graphics: rework IComposer
Similar to IAllocator, introduce IComposerClient to manage resources.
Rework the interface such that most state changing calls are batched in a
"command buffer" and execute together. The goal is to reduce the number
of IPC calls needed to set up the composer.
Test: builds and boots
Change-Id: I324009243234c4d2482ca0ef2591377b11530fc9
diff --git a/graphics/composer/2.1/IComposerClient.hal b/graphics/composer/2.1/IComposerClient.hal
new file mode 100644
index 0000000..1a82215
--- /dev/null
+++ b/graphics/composer/2.1/IComposerClient.hal
@@ -0,0 +1,1118 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.graphics.composer@2.1;
+
+import android.hardware.graphics.common@1.0;
+import IComposerCallback;
+
+interface IComposerClient {
+ /* Display attributes queryable through getDisplayAttribute. */
+ enum Attribute : int32_t {
+ INVALID = 0,
+
+ /* Dimensions in pixels */
+ WIDTH = 1,
+ HEIGHT = 2,
+
+ /* Vsync period in nanoseconds */
+ VSYNC_PERIOD = 3,
+
+ /*
+ * Dots per thousand inches (DPI * 1000). Scaling by 1000 allows these
+ * numbers to be stored in an int32_t without losing too much
+ * precision. If the DPI for a configuration is unavailable or is
+ * considered unreliable, the device may return UNSUPPORTED instead.
+ */
+ DPI_X = 4,
+ DPI_Y = 5,
+ };
+
+ /* Display requests returned by getDisplayRequests. */
+ enum DisplayRequest : uint32_t {
+ /*
+ * Instructs the client to provide a new client target buffer, even if
+ * no layers are marked for client composition.
+ */
+ FLIP_CLIENT_TARGET = 1 << 0,
+
+ /*
+ * Instructs the client to write the result of client composition
+ * directly into the virtual display output buffer. If any of the
+ * layers are not marked as Composition::CLIENT or the given display
+ * is not a virtual display, this request has no effect.
+ */
+ WRITE_CLIENT_TARGET_TO_OUTPUT = 1 << 1,
+ };
+
+ /* Layer requests returned from getDisplayRequests. */
+ enum LayerRequest : uint32_t {
+ /*
+ * The client must clear its target with transparent pixels where
+ * this layer would be. The client may ignore this request if the
+ * layer must be blended.
+ */
+ CLEAR_CLIENT_TARGET = 1 << 0,
+ };
+
+ /* Power modes for use with setPowerMode. */
+ enum PowerMode : int32_t {
+ /* The display is fully off (blanked). */
+ OFF = 0,
+
+ /*
+ * These are optional low power modes. getDozeSupport may be called to
+ * determine whether a given display supports these modes.
+ */
+
+ /*
+ * The display is turned on and configured in a low power state that
+ * is suitable for presenting ambient information to the user,
+ * possibly with lower fidelity than ON, but with greater efficiency.
+ */
+ DOZE = 1,
+
+ /*
+ * The display is configured as in DOZE but may stop applying display
+ * updates from the client. This is effectively a hint to the device
+ * that drawing to the display has been suspended and that the the
+ * device must remain on in a low power state and continue
+ * displaying its current contents indefinitely until the power mode
+ * changes.
+ *
+ * This mode may also be used as a signal to enable hardware-based
+ * doze functionality. In this case, the device is free to take over
+ * the display and manage it autonomously to implement a low power
+ * always-on display.
+ */
+ DOZE_SUSPEND = 3,
+
+ /* The display is fully on. */
+ ON = 2,
+ };
+
+ /* Vsync values passed to setVsyncEnabled. */
+ enum Vsync : int32_t {
+ INVALID = 0,
+
+ /* Enable vsync. */
+ ENABLE = 1,
+
+ /* Disable vsync. */
+ DISABLE = 2,
+ };
+
+ /* Blend modes, settable per layer. */
+ enum BlendMode : int32_t {
+ INVALID = 0,
+
+ /* colorOut = colorSrc */
+ NONE = 1,
+
+ /* colorOut = colorSrc + colorDst * (1 - alphaSrc) */
+ PREMULTIPLIED = 2,
+
+ /* colorOut = colorSrc * alphaSrc + colorDst * (1 - alphaSrc) */
+ COVERAGE = 3,
+ };
+
+ /* Possible composition types for a given layer. */
+ enum Composition : int32_t {
+ INVALID = 0,
+
+ /*
+ * The client must composite this layer into the client target buffer
+ * (provided to the device through setClientTarget).
+ *
+ * The device must not request any composition type changes for layers
+ * of this type.
+ */
+ CLIENT = 1,
+
+ /*
+ * The device must handle the composition of this layer through a
+ * hardware overlay or other similar means.
+ *
+ * Upon validateDisplay, the device may request a change from this
+ * type to CLIENT.
+ */
+ DEVICE = 2,
+
+ /*
+ * The device must render this layer using the color set through
+ * setLayerColor. If this functionality is not supported on a layer
+ * that the client sets to SOLID_COLOR, the device must request that
+ * the composition type of that layer is changed to CLIENT upon the
+ * next call to validateDisplay.
+ *
+ * Upon validateDisplay, the device may request a change from this
+ * type to CLIENT.
+ */
+ SOLID_COLOR = 3,
+
+ /*
+ * Similar to DEVICE, but the position of this layer may also be set
+ * asynchronously through setCursorPosition. If this functionality is
+ * not supported on a layer that the client sets to CURSOR, the device
+ * must request that the composition type of that layer is changed to
+ * CLIENT upon the next call to validateDisplay.
+ *
+ * Upon validateDisplay, the device may request a change from this
+ * type to either DEVICE or CLIENT. Changing to DEVICE will prevent
+ * the use of setCursorPosition but still permit the device to
+ * composite the layer.
+ */
+ CURSOR = 4,
+
+ /*
+ * The device must handle the composition of this layer, as well as
+ * its buffer updates and content synchronization. Only supported on
+ * devices which provide Capability::SIDEBAND_STREAM.
+ *
+ * Upon validateDisplay, the device may request a change from this
+ * type to either DEVICE or CLIENT, but it is unlikely that content
+ * will display correctly in these cases.
+ */
+ SIDEBAND = 5,
+ };
+
+ /* Display types returned by getDisplayType. */
+ enum DisplayType : int32_t {
+ INVALID = 0,
+
+ /*
+ * All physical displays, including both internal displays and
+ * hotpluggable external displays.
+ */
+ PHYSICAL = 1,
+
+ /* Virtual displays created by createVirtualDisplay. */
+ VIRTUAL = 2,
+ };
+
+ /* Special index values (always negative) for command queue commands. */
+ enum HandleIndex : int32_t {
+ /* No handle */
+ EMPTY = -1,
+
+ /* Use cached handle */
+ CACHED = -2,
+ };
+
+ struct Rect {
+ int32_t left;
+ int32_t top;
+ int32_t right;
+ int32_t bottom;
+ };
+
+ struct FRect {
+ float left;
+ float top;
+ float right;
+ float bottom;
+ };
+
+ struct Color {
+ uint8_t r;
+ uint8_t g;
+ uint8_t b;
+ uint8_t a;
+ };
+
+ /*
+ * Provides a IComposerCallback object for the device to call.
+ *
+ * This function must be called only once.
+ *
+ * @param callback is the IComposerCallback object.
+ */
+ registerCallback(IComposerCallback callback);
+
+ /*
+ * Returns the maximum number of virtual displays supported by this device
+ * (which may be 0). The client must not attempt to create more than this
+ * many virtual displays on this device. This number must not change for
+ * the lifetime of the device.
+ *
+ * @return count is the maximum number of virtual displays supported.
+ */
+ getMaxVirtualDisplayCount() generates (uint32_t count);
+
+ /*
+ * Creates a new virtual display with the given width and height. The
+ * format passed into this function is the default format requested by the
+ * consumer of the virtual display output buffers.
+ *
+ * The display must be assumed to be on from the time the first frame is
+ * presented until the display is destroyed.
+ *
+ * @param width is the width in pixels.
+ * @param height is the height in pixels.
+ * @param formatHint is the default output buffer format selected by
+ * the consumer.
+ * @param outputBufferSlotCount is the number of output buffer slots to be
+ * reserved.
+ * @return error is NONE upon success. Otherwise,
+ * UNSUPPORTED when the width or height is too large for the
+ * device to be able to create a virtual display.
+ * NO_RESOURCES when the device is unable to create a new virtual
+ * display at this time.
+ * @return display is the newly-created virtual display.
+ * @return format is the format of the buffer the device will produce.
+ */
+ createVirtualDisplay(uint32_t width,
+ uint32_t height,
+ PixelFormat formatHint,
+ uint32_t outputBufferSlotCount)
+ generates (Error error,
+ Display display,
+ PixelFormat format);
+
+ /*
+ * Destroys a virtual display. After this call all resources consumed by
+ * this display may be freed by the device and any operations performed on
+ * this display must fail.
+ *
+ * @param display is the virtual display to destroy.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * BAD_PARAMETER when the display handle which was passed in does
+ * not refer to a virtual display.
+ */
+ destroyVirtualDisplay(Display display) generates (Error error);
+
+ /*
+ * Creates a new layer on the given display.
+ *
+ * @param display is the display on which to create the layer.
+ * @param bufferSlotCount is the number of buffer slot to be reserved.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * NO_RESOURCES when the device was unable to create a layer this
+ * time.
+ * @return layer is the handle of the new layer.
+ */
+ createLayer(Display display,
+ uint32_t bufferSlotCount)
+ generates (Error error,
+ Layer layer);
+
+ /*
+ * Destroys the given layer.
+ *
+ * @param display is the display on which the layer was created.
+ * @param layer is the layer to destroy.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * BAD_LAYER when an invalid layer handle was passed in.
+ */
+ destroyLayer(Display display, Layer layer) generates (Error error);
+
+ /*
+ * Retrieves which display configuration is currently active.
+ *
+ * If no display configuration is currently active, this function must
+ * return BAD_CONFIG. It is the responsibility of the client to call
+ * setActiveConfig with a valid configuration before attempting to present
+ * anything on the display.
+ *
+ * @param display is the display to which the active config is queried.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * BAD_CONFIG when no configuration is currently active.
+ * @return config is the currently active display configuration.
+ */
+ getActiveConfig(Display display) generates (Error error, Config config);
+
+ /*
+ * Returns whether a client target with the given properties can be
+ * handled by the device.
+ *
+ * This function must return true for a client target with width and
+ * height equal to the active display configuration dimensions,
+ * PixelFormat::RGBA_8888, and Dataspace::UNKNOWN. It is not required to
+ * return true for any other configuration.
+ *
+ * @param display is the display to query.
+ * @param width is the client target width in pixels.
+ * @param height is the client target height in pixels.
+ * @param format is the client target format.
+ * @param dataspace is the client target dataspace, as described in
+ * setLayerDataspace.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * UNSUPPORTED when the given configuration is not supported.
+ */
+ getClientTargetSupport(Display display,
+ uint32_t width,
+ uint32_t height,
+ PixelFormat format,
+ Dataspace dataspace)
+ generates (Error error);
+
+ /*
+ * Returns the color modes supported on this display.
+ *
+ * All devices must support at least ColorMode::NATIVE.
+ *
+ * @param display is the display to query.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * @return modes is an array of color modes.
+ */
+ getColorModes(Display display)
+ generates (Error error,
+ vec<ColorMode> modes);
+
+ /*
+ * Returns a display attribute value for a particular display
+ * configuration.
+ *
+ * @param display is the display to query.
+ * @param config is the display configuration for which to return
+ * attribute values.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * BAD_CONFIG when config does not name a valid configuration for
+ * this display.
+ * BAD_PARAMETER when attribute is unrecognized.
+ * UNSUPPORTED when attribute cannot be queried for the config.
+ * @return value is the value of the attribute.
+ */
+ getDisplayAttribute(Display display,
+ Config config,
+ Attribute attribute)
+ generates (Error error,
+ int32_t value);
+
+ /*
+ * Returns handles for all of the valid display configurations on this
+ * display.
+ *
+ * @param display is the display to query.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * @return configs is an array of configuration handles.
+ */
+ getDisplayConfigs(Display display)
+ generates (Error error,
+ vec<Config> configs);
+
+ /*
+ * Returns a human-readable version of the display's name.
+ *
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * @return name is the name of the display.
+ */
+ getDisplayName(Display display) generates (Error error, string name);
+
+ /*
+ * Returns whether the given display is a physical or virtual display.
+ *
+ * @param display is the display to query.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * @return type is the type of the display.
+ */
+ getDisplayType(Display display) generates (Error error, DisplayType type);
+
+ /*
+ * Returns whether the given display supports PowerMode::DOZE and
+ * PowerMode::DOZE_SUSPEND. DOZE_SUSPEND may not provide any benefit over
+ * DOZE (see the definition of PowerMode for more information), but if
+ * both DOZE and DOZE_SUSPEND are no different from PowerMode::ON, the
+ * device must not claim support.
+ *
+ * @param display is the display to query.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * @return support is true only when the display supports doze modes.
+ */
+ getDozeSupport(Display display) generates (Error error, bool support);
+
+ /*
+ * Returns the high dynamic range (HDR) capabilities of the given display,
+ * which are invariant with regard to the active configuration.
+ *
+ * Displays which are not HDR-capable must return no types.
+ *
+ * @param display is the display to query.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * @return types is an array of HDR types, may have 0 elements if the
+ * display is not HDR-capable.
+ * @return maxLuminance is the desired content maximum luminance for this
+ * display in cd/m^2.
+ * @return maxAverageLuminance - the desired content maximum frame-average
+ * luminance for this display in cd/m^2.
+ * @return minLuminance is the desired content minimum luminance for this
+ * display in cd/m^2.
+ */
+ getHdrCapabilities(Display display)
+ generates (Error error,
+ vec<Hdr> types,
+ float maxLuminance,
+ float maxAverageLuminance,
+ float minLuminance);
+
+ /*
+ * Set the number of client target slots to be reserved.
+ *
+ * @param display is the display to which the slots are reserved.
+ * @param clientTargetSlotCount is the slot count for client targets.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * NO_RESOURCES when unable to reserve the slots.
+ */
+ setClientTargetSlotCount(Display display,
+ uint32_t clientTargetSlotCount)
+ generates (Error error);
+
+ /*
+ * Sets the active configuration for this display. Upon returning, the
+ * given display configuration must be active and remain so until either
+ * this function is called again or the display is disconnected.
+ *
+ * @param display is the display to which the active config is set.
+ * @param config is the new display configuration.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * BAD_CONFIG when the configuration handle passed in is not valid
+ * for this display.
+ */
+ setActiveConfig(Display display, Config config) generates (Error error);
+
+ /*
+ * Sets the color mode of the given display.
+ *
+ * Upon returning from this function, the color mode change must have
+ * fully taken effect.
+ *
+ * All devices must support at least ColorMode::NATIVE, and displays are
+ * assumed to be in this mode upon hotplug.
+ *
+ * @param display is the display to which the color mode is set.
+ * @param mode is the mode to set to.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * BAD_PARAMETER when mode is not a valid color mode.
+ * UNSUPPORTED when mode is not supported on this display.
+ */
+ setColorMode(Display display, ColorMode mode) generates (Error error);
+
+ /*
+ * Sets the power mode of the given display. The transition must be
+ * complete when this function returns. It is valid to call this function
+ * multiple times with the same power mode.
+ *
+ * All displays must support PowerMode::ON and PowerMode::OFF. Whether a
+ * display supports PowerMode::DOZE or PowerMode::DOZE_SUSPEND may be
+ * queried using getDozeSupport.
+ *
+ * @param display is the display to which the power mode is set.
+ * @param mode is the new power mode.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * BAD_PARAMETER when mode was not a valid power mode.
+ * UNSUPPORTED when mode is not supported on this display.
+ */
+ setPowerMode(Display display, PowerMode mode) generates (Error error);
+
+ /*
+ * Enables or disables the vsync signal for the given display. Virtual
+ * displays never generate vsync callbacks, and any attempt to enable
+ * vsync for a virtual display though this function must succeed and have
+ * no other effect.
+ *
+ * @param display is the display to which the vsync mode is set.
+ * @param enabled indicates whether to enable or disable vsync
+ * @return error is NONE upon success. Otherwise,
+ * BAD_DISPLAY when an invalid display handle was passed in.
+ * BAD_PARAMETER when enabled was an invalid value.
+ */
+ setVsyncEnabled(Display display, Vsync enabled) generates (Error error);
+
+ /*
+ * Sets the input command message queue.
+ *
+ * @param descriptor is the descriptor of the input command message queue.
+ * @return error is NONE upon success. Otherwise,
+ * NO_RESOURCES when failed to set the queue temporarily.
+ */
+ setInputCommandQueue(MQDescriptorSync descriptor)
+ generates (Error error);
+
+ /*
+ * Gets the output command message queue.
+ *
+ * This function must only be called inside executeCommands closure.
+ *
+ * @return error is NONE upon success. Otherwise,
+ * NO_RESOURCES when failed to get the queue temporarily.
+ * @return descriptor is the descriptor of the output command queue.
+ */
+ getOutputCommandQueue()
+ generates (Error error,
+ MQDescriptorSync descriptor);
+
+ /*
+ * Executes commands from the input command message queue. Return values
+ * generated by the input commands are written to the output command
+ * message queue in the form of value commands.
+ *
+ * @param inLength is the length of input commands.
+ * @param inHandles is an array of handles referenced by the input
+ * commands.
+ * @return error is NONE upon success. Otherwise,
+ * BAD_PARAMETER when inLength is not equal to the length of
+ * commands in the input command message queue.
+ * NO_RESOURCES when the output command message queue was not
+ * properly drained.
+ * @param outQueueChanged indicates whether the output command message
+ * queue has changed.
+ * @param outLength is the length of output commands.
+ * @param outHandles is an array of handles referenced by the output
+ * commands.
+ */
+ executeCommands(uint32_t inLength,
+ vec<handle> inHandles)
+ generates (Error error,
+ bool outQueueChanged,
+ uint32_t outLength,
+ vec<handle> outHandles);
+
+ /*
+ * SELECT_DISPLAY has this pseudo prototype
+ *
+ * selectDisplay(Display display);
+ *
+ * Selects the current display implied by all other commands.
+ *
+ * @param display is the newly selected display.
+ *
+ *
+ * SELECT_LAYER has this pseudo prototype
+ *
+ * selectLayer(Layer layer);
+ *
+ * Selects the current layer implied by all implicit layer commands.
+ *
+ * @param layer is the newly selected layer.
+ *
+ *
+ * SET_ERROR has this pseudo prototype
+ *
+ * setError(uint32_t location, Error error);
+ *
+ * Indicates an error generated by a command.
+ *
+ * @param location is the offset of the command in the input command
+ * message queue.
+ * @param error is the error generated by the command.
+ *
+ *
+ * SET_CHANGED_COMPOSITION_TYPES has this pseudo prototype
+ *
+ * setChangedCompositionTypes(vec<Layer> layers,
+ * vec<Composition> types);
+ *
+ * Sets the layers for which the device requires a different composition
+ * type than had been set prior to the last call to VALIDATE_DISPLAY. The
+ * client must either update its state with these types and call
+ * ACCEPT_DISPLAY_CHANGES, or must set new types and attempt to validate
+ * the display again.
+ *
+ * @param layers is an array of layer handles.
+ * @param types is an array of composition types, each corresponding to
+ * an element of layers.
+ *
+ *
+ * SET_DISPLAY_REQUESTS has this pseudo prototype
+ *
+ * setDisplayRequests(uint32_t displayRequestMask,
+ * vec<Layer> layers,
+ * vec<uint32_t> layerRequestMasks);
+ *
+ * Sets the display requests and the layer requests required for the last
+ * validated configuration.
+ *
+ * Display requests provide information about how the client must handle
+ * the client target. Layer requests provide information about how the
+ * client must handle an individual layer.
+ *
+ * @param displayRequestMask is the display requests for the current
+ * validated state.
+ * @param layers is an array of layers which all have at least one
+ * request.
+ * @param layerRequestMasks is the requests corresponding to each element
+ * of layers.
+ *
+ *
+ * SET_PRESENT_FENCE has this pseudo prototype
+ *
+ * setPresentFence(int32_t presentFenceIndex);
+ *
+ * Sets the present fence as a result of PRESENT_DISPLAY. For physical
+ * displays, this fence must be signaled at the vsync when the result
+ * of composition of this frame starts to appear (for video-mode panels)
+ * or starts to transfer to panel memory (for command-mode panels). For
+ * virtual displays, this fence must be signaled when writes to the output
+ * buffer have completed and it is safe to read from it.
+ *
+ * @param presentFenceIndex is an index into outHandles array.
+ *
+ *
+ * SET_RELEASE_FENCES has this pseudo prototype
+ *
+ * setReleaseFences(vec<Layer> layers,
+ * vec<int32_t> releaseFenceIndices);
+ *
+ * Sets the release fences for device layers on this display which will
+ * receive new buffer contents this frame.
+ *
+ * A release fence is a file descriptor referring to a sync fence object
+ * which must be signaled after the device has finished reading from the
+ * buffer presented in the prior frame. This indicates that it is safe to
+ * start writing to the buffer again. If a given layer's fence is not
+ * returned from this function, it must be assumed that the buffer
+ * presented on the previous frame is ready to be written.
+ *
+ * The fences returned by this function must be unique for each layer
+ * (even if they point to the same underlying sync object).
+ *
+ * @param layers is an array of layer handles.
+ * @param releaseFenceIndices are indices into outHandles array, each
+ * corresponding to an element of layers.
+ *
+ *
+ * SET_COLOR_TRANSFORM has this pseudo prototype
+ *
+ * setColorTransform(float[16] matrix,
+ * ColorTransform hint);
+ *
+ * Sets a color transform which will be applied after composition.
+ *
+ * If hint is not ColorTransform::ARBITRARY, then the device may use the
+ * hint to apply the desired color transform instead of using the color
+ * matrix directly.
+ *
+ * If the device is not capable of either using the hint or the matrix to
+ * apply the desired color transform, it must force all layers to client
+ * composition during VALIDATE_DISPLAY.
+ *
+ * If IComposer::Capability::SKIP_CLIENT_COLOR_TRANSFORM is present, then
+ * the client must never apply the color transform during client
+ * composition, even if all layers are being composed by the client.
+ *
+ * The matrix provided is an affine color transformation of the following
+ * form:
+ *
+ * |r.r r.g r.b 0|
+ * |g.r g.g g.b 0|
+ * |b.r b.g b.b 0|
+ * |Tr Tg Tb 1|
+ *
+ * This matrix must be provided in row-major form:
+ *
+ * {r.r, r.g, r.b, 0, g.r, ...}.
+ *
+ * Given a matrix of this form and an input color [R_in, G_in, B_in], the
+ * output color [R_out, G_out, B_out] will be:
+ *
+ * R_out = R_in * r.r + G_in * g.r + B_in * b.r + Tr
+ * G_out = R_in * r.g + G_in * g.g + B_in * b.g + Tg
+ * B_out = R_in * r.b + G_in * g.b + B_in * b.b + Tb
+ *
+ * @param matrix is a 4x4 transform matrix (16 floats) as described above.
+ * @param hint is a hint value which may be used instead of the given
+ * matrix unless it is ColorTransform::ARBITRARY.
+ *
+ *
+ * SET_CLIENT_TARGET has this pseudo prototype
+ *
+ * setClientTarget(uint32_t targetSlot,
+ * int32_t targetIndex,
+ * int32_t acquireFenceIndex,
+ * Dataspace dataspace,
+ * vec<Rect> damage);
+ *
+ * Sets the buffer handle which will receive the output of client
+ * composition. Layers marked as Composition::CLIENT must be composited
+ * into this buffer prior to the call to PRESENT_DISPLAY, and layers not
+ * marked as Composition::CLIENT must be composited with this buffer by
+ * the device.
+ *
+ * The buffer handle provided may be empty if no layers are being
+ * composited by the client. This must not result in an error (unless an
+ * invalid display handle is also provided).
+ *
+ * Also provides a file descriptor referring to an acquire sync fence
+ * object, which must be signaled when it is safe to read from the client
+ * target buffer. If it is already safe to read from this buffer, an
+ * empty handle may be passed instead.
+ *
+ * For more about dataspaces, see SET_LAYER_DATASPACE.
+ *
+ * The damage parameter describes a surface damage region as defined in
+ * the description of SET_LAYER_SURFACE_DAMAGE.
+ *
+ * Will be called before PRESENT_DISPLAY if any of the layers are marked
+ * as Composition::CLIENT. If no layers are so marked, then it is not
+ * necessary to call this function. It is not necessary to call
+ * validateDisplay after changing the target through this function.
+ *
+ * @param targetSlot is the client target buffer slot to use.
+ * @param targetIndex is an index into inHandles for the new target
+ * buffer.
+ * @param acquireFenceIndex is an index into inHandles for a sync fence
+ * file descriptor as described above.
+ * @param dataspace is the dataspace of the buffer, as described in
+ * setLayerDataspace.
+ * @param damage is the surface damage region.
+ *
+ *
+ * SET_OUTPUT_BUFFER has this pseudo prototype
+ *
+ * setOutputBuffer(uint32_t bufferSlot,
+ * int32_t bufferIndex,
+ * int32_t releaseFenceIndex);
+ *
+ * Sets the output buffer for a virtual display. That is, the buffer to
+ * which the composition result will be written.
+ *
+ * Also provides a file descriptor referring to a release sync fence
+ * object, which must be signaled when it is safe to write to the output
+ * buffer. If it is already safe to write to the output buffer, an empty
+ * handle may be passed instead.
+ *
+ * Must be called at least once before PRESENT_DISPLAY, but does not have
+ * any interaction with layer state or display validation.
+ *
+ * @param bufferSlot is the new output buffer.
+ * @param bufferIndex is the new output buffer.
+ * @param releaseFenceIndex is a sync fence file descriptor as described
+ * above.
+ *
+ *
+ * VALIDATE_DISPLAY has this pseudo prototype
+ *
+ * validateDisplay();
+ *
+ * Instructs the device to inspect all of the layer state and determine if
+ * there are any composition type changes necessary before presenting the
+ * display. Permitted changes are described in the definition of
+ * Composition above.
+ *
+ *
+ * ACCEPT_DISPLAY_CHANGES has this pseudo prototype
+ *
+ * acceptDisplayChanges();
+ *
+ * Accepts the changes required by the device from the previous
+ * validateDisplay call (which may be queried using
+ * getChangedCompositionTypes) and revalidates the display. This function
+ * is equivalent to requesting the changed types from
+ * getChangedCompositionTypes, setting those types on the corresponding
+ * layers, and then calling validateDisplay again.
+ *
+ * After this call it must be valid to present this display. Calling this
+ * after validateDisplay returns 0 changes must succeed with NONE, but
+ * must have no other effect.
+ *
+ *
+ * PRESENT_DISPLAY has this pseudo prototype
+ *
+ * presentDisplay();
+ *
+ * Presents the current display contents on the screen (or in the case of
+ * virtual displays, into the output buffer).
+ *
+ * Prior to calling this function, the display must be successfully
+ * validated with validateDisplay. Note that setLayerBuffer and
+ * setLayerSurfaceDamage specifically do not count as layer state, so if
+ * there are no other changes to the layer state (or to the buffer's
+ * properties as described in setLayerBuffer), then it is safe to call
+ * this function without first validating the display.
+ *
+ *
+ * SET_LAYER_CURSOR_POSITION has this pseudo prototype
+ *
+ * setLayerCursorPosition(int32_t x, int32_t y);
+ *
+ * Asynchronously sets the position of a cursor layer.
+ *
+ * Prior to validateDisplay, a layer may be marked as Composition::CURSOR.
+ * If validation succeeds (i.e., the device does not request a composition
+ * change for that layer), then once a buffer has been set for the layer
+ * and it has been presented, its position may be set by this function at
+ * any time between presentDisplay and any subsequent validateDisplay
+ * calls for this display.
+ *
+ * Once validateDisplay is called, this function must not be called again
+ * until the validate/present sequence is completed.
+ *
+ * May be called from any thread so long as it is not interleaved with the
+ * validate/present sequence as described above.
+ *
+ * @param layer is the layer to which the position is set.
+ * @param x is the new x coordinate (in pixels from the left of the
+ * screen).
+ * @param y is the new y coordinate (in pixels from the top of the
+ * screen).
+ *
+ *
+ * SET_LAYER_BUFFER has this pseudo prototype
+ *
+ * setLayerBuffer(uint32_t bufferSlot,
+ * int32_t bufferIndex,
+ * int32_t acquireFenceIndex);
+ *
+ * Sets the buffer handle to be displayed for this layer. If the buffer
+ * properties set at allocation time (width, height, format, and usage)
+ * have not changed since the previous frame, it is not necessary to call
+ * validateDisplay before calling presentDisplay unless new state needs to
+ * be validated in the interim.
+ *
+ * Also provides a file descriptor referring to an acquire sync fence
+ * object, which must be signaled when it is safe to read from the given
+ * buffer. If it is already safe to read from the buffer, an empty handle
+ * may be passed instead.
+ *
+ * This function must return NONE and have no other effect if called for a
+ * layer with a composition type of Composition::SOLID_COLOR (because it
+ * has no buffer) or Composition::SIDEBAND or Composition::CLIENT (because
+ * synchronization and buffer updates for these layers are handled
+ * elsewhere).
+ *
+ * @param layer is the layer to which the buffer is set.
+ * @param bufferSlot is the buffer slot to use.
+ * @param bufferIndex is the buffer handle to set.
+ * @param acquireFenceIndex is a sync fence file descriptor as described above.
+ *
+ *
+ * SET_LAYER_SURFACE_DAMAGE has this pseudo prototype
+ *
+ * setLayerSurfaceDamage(vec<Rect> damage);
+ *
+ * Provides the region of the source buffer which has been modified since
+ * the last frame. This region does not need to be validated before
+ * calling presentDisplay.
+ *
+ * Once set through this function, the damage region remains the same
+ * until a subsequent call to this function.
+ *
+ * If damage is non-empty, then it may be assumed that any portion of the
+ * source buffer not covered by one of the rects has not been modified
+ * this frame. If damage is empty, then the whole source buffer must be
+ * treated as if it has been modified.
+ *
+ * If the layer's contents are not modified relative to the prior frame,
+ * damage must contain exactly one empty rect([0, 0, 0, 0]).
+ *
+ * The damage rects are relative to the pre-transformed buffer, and their
+ * origin is the top-left corner. They must not exceed the dimensions of
+ * the latched buffer.
+ *
+ * @param layer is the layer to which the damage region is set.
+ * @param damage is the new surface damage region.
+ *
+ *
+ * SET_LAYER_BLEND_MODE has this pseudo prototype
+ *
+ * setLayerBlendMode(BlendMode mode)
+ *
+ * Sets the blend mode of the given layer.
+ *
+ * @param mode is the new blend mode.
+ *
+ *
+ * SET_LAYER_COLOR has this pseudo prototype
+ *
+ * setLayerColor(Color color);
+ *
+ * Sets the color of the given layer. If the composition type of the layer
+ * is not Composition::SOLID_COLOR, this call must succeed and have no
+ * other effect.
+ *
+ * @param color is the new color.
+ *
+ *
+ * SET_LAYER_COMPOSITION_TYPE has this pseudo prototype
+ *
+ * setLayerCompositionType(Composition type);
+ *
+ * Sets the desired composition type of the given layer. During
+ * validateDisplay, the device may request changes to the composition
+ * types of any of the layers as described in the definition of
+ * Composition above.
+ *
+ * @param type is the new composition type.
+ *
+ *
+ * SET_LAYER_DATASPACE has this pseudo prototype
+ *
+ * setLayerDataspace(Dataspace dataspace);
+ *
+ * Sets the dataspace that the current buffer on this layer is in.
+ *
+ * The dataspace provides more information about how to interpret the
+ * buffer contents, such as the encoding standard and color transform.
+ *
+ * See the values of Dataspace for more information.
+ *
+ * @param dataspace is the new dataspace.
+ *
+ *
+ * SET_LAYER_DISPLAY_FRAME has this pseudo prototype
+ *
+ * setLayerDisplayFrame(Rect frame);
+ *
+ * Sets the display frame (the portion of the display covered by a layer)
+ * of the given layer. This frame must not exceed the display dimensions.
+ *
+ * @param frame is the new display frame.
+ *
+ *
+ * SET_LAYER_PLANE_ALPHA has this pseudo prototype
+ *
+ * setLayerPlaneAlpha(float alpha);
+ *
+ * Sets an alpha value (a floating point value in the range [0.0, 1.0])
+ * which will be applied to the whole layer. It can be conceptualized as a
+ * preprocessing step which applies the following function:
+ * if (blendMode == BlendMode::PREMULTIPLIED)
+ * out.rgb = in.rgb * planeAlpha
+ * out.a = in.a * planeAlpha
+ *
+ * If the device does not support this operation on a layer which is
+ * marked Composition::DEVICE, it must request a composition type change
+ * to Composition::CLIENT upon the next validateDisplay call.
+ *
+ * @param alpha is the plane alpha value to apply.
+ *
+ *
+ * SET_LAYER_SIDEBAND_STREAM has this pseudo prototype
+ *
+ * setLayerSidebandStream(int32_t streamIndex)
+ *
+ * Sets the sideband stream for this layer. If the composition type of the
+ * given layer is not Composition::SIDEBAND, this call must succeed and
+ * have no other effect.
+ *
+ * @param streamIndex is the new sideband stream.
+ *
+ *
+ * SET_LAYER_SOURCE_CROP has this pseudo prototype
+ *
+ * setLayerSourceCrop(FRect crop);
+ *
+ * Sets the source crop (the portion of the source buffer which will fill
+ * the display frame) of the given layer. This crop rectangle must not
+ * exceed the dimensions of the latched buffer.
+ *
+ * If the device is not capable of supporting a true float source crop
+ * (i.e., it will truncate or round the floats to integers), it must set
+ * this layer to Composition::CLIENT when crop is non-integral for the
+ * most accurate rendering.
+ *
+ * If the device cannot support float source crops, but still wants to
+ * handle the layer, it must use the following code (or similar) to
+ * convert to an integer crop:
+ * intCrop.left = (int) ceilf(crop.left);
+ * intCrop.top = (int) ceilf(crop.top);
+ * intCrop.right = (int) floorf(crop.right);
+ * intCrop.bottom = (int) floorf(crop.bottom);
+ *
+ * @param crop is the new source crop.
+ *
+ *
+ * SET_LAYER_TRANSFORM has this pseudo prototype
+ *
+ * Sets the transform (rotation/flip) of the given layer.
+ *
+ * setLayerTransform(Transform transform);
+ *
+ * @param transform is the new transform.
+ *
+ *
+ * SET_LAYER_VISIBLE_REGION has this pseudo prototype
+ *
+ * setLayerVisibleRegion(vec<Rect> visible);
+ *
+ * Specifies the portion of the layer that is visible, including portions
+ * under translucent areas of other layers. The region is in screen space,
+ * and must not exceed the dimensions of the screen.
+ *
+ * @param visible is the new visible region, in screen space.
+ *
+ *
+ * SET_LAYER_Z_ORDER has this pseudo prototype
+ *
+ * setLayerZOrder(uint32_t z);
+ *
+ * Sets the desired Z order (height) of the given layer. A layer with a
+ * greater Z value occludes a layer with a lesser Z value.
+ *
+ * @param z is the new Z order.
+ */
+ enum Command : int32_t {
+ LENGTH_MASK = 0xffff,
+ OPCODE_SHIFT = 16,
+ OPCODE_MASK = 0xffff << OPCODE_SHIFT,
+
+ /* special commands */
+ SELECT_DISPLAY = 0x000 << OPCODE_SHIFT,
+ SELECT_LAYER = 0x001 << OPCODE_SHIFT,
+
+ /* value commands (for return values) */
+ SET_ERROR = 0x100 << OPCODE_SHIFT,
+ SET_CHANGED_COMPOSITION_TYPES = 0x101 << OPCODE_SHIFT,
+ SET_DISPLAY_REQUESTS = 0x102 << OPCODE_SHIFT,
+ SET_PRESENT_FENCE = 0x103 << OPCODE_SHIFT,
+ SET_RELEASE_FENCES = 0x104 << OPCODE_SHIFT,
+
+ /* display commands */
+ SET_COLOR_TRANSFORM = 0x200 << OPCODE_SHIFT,
+ SET_CLIENT_TARGET = 0x201 << OPCODE_SHIFT,
+ SET_OUTPUT_BUFFER = 0x202 << OPCODE_SHIFT,
+ VALIDATE_DISPLAY = 0x203 << OPCODE_SHIFT,
+ ACCEPT_DISPLAY_CHANGES = 0x204 << OPCODE_SHIFT,
+ PRESENT_DISPLAY = 0x205 << OPCODE_SHIFT,
+
+ /* layer commands (VALIDATE_DISPLAY not required) */
+ SET_LAYER_CURSOR_POSITION = 0x300 << OPCODE_SHIFT,
+ SET_LAYER_BUFFER = 0x301 << OPCODE_SHIFT,
+ SET_LAYER_SURFACE_DAMAGE = 0x302 << OPCODE_SHIFT,
+
+ /* layer state commands (VALIDATE_DISPLAY required) */
+ SET_LAYER_BLEND_MODE = 0x400 << OPCODE_SHIFT,
+ SET_LAYER_COLOR = 0x401 << OPCODE_SHIFT,
+ SET_LAYER_COMPOSITION_TYPE = 0x402 << OPCODE_SHIFT,
+ SET_LAYER_DATASPACE = 0x403 << OPCODE_SHIFT,
+ SET_LAYER_DISPLAY_FRAME = 0x404 << OPCODE_SHIFT,
+ SET_LAYER_PLANE_ALPHA = 0x405 << OPCODE_SHIFT,
+ SET_LAYER_SIDEBAND_STREAM = 0x406 << OPCODE_SHIFT,
+ SET_LAYER_SOURCE_CROP = 0x407 << OPCODE_SHIFT,
+ SET_LAYER_TRANSFORM = 0x408 << OPCODE_SHIFT,
+ SET_LAYER_VISIBLE_REGION = 0x409 << OPCODE_SHIFT,
+ SET_LAYER_Z_ORDER = 0x40a << OPCODE_SHIFT,
+
+ /* 0x800 - 0xfff are reserved for vendor extensions */
+ /* 0x1000 - 0xffff are reserved */
+ };
+};