/* * Copyright (C) 2010 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. */ #ifndef ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H #define ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H #include #include #include #include #include #include __BEGIN_DECLS /*****************************************************************************/ /* for compatibility */ #define HWC_MODULE_API_VERSION HWC_MODULE_API_VERSION_0_1 #define HWC_DEVICE_API_VERSION HWC_DEVICE_API_VERSION_0_1 #define HWC_API_VERSION HWC_DEVICE_API_VERSION /*****************************************************************************/ typedef struct hwc_layer_1 { /* * compositionType is used to specify this layer's type and is set by either * the hardware composer implementation, or by the caller (see below). * * This field is always reset to HWC_BACKGROUND or HWC_FRAMEBUFFER * before (*prepare)() is called when the HWC_GEOMETRY_CHANGED flag is * also set, otherwise, this field is preserved between (*prepare)() * calls. * * HWC_BACKGROUND * Always set by the caller before calling (*prepare)(), this value * indicates this is a special "background" layer. The only valid field * is backgroundColor. * The HWC can toggle this value to HWC_FRAMEBUFFER to indicate it CANNOT * handle the background color. * * * HWC_FRAMEBUFFER_TARGET * Always set by the caller before calling (*prepare)(), this value * indicates this layer is the framebuffer surface used as the target of * OpenGL ES composition. If the HWC sets all other layers to HWC_OVERLAY * or HWC_BACKGROUND, then no OpenGL ES composition will be done, and * this layer should be ignored during set(). * * This flag (and the framebuffer surface layer) will only be used if the * HWC version is HWC_DEVICE_API_VERSION_1_1 or higher. In older versions, * the OpenGL ES target surface is communicated by the (dpy, sur) fields * in hwc_compositor_device_1_t. * * This value cannot be set by the HWC implementation. * * * HWC_FRAMEBUFFER * Set by the caller before calling (*prepare)() ONLY when the * HWC_GEOMETRY_CHANGED flag is also set. * * Set by the HWC implementation during (*prepare)(), this indicates * that the layer will be drawn into the framebuffer using OpenGL ES. * The HWC can toggle this value to HWC_OVERLAY to indicate it will * handle the layer. * * * HWC_OVERLAY * Set by the HWC implementation during (*prepare)(), this indicates * that the layer will be handled by the HWC (ie: it must not be * composited with OpenGL ES). * * * HWC_SIDEBAND * Set by the caller before calling (*prepare)(), this value indicates * the contents of this layer come from a sideband video stream. * * The h/w composer is responsible for receiving new image buffers from * the stream at the appropriate time (e.g. synchronized to a separate * audio stream), compositing them with the current contents of other * layers, and displaying the resulting image. This happens * independently of the normal prepare/set cycle. The prepare/set calls * only happen when other layers change, or when properties of the * sideband layer such as position or size change. * * If the h/w composer can't handle the layer as a sideband stream for * some reason (e.g. unsupported scaling/blending/rotation, or too many * sideband layers) it can set compositionType to HWC_FRAMEBUFFER in * (*prepare)(). However, doing so will result in the layer being shown * as a solid color since the platform is not currently able to composite * sideband layers with the GPU. This may be improved in future * versions of the platform. * * * HWC_CURSOR_OVERLAY * Set by the HWC implementation during (*prepare)(), this value * indicates the layer's composition will now be handled by the HWC. * Additionally, the client can now asynchronously update the on-screen * position of this layer using the setCursorPositionAsync() api. */ int32_t compositionType; /* * hints is bit mask set by the HWC implementation during (*prepare)(). * It is preserved between (*prepare)() calls, unless the * HWC_GEOMETRY_CHANGED flag is set, in which case it is reset to 0. * * see hwc_layer_t::hints */ uint32_t hints; /* see hwc_layer_t::flags */ uint32_t flags; union { /* color of the background. hwc_color_t.a is ignored */ hwc_color_t backgroundColor; struct { union { /* When compositionType is HWC_FRAMEBUFFER, HWC_OVERLAY, * HWC_FRAMEBUFFER_TARGET, this is the handle of the buffer to * compose. This handle is guaranteed to have been allocated * from gralloc using the GRALLOC_USAGE_HW_COMPOSER usage flag. * If the layer's handle is unchanged across two consecutive * prepare calls and the HWC_GEOMETRY_CHANGED flag is not set * for the second call then the HWComposer implementation may * assume that the contents of the buffer have not changed. */ buffer_handle_t handle; /* When compositionType is HWC_SIDEBAND, this is the handle * of the sideband video stream to compose. */ const native_handle_t* sidebandStream; }; /* transformation to apply to the buffer during composition */ uint32_t transform; /* blending to apply during composition */ int32_t blending; /* area of the source to consider, the origin is the top-left corner of * the buffer. As of HWC_DEVICE_API_VERSION_1_3, sourceRect uses floats. * If the h/w can't support a non-integer source crop rectangle, it should * punt to OpenGL ES composition. */ union { // crop rectangle in integer (pre HWC_DEVICE_API_VERSION_1_3) hwc_rect_t sourceCropi; hwc_rect_t sourceCrop; // just for source compatibility // crop rectangle in floats (as of HWC_DEVICE_API_VERSION_1_3) hwc_frect_t sourceCropf; }; /* where to composite the sourceCrop onto the display. The sourceCrop * is scaled using linear filtering to the displayFrame. The origin is the * top-left corner of the screen. */ hwc_rect_t displayFrame; /* visible region in screen space. The origin is the * top-left corner of the screen. * The visible region INCLUDES areas overlapped by a translucent layer. */ hwc_region_t visibleRegionScreen; /* Sync fence object that will be signaled when the buffer's * contents are available. May be -1 if the contents are already * available. This field is only valid during set(), and should be * ignored during prepare(). The set() call must not wait for the * fence to be signaled before returning, but the HWC must wait for * all buffers to be signaled before reading from them. * * HWC_FRAMEBUFFER layers will never have an acquire fence, since * reads from them are complete before the framebuffer is ready for * display. * * HWC_SIDEBAND layers will never have an acquire fence, since * synchronization is handled through implementation-defined * sideband mechanisms. * * The HWC takes ownership of the acquireFenceFd and is responsible * for closing it when no longer needed. */ int acquireFenceFd; /* During set() the HWC must set this field to a file descriptor for * a sync fence object that will signal after the HWC has finished * reading from the buffer. The field is ignored by prepare(). Each * layer should have a unique file descriptor, even if more than one * refer to the same underlying fence object; this allows each to be * closed independently. * * If buffer reads can complete at significantly different times, * then using independent fences is preferred. For example, if the * HWC handles some layers with a blit engine and others with * overlays, then the blit layers can be reused immediately after * the blit completes, but the overlay layers can't be reused until * a subsequent frame has been displayed. * * Since HWC doesn't read from HWC_FRAMEBUFFER layers, it shouldn't * produce a release fence for them. The releaseFenceFd will be -1 * for these layers when set() is called. * * Since HWC_SIDEBAND buffers don't pass through the HWC client, * the HWC shouldn't produce a release fence for them. The * releaseFenceFd will be -1 for these layers when set() is called. * * The HWC client taks ownership of the releaseFenceFd and is * responsible for closing it when no longer needed. */ int releaseFenceFd; /* * Availability: HWC_DEVICE_API_VERSION_1_2 * * Alpha value applied to the whole layer. The effective * value of each pixel is computed as: * * if (blending == HWC_BLENDING_PREMULT) * pixel.rgb = pixel.rgb * planeAlpha / 255 * pixel.a = pixel.a * planeAlpha / 255 * * Then blending proceeds as usual according to the "blending" * field above. * * NOTE: planeAlpha applies to YUV layers as well: * * pixel.rgb = yuv_to_rgb(pixel.yuv) * if (blending == HWC_BLENDING_PREMULT) * pixel.rgb = pixel.rgb * planeAlpha / 255 * pixel.a = planeAlpha * * * IMPLEMENTATION NOTE: * * If the source image doesn't have an alpha channel, then * the h/w can use the HWC_BLENDING_COVERAGE equations instead of * HWC_BLENDING_PREMULT and simply set the alpha channel to * planeAlpha. * * e.g.: * * if (blending == HWC_BLENDING_PREMULT) * blending = HWC_BLENDING_COVERAGE; * pixel.a = planeAlpha; * */ uint8_t planeAlpha; /* Pad to 32 bits */ uint8_t _pad[3]; /* * Availability: HWC_DEVICE_API_VERSION_1_5 * * This defines the region of the source buffer that has been * modified since the last frame. * * If surfaceDamage.numRects > 0, 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 surfaceDamage.numRects == 0, * then the whole source buffer must be treated as if it had been * modified. * * If the layer's contents are not modified relative to the prior * prepare/set cycle, surfaceDamage will 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. */ hwc_region_t surfaceDamage; }; }; #ifdef __LP64__ /* * For 64-bit mode, this struct is 120 bytes (and 8-byte aligned), and needs * to be padded as such to maintain binary compatibility. */ uint8_t reserved[120 - 112]; #else /* * For 32-bit mode, this struct is 96 bytes, and needs to be padded as such * to maintain binary compatibility. */ uint8_t reserved[96 - 84]; #endif } hwc_layer_1_t; /* This represents a display, typically an EGLDisplay object */ typedef void* hwc_display_t; /* This represents a surface, typically an EGLSurface object */ typedef void* hwc_surface_t; /* * hwc_display_contents_1_t::flags values */ enum { /* * HWC_GEOMETRY_CHANGED is set by SurfaceFlinger to indicate that the list * passed to (*prepare)() has changed by more than just the buffer handles * and acquire fences. */ HWC_GEOMETRY_CHANGED = 0x00000001, }; /* * Description of the contents to output on a display. * * This is the top-level structure passed to the prepare and set calls to * negotiate and commit the composition of a display image. */ typedef struct hwc_display_contents_1 { /* File descriptor referring to a Sync HAL fence object which will signal * when this composition is retired. For a physical display, a composition * is retired when it has been replaced on-screen by a subsequent set. For * a virtual display, the composition is retired when the writes to * outputBuffer are complete and can be read. The fence object is created * and returned by the set call; this field will be -1 on entry to prepare * and set. SurfaceFlinger will close the returned file descriptor. */ int retireFenceFd; union { /* Fields only relevant for HWC_DEVICE_VERSION_1_0. */ struct { /* (dpy, sur) is the target of SurfaceFlinger's OpenGL ES * composition for HWC_DEVICE_VERSION_1_0. They aren't relevant to * prepare. The set call should commit this surface atomically to * the display along with any overlay layers. */ hwc_display_t dpy; hwc_surface_t sur; }; /* These fields are used for virtual displays when the h/w composer * version is at least HWC_DEVICE_VERSION_1_3. */ struct { /* outbuf is the buffer that receives the composed image for * virtual displays. Writes to the outbuf must wait until * outbufAcquireFenceFd signals. A fence that will signal when * writes to outbuf are complete should be returned in * retireFenceFd. * * This field is set before prepare(), so properties of the buffer * can be used to decide which layers can be handled by h/w * composer. * * If prepare() sets all layers to FRAMEBUFFER, then GLES * composition will happen directly to the output buffer. In this * case, both outbuf and the FRAMEBUFFER_TARGET layer's buffer will * be the same, and set() has no work to do besides managing fences. * * If the TARGET_FORCE_HWC_FOR_VIRTUAL_DISPLAYS board config * variable is defined (not the default), then this behavior is * changed: if all layers are marked for FRAMEBUFFER, GLES * composition will take place to a scratch framebuffer, and * h/w composer must copy it to the output buffer. This allows the * h/w composer to do format conversion if there are cases where * that is more desirable than doing it in the GLES driver or at the * virtual display consumer. * * If some or all layers are marked OVERLAY, then the framebuffer * and output buffer will be different. As with physical displays, * the framebuffer handle will not change between frames if all * layers are marked for OVERLAY. */ buffer_handle_t outbuf; /* File descriptor for a fence that will signal when outbuf is * ready to be written. The h/w composer is responsible for closing * this when no longer needed. * * Will be -1 whenever outbuf is NULL, or when the outbuf can be * written immediately. */ int outbufAcquireFenceFd; }; }; /* List of layers that will be composed on the display. The buffer handles * in the list will be unique. If numHwLayers is 0, all composition will be * performed by SurfaceFlinger. */ uint32_t flags; size_t numHwLayers; hwc_layer_1_t hwLayers[0]; } hwc_display_contents_1_t; /* see hwc_composer_device::registerProcs() * All of the callbacks are required and non-NULL unless otherwise noted. */ typedef struct hwc_procs { /* * (*invalidate)() triggers a screen refresh, in particular prepare and set * will be called shortly after this call is made. Note that there is * NO GUARANTEE that the screen refresh will happen after invalidate() * returns (in particular, it could happen before). * invalidate() is GUARANTEED TO NOT CALL BACK into the h/w composer HAL and * it is safe to call invalidate() from any of hwc_composer_device * hooks, unless noted otherwise. */ void (*invalidate)(const struct hwc_procs* procs); /* * (*vsync)() is called by the h/w composer HAL when a vsync event is * received and HWC_EVENT_VSYNC is enabled on a display * (see: hwc_event_control). * * the "disp" parameter indicates which display the vsync event is for. * the "timestamp" parameter is the system monotonic clock timestamp in * nanosecond of when the vsync event happened. * * vsync() is GUARANTEED TO NOT CALL BACK into the h/w composer HAL. * * It is expected that vsync() is called from a thread of at least * HAL_PRIORITY_URGENT_DISPLAY with as little latency as possible, * typically less than 0.5 ms. * * It is a (silent) error to have HWC_EVENT_VSYNC enabled when calling * hwc_composer_device.set(..., 0, 0, 0) (screen off). The implementation * can either stop or continue to process VSYNC events, but must not * crash or cause other problems. */ void (*vsync)(const struct hwc_procs* procs, int disp, int64_t timestamp); /* * (*hotplug)() is called by the h/w composer HAL when a display is * connected or disconnected. The PRIMARY display is always connected and * the hotplug callback should not be called for it. * * The disp parameter indicates which display type this event is for. * The connected parameter indicates whether the display has just been * connected (1) or disconnected (0). * * The hotplug() callback may call back into the h/w composer on the same * thread to query refresh rate and dpi for the display. Additionally, * other threads may be calling into the h/w composer while the callback * is in progress. * * The h/w composer must serialize calls to the hotplug callback; only * one thread may call it at a time. * * This callback will be NULL if the h/w composer is using * HWC_DEVICE_API_VERSION_1_0. */ void (*hotplug)(const struct hwc_procs* procs, int disp, int connected); } hwc_procs_t; /*****************************************************************************/ typedef struct hwc_module { /** * Common methods of the hardware composer module. This *must* be the first member of * hwc_module as users of this structure will cast a hw_module_t to * hwc_module pointer in contexts where it's known the hw_module_t references a * hwc_module. */ struct hw_module_t common; } hwc_module_t; #define HWC_ERROR (-1) typedef struct hwc_composer_device_1 { /** * Common methods of the hardware composer device. This *must* be the first member of * hwc_composer_device_1 as users of this structure will cast a hw_device_t to * hwc_composer_device_1 pointer in contexts where it's known the hw_device_t references a * hwc_composer_device_1. */ struct hw_device_t common; /* * (*prepare)() is called for each frame before composition and is used by * SurfaceFlinger to determine what composition steps the HWC can handle. * * (*prepare)() can be called more than once, the last call prevails. * * The HWC responds by setting the compositionType field in each layer to * either HWC_FRAMEBUFFER, HWC_OVERLAY, or HWC_CURSOR_OVERLAY. For the * HWC_FRAMEBUFFER type, composition for the layer is handled by * SurfaceFlinger with OpenGL ES. For the latter two overlay types, * the HWC will have to handle the layer's composition. compositionType * and hints are preserved between (*prepare)() calles unless the * HWC_GEOMETRY_CHANGED flag is set. * * (*prepare)() is called with HWC_GEOMETRY_CHANGED to indicate that the * list's geometry has changed, that is, when more than just the buffer's * handles have been updated. Typically this happens (but is not limited to) * when a window is added, removed, resized or moved. In this case * compositionType and hints are reset to their default value. * * For HWC 1.0, numDisplays will always be one, and displays[0] will be * non-NULL. * * For HWC 1.1, numDisplays will always be HWC_NUM_PHYSICAL_DISPLAY_TYPES. * Entries for unsupported or disabled/disconnected display types will be * NULL. * * In HWC 1.3, numDisplays may be up to HWC_NUM_DISPLAY_TYPES. The extra * entries correspond to enabled virtual displays, and will be non-NULL. * * returns: 0 on success. An negative error code on error. If an error is * returned, SurfaceFlinger will assume that none of the layer will be * handled by the HWC. */ int (*prepare)(struct hwc_composer_device_1 *dev, size_t numDisplays, hwc_display_contents_1_t** displays); /* * (*set)() is used in place of eglSwapBuffers(), and assumes the same * functionality, except it also commits the work list atomically with * the actual eglSwapBuffers(). * * The layer lists are guaranteed to be the same as the ones returned from * the last call to (*prepare)(). * * When this call returns the caller assumes that the displays will be * updated in the near future with the content of their work lists, without * artifacts during the transition from the previous frame. * * A display with zero layers indicates that the entire composition has * been handled by SurfaceFlinger with OpenGL ES. In this case, (*set)() * behaves just like eglSwapBuffers(). * * For HWC 1.0, numDisplays will always be one, and displays[0] will be * non-NULL. * * For HWC 1.1, numDisplays will always be HWC_NUM_PHYSICAL_DISPLAY_TYPES. * Entries for unsupported or disabled/disconnected display types will be * NULL. * * In HWC 1.3, numDisplays may be up to HWC_NUM_DISPLAY_TYPES. The extra * entries correspond to enabled virtual displays, and will be non-NULL. * * IMPORTANT NOTE: There is an implicit layer containing opaque black * pixels behind all the layers in the list. It is the responsibility of * the hwcomposer module to make sure black pixels are output (or blended * from). * * IMPORTANT NOTE: In the event of an error this call *MUST* still cause * any fences returned in the previous call to set to eventually become * signaled. The caller may have already issued wait commands on these * fences, and having set return without causing those fences to signal * will likely result in a deadlock. * * returns: 0 on success. A negative error code on error: * HWC_EGL_ERROR: eglGetError() will provide the proper error code (only * allowed prior to HWComposer 1.1) * Another code for non EGL errors. */ int (*set)(struct hwc_composer_device_1 *dev, size_t numDisplays, hwc_display_contents_1_t** displays); /* * eventControl(..., event, enabled) * Enables or disables h/w composer events for a display. * * eventControl can be called from any thread and takes effect * immediately. * * Supported events are: * HWC_EVENT_VSYNC * * returns -EINVAL if the "event" parameter is not one of the value above * or if the "enabled" parameter is not 0 or 1. */ int (*eventControl)(struct hwc_composer_device_1* dev, int disp, int event, int enabled); union { /* * For HWC 1.3 and earlier, the blank() interface is used. * * blank(..., blank) * Blanks or unblanks a display's screen. * * Turns the screen off when blank is nonzero, on when blank is zero. * Multiple sequential calls with the same blank value must be * supported. * The screen state transition must be be complete when the function * returns. * * returns 0 on success, negative on error. */ int (*blank)(struct hwc_composer_device_1* dev, int disp, int blank); /* * For HWC 1.4 and above, setPowerMode() will be used in place of * blank(). * * setPowerMode(..., mode) * Sets the display screen's power state. * * Refer to the documentation of the HWC_POWER_MODE_* constants * for information about each power mode. * * The functionality is similar to the blank() command in previous * versions of HWC, but with support for more power states. * * The display driver is expected to retain and restore the low power * state of the display while entering and exiting from suspend. * * Multiple sequential calls with the same mode value must be supported. * * The screen state transition must be be complete when the function * returns. * * returns 0 on success, negative on error. */ int (*setPowerMode)(struct hwc_composer_device_1* dev, int disp, int mode); }; /* * Used to retrieve information about the h/w composer * * Returns 0 on success or -errno on error. */ int (*query)(struct hwc_composer_device_1* dev, int what, int* value); /* * (*registerProcs)() registers callbacks that the h/w composer HAL can * later use. It will be called immediately after the composer device is * opened with non-NULL procs. It is FORBIDDEN to call any of the callbacks * from within registerProcs(). registerProcs() must save the hwc_procs_t * pointer which is needed when calling a registered callback. */ void (*registerProcs)(struct hwc_composer_device_1* dev, hwc_procs_t const* procs); /* * This field is OPTIONAL and can be NULL. * * If non NULL it will be called by SurfaceFlinger on dumpsys */ void (*dump)(struct hwc_composer_device_1* dev, char *buff, int buff_len); /* * (*getDisplayConfigs)() returns handles for the configurations available * on the connected display. These handles must remain valid as long as the * display is connected. * * Configuration handles are written to configs. The number of entries * allocated by the caller is passed in *numConfigs; getDisplayConfigs must * not try to write more than this number of config handles. On return, the * total number of configurations available for the display is returned in * *numConfigs. If *numConfigs is zero on entry, then configs may be NULL. * * Hardware composers implementing HWC_DEVICE_API_VERSION_1_3 or prior * shall choose one configuration to activate and report it as the first * entry in the returned list. Reporting the inactive configurations is not * required. * * HWC_DEVICE_API_VERSION_1_4 and later provide configuration management * through SurfaceFlinger, and hardware composers implementing these APIs * must also provide getActiveConfig and setActiveConfig. Hardware composers * implementing these API versions may choose not to activate any * configuration, leaving configuration selection to higher levels of the * framework. * * Returns 0 on success or a negative error code on error. If disp is a * hotpluggable display type and no display is connected, an error shall be * returned. * * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_1 and later. * It shall be NULL for previous versions. */ int (*getDisplayConfigs)(struct hwc_composer_device_1* dev, int disp, uint32_t* configs, size_t* numConfigs); /* * (*getDisplayAttributes)() returns attributes for a specific config of a * connected display. The config parameter is one of the config handles * returned by getDisplayConfigs. * * The list of attributes to return is provided in the attributes * parameter, terminated by HWC_DISPLAY_NO_ATTRIBUTE. The value for each * requested attribute is written in order to the values array. The * HWC_DISPLAY_NO_ATTRIBUTE attribute does not have a value, so the values * array will have one less value than the attributes array. * * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_1 and later. * It shall be NULL for previous versions. * * If disp is a hotpluggable display type and no display is connected, * or if config is not a valid configuration for the display, a negative * error code shall be returned. */ int (*getDisplayAttributes)(struct hwc_composer_device_1* dev, int disp, uint32_t config, const uint32_t* attributes, int32_t* values); /* * (*getActiveConfig)() returns the index of the configuration that is * currently active on the connected display. The index is relative to * the list of configuration handles returned by getDisplayConfigs. If there * is no active configuration, HWC_ERROR shall be returned. * * Returns the configuration index on success or HWC_ERROR on error. * * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_4 and later. * It shall be NULL for previous versions. */ int (*getActiveConfig)(struct hwc_composer_device_1* dev, int disp); /* * (*setActiveConfig)() instructs the hardware composer to switch to the * display configuration at the given index in the list of configuration * handles returned by getDisplayConfigs. * * If this function returns without error, any subsequent calls to * getActiveConfig shall return the index set by this function until one * of the following occurs: * 1) Another successful call of this function * 2) The display is disconnected * * Returns 0 on success or a negative error code on error. If disp is a * hotpluggable display type and no display is connected, or if index is * outside of the range of hardware configurations returned by * getDisplayConfigs, an error shall be returned. * * This field is REQUIRED for HWC_DEVICE_API_VERSION_1_4 and later. * It shall be NULL for previous versions. */ int (*setActiveConfig)(struct hwc_composer_device_1* dev, int disp, int index); /* * Asynchronously update the location of the cursor layer. * * Within the standard prepare()/set() composition loop, the client * (surfaceflinger) can request that a given layer uses dedicated cursor * composition hardware by specifiying the HWC_IS_CURSOR_LAYER flag. Only * one layer per display can have this flag set. If the layer is suitable * for the platform's cursor hardware, hwcomposer will return from prepare() * a composition type of HWC_CURSOR_OVERLAY for that layer. This indicates * not only that the client is not responsible for compositing that layer, * but also that the client can continue to update the position of that layer * after a call to set(). This can reduce the visible latency of mouse * movement to visible, on-screen cursor updates. Calls to * setCursorPositionAsync() may be made from a different thread doing the * prepare()/set() composition loop, but care must be taken to not interleave * calls of setCursorPositionAsync() between calls of set()/prepare(). * * Notes: * - Only one layer per display can be specified as a cursor layer with * HWC_IS_CURSOR_LAYER. * - hwcomposer will only return one layer per display as HWC_CURSOR_OVERLAY * - This returns 0 on success or -errno on error. * - This field is optional for HWC_DEVICE_API_VERSION_1_4 and later. It * should be null for previous versions. */ int (*setCursorPositionAsync)(struct hwc_composer_device_1 *dev, int disp, int x_pos, int y_pos); /* * Reserved for future use. Must be NULL. */ void* reserved_proc[1]; } hwc_composer_device_1_t; /** convenience API for opening and closing a device */ static inline int hwc_open_1(const struct hw_module_t* module, hwc_composer_device_1_t** device) { return module->methods->open(module, HWC_HARDWARE_COMPOSER, TO_HW_DEVICE_T_OPEN(device)); } static inline int hwc_close_1(hwc_composer_device_1_t* device) { return device->common.close(&device->common); } /*****************************************************************************/ __END_DECLS #endif /* ANDROID_INCLUDE_HARDWARE_HWCOMPOSER_H */