportResourceCmd.

NOTE: Currently just an enum of importable resource types, but may later be expanded to express concepts like "meshes with a particular vertex format".

Name	Value	Description
NODE	0

MeshIndexFormat strict

Type: uint32

Defined in fuchsia.ui.gfx/commands.fidl

Set a mesh's indices and vertices.

mesh_id refs the Mesh to be updated. index_buffer_id refs a Buffer that contains the mesh indices. index_format defines how the index buffer data is to be interpreted. index_offset number of bytes from the start of the index Buffer. index_count number of indices. vertex_buffer_id refs a Buffer that contains the mesh vertices. vertex_format defines how the vertex buffer data is to be interpreted. vertex_offset number of bytes from the start of the vertex Buffer. vertex_count number of vertices. bounding_box must contain all vertices within the specified range.

The MeshVertexFormat defines which per-vertex attributes are provided by the mesh, and the size of each attribute (and therefore the size of each vertex). The attributes are ordered within the vertex in the same order that they appear within the MeshVertexFormat struct. For example, if the values are kVector3, kNone and kVector2, then:

• each vertex has a position and UV-coordinates, but no surface normal.
• the 3D position occupies bytes 0-11 (3 dimensions * 4 bytes per float32).
• the UV coords occupy bytes 12-19, since no surface normal is provided.

Name	Value	Description
kUint16	1
kUint32	2

RenderFrequency strict

Type: uint32

Defined in fuchsia.ui.gfx/renderer.fidl

Name	Value	Description
WHEN_REQUESTED	0
CONTINUOUSLY	1

ShadowTechnique strict

Type: uint32

Defined in fuchsia.ui.gfx/renderer.fidl

Represents the shadow algorithm that the Renderer should use when lighting the scene.

Name	Value	Description
UNSHADOWED	0	No shadows.
SCREEN_SPACE	1	Default. Screen-space, depth-buffer based shadows; SSDO-ish.
SHADOW_MAP	2	Basic shadow map.
MOMENT_SHADOW_MAP	3	Moment shadow map (see http:///momentsingraphics.de).
STENCIL_SHADOW_VOLUME	4	Stencil shadow volume.

ValueType strict

Type: uint32

Defined in fuchsia.ui.gfx/types.fidl

Name	Value	Description
kNone	0
kVector1	1
kVector2	2
kVector3	3
kVector4	4
kMatrix4	5
kColorRgb	6
kColorRgba	7
kQuaternion	8
kFactoredTransform	9

UNIONS

Command strict resource

Defined in fuchsia.ui.gfx/commands.fidl

Commands that are used to modify the state of a Session.

<tr id="Command.scene_add_ambientlight"> <tr id="Command.scene_add_directionallight"> <tr id="Command.scene_add_pointlight">

Ordinal	Variant	Type	Description
1	create_resource	CreateResourceCmd
2	release_resource	ReleaseResourceCmd
3	export_resource	ExportResourceCmdDeprecated
4	import_resource	ImportResourceCmdDeprecated
5	set_tag	SetTagCmd	Tagging commands.
6	detach	DetachCmd	Grouping commands.
7	set_translation	SetTranslationCmd	Spatial commands.
8	set_scale	SetScaleCmd
9	set_rotation	SetRotationCmd
10	set_anchor	SetAnchorCmd
11	set_size	SetSizeCmd
12	set_opacity	SetOpacityCmd
13	send_size_change_hint_hack	SendSizeChangeHintCmdHACK
14	add_child	AddChildCmd	Node-specific commands.
15	add_part	AddPartCmd	re-parenting?
16	detach_children	DetachChildrenCmd
17	set_shape	SetShapeCmd
18	set_material	SetMaterialCmd
19	set_clip	SetClipCmd
20	set_hit_test_behavior	SetHitTestBehaviorCmd
21	set_view_properties	SetViewPropertiesCmd
22	take_snapshot_cmd	TakeSnapshotCmdDEPRECATED
23	set_camera	SetCameraCmd	Camera and lighting commands.
24	set_camera_transform	SetCameraTransformCmd
25	set_camera_projection	SetCameraProjectionCmd
26	set_stereo_camera_projection	SetStereoCameraProjectionCmd
27	set_camera_pose_buffer	SetCameraPoseBufferCmd
28	set_light_color	SetLightColorCmd
29	set_light_direction	SetLightDirectionCmd
30	add_light	AddLightCmd
31	detach_light	DetachLightCmd
32	detach_lights	DetachLightsCmd
33	set_texture	SetTextureCmd
34	set_color	SetColorCmd
35	bind_mesh_buffers	BindMeshBuffersCmd	Mesh commands.
36	add_layer	AddLayerCmd	Layer and renderer commands.
37	remove_layer	RemoveLayerCmd
38	remove_all_layers	RemoveAllLayersCmd
39	set_layer_stack	SetLayerStackCmd
40	set_renderer	SetRendererCmd
41	set_renderer_param	SetRendererParamCmd
42	set_event_mask	SetEventMaskCmd	Events.
43	set_label	SetLabelCmd	Diagnostic commands.
44	set_disable_clipping	SetDisableClippingCmd	Debugging commands.
45	set_import_focus	SetImportFocusCmdDEPRECATED
46	set_clip_planes	SetClipPlanesCmd
47	set_point_light_position	SetPointLightPositionCmd
48	set_point_lightfalloff	SetPointLightFalloffCmd
<h3 id="Command.scene_add_ambientlight" class="add-link hide-from-toc">49	scene_add_ambientlight	SceneAddAmbientLightCmd
<h3 id="Command.scene_add_directionallight" class="add-link hide-from-toc">50	scene_add_directionallight	SceneAddDirectionalLightCmd
<h3 id="Command.scene_add_pointlight" class="add-link hide-from-toc">51	scene_add_point_light	SceneAddPointLightCmd
52	set_display_color_conversion	SetDisplayColorConversionCmdHACK
53	set_display_rotation	SetDisplayRotationCmdHACK
54	set_enable_view_debug_bounds	SetEnableDebugViewBoundsCmd
55	set_view_holder_bounds_color	SetViewHolderBoundsColorCmd
56	set_camera_clip_space_transform	SetCameraClipSpaceTransformCmd
57	set_display_minimum_rgb	SetDisplayMinimumRgbCmdHACK
58	set_semantic_visibility	SetSemanticVisibilityCmd

Event strict

Defined in fuchsia.ui.gfx/events.fidl

These are all of the types of events which can be reported by a Session. Use SetEventMaskCmd to enable event delivery for a resource.

Removed: 17 Deprecated: 13

Ordinal	Variant	Type	Description
1	metrics	MetricsEvent	Events which are controlled by a mask.
2	size_change_hint	SizeChangeHintEvent
3	import_unbound	ImportUnboundEvent	Events which are always delivered, regardless of mask.
4	view_connected	ViewConnectedEvent
5	view_disconnected	ViewDisconnectedEvent
6	view_holder_disconnected	ViewHolderDisconnectedEvent
7	view_attached_to_scene	ViewAttachedToSceneEvent
8	view_detached_from_scene	ViewDetachedFromSceneEvent
9	view_properties_changed	ViewPropertiesChangedEvent
10	view_state_changed	ViewStateChangedEvent
11	view_holder_connected	ViewHolderConnectedEvent

RendererParam strict

Defined in fuchsia.ui.gfx/renderer.fidl

These are all of the types of parameters that can be set to configure a Renderer.

Removed: 17 Deprecated: 13

Ordinal	Variant	Type	Description
1	shadow_technique	ShadowTechnique
2	reserved	RenderFrequency	DEPRECATED
3	enable_debugging	bool

ResourceArgs strict resource

Defined in fuchsia.ui.gfx/resources.fidl

These are all of the types of resources that can be created within a Session. Add new fields only to the bottom of the list.

Removed: 17 Deprecated: 13

Ordinal	Variant	Type	Description
1	memory	MemoryArgs
2	image	ImageArgs
4	buffer	BufferArgs
5	view	ViewArgs
6	view_holder	ViewHolderArgs
7	rectangle	RectangleArgs
8	rounded_rectangle	RoundedRectangleArgs
9	circle	CircleArgs
10	mesh	MeshArgs
11	shape_node	ShapeNodeArgs
12	clip_node	ClipNodeArgs
13	entity_node	EntityNodeArgs
14	opacity_node	OpacityNodeArgsHACK
15	material	MaterialArgs
16	compositor	CompositorArgs
17	display_compositor	DisplayCompositorArgs
19	layer_stack	LayerStackArgs
20	layer	LayerArgs
21	scene	SceneArgs
22	camera	CameraArgs
23	stereo_camera	StereoCameraArgs
24	renderer	RendererArgs
25	ambient_light	AmbientLightArgs
26	directional_light	DirectionalLightArgs
27	variable	VariableArgs
28	point_light	PointLightArgs
31	view3	ViewArgs3
32	image_pipe2	ImagePipe2Args
33	image2	ImageArgs2
34	image3	ImageArgs3

Value strict

Defined in fuchsia.ui.gfx/types.fidl

Removed: 17 Deprecated: 13

Ordinal	Variant	Type	Description
1	vector1	float32
2	vector2	vec2
3	vector3	vec3
4	vector4	vec4
5	matrix4x4	mat4
6	color_rgba	ColorRgba
7	color_rgb	ColorRgb
8	degrees	float32	Degrees of counter-clockwise rotation in the XY plane.
9	quaternion	Quaternion
10	transform	FactoredTransform
11	variable_id	uint32	ID of a value-producing resource (an animation or an expression). The type of this value matches the type produced by the named resource.

CONSTANTS

Name	Value	Type	Description
kLabelMaxLength	32	uint32	Maximum length for a resource label. Removed: 17 Deprecated: 13
kMetricsEventMask	1	uint32	Reports metrics information. This event type is only reported for node resources. Removed: 17 Deprecated: 13
kSizeChangeHintEventMask	2	uint32	Removed: 17 Deprecated: 13