| /* | |
| * Copyright 2018 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. | |
| */ | |
| /** | |
| * @addtogroup NativeActivity Native Activity | |
| * @{ | |
| */ | |
| /** | |
| * @file surface_control.h | |
| */ | |
| #ifndef ANDROID_SURFACE_CONTROL_H | |
| #define ANDROID_SURFACE_CONTROL_H | |
| #include <sys/cdefs.h> | |
| #include <android/data_space.h> | |
| #include <android/hardware_buffer.h> | |
| #include <android/hdr_metadata.h> | |
| #include <android/native_window.h> | |
| __BEGIN_DECLS | |
| struct ASurfaceControl; | |
| /** | |
| * The SurfaceControl API can be used to provide a hierarchy of surfaces for | |
| * composition to the system compositor. ASurfaceControl represents a content node in | |
| * this hierarchy. | |
| */ | |
| typedef struct ASurfaceControl ASurfaceControl; | |
| /** | |
| * Creates an ASurfaceControl with either ANativeWindow or an ASurfaceControl as its parent. | |
| * \a debug_name is a debug name associated with this surface. It can be used to | |
| * identify this surface in the SurfaceFlinger's layer tree. It must not be | |
| * null. | |
| * | |
| * The caller takes ownership of the ASurfaceControl returned and must release it | |
| * using ASurfaceControl_release below. | |
| * | |
| * Available since API level 29. | |
| */ | |
| ASurfaceControl* ASurfaceControl_createFromWindow(ANativeWindow* parent, const char* debug_name) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * See ASurfaceControl_createFromWindow. | |
| * | |
| * Available since API level 29. | |
| */ | |
| ASurfaceControl* ASurfaceControl_create(ASurfaceControl* parent, const char* debug_name) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Acquires a reference on the given ASurfaceControl object. This prevents the object | |
| * from being deleted until the reference is removed. | |
| * | |
| * To release the reference, use the ASurfaceControl_release function. | |
| * | |
| * Available since API level 31. | |
| */ | |
| void ASurfaceControl_acquire(ASurfaceControl* surface_control) __INTRODUCED_IN(31); | |
| /** | |
| * Removes a reference that was previously acquired with one of the following functions: | |
| * ASurfaceControl_createFromWindow | |
| * ASurfaceControl_create | |
| * ANativeWindow_acquire | |
| * The surface and its children may remain on display as long as their parent remains on display. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceControl_release(ASurfaceControl* surface_control) __INTRODUCED_IN(29); | |
| struct ASurfaceTransaction; | |
| /** | |
| * ASurfaceTransaction is a collection of updates to the surface tree that must | |
| * be applied atomically. | |
| */ | |
| typedef struct ASurfaceTransaction ASurfaceTransaction; | |
| /** | |
| * The caller takes ownership of the transaction and must release it using | |
| * ASurfaceTransaction_delete() below. | |
| * | |
| * Available since API level 29. | |
| */ | |
| ASurfaceTransaction* ASurfaceTransaction_create() __INTRODUCED_IN(29); | |
| /** | |
| * Destroys the \a transaction object. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_delete(ASurfaceTransaction* transaction) __INTRODUCED_IN(29); | |
| /** | |
| * Applies the updates accumulated in \a transaction. | |
| * | |
| * Note that the transaction is guaranteed to be applied atomically. The | |
| * transactions which are applied on the same thread are also guaranteed to be | |
| * applied in order. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_apply(ASurfaceTransaction* transaction) __INTRODUCED_IN(29); | |
| /** | |
| * An opaque handle returned during a callback that can be used to query general stats and stats for | |
| * surfaces which were either removed or for which buffers were updated after this transaction was | |
| * applied. | |
| */ | |
| typedef struct ASurfaceTransactionStats ASurfaceTransactionStats; | |
| /** | |
| * Since the transactions are applied asynchronously, the | |
| * ASurfaceTransaction_OnComplete callback can be used to be notified when a frame | |
| * including the updates in a transaction was presented. | |
| * | |
| * Buffers which are replaced or removed from the scene in the transaction invoking | |
| * this callback may be reused after this point. | |
| * | |
| * \param context Optional context provided by the client that is passed into | |
| * the callback. | |
| * | |
| * \param stats Opaque handle that can be passed to ASurfaceTransactionStats functions to query | |
| * information about the transaction. The handle is only valid during the callback. | |
| * | |
| * THREADING | |
| * The transaction completed callback can be invoked on any thread. | |
| * | |
| * Available since API level 29. | |
| */ | |
| typedef void (*ASurfaceTransaction_OnComplete)(void* context, ASurfaceTransactionStats* stats) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * The ASurfaceTransaction_OnCommit callback is invoked when transaction is applied and the updates | |
| * are ready to be presented. This callback will be invoked before the | |
| * ASurfaceTransaction_OnComplete callback. | |
| * | |
| * This callback does not mean buffers have been released! It simply means that any new | |
| * transactions applied will not overwrite the transaction for which we are receiving | |
| * a callback and instead will be included in the next frame. If you are trying to avoid | |
| * dropping frames (overwriting transactions), and unable to use timestamps (Which provide | |
| * a more efficient solution), then this method provides a method to pace your transaction | |
| * application. | |
| * | |
| * \param context Optional context provided by the client that is passed into the callback. | |
| * | |
| * \param stats Opaque handle that can be passed to ASurfaceTransactionStats functions to query | |
| * information about the transaction. The handle is only valid during the callback. | |
| * Present and release fences are not available for this callback. Querying them using | |
| * ASurfaceTransactionStats_getPresentFenceFd and ASurfaceTransactionStats_getPreviousReleaseFenceFd | |
| * will result in failure. | |
| * | |
| * THREADING | |
| * The transaction committed callback can be invoked on any thread. | |
| * | |
| * Available since API level 31. | |
| */ | |
| typedef void (*ASurfaceTransaction_OnCommit)(void* context, ASurfaceTransactionStats* stats) | |
| __INTRODUCED_IN(31); | |
| /** | |
| * Returns the timestamp of when the frame was latched by the framework. Once a frame is | |
| * latched by the framework, it is presented at the following hardware vsync. | |
| * | |
| * Available since API level 29. | |
| */ | |
| int64_t ASurfaceTransactionStats_getLatchTime(ASurfaceTransactionStats* surface_transaction_stats) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Returns a sync fence that signals when the transaction has been presented. | |
| * The recipient of the callback takes ownership of the fence and is responsible for closing | |
| * it. If a device does not support present fences, a -1 will be returned. | |
| * | |
| * This query is not valid for ASurfaceTransaction_OnCommit callback. | |
| * | |
| * Available since API level 29. | |
| */ | |
| int ASurfaceTransactionStats_getPresentFenceFd(ASurfaceTransactionStats* surface_transaction_stats) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * \a outASurfaceControls returns an array of ASurfaceControl pointers that were updated during the | |
| * transaction. Stats for the surfaces can be queried through ASurfaceTransactionStats functions. | |
| * When the client is done using the array, it must release it by calling | |
| * ASurfaceTransactionStats_releaseASurfaceControls. | |
| * | |
| * Available since API level 29. | |
| * | |
| * \a outASurfaceControlsSize returns the size of the ASurfaceControls array. | |
| */ | |
| void ASurfaceTransactionStats_getASurfaceControls(ASurfaceTransactionStats* surface_transaction_stats, | |
| ASurfaceControl*** outASurfaceControls, | |
| size_t* outASurfaceControlsSize) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Releases the array of ASurfaceControls that were returned by | |
| * ASurfaceTransactionStats_getASurfaceControls(). | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransactionStats_releaseASurfaceControls(ASurfaceControl** surface_controls) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Returns the timestamp of when the CURRENT buffer was acquired. A buffer is considered | |
| * acquired when its acquire_fence_fd has signaled. A buffer cannot be latched or presented until | |
| * it is acquired. If no acquire_fence_fd was provided, this timestamp will be set to -1. | |
| * | |
| * Available since API level 29. | |
| */ | |
| int64_t ASurfaceTransactionStats_getAcquireTime(ASurfaceTransactionStats* surface_transaction_stats, | |
| ASurfaceControl* surface_control) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * The returns the fence used to signal the release of the PREVIOUS buffer set on | |
| * this surface. If this fence is valid (>=0), the PREVIOUS buffer has not yet been released and the | |
| * fence will signal when the PREVIOUS buffer has been released. If the fence is -1 , the PREVIOUS | |
| * buffer is already released. The recipient of the callback takes ownership of the | |
| * previousReleaseFenceFd and is responsible for closing it. | |
| * | |
| * Each time a buffer is set through ASurfaceTransaction_setBuffer() on a transaction | |
| * which is applied, the framework takes a ref on this buffer. The framework treats the | |
| * addition of a buffer to a particular surface as a unique ref. When a transaction updates or | |
| * removes a buffer from a surface, or removes the surface itself from the tree, this ref is | |
| * guaranteed to be released in the OnComplete callback for this transaction. The | |
| * ASurfaceControlStats provided in the callback for this surface may contain an optional fence | |
| * which must be signaled before the ref is assumed to be released. | |
| * | |
| * The client must ensure that all pending refs on a buffer are released before attempting to reuse | |
| * this buffer, otherwise synchronization errors may occur. | |
| * | |
| * This query is not valid for ASurfaceTransaction_OnCommit callback. | |
| * | |
| * Available since API level 29. | |
| */ | |
| int ASurfaceTransactionStats_getPreviousReleaseFenceFd( | |
| ASurfaceTransactionStats* surface_transaction_stats, | |
| ASurfaceControl* surface_control) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Sets the callback that will be invoked when the updates from this transaction | |
| * are presented. For details on the callback semantics and data, see the | |
| * comments on the ASurfaceTransaction_OnComplete declaration above. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setOnComplete(ASurfaceTransaction* transaction, void* context, | |
| ASurfaceTransaction_OnComplete func) __INTRODUCED_IN(29); | |
| /** | |
| * Sets the callback that will be invoked when the updates from this transaction are applied and are | |
| * ready to be presented. This callback will be invoked before the ASurfaceTransaction_OnComplete | |
| * callback. | |
| * | |
| * Available since API level 31. | |
| */ | |
| void ASurfaceTransaction_setOnCommit(ASurfaceTransaction* transaction, void* context, | |
| ASurfaceTransaction_OnCommit func) __INTRODUCED_IN(31); | |
| /** | |
| * Reparents the \a surface_control from its old parent to the \a new_parent surface control. | |
| * Any children of the reparented \a surface_control will remain children of the \a surface_control. | |
| * | |
| * The \a new_parent can be null. Surface controls with a null parent do not appear on the display. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_reparent(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, ASurfaceControl* new_parent) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Parameter for ASurfaceTransaction_setVisibility(). | |
| */ | |
| enum { | |
| ASURFACE_TRANSACTION_VISIBILITY_HIDE = 0, | |
| ASURFACE_TRANSACTION_VISIBILITY_SHOW = 1, | |
| }; | |
| /** | |
| * Updates the visibility of \a surface_control. If show is set to | |
| * ASURFACE_TRANSACTION_VISIBILITY_HIDE, the \a surface_control and all surfaces in its subtree will | |
| * be hidden. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setVisibility(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, int8_t visibility) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Updates the z order index for \a surface_control. Note that the z order for a surface | |
| * is relative to other surfaces which are siblings of this surface. The behavior of sibilings with | |
| * the same z order is undefined. | |
| * | |
| * Z orders may be from MIN_INT32 to MAX_INT32. A layer's default z order index is 0. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setZOrder(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, int32_t z_order) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Updates the AHardwareBuffer displayed for \a surface_control. If not -1, the | |
| * acquire_fence_fd should be a file descriptor that is signaled when all pending work | |
| * for the buffer is complete and the buffer can be safely read. | |
| * | |
| * The frameworks takes ownership of the \a acquire_fence_fd passed and is responsible | |
| * for closing it. | |
| * | |
| * Note that the buffer must be allocated with AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE | |
| * as the surface control might be composited using the GPU. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setBuffer(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, AHardwareBuffer* buffer, | |
| int acquire_fence_fd = -1) __INTRODUCED_IN(29); | |
| /** | |
| * Updates the color for \a surface_control. This will make the background color for the | |
| * ASurfaceControl visible in transparent regions of the surface. Colors \a r, \a g, | |
| * and \a b must be within the range that is valid for \a dataspace. \a dataspace and \a alpha | |
| * will be the dataspace and alpha set for the background color layer. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setColor(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, float r, float g, float b, | |
| float alpha, ADataSpace dataspace) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * \param source The sub-rect within the buffer's content to be rendered inside the surface's area | |
| * The surface's source rect is clipped by the bounds of its current buffer. The source rect's width | |
| * and height must be > 0. | |
| * | |
| * \param destination Specifies the rect in the parent's space where this surface will be drawn. The post | |
| * source rect bounds are scaled to fit the destination rect. The surface's destination rect is | |
| * clipped by the bounds of its parent. The destination rect's width and height must be > 0. | |
| * | |
| * \param transform The transform applied after the source rect is applied to the buffer. This parameter | |
| * should be set to 0 for no transform. To specify a transfrom use the NATIVE_WINDOW_TRANSFORM_* | |
| * enum. | |
| * | |
| * Available since API level 29. | |
| * | |
| * @deprecated Use setCrop, setPosition, setBufferTransform, and setScale instead. Those functions | |
| * provide well defined behavior and allows for more control by the apps. It also allows the caller | |
| * to set different properties at different times, instead of having to specify all the desired | |
| * properties at once. | |
| */ | |
| void ASurfaceTransaction_setGeometry(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, const ARect& source, | |
| const ARect& destination, int32_t transform) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Bounds the surface and its children to the bounds specified. The crop and buffer size will be | |
| * used to determine the bounds of the surface. If no crop is specified and the surface has no | |
| * buffer, the surface bounds is only constrained by the size of its parent bounds. | |
| * | |
| * \param crop The bounds of the crop to apply. | |
| * | |
| * Available since API level 31. | |
| */ | |
| void ASurfaceTransaction_setCrop(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, const ARect& crop) | |
| __INTRODUCED_IN(31); | |
| /** | |
| * Specifies the position in the parent's space where the surface will be drawn. | |
| * | |
| * \param x The x position to render the surface. | |
| * \param y The y position to render the surface. | |
| * | |
| * Available since API level 31. | |
| */ | |
| void ASurfaceTransaction_setPosition(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, int32_t x, int32_t y) | |
| __INTRODUCED_IN(31); | |
| /** | |
| * \param transform The transform applied after the source rect is applied to the buffer. This | |
| * parameter should be set to 0 for no transform. To specify a transform use the | |
| * NATIVE_WINDOW_TRANSFORM_* enum. | |
| * | |
| * Available since API level 31. | |
| */ | |
| void ASurfaceTransaction_setBufferTransform(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, int32_t transform) | |
| __INTRODUCED_IN(31); | |
| /** | |
| * Sets an x and y scale of a surface with (0, 0) as the centerpoint of the scale. | |
| * | |
| * \param xScale The scale in the x direction. Must be greater than 0. | |
| * \param yScale The scale in the y direction. Must be greater than 0. | |
| * | |
| * Available since API level 31. | |
| */ | |
| void ASurfaceTransaction_setScale(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, float xScale, float yScale) | |
| __INTRODUCED_IN(31); | |
| /** | |
| * Parameter for ASurfaceTransaction_setBufferTransparency(). | |
| */ | |
| enum { | |
| ASURFACE_TRANSACTION_TRANSPARENCY_TRANSPARENT = 0, | |
| ASURFACE_TRANSACTION_TRANSPARENCY_TRANSLUCENT = 1, | |
| ASURFACE_TRANSACTION_TRANSPARENCY_OPAQUE = 2, | |
| }; | |
| /** | |
| * Updates whether the content for the buffer associated with this surface is | |
| * completely opaque. If true, every pixel of content inside the buffer must be | |
| * opaque or visual errors can occur. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setBufferTransparency(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, | |
| int8_t transparency) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Updates the region for the content on this surface updated in this | |
| * transaction. If unspecified, the complete surface is assumed to be damaged. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setDamageRegion(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, const ARect rects[], | |
| uint32_t count) __INTRODUCED_IN(29); | |
| /** | |
| * Specifies a desiredPresentTime for the transaction. The framework will try to present | |
| * the transaction at or after the time specified. | |
| * | |
| * Transactions will not be presented until all of their acquire fences have signaled even if the | |
| * app requests an earlier present time. | |
| * | |
| * If an earlier transaction has a desired present time of x, and a later transaction has a desired | |
| * present time that is before x, the later transaction will not preempt the earlier transaction. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setDesiredPresentTime(ASurfaceTransaction* transaction, | |
| int64_t desiredPresentTime) __INTRODUCED_IN(29); | |
| /** | |
| * Sets the alpha for the buffer. It uses a premultiplied blending. | |
| * | |
| * The \a alpha must be between 0.0 and 1.0. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setBufferAlpha(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, float alpha) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Sets the data space of the surface_control's buffers. | |
| * | |
| * If no data space is set, the surface control defaults to ADATASPACE_SRGB. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setBufferDataSpace(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, ADataSpace data_space) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * SMPTE ST 2086 "Mastering Display Color Volume" static metadata | |
| * | |
| * When \a metadata is set to null, the framework does not use any smpte2086 metadata when rendering | |
| * the surface's buffer. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setHdrMetadata_smpte2086(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, | |
| struct AHdrMetadata_smpte2086* metadata) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Sets the CTA 861.3 "HDR Static Metadata Extension" static metadata on a surface. | |
| * | |
| * When \a metadata is set to null, the framework does not use any cta861.3 metadata when rendering | |
| * the surface's buffer. | |
| * | |
| * Available since API level 29. | |
| */ | |
| void ASurfaceTransaction_setHdrMetadata_cta861_3(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, | |
| struct AHdrMetadata_cta861_3* metadata) | |
| __INTRODUCED_IN(29); | |
| /** | |
| * Same as ASurfaceTransaction_setFrameRateWithChangeStrategy(transaction, surface_control, | |
| * frameRate, compatibility, ANATIVEWINDOW_CHANGE_FRAME_RATE_ONLY_IF_SEAMLESS). | |
| * | |
| * See ASurfaceTransaction_setFrameRateWithChangeStrategy(). | |
| * | |
| * Available since API level 30. | |
| */ | |
| void ASurfaceTransaction_setFrameRate(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, float frameRate, | |
| int8_t compatibility) __INTRODUCED_IN(30); | |
| /** | |
| * Sets the intended frame rate for \a surface_control. | |
| * | |
| * On devices that are capable of running the display at different refresh rates, the system may | |
| * choose a display refresh rate to better match this surface's frame rate. Usage of this API won't | |
| * directly affect the application's frame production pipeline. However, because the system may | |
| * change the display refresh rate, calls to this function may result in changes to Choreographer | |
| * callback timings, and changes to the time interval at which the system releases buffers back to | |
| * the application. | |
| * | |
| * You can register for changes in the refresh rate using | |
| * \a AChoreographer_registerRefreshRateCallback. | |
| * | |
| * \param frameRate is the intended frame rate of this surface, in frames per second. 0 is a special | |
| * value that indicates the app will accept the system's choice for the display frame rate, which is | |
| * the default behavior if this function isn't called. The frameRate param does <em>not</em> need to | |
| * be a valid refresh rate for this device's display - e.g., it's fine to pass 30fps to a device | |
| * that can only run the display at 60fps. | |
| * | |
| * \param compatibility The frame rate compatibility of this surface. The compatibility value may | |
| * influence the system's choice of display frame rate. To specify a compatibility use the | |
| * ANATIVEWINDOW_FRAME_RATE_COMPATIBILITY_* enum. This parameter is ignored when frameRate is 0. | |
| * | |
| * \param changeFrameRateStrategy Whether display refresh rate transitions caused by this | |
| * surface should be seamless. A seamless transition is one that doesn't have any visual | |
| * interruptions, such as a black screen for a second or two. See the | |
| * ANATIVEWINDOW_CHANGE_FRAME_RATE_* values. This parameter is ignored when frameRate is 0. | |
| * | |
| * Available since API level 31. | |
| */ | |
| void ASurfaceTransaction_setFrameRateWithChangeStrategy(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, float frameRate, | |
| int8_t compatibility, int8_t changeFrameRateStrategy) | |
| __INTRODUCED_IN(31); | |
| /** | |
| * Indicate whether to enable backpressure for buffer submission to a given SurfaceControl. | |
| * | |
| * By default backpressure is disabled, which means submitting a buffer prior to receiving | |
| * a callback for the previous buffer could lead to that buffer being "dropped". In cases | |
| * where you are selecting for latency, this may be a desirable behavior! We had a new buffer | |
| * ready, why shouldn't we show it? | |
| * | |
| * When back pressure is enabled, each buffer will be required to be presented | |
| * before it is released and the callback delivered | |
| * (absent the whole SurfaceControl being removed). | |
| * | |
| * Most apps are likely to have some sort of backpressure internally, e.g. you are | |
| * waiting on the callback from frame N-2 before starting frame N. In high refresh | |
| * rate scenarios there may not be much time between SurfaceFlinger completing frame | |
| * N-1 (and therefore releasing buffer N-2) and beginning frame N. This means | |
| * your app may not have enough time to respond in the callback. Using this flag | |
| * and pushing buffers earlier for server side queuing will be advantageous | |
| * in such cases. | |
| * | |
| * \param transaction The transaction in which to make the change. | |
| * \param surface_control The ASurfaceControl on which to control buffer backpressure behavior. | |
| * \param enableBackPressure Whether to enable back pressure. | |
| */ | |
| void ASurfaceTransaction_setEnableBackPressure(ASurfaceTransaction* transaction, | |
| ASurfaceControl* surface_control, | |
| bool enableBackPressure) | |
| __INTRODUCED_IN(31); | |
| __END_DECLS | |
| #endif // ANDROID_SURFACE_CONTROL_H | |
| /** @} */ |