SurfaceTexture.h revision 9abe1ebc9575dc5a19bf1dfce6e9b02e03374457
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 // setBufferCountServer set the buffer count. If the client has requested 95 // a buffer count using setBufferCount, the server-buffer count will 96 // take effect once the client sets the count back to zero. 97 status_t setBufferCountServer(int bufferCount); 98 99 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 100 // associated with the texture image set by the most recent call to 101 // updateTexImage. 102 // 103 // This transform matrix maps 2D homogeneous texture coordinates of the form 104 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 105 // coordinate that should be used to sample that location from the texture. 106 // Sampling the texture outside of the range of this transform is undefined. 107 // 108 // This transform is necessary to compensate for transforms that the stream 109 // content producer may implicitly apply to the content. By forcing users of 110 // a SurfaceTexture to apply this transform we avoid performing an extra 111 // copy of the data that would be needed to hide the transform from the 112 // user. 113 // 114 // The matrix is stored in column-major order so that it may be passed 115 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 116 // functions. 117 void getTransformMatrix(float mtx[16]); 118 119 // getTimestamp retrieves the timestamp associated with the texture image 120 // set by the most recent call to updateTexImage. 121 // 122 // The timestamp is in nanoseconds, and is monotonically increasing. Its 123 // other semantics (zero point, etc) are source-dependent and should be 124 // documented by the source. 125 int64_t getTimestamp(); 126 127 // setFrameAvailableListener sets the listener object that will be notified 128 // when a new frame becomes available. 129 void setFrameAvailableListener(const sp<FrameAvailableListener>& listener); 130 131 // getAllocator retrieves the binder object that must be referenced as long 132 // as the GraphicBuffers dequeued from this SurfaceTexture are referenced. 133 // Holding this binder reference prevents SurfaceFlinger from freeing the 134 // buffers before the client is done with them. 135 sp<IBinder> getAllocator(); 136 137 // setDefaultBufferSize is used to set the size of buffers returned by 138 // requestBuffers when a with and height of zero is requested. 139 // A call to setDefaultBufferSize() may trigger requestBuffers() to 140 // be called from the client. 141 // The width and height parameters must be no greater than the minimum of 142 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 143 // An error due to invalid dimensions might not be reported until 144 // updateTexImage() is called. 145 status_t setDefaultBufferSize(uint32_t width, uint32_t height); 146 147 // getCurrentBuffer returns the buffer associated with the current image. 148 sp<GraphicBuffer> getCurrentBuffer() const; 149 150 // getCurrentTextureTarget returns the texture target of the current 151 // texture as returned by updateTexImage(). 152 GLenum getCurrentTextureTarget() const; 153 154 // getCurrentCrop returns the cropping rectangle of the current buffer 155 Rect getCurrentCrop() const; 156 157 // getCurrentTransform returns the transform of the current buffer 158 uint32_t getCurrentTransform() const; 159 160 // getCurrentScalingMode returns the scaling mode of the current buffer 161 uint32_t getCurrentScalingMode() const; 162 163 // isSynchronousMode returns whether the SurfaceTexture is currently in 164 // synchronous mode. 165 bool isSynchronousMode() const; 166 167 // abandon frees all the buffers and puts the SurfaceTexture into the 168 // 'abandoned' state. Once put in this state the SurfaceTexture can never 169 // leave it. When in the 'abandoned' state, all methods of the 170 // ISurfaceTexture interface will fail with the NO_INIT error. 171 // 172 // Note that while calling this method causes all the buffers to be freed 173 // from the perspective of the the SurfaceTexture, if there are additional 174 // references on the buffers (e.g. if a buffer is referenced by a client or 175 // by OpenGL ES as a texture) then those buffer will remain allocated. 176 void abandon(); 177 178 // set the name of the SurfaceTexture that will be used to identify it in 179 // log messages. 180 void setName(const String8& name); 181 182 // These functions call the corresponding BufferQueue implementation 183 // so the refactoring can proceed smoothly 184 status_t setDefaultBufferFormat(uint32_t defaultFormat); 185 status_t setConsumerUsageBits(uint32_t usage); 186 status_t setTransformHint(uint32_t hint); 187 virtual status_t setSynchronousMode(bool enabled); 188 virtual status_t connect(int api, 189 uint32_t* outWidth, uint32_t* outHeight, uint32_t* outTransform); 190 191 // getBufferQueue returns the BufferQueue object to which this 192 // SurfaceTexture is connected. 193 sp<BufferQueue> getBufferQueue() const; 194 195 // detachFromContext detaches the SurfaceTexture from the calling thread's 196 // current OpenGL ES context. This context must be the same as the context 197 // that was current for previous calls to updateTexImage. 198 // 199 // Detaching a SurfaceTexture from an OpenGL ES context will result in the 200 // deletion of the OpenGL ES texture object into which the images were being 201 // streamed. After a SurfaceTexture has been detached from the OpenGL ES 202 // context calls to updateTexImage will fail returning INVALID_OPERATION 203 // until the SurfaceTexture is attached to a new OpenGL ES context using the 204 // attachToContext method. 205 status_t detachFromContext(); 206 207 // attachToContext attaches a SurfaceTexture that is currently in the 208 // 'detached' state to the current OpenGL ES context. A SurfaceTexture is 209 // in the 'detached' state iff detachFromContext has successfully been 210 // called and no calls to attachToContext have succeeded since the last 211 // detachFromContext call. Calls to attachToContext made on a 212 // SurfaceTexture that is not in the 'detached' state will result in an 213 // INVALID_OPERATION error. 214 // 215 // The tex argument specifies the OpenGL ES texture object name in the 216 // new context into which the image contents will be streamed. A successful 217 // call to attachToContext will result in this texture object being bound to 218 // the texture target and populated with the image contents that were 219 // current at the time of the last call to detachFromContext. 220 status_t attachToContext(GLuint tex); 221 222 // dump our state in a String 223 virtual void dump(String8& result) const; 224 virtual void dump(String8& result, const char* prefix, char* buffer, size_t SIZE) const; 225 226protected: 227 228 // Implementation of the BufferQueue::ConsumerListener interface. These 229 // calls are used to notify the SurfaceTexture of asynchronous events in the 230 // BufferQueue. 231 virtual void onFrameAvailable(); 232 virtual void onBuffersReleased(); 233 234 static bool isExternalFormat(uint32_t format); 235 236private: 237 238 // createImage creates a new EGLImage from a GraphicBuffer. 239 EGLImageKHR createImage(EGLDisplay dpy, 240 const sp<GraphicBuffer>& graphicBuffer); 241 242 // freeBufferLocked frees up the given buffer slot. If the slot has been 243 // initialized this will release the reference to the GraphicBuffer in that 244 // slot and destroy the EGLImage in that slot. Otherwise it has no effect. 245 // 246 // This method must be called with mMutex locked. 247 void freeBufferLocked(int slotIndex); 248 249 // computeCurrentTransformMatrix computes the transform matrix for the 250 // current texture. It uses mCurrentTransform and the current GraphicBuffer 251 // to compute this matrix and stores it in mCurrentTransformMatrix. 252 void computeCurrentTransformMatrix(); 253 254 // syncForReleaseLocked performs the synchronization needed to release the 255 // current slot from an OpenGL ES context. If needed it will set the 256 // current slot's fence to guard against a producer accessing the buffer 257 // before the outstanding accesses have completed. 258 status_t syncForReleaseLocked(EGLDisplay dpy); 259 260 // mCurrentTextureBuf is the graphic buffer of the current texture. It's 261 // possible that this buffer is not associated with any buffer slot, so we 262 // must track it separately in order to support the getCurrentBuffer method. 263 sp<GraphicBuffer> mCurrentTextureBuf; 264 265 // mCurrentCrop is the crop rectangle that applies to the current texture. 266 // It gets set each time updateTexImage is called. 267 Rect mCurrentCrop; 268 269 // mCurrentTransform is the transform identifier for the current texture. It 270 // gets set each time updateTexImage is called. 271 uint32_t mCurrentTransform; 272 273 // mCurrentScalingMode is the scaling mode for the current texture. It gets 274 // set to each time updateTexImage is called. 275 uint32_t mCurrentScalingMode; 276 277 // mCurrentTransformMatrix is the transform matrix for the current texture. 278 // It gets computed by computeTransformMatrix each time updateTexImage is 279 // called. 280 float mCurrentTransformMatrix[16]; 281 282 // mCurrentTimestamp is the timestamp for the current texture. It 283 // gets set each time updateTexImage is called. 284 int64_t mCurrentTimestamp; 285 286 // mTexName is the name of the OpenGL texture to which streamed images will 287 // be bound when updateTexImage is called. It is set at construction time 288 // and can be changed with a call to attachToContext. 289 GLuint mTexName; 290 291 // mUseFenceSync indicates whether creation of the EGL_KHR_fence_sync 292 // extension should be used to prevent buffers from being dequeued before 293 // it's safe for them to be written. It gets set at construction time and 294 // never changes. 295 const bool mUseFenceSync; 296 297 // mTexTarget is the GL texture target with which the GL texture object is 298 // associated. It is set in the constructor and never changed. It is 299 // almost always GL_TEXTURE_EXTERNAL_OES except for one use case in Android 300 // Browser. In that case it is set to GL_TEXTURE_2D to allow 301 // glCopyTexSubImage to read from the texture. This is a hack to work 302 // around a GL driver limitation on the number of FBO attachments, which the 303 // browser's tile cache exceeds. 304 const GLenum mTexTarget; 305 306 // EGLSlot contains the information and object references that 307 // SurfaceTexture maintains about a BufferQueue buffer slot. 308 struct EGLSlot { 309 EGLSlot() 310 : mEglImage(EGL_NO_IMAGE_KHR), 311 mFence(EGL_NO_SYNC_KHR) { 312 } 313 314 sp<GraphicBuffer> mGraphicBuffer; 315 316 // mEglImage is the EGLImage created from mGraphicBuffer. 317 EGLImageKHR mEglImage; 318 319 // mFence is the EGL sync object that must signal before the buffer 320 // associated with this buffer slot may be dequeued. It is initialized 321 // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based 322 // on a compile-time option) set to a new sync object in updateTexImage. 323 EGLSyncKHR mFence; 324 }; 325 326 // mEglDisplay is the EGLDisplay with which this SurfaceTexture is currently 327 // associated. It is intialized to EGL_NO_DISPLAY and gets set to the 328 // current display when updateTexImage is called for the first time and when 329 // attachToContext is called. 330 EGLDisplay mEglDisplay; 331 332 // mEglContext is the OpenGL ES context with which this SurfaceTexture is 333 // currently associated. It is initialized to EGL_NO_CONTEXT and gets set 334 // to the current GL context when updateTexImage is called for the first 335 // time and when attachToContext is called. 336 EGLContext mEglContext; 337 338 // mEGLSlots stores the buffers that have been allocated by the BufferQueue 339 // for each buffer slot. It is initialized to null pointers, and gets 340 // filled in with the result of BufferQueue::acquire when the 341 // client dequeues a buffer from a 342 // slot that has not yet been used. The buffer allocated to a slot will also 343 // be replaced if the requested buffer usage or geometry differs from that 344 // of the buffer allocated to a slot. 345 EGLSlot mEGLSlots[BufferQueue::NUM_BUFFER_SLOTS]; 346 347 // mAbandoned indicates that the BufferQueue will no longer be used to 348 // consume images buffers pushed to it using the ISurfaceTexture interface. 349 // It is initialized to false, and set to true in the abandon method. A 350 // BufferQueue that has been abandoned will return the NO_INIT error from 351 // all ISurfaceTexture methods capable of returning an error. 352 bool mAbandoned; 353 354 // mName is a string used to identify the SurfaceTexture in log messages. 355 // It can be set by the setName method. 356 String8 mName; 357 358 // mFrameAvailableListener is the listener object that will be called when a 359 // new frame becomes available. If it is not NULL it will be called from 360 // queueBuffer. 361 sp<FrameAvailableListener> mFrameAvailableListener; 362 363 // mCurrentTexture is the buffer slot index of the buffer that is currently 364 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 365 // indicating that no buffer slot is currently bound to the texture. Note, 366 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 367 // that no buffer is bound to the texture. A call to setBufferCount will 368 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 369 int mCurrentTexture; 370 371 // The SurfaceTexture has-a BufferQueue and is responsible for creating this object 372 // if none is supplied 373 sp<BufferQueue> mBufferQueue; 374 375 // mAttached indicates whether the SurfaceTexture is currently attached to 376 // an OpenGL ES context. For legacy reasons, this is initialized to true, 377 // indicating that the SurfaceTexture is considered to be attached to 378 // whatever context is current at the time of the first updateTexImage call. 379 // It is set to false by detachFromContext, and then set to true again by 380 // attachToContext. 381 bool mAttached; 382 383 // mMutex is the mutex used to prevent concurrent access to the member 384 // variables of SurfaceTexture objects. It must be locked whenever the 385 // member variables are accessed. 386 mutable Mutex mMutex; 387}; 388 389// ---------------------------------------------------------------------------- 390}; // namespace android 391 392#endif // ANDROID_GUI_SURFACETEXTURE_H 393