SurfaceTexture.h revision dc5b485f74edf2d2f31c62054eb6c180421a3ade
1/* 2 * Copyright (C) 2010 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#ifndef ANDROID_GUI_SURFACETEXTURE_H 18#define ANDROID_GUI_SURFACETEXTURE_H 19 20#include <EGL/egl.h> 21#include <EGL/eglext.h> 22#include <GLES2/gl2.h> 23#include <GLES2/gl2ext.h> 24 25#include <gui/ISurfaceTexture.h> 26#include <gui/BufferQueue.h> 27 28#include <ui/GraphicBuffer.h> 29 30#include <utils/String8.h> 31#include <utils/Vector.h> 32#include <utils/threads.h> 33 34#define ANDROID_GRAPHICS_SURFACETEXTURE_JNI_ID "mSurfaceTexture" 35 36namespace android { 37// ---------------------------------------------------------------------------- 38 39 40class String8; 41 42class SurfaceTexture : public virtual RefBase, 43 protected BufferQueue::ConsumerListener { 44public: 45 struct FrameAvailableListener : public virtual RefBase { 46 // onFrameAvailable() is called each time an additional frame becomes 47 // available for consumption. This means that frames that are queued 48 // while in asynchronous mode only trigger the callback if no previous 49 // frames are pending. Frames queued while in synchronous mode always 50 // trigger the callback. 51 // 52 // This is called without any lock held and can be called concurrently 53 // by multiple threads. 54 virtual void onFrameAvailable() = 0; 55 }; 56 57 // SurfaceTexture constructs a new SurfaceTexture object. tex indicates the 58 // name of the OpenGL ES texture to which images are to be streamed. 59 // allowSynchronousMode specifies whether or not synchronous mode can be 60 // enabled. texTarget specifies the OpenGL ES texture target to which the 61 // texture will be bound in updateTexImage. useFenceSync specifies whether 62 // fences should be used to synchronize access to buffers if that behavior 63 // is enabled at compile-time. A custom bufferQueue can be specified 64 // if behavior for queue/dequeue/connect etc needs to be customized. 65 // Otherwise a default BufferQueue will be created and used. 66 // 67 // For legacy reasons, the SurfaceTexture is created in a state where it is 68 // considered attached to an OpenGL ES context for the purposes of the 69 // attachToContext and detachFromContext methods. However, despite being 70 // considered "attached" to a context, the specific OpenGL ES context 71 // doesn't get latched until the first call to updateTexImage. After that 72 // point, all calls to updateTexImage must be made with the same OpenGL ES 73 // context current. 74 // 75 // A SurfaceTexture may be detached from one OpenGL ES context and then 76 // attached to a different context using the detachFromContext and 77 // attachToContext methods, respectively. The intention of these methods is 78 // purely to allow a SurfaceTexture to be transferred from one consumer 79 // context to another. If such a transfer is not needed there is no 80 // requirement that either of these methods be called. 81 SurfaceTexture(GLuint tex, bool allowSynchronousMode = true, 82 GLenum texTarget = GL_TEXTURE_EXTERNAL_OES, bool useFenceSync = true, 83 const sp<BufferQueue> &bufferQueue = 0); 84 85 virtual ~SurfaceTexture(); 86 87 // updateTexImage sets the image contents of the target texture to that of 88 // the most recently queued buffer. 89 // 90 // This call may only be made while the OpenGL ES context to which the 91 // target texture belongs is bound to the calling thread. 92 status_t updateTexImage(); 93 94 // setReleaseFence stores a fence file descriptor that will signal when the 95 // current buffer is no longer being read. This fence will be returned to 96 // the producer when the current buffer is released by updateTexImage(). 97 // Multiple fences can be set for a given buffer; they will be merged into 98 // a single union fence. The SurfaceTexture will close the file descriptor 99 // when finished with it. 100 void setReleaseFence(int fenceFd); 101 102 // setBufferCountServer set the buffer count. If the client has requested 103 // a buffer count using setBufferCount, the server-buffer count will 104 // take effect once the client sets the count back to zero. 105 status_t setBufferCountServer(int bufferCount); 106 107 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 108 // associated with the texture image set by the most recent call to 109 // updateTexImage. 110 // 111 // This transform matrix maps 2D homogeneous texture coordinates of the form 112 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 113 // coordinate that should be used to sample that location from the texture. 114 // Sampling the texture outside of the range of this transform is undefined. 115 // 116 // This transform is necessary to compensate for transforms that the stream 117 // content producer may implicitly apply to the content. By forcing users of 118 // a SurfaceTexture to apply this transform we avoid performing an extra 119 // copy of the data that would be needed to hide the transform from the 120 // user. 121 // 122 // The matrix is stored in column-major order so that it may be passed 123 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 124 // functions. 125 void getTransformMatrix(float mtx[16]); 126 127 // getTimestamp retrieves the timestamp associated with the texture image 128 // set by the most recent call to updateTexImage. 129 // 130 // The timestamp is in nanoseconds, and is monotonically increasing. Its 131 // other semantics (zero point, etc) are source-dependent and should be 132 // documented by the source. 133 int64_t getTimestamp(); 134 135 // setFrameAvailableListener sets the listener object that will be notified 136 // when a new frame becomes available. 137 void setFrameAvailableListener(const sp<FrameAvailableListener>& listener); 138 139 // getAllocator retrieves the binder object that must be referenced as long 140 // as the GraphicBuffers dequeued from this SurfaceTexture are referenced. 141 // Holding this binder reference prevents SurfaceFlinger from freeing the 142 // buffers before the client is done with them. 143 sp<IBinder> getAllocator(); 144 145 // setDefaultBufferSize is used to set the size of buffers returned by 146 // requestBuffers when a with and height of zero is requested. 147 // A call to setDefaultBufferSize() may trigger requestBuffers() to 148 // be called from the client. 149 // The width and height parameters must be no greater than the minimum of 150 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 151 // An error due to invalid dimensions might not be reported until 152 // updateTexImage() is called. 153 status_t setDefaultBufferSize(uint32_t width, uint32_t height); 154 155 // setFilteringEnabled sets whether the transform matrix should be computed 156 // for use with bilinear filtering. 157 void setFilteringEnabled(bool enabled); 158 159 // getCurrentBuffer returns the buffer associated with the current image. 160 sp<GraphicBuffer> getCurrentBuffer() const; 161 162 // getCurrentTextureTarget returns the texture target of the current 163 // texture as returned by updateTexImage(). 164 GLenum getCurrentTextureTarget() const; 165 166 // getCurrentCrop returns the cropping rectangle of the current buffer. 167 Rect getCurrentCrop() const; 168 169 // getCurrentTransform returns the transform of the current buffer. 170 uint32_t getCurrentTransform() const; 171 172 // getCurrentScalingMode returns the scaling mode of the current buffer. 173 uint32_t getCurrentScalingMode() const; 174 175 // getCurrentFence returns the fence indicating when the current buffer is 176 // ready to be read from. 177 sp<Fence> getCurrentFence() const; 178 179 // isSynchronousMode returns whether the SurfaceTexture is currently in 180 // synchronous mode. 181 bool isSynchronousMode() const; 182 183 // abandon frees all the buffers and puts the SurfaceTexture into the 184 // 'abandoned' state. Once put in this state the SurfaceTexture can never 185 // leave it. When in the 'abandoned' state, all methods of the 186 // ISurfaceTexture interface will fail with the NO_INIT error. 187 // 188 // Note that while calling this method causes all the buffers to be freed 189 // from the perspective of the the SurfaceTexture, if there are additional 190 // references on the buffers (e.g. if a buffer is referenced by a client or 191 // by OpenGL ES as a texture) then those buffer will remain allocated. 192 void abandon(); 193 194 // set the name of the SurfaceTexture that will be used to identify it in 195 // log messages. 196 void setName(const String8& name); 197 198 // These functions call the corresponding BufferQueue implementation 199 // so the refactoring can proceed smoothly 200 status_t setDefaultBufferFormat(uint32_t defaultFormat); 201 status_t setConsumerUsageBits(uint32_t usage); 202 status_t setTransformHint(uint32_t hint); 203 virtual status_t setSynchronousMode(bool enabled); 204 205 // getBufferQueue returns the BufferQueue object to which this 206 // SurfaceTexture is connected. 207 sp<BufferQueue> getBufferQueue() const; 208 209 // detachFromContext detaches the SurfaceTexture from the calling thread's 210 // current OpenGL ES context. This context must be the same as the context 211 // that was current for previous calls to updateTexImage. 212 // 213 // Detaching a SurfaceTexture from an OpenGL ES context will result in the 214 // deletion of the OpenGL ES texture object into which the images were being 215 // streamed. After a SurfaceTexture has been detached from the OpenGL ES 216 // context calls to updateTexImage will fail returning INVALID_OPERATION 217 // until the SurfaceTexture is attached to a new OpenGL ES context using the 218 // attachToContext method. 219 status_t detachFromContext(); 220 221 // attachToContext attaches a SurfaceTexture that is currently in the 222 // 'detached' state to the current OpenGL ES context. A SurfaceTexture is 223 // in the 'detached' state iff detachFromContext has successfully been 224 // called and no calls to attachToContext have succeeded since the last 225 // detachFromContext call. Calls to attachToContext made on a 226 // SurfaceTexture that is not in the 'detached' state will result in an 227 // INVALID_OPERATION error. 228 // 229 // The tex argument specifies the OpenGL ES texture object name in the 230 // new context into which the image contents will be streamed. A successful 231 // call to attachToContext will result in this texture object being bound to 232 // the texture target and populated with the image contents that were 233 // current at the time of the last call to detachFromContext. 234 status_t attachToContext(GLuint tex); 235 236 // dump our state in a String 237 virtual void dump(String8& result) const; 238 virtual void dump(String8& result, const char* prefix, char* buffer, size_t SIZE) const; 239 240protected: 241 242 // Implementation of the BufferQueue::ConsumerListener interface. These 243 // calls are used to notify the SurfaceTexture of asynchronous events in the 244 // BufferQueue. 245 virtual void onFrameAvailable(); 246 virtual void onBuffersReleased(); 247 248 static bool isExternalFormat(uint32_t format); 249 250private: 251 // this version of updateTexImage() takes a functor used to reject or not 252 // the newly acquired buffer. 253 // this API is TEMPORARY and intended to be used by SurfaceFlinger only, 254 // which is why class Layer is made a friend of SurfaceTexture below. 255 class BufferRejecter { 256 friend class SurfaceTexture; 257 virtual bool reject(const sp<GraphicBuffer>& buf, 258 const BufferQueue::BufferItem& item) = 0; 259 protected: 260 virtual ~BufferRejecter() { } 261 }; 262 friend class Layer; 263 status_t updateTexImage(BufferRejecter* rejecter); 264 265 // createImage creates a new EGLImage from a GraphicBuffer. 266 EGLImageKHR createImage(EGLDisplay dpy, 267 const sp<GraphicBuffer>& graphicBuffer); 268 269 // freeBufferLocked frees up the given buffer slot. If the slot has been 270 // initialized this will release the reference to the GraphicBuffer in that 271 // slot and destroy the EGLImage in that slot. Otherwise it has no effect. 272 // 273 // This method must be called with mMutex locked. 274 void freeBufferLocked(int slotIndex); 275 276 // computeCurrentTransformMatrix computes the transform matrix for the 277 // current texture. It uses mCurrentTransform and the current GraphicBuffer 278 // to compute this matrix and stores it in mCurrentTransformMatrix. 279 void computeCurrentTransformMatrix(); 280 281 // syncForReleaseLocked performs the synchronization needed to release the 282 // current slot from an OpenGL ES context. If needed it will set the 283 // current slot's fence to guard against a producer accessing the buffer 284 // before the outstanding accesses have completed. 285 status_t syncForReleaseLocked(EGLDisplay dpy); 286 287 // The default consumer usage flags that SurfaceTexture always sets on its 288 // BufferQueue instance; these will be OR:d with any additional flags passed 289 // from the SurfaceTexture user. In particular, SurfaceTexture will always 290 // consume buffers as hardware textures. 291 static const uint32_t DEFAULT_USAGE_FLAGS = GraphicBuffer::USAGE_HW_TEXTURE; 292 293 // mCurrentTextureBuf is the graphic buffer of the current texture. It's 294 // possible that this buffer is not associated with any buffer slot, so we 295 // must track it separately in order to support the getCurrentBuffer method. 296 sp<GraphicBuffer> mCurrentTextureBuf; 297 298 // mCurrentCrop is the crop rectangle that applies to the current texture. 299 // It gets set each time updateTexImage is called. 300 Rect mCurrentCrop; 301 302 // mCurrentTransform is the transform identifier for the current texture. It 303 // gets set each time updateTexImage is called. 304 uint32_t mCurrentTransform; 305 306 // mCurrentScalingMode is the scaling mode for the current texture. It gets 307 // set to each time updateTexImage is called. 308 uint32_t mCurrentScalingMode; 309 310 // mCurrentFence is the fence received from BufferQueue in updateTexImage. 311 sp<Fence> mCurrentFence; 312 313 // mCurrentTransformMatrix is the transform matrix for the current texture. 314 // It gets computed by computeTransformMatrix each time updateTexImage is 315 // called. 316 float mCurrentTransformMatrix[16]; 317 318 // mCurrentTimestamp is the timestamp for the current texture. It 319 // gets set each time updateTexImage is called. 320 int64_t mCurrentTimestamp; 321 322 uint32_t mDefaultWidth, mDefaultHeight; 323 324 // mFilteringEnabled indicates whether the transform matrix is computed for 325 // use with bilinear filtering. It defaults to true and is changed by 326 // setFilteringEnabled(). 327 bool mFilteringEnabled; 328 329 // mTexName is the name of the OpenGL texture to which streamed images will 330 // be bound when updateTexImage is called. It is set at construction time 331 // and can be changed with a call to attachToContext. 332 GLuint mTexName; 333 334 // mUseFenceSync indicates whether creation of the EGL_KHR_fence_sync 335 // extension should be used to prevent buffers from being dequeued before 336 // it's safe for them to be written. It gets set at construction time and 337 // never changes. 338 const bool mUseFenceSync; 339 340 // mTexTarget is the GL texture target with which the GL texture object is 341 // associated. It is set in the constructor and never changed. It is 342 // almost always GL_TEXTURE_EXTERNAL_OES except for one use case in Android 343 // Browser. In that case it is set to GL_TEXTURE_2D to allow 344 // glCopyTexSubImage to read from the texture. This is a hack to work 345 // around a GL driver limitation on the number of FBO attachments, which the 346 // browser's tile cache exceeds. 347 const GLenum mTexTarget; 348 349 // EGLSlot contains the information and object references that 350 // SurfaceTexture maintains about a BufferQueue buffer slot. 351 struct EGLSlot { 352 EGLSlot() 353 : mEglImage(EGL_NO_IMAGE_KHR), 354 mFence(EGL_NO_SYNC_KHR) { 355 } 356 357 sp<GraphicBuffer> mGraphicBuffer; 358 359 // mEglImage is the EGLImage created from mGraphicBuffer. 360 EGLImageKHR mEglImage; 361 362 // mFence is the EGL sync object that must signal before the buffer 363 // associated with this buffer slot may be dequeued. It is initialized 364 // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based 365 // on a compile-time option) set to a new sync object in updateTexImage. 366 EGLSyncKHR mFence; 367 368 // mReleaseFence is a fence which will signal when the buffer 369 // associated with this buffer slot is no longer being used by the 370 // consumer and can be overwritten. The buffer can be dequeued before 371 // the fence signals; the producer is responsible for delaying writes 372 // until it signals. 373 sp<Fence> mReleaseFence; 374 }; 375 376 // mEglDisplay is the EGLDisplay with which this SurfaceTexture is currently 377 // associated. It is intialized to EGL_NO_DISPLAY and gets set to the 378 // current display when updateTexImage is called for the first time and when 379 // attachToContext is called. 380 EGLDisplay mEglDisplay; 381 382 // mEglContext is the OpenGL ES context with which this SurfaceTexture is 383 // currently associated. It is initialized to EGL_NO_CONTEXT and gets set 384 // to the current GL context when updateTexImage is called for the first 385 // time and when attachToContext is called. 386 EGLContext mEglContext; 387 388 // mEGLSlots stores the buffers that have been allocated by the BufferQueue 389 // for each buffer slot. It is initialized to null pointers, and gets 390 // filled in with the result of BufferQueue::acquire when the 391 // client dequeues a buffer from a 392 // slot that has not yet been used. The buffer allocated to a slot will also 393 // be replaced if the requested buffer usage or geometry differs from that 394 // of the buffer allocated to a slot. 395 EGLSlot mEGLSlots[BufferQueue::NUM_BUFFER_SLOTS]; 396 397 // mAbandoned indicates that the BufferQueue will no longer be used to 398 // consume images buffers pushed to it using the ISurfaceTexture interface. 399 // It is initialized to false, and set to true in the abandon method. A 400 // BufferQueue that has been abandoned will return the NO_INIT error from 401 // all ISurfaceTexture methods capable of returning an error. 402 bool mAbandoned; 403 404 // mName is a string used to identify the SurfaceTexture in log messages. 405 // It can be set by the setName method. 406 String8 mName; 407 408 // mFrameAvailableListener is the listener object that will be called when a 409 // new frame becomes available. If it is not NULL it will be called from 410 // queueBuffer. 411 sp<FrameAvailableListener> mFrameAvailableListener; 412 413 // mCurrentTexture is the buffer slot index of the buffer that is currently 414 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 415 // indicating that no buffer slot is currently bound to the texture. Note, 416 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 417 // that no buffer is bound to the texture. A call to setBufferCount will 418 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 419 int mCurrentTexture; 420 421 // The SurfaceTexture has-a BufferQueue and is responsible for creating this object 422 // if none is supplied 423 sp<BufferQueue> mBufferQueue; 424 425 // mAttached indicates whether the SurfaceTexture is currently attached to 426 // an OpenGL ES context. For legacy reasons, this is initialized to true, 427 // indicating that the SurfaceTexture is considered to be attached to 428 // whatever context is current at the time of the first updateTexImage call. 429 // It is set to false by detachFromContext, and then set to true again by 430 // attachToContext. 431 bool mAttached; 432 433 // mMutex is the mutex used to prevent concurrent access to the member 434 // variables of SurfaceTexture objects. It must be locked whenever the 435 // member variables are accessed. 436 mutable Mutex mMutex; 437}; 438 439// ---------------------------------------------------------------------------- 440}; // namespace android 441 442#endif // ANDROID_GUI_SURFACETEXTURE_H 443