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1 /*
2  * Copyright 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <android/hardware_buffer.h>
20 #include <gui/BufferQueueDefs.h>
21 #include <gui/ConsumerBase.h>
22 
23 #include <gui/IGraphicBufferProducer.h>
24 #include <sys/cdefs.h>
25 #include <system/graphics.h>
26 #include <ui/FenceTime.h>
27 #include <ui/GraphicBuffer.h>
28 #include <utils/Mutex.h>
29 #include <utils/String8.h>
30 
31 #include "EGLConsumer.h"
32 #include "ImageConsumer.h"
33 
34 namespace android {
35 
36 /*
37  * SurfaceTexture consumes buffers of graphics data from a BufferQueue,
38  * and makes them available to HWUI render thread as a SkImage and to
39  * an application GL render thread as an OpenGL texture.
40  *
41  * When attached to an application GL render thread, a typical usage
42  * pattern is to set up the SurfaceTexture with the
43  * desired options, and call updateTexImage() when a new frame is desired.
44  * If a new frame is available, the texture will be updated.  If not,
45  * the previous contents are retained.
46  *
47  * When attached to a HWUI render thread, the TextureView implementation
48  * calls dequeueBuffer, which either pulls a new buffer or returns the
49  * last cached buffer if BufferQueue is empty.
50  * When attached to HWUI render thread, SurfaceTexture is compatible to
51  * both Vulkan and GL drawing pipelines.
52  */
53 class ANDROID_API SurfaceTexture : public ConsumerBase {
54 public:
55     /**
56      * Callback function needed by dequeueBuffer. It creates a fence,
57      * that is signalled, when the previous buffer is no longer in use by HWUI
58      * and can be used by written by the producer.
59      */
60     typedef status_t (*SurfaceTexture_createReleaseFence)(bool useFenceSync, EGLSyncKHR* eglFence,
61                                                           EGLDisplay* display, int* releaseFence,
62                                                           void* passThroughHandle);
63 
64     /**
65      * Callback function needed by dequeueBuffer. It waits for the new buffer
66      * fence to signal, before issuing any draw commands.
67      */
68     typedef status_t (*SurfaceTexture_fenceWait)(int fence, void* passThroughHandle);
69 
70     enum { TEXTURE_EXTERNAL = 0x8D65 }; // GL_TEXTURE_EXTERNAL_OES
71     typedef ConsumerBase::FrameAvailableListener FrameAvailableListener;
72 
73     /**
74      * SurfaceTexture constructs a new SurfaceTexture object. If the constructor
75      * with the tex parameter is used, tex indicates the name of the OpenGL ES
76      * texture to which images are to be streamed. texTarget specifies the
77      * OpenGL ES texture target to which the texture will be bound in
78      * updateTexImage. useFenceSync specifies whether fences should be used to
79      * synchronize access to buffers if that behavior is enabled at
80      * compile-time.
81      *
82      * A SurfaceTexture may be detached from one OpenGL ES context and then
83      * attached to a different context using the detachFromContext and
84      * attachToContext methods, respectively. The intention of these methods is
85      * purely to allow a SurfaceTexture to be transferred from one consumer
86      * context to another. If such a transfer is not needed there is no
87      * requirement that either of these methods be called.
88      *
89      * If the constructor with the tex parameter is used, the SurfaceTexture is
90      * created in a state where it is considered attached to an OpenGL ES
91      * context for the purposes of the attachToContext and detachFromContext
92      * methods. However, despite being considered "attached" to a context, the
93      * specific OpenGL ES context doesn't get latched until the first call to
94      * updateTexImage. After that point, all calls to updateTexImage must be
95      * made with the same OpenGL ES context current.
96      *
97      * If the constructor without the tex parameter is used, the SurfaceTexture
98      * is created in a detached state, and attachToContext must be called before
99      * calls to updateTexImage.
100      */
101 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_CONSUMER_BASE_OWNS_BQ)
102     SurfaceTexture(uint32_t tex, uint32_t textureTarget, bool useFenceSync, bool isControlledByApp);
103 
104     SurfaceTexture(uint32_t textureTarget, bool useFenceSync, bool isControlledByApp);
105 
106     SurfaceTexture(const sp<IGraphicBufferConsumer>& bq, uint32_t tex, uint32_t textureTarget,
107                    bool useFenceSync, bool isControlledByApp)
108             __attribute((deprecated("Prefer ctors that create their own surface and consumer.")));
109 
110     SurfaceTexture(const sp<IGraphicBufferConsumer>& bq, uint32_t textureTarget, bool useFenceSync,
111                    bool isControlledByApp)
112             __attribute((deprecated("Prefer ctors that create their own surface and consumer.")));
113 #else
114     SurfaceTexture(const sp<IGraphicBufferConsumer>& bq, uint32_t tex, uint32_t textureTarget,
115                    bool useFenceSync, bool isControlledByApp);
116 
117     SurfaceTexture(const sp<IGraphicBufferConsumer>& bq, uint32_t textureTarget, bool useFenceSync,
118                    bool isControlledByApp);
119 #endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_CONSUMER_BASE_OWNS_BQ)
120 
121     /**
122      * updateTexImage acquires the most recently queued buffer, and sets the
123      * image contents of the target texture to it.
124      *
125      * This call may only be made while the OpenGL ES context to which the
126      * target texture belongs is bound to the calling thread.
127      *
128      * This calls doGLFenceWait to ensure proper synchronization.
129      */
130     status_t updateTexImage();
131 
132     /**
133      * releaseTexImage releases the texture acquired in updateTexImage().
134      * This is intended to be used in single buffer mode.
135      *
136      * This call may only be made while the OpenGL ES context to which the
137      * target texture belongs is bound to the calling thread.
138      */
139     status_t releaseTexImage();
140 
141     /**
142      * getTransformMatrix retrieves the 4x4 texture coordinate transform matrix
143      * associated with the texture image set by the most recent call to
144      * updateTexImage.
145      *
146      * This transform matrix maps 2D homogeneous texture coordinates of the form
147      * (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture
148      * coordinate that should be used to sample that location from the texture.
149      * Sampling the texture outside of the range of this transform is undefined.
150      *
151      * This transform is necessary to compensate for transforms that the stream
152      * content producer may implicitly apply to the content. By forcing users of
153      * a SurfaceTexture to apply this transform we avoid performing an extra
154      * copy of the data that would be needed to hide the transform from the
155      * user.
156      *
157      * The matrix is stored in column-major order so that it may be passed
158      * directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv
159      * functions.
160      */
161     void getTransformMatrix(float mtx[16]);
162 
163     /**
164      * Computes the transform matrix documented by getTransformMatrix
165      * from the BufferItem sub parts.
166      */
167     static void computeTransformMatrix(float outTransform[16], const sp<GraphicBuffer>& buf,
168                                        const Rect& cropRect, uint32_t transform, bool filtering);
169 
170     /**
171      * Scale the crop down horizontally or vertically such that it has the
172      * same aspect ratio as the buffer does.
173      */
174     static Rect scaleDownCrop(const Rect& crop, uint32_t bufferWidth, uint32_t bufferHeight);
175 
176     /**
177      * getTimestamp retrieves the timestamp associated with the texture image
178      * set by the most recent call to updateTexImage.
179      *
180      * The timestamp is in nanoseconds, and is monotonically increasing. Its
181      * other semantics (zero point, etc) are source-dependent and should be
182      * documented by the source.
183      */
184     int64_t getTimestamp();
185 
186     /**
187      * getDataSpace retrieves the DataSpace associated with the texture image
188      * set by the most recent call to updateTexImage.
189      */
190     android_dataspace getCurrentDataSpace();
191 
192     /**
193      * getFrameNumber retrieves the frame number associated with the texture
194      * image set by the most recent call to updateTexImage.
195      *
196      * The frame number is an incrementing counter set to 0 at the creation of
197      * the BufferQueue associated with this consumer.
198      */
199     uint64_t getFrameNumber();
200 
201     /**
202      * setDefaultBufferSize is used to set the size of buffers returned by
203      * requestBuffers when a with and height of zero is requested.
204      * A call to setDefaultBufferSize() may trigger requestBuffers() to
205      * be called from the client.
206      * The width and height parameters must be no greater than the minimum of
207      * GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv).
208      * An error due to invalid dimensions might not be reported until
209      * updateTexImage() is called.
210      */
211     status_t setDefaultBufferSize(uint32_t width, uint32_t height);
212 
213     /**
214      * setFilteringEnabled sets whether the transform matrix should be computed
215      * for use with bilinear filtering.
216      */
217     void setFilteringEnabled(bool enabled);
218 
219     /**
220      * getCurrentTextureTarget returns the texture target of the current
221      * texture as returned by updateTexImage().
222      */
223     uint32_t getCurrentTextureTarget() const;
224 
225     /**
226      * getCurrentCrop returns the cropping rectangle of the current buffer.
227      */
228     Rect getCurrentCrop() const;
229 
230     /**
231      * getCurrentTransform returns the transform of the current buffer.
232      */
233     uint32_t getCurrentTransform() const;
234 
235     /**
236      * getCurrentScalingMode returns the scaling mode of the current buffer.
237      */
238     uint32_t getCurrentScalingMode() const;
239 
240     /**
241      * getCurrentFence returns the fence indicating when the current buffer is
242      * ready to be read from.
243      */
244     sp<Fence> getCurrentFence() const;
245 
246     /**
247      * getCurrentFence returns the FenceTime indicating when the current
248      * buffer is ready to be read from.
249      */
250     std::shared_ptr<FenceTime> getCurrentFenceTime() const;
251 
252     /**
253      * setConsumerUsageBits overrides the ConsumerBase method to OR
254      * DEFAULT_USAGE_FLAGS to usage.
255      */
256     status_t setConsumerUsageBits(uint64_t usage);
257 
258     /**
259      * detachFromContext detaches the SurfaceTexture from the calling thread's
260      * current OpenGL ES context.  This context must be the same as the context
261      * that was current for previous calls to updateTexImage.
262      *
263      * Detaching a SurfaceTexture from an OpenGL ES context will result in the
264      * deletion of the OpenGL ES texture object into which the images were being
265      * streamed.  After a SurfaceTexture has been detached from the OpenGL ES
266      * context calls to updateTexImage will fail returning INVALID_OPERATION
267      * until the SurfaceTexture is attached to a new OpenGL ES context using the
268      * attachToContext method.
269      */
270     status_t detachFromContext();
271 
272     /**
273      * attachToContext attaches a SurfaceTexture that is currently in the
274      * 'detached' state to the current OpenGL ES context.  A SurfaceTexture is
275      * in the 'detached' state iff detachFromContext has successfully been
276      * called and no calls to attachToContext have succeeded since the last
277      * detachFromContext call.  Calls to attachToContext made on a
278      * SurfaceTexture that is not in the 'detached' state will result in an
279      * INVALID_OPERATION error.
280      *
281      * The tex argument specifies the OpenGL ES texture object name in the
282      * new context into which the image contents will be streamed.  A successful
283      * call to attachToContext will result in this texture object being bound to
284      * the texture target and populated with the image contents that were
285      * current at the time of the last call to detachFromContext.
286      */
287     status_t attachToContext(uint32_t tex);
288 
289     sp<GraphicBuffer> dequeueBuffer(int* outSlotid, android_dataspace* outDataspace,
290                                     HdrMetadata* outHdrMetadata, float* outTransformMatrix,
291                                     uint32_t* outTransform, bool* outQueueEmpty,
292                                     SurfaceTexture_createReleaseFence createFence,
293                                     SurfaceTexture_fenceWait fenceWait,
294                                     void* fencePassThroughHandle, ARect* currentCrop);
295 
296     /**
297      * takeConsumerOwnership attaches a SurfaceTexture that is currently in the
298      * 'detached' state to a consumer context (usually HWUI RenderThread).
299      */
300     void takeConsumerOwnership();
301 
302     /**
303      * releaseConsumerOwnership detaches a SurfaceTexture from a consumer
304      * context (usually HWUI RenderThread).
305      */
306     void releaseConsumerOwnership();
307 
308     /**
309      * Interface for SurfaceTexture callback(s).
310      */
311     struct SurfaceTextureListener : public RefBase {
312         virtual void onFrameAvailable(const BufferItem& item) = 0;
313         virtual void onSetFrameRate(float frameRate, int8_t compatibility,
314                                     int8_t changeFrameRateStrategy) = 0;
315     };
316 
317     /**
318      * setSurfaceTextureListener registers a SurfaceTextureListener.
319      */
320     void setSurfaceTextureListener(const sp<SurfaceTextureListener>&);
321 
322 protected:
323     /**
324      * abandonLocked overrides the ConsumerBase method to clear
325      * mCurrentTextureImage in addition to the ConsumerBase behavior.
326      */
327     virtual void abandonLocked();
328 
329     /**
330      * dumpLocked overrides the ConsumerBase method to dump SurfaceTexture-
331      * specific info in addition to the ConsumerBase behavior.
332      */
333     virtual void dumpLocked(String8& result, const char* prefix) const override;
334 
335     /**
336      * acquireBufferLocked overrides the ConsumerBase method to update the
337      * mEglSlots array in addition to the ConsumerBase behavior.
338      */
339     virtual status_t acquireBufferLocked(BufferItem* item, nsecs_t presentWhen,
340                                          uint64_t maxFrameNumber = 0) override;
341 
342     /**
343      * releaseBufferLocked overrides the ConsumerBase method to update the
344      * mEglSlots array in addition to the ConsumerBase.
345      */
346 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(BQ_GL_FENCE_CLEANUP)
347     virtual status_t releaseBufferLocked(int slot, const sp<GraphicBuffer> graphicBuffer) override;
348 #else
349     virtual status_t releaseBufferLocked(int slot, const sp<GraphicBuffer> graphicBuffer,
350                                          EGLDisplay display = EGL_NO_DISPLAY,
351                                          EGLSyncKHR eglFence = EGL_NO_SYNC_KHR) override;
352 #endif
353 
354     /**
355      * freeBufferLocked frees up the given buffer slot. If the slot has been
356      * initialized this will release the reference to the GraphicBuffer in that
357      * slot and destroy the EGLImage in that slot.  Otherwise it has no effect.
358      *
359      * This method must be called with mMutex locked.
360      */
361     virtual void freeBufferLocked(int slotIndex);
362 
363     /**
364      * computeCurrentTransformMatrixLocked computes the transform matrix for the
365      * current texture.  It uses mCurrentTransform and the current GraphicBuffer
366      * to compute this matrix and stores it in mCurrentTransformMatrix.
367      * mCurrentTextureImage must not be NULL.
368      */
369     void computeCurrentTransformMatrixLocked();
370 
371     /**
372      * onSetFrameRate Notifies the consumer of a setFrameRate call from the producer side.
373      */
374 #if COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(BQ_SETFRAMERATE)
375     void onSetFrameRate(float frameRate, int8_t compatibility,
376                         int8_t changeFrameRateStrategy) override;
377 #endif
378 
379     /**
380      * The default consumer usage flags that SurfaceTexture always sets on its
381      * BufferQueue instance; these will be OR:d with any additional flags passed
382      * from the SurfaceTexture user. In particular, SurfaceTexture will always
383      * consume buffers as hardware textures.
384      */
385     static const uint64_t DEFAULT_USAGE_FLAGS = GraphicBuffer::USAGE_HW_TEXTURE;
386 
387     /**
388      * mCurrentCrop is the crop rectangle that applies to the current texture.
389      * It gets set each time updateTexImage is called.
390      */
391     Rect mCurrentCrop;
392 
393     /**
394      * mCurrentTransform is the transform identifier for the current texture. It
395      * gets set each time updateTexImage is called.
396      */
397     uint32_t mCurrentTransform;
398 
399     /**
400      * mCurrentScalingMode is the scaling mode for the current texture. It gets
401      * set each time updateTexImage is called.
402      */
403     uint32_t mCurrentScalingMode;
404 
405     /**
406      * mCurrentFence is the fence received from BufferQueue in updateTexImage.
407      */
408     sp<Fence> mCurrentFence;
409 
410     /**
411      * The FenceTime wrapper around mCurrentFence.
412      */
413     std::shared_ptr<FenceTime> mCurrentFenceTime{FenceTime::NO_FENCE};
414 
415     /**
416      * mCurrentTransformMatrix is the transform matrix for the current texture.
417      * It gets computed by computeTransformMatrix each time updateTexImage is
418      * called.
419      */
420     float mCurrentTransformMatrix[16];
421 
422     /**
423      * mCurrentTimestamp is the timestamp for the current texture. It
424      * gets set each time updateTexImage is called.
425      */
426     int64_t mCurrentTimestamp;
427 
428     /**
429      * mCurrentDataSpace is the dataspace for the current texture. It
430      * gets set each time updateTexImage is called.
431      */
432     android_dataspace mCurrentDataSpace;
433 
434     /**
435      * mCurrentFrameNumber is the frame counter for the current texture.
436      * It gets set each time updateTexImage is called.
437      */
438     uint64_t mCurrentFrameNumber;
439 
440     uint32_t mDefaultWidth, mDefaultHeight;
441 
442     /**
443      * mFilteringEnabled indicates whether the transform matrix is computed for
444      * use with bilinear filtering. It defaults to true and is changed by
445      * setFilteringEnabled().
446      */
447     bool mFilteringEnabled;
448 
449     /**
450      * mTexName is the name of the OpenGL texture to which streamed images will
451      * be bound when updateTexImage is called. It is set at construction time
452      * and can be changed with a call to attachToContext.
453      */
454     uint32_t mTexName;
455 
456     /**
457      * mUseFenceSync indicates whether creation of the EGL_KHR_fence_sync
458      * extension should be used to prevent buffers from being dequeued before
459      * it's safe for them to be written. It gets set at construction time and
460      * never changes.
461      */
462     const bool mUseFenceSync;
463 
464     /**
465      * mTexTarget is the GL texture target with which the GL texture object is
466      * associated.  It is set in the constructor and never changed.  It is
467      * almost always GL_TEXTURE_EXTERNAL_OES except for one use case in Android
468      * Browser.  In that case it is set to GL_TEXTURE_2D to allow
469      * glCopyTexSubImage to read from the texture.  This is a hack to work
470      * around a GL driver limitation on the number of FBO attachments, which the
471      * browser's tile cache exceeds.
472      */
473     const uint32_t mTexTarget;
474 
475     /**
476      * mCurrentTexture is the buffer slot index of the buffer that is currently
477      * bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT,
478      * indicating that no buffer slot is currently bound to the texture. Note,
479      * however, that a value of INVALID_BUFFER_SLOT does not necessarily mean
480      * that no buffer is bound to the texture. A call to setBufferCount will
481      * reset mCurrentTexture to INVALID_BUFFER_SLOT.
482      */
483     int mCurrentTexture;
484 
485     enum class OpMode { detached, attachedToConsumer, attachedToGL };
486     /**
487      * mOpMode indicates whether the SurfaceTexture is currently attached to
488      * an OpenGL ES context or the consumer context.  For legacy reasons, this
489      * is initialized to, "attachedToGL" indicating that the SurfaceTexture is
490      * considered to be attached to whatever GL context is current at the time
491      * of the first updateTexImage call.
492      * It is set to "detached" by detachFromContext, and then set to
493      * "attachedToGL" again by attachToContext.
494      * takeConsumerOwnership/releaseConsumerOwnership are used to attach/detach
495      * from a consumer context - usually HWUI RenderThread.
496      */
497     OpMode mOpMode;
498 
499     /**
500      * mEGLConsumer has SurfaceTexture logic used when attached to GL context.
501      */
502     EGLConsumer mEGLConsumer;
503 
504     /**
505      * mImageConsumer has SurfaceTexture logic used when attached to a consumer
506      * context (usually HWUI RenderThread).
507      */
508     ImageConsumer mImageConsumer;
509 
510     /**
511      * mSurfaceTextureListener holds the registered SurfaceTextureListener.
512      * Note that SurfaceTexture holds the lister with an sp<>, which means that the listener
513      * must only hold a wp<> to SurfaceTexture and not an sp<>.
514      */
515     sp<SurfaceTextureListener> mSurfaceTextureListener;
516 
517     friend class ImageConsumer;
518     friend class EGLConsumer;
519 
520 private:
521     void initialize();
522 
523     // Proxy listener to avoid having SurfaceTexture directly implement FrameAvailableListener as it
524     // is extending ConsumerBase which also implements FrameAvailableListener.
525     class FrameAvailableListenerProxy : public ConsumerBase::FrameAvailableListener {
526     public:
FrameAvailableListenerProxy(const wp<SurfaceTextureListener> & listener)527         FrameAvailableListenerProxy(const wp<SurfaceTextureListener>& listener)
528               : mSurfaceTextureListener(listener) {}
529 
530     private:
531         void onFrameAvailable(const BufferItem& item) override;
532 
533         const wp<SurfaceTextureListener> mSurfaceTextureListener;
534     };
535     sp<FrameAvailableListenerProxy> mFrameAvailableListenerProxy;
536 };
537 
538 // ----------------------------------------------------------------------------
539 } // namespace android
540