GLConsumer.h revision e49ba8e2ed8e17156eb00c8fc8e2285df62bc018
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_CONSUMER_H 18#define ANDROID_GUI_CONSUMER_H 19 20#include <EGL/egl.h> 21#include <EGL/eglext.h> 22 23#include <gui/IGraphicBufferProducer.h> 24#include <gui/BufferQueue.h> 25#include <gui/ConsumerBase.h> 26 27#include <ui/GraphicBuffer.h> 28 29#include <utils/String8.h> 30#include <utils/Vector.h> 31#include <utils/threads.h> 32 33namespace android { 34// ---------------------------------------------------------------------------- 35 36 37class String8; 38 39/* 40 * GLConsumer consumes buffers of graphics data from a BufferQueue, 41 * and makes them available to OpenGL as a texture. 42 * 43 * A typical usage pattern is to set up the GLConsumer with the 44 * desired options, and call updateTexImage() when a new frame is desired. 45 * If a new frame is available, the texture will be updated. If not, 46 * the previous contents are retained. 47 * 48 * By default, the texture is attached to the GL_TEXTURE_EXTERNAL_OES 49 * texture target, in the EGL context of the first thread that calls 50 * updateTexImage(). 51 * 52 * This class was previously called SurfaceTexture. 53 */ 54class GLConsumer : public ConsumerBase { 55public: 56 enum { TEXTURE_EXTERNAL = 0x8D65 }; // GL_TEXTURE_EXTERNAL_OES 57 typedef ConsumerBase::FrameAvailableListener FrameAvailableListener; 58 59 // GLConsumer constructs a new GLConsumer object. tex indicates the 60 // name of the OpenGL ES texture to which images are to be streamed. 61 // allowSynchronousMode specifies whether or not synchronous mode can be 62 // enabled. texTarget specifies the OpenGL ES texture target to which the 63 // texture will be bound in updateTexImage. useFenceSync specifies whether 64 // fences should be used to synchronize access to buffers if that behavior 65 // is enabled at compile-time. A custom bufferQueue can be specified 66 // if behavior for queue/dequeue/connect etc needs to be customized. 67 // Otherwise a default BufferQueue will be created and used. 68 // 69 // For legacy reasons, the GLConsumer is created in a state where it is 70 // considered attached to an OpenGL ES context for the purposes of the 71 // attachToContext and detachFromContext methods. However, despite being 72 // considered "attached" to a context, the specific OpenGL ES context 73 // doesn't get latched until the first call to updateTexImage. After that 74 // point, all calls to updateTexImage must be made with the same OpenGL ES 75 // context current. 76 // 77 // A GLConsumer may be detached from one OpenGL ES context and then 78 // attached to a different context using the detachFromContext and 79 // attachToContext methods, respectively. The intention of these methods is 80 // purely to allow a GLConsumer to be transferred from one consumer 81 // context to another. If such a transfer is not needed there is no 82 // requirement that either of these methods be called. 83 GLConsumer(const sp<IGraphicBufferConsumer>& bq, 84 uint32_t tex, uint32_t texureTarget, bool useFenceSync, 85 bool isControlledByApp); 86 87 // updateTexImage acquires the most recently queued buffer, and sets the 88 // image contents of the target texture to it. 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 // 93 // This calls doGLFenceWait to ensure proper synchronization. 94 status_t updateTexImage(); 95 96 // releaseTexImage releases the texture acquired in updateTexImage(). 97 // This is intended to be used in single buffer mode. 98 // 99 // This call may only be made while the OpenGL ES context to which the 100 // target texture belongs is bound to the calling thread. 101 status_t releaseTexImage(); 102 103 // setReleaseFence stores a fence that will signal when the current buffer 104 // is no longer being read. This fence will be returned to the producer 105 // when the current buffer is released by updateTexImage(). Multiple 106 // fences can be set for a given buffer; they will be merged into a single 107 // union fence. 108 void setReleaseFence(const sp<Fence>& fence); 109 110 // setDefaultMaxBufferCount sets the default limit on the maximum number 111 // of buffers that will be allocated at one time. The image producer may 112 // override the limit. 113 status_t setDefaultMaxBufferCount(int bufferCount); 114 115 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 116 // associated with the texture image set by the most recent call to 117 // updateTexImage. 118 // 119 // This transform matrix maps 2D homogeneous texture coordinates of the form 120 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 121 // coordinate that should be used to sample that location from the texture. 122 // Sampling the texture outside of the range of this transform is undefined. 123 // 124 // This transform is necessary to compensate for transforms that the stream 125 // content producer may implicitly apply to the content. By forcing users of 126 // a GLConsumer to apply this transform we avoid performing an extra 127 // copy of the data that would be needed to hide the transform from the 128 // user. 129 // 130 // The matrix is stored in column-major order so that it may be passed 131 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 132 // functions. 133 void getTransformMatrix(float mtx[16]); 134 135 // getTimestamp retrieves the timestamp associated with the texture image 136 // set by the most recent call to updateTexImage. 137 // 138 // The timestamp is in nanoseconds, and is monotonically increasing. Its 139 // other semantics (zero point, etc) are source-dependent and should be 140 // documented by the source. 141 int64_t getTimestamp(); 142 143 // getFrameNumber retrieves the frame number associated with the texture 144 // image set by the most recent call to updateTexImage. 145 // 146 // The frame number is an incrementing counter set to 0 at the creation of 147 // the BufferQueue associated with this consumer. 148 int64_t getFrameNumber(); 149 150 // setDefaultBufferSize is used to set the size of buffers returned by 151 // requestBuffers when a with and height of zero is requested. 152 // A call to setDefaultBufferSize() may trigger requestBuffers() to 153 // be called from the client. 154 // The width and height parameters must be no greater than the minimum of 155 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 156 // An error due to invalid dimensions might not be reported until 157 // updateTexImage() is called. 158 status_t setDefaultBufferSize(uint32_t width, uint32_t height); 159 160 // setFilteringEnabled sets whether the transform matrix should be computed 161 // for use with bilinear filtering. 162 void setFilteringEnabled(bool enabled); 163 164 // getCurrentBuffer returns the buffer associated with the current image. 165 sp<GraphicBuffer> getCurrentBuffer() const; 166 167 // getCurrentTextureTarget returns the texture target of the current 168 // texture as returned by updateTexImage(). 169 uint32_t getCurrentTextureTarget() const; 170 171 // getCurrentCrop returns the cropping rectangle of the current buffer. 172 Rect getCurrentCrop() const; 173 174 // getCurrentTransform returns the transform of the current buffer. 175 uint32_t getCurrentTransform() const; 176 177 // getCurrentScalingMode returns the scaling mode of the current buffer. 178 uint32_t getCurrentScalingMode() const; 179 180 // getCurrentFence returns the fence indicating when the current buffer is 181 // ready to be read from. 182 sp<Fence> getCurrentFence() const; 183 184 // doGLFenceWait inserts a wait command into the OpenGL ES command stream 185 // to ensure that it is safe for future OpenGL ES commands to access the 186 // current texture buffer. 187 status_t doGLFenceWait() const; 188 189 // set the name of the GLConsumer that will be used to identify it in 190 // log messages. 191 void setName(const String8& name); 192 193 // These functions call the corresponding BufferQueue implementation 194 // so the refactoring can proceed smoothly 195 status_t setDefaultBufferFormat(uint32_t defaultFormat); 196 status_t setConsumerUsageBits(uint32_t usage); 197 status_t setTransformHint(uint32_t hint); 198 199 // detachFromContext detaches the GLConsumer from the calling thread's 200 // current OpenGL ES context. This context must be the same as the context 201 // that was current for previous calls to updateTexImage. 202 // 203 // Detaching a GLConsumer from an OpenGL ES context will result in the 204 // deletion of the OpenGL ES texture object into which the images were being 205 // streamed. After a GLConsumer has been detached from the OpenGL ES 206 // context calls to updateTexImage will fail returning INVALID_OPERATION 207 // until the GLConsumer is attached to a new OpenGL ES context using the 208 // attachToContext method. 209 status_t detachFromContext(); 210 211 // attachToContext attaches a GLConsumer that is currently in the 212 // 'detached' state to the current OpenGL ES context. A GLConsumer is 213 // in the 'detached' state iff detachFromContext has successfully been 214 // called and no calls to attachToContext have succeeded since the last 215 // detachFromContext call. Calls to attachToContext made on a 216 // GLConsumer that is not in the 'detached' state will result in an 217 // INVALID_OPERATION error. 218 // 219 // The tex argument specifies the OpenGL ES texture object name in the 220 // new context into which the image contents will be streamed. A successful 221 // call to attachToContext will result in this texture object being bound to 222 // the texture target and populated with the image contents that were 223 // current at the time of the last call to detachFromContext. 224 status_t attachToContext(uint32_t tex); 225 226protected: 227 228 // abandonLocked overrides the ConsumerBase method to clear 229 // mCurrentTextureBuf in addition to the ConsumerBase behavior. 230 virtual void abandonLocked(); 231 232 // dumpLocked overrides the ConsumerBase method to dump GLConsumer- 233 // specific info in addition to the ConsumerBase behavior. 234 virtual void dumpLocked(String8& result, const char* prefix) const; 235 236 // acquireBufferLocked overrides the ConsumerBase method to update the 237 // mEglSlots array in addition to the ConsumerBase behavior. 238 virtual status_t acquireBufferLocked(BufferQueue::BufferItem *item, 239 nsecs_t presentWhen); 240 241 // releaseBufferLocked overrides the ConsumerBase method to update the 242 // mEglSlots array in addition to the ConsumerBase. 243 virtual status_t releaseBufferLocked(int slot, 244 const sp<GraphicBuffer> graphicBuffer, 245 EGLDisplay display, EGLSyncKHR eglFence); 246 247 status_t releaseBufferLocked(int slot, 248 const sp<GraphicBuffer> graphicBuffer, EGLSyncKHR eglFence) { 249 return releaseBufferLocked(slot, graphicBuffer, mEglDisplay, eglFence); 250 } 251 252 static bool isExternalFormat(uint32_t format); 253 254 // This releases the buffer in the slot referenced by mCurrentTexture, 255 // then updates state to refer to the BufferItem, which must be a 256 // newly-acquired buffer. 257 status_t updateAndReleaseLocked(const BufferQueue::BufferItem& item); 258 259 // Binds mTexName and the current buffer to mTexTarget. Uses 260 // mCurrentTexture if it's set, mCurrentTextureBuf if not. If the 261 // bind succeeds, this calls doGLFenceWait. 262 status_t bindTextureImageLocked(); 263 264 // Gets the current EGLDisplay and EGLContext values, and compares them 265 // to mEglDisplay and mEglContext. If the fields have been previously 266 // set, the values must match; if not, the fields are set to the current 267 // values. 268 // The contextCheck argument is used to ensure that a GL context is 269 // properly set; when set to false, the check is not performed. 270 status_t checkAndUpdateEglStateLocked(bool contextCheck = false); 271 272private: 273 // createImage creates a new EGLImage from a GraphicBuffer. 274 EGLImageKHR createImage(EGLDisplay dpy, 275 const sp<GraphicBuffer>& graphicBuffer, const Rect& crop); 276 277 // freeBufferLocked frees up the given buffer slot. If the slot has been 278 // initialized this will release the reference to the GraphicBuffer in that 279 // slot and destroy the EGLImage in that slot. Otherwise it has no effect. 280 // 281 // This method must be called with mMutex locked. 282 virtual void freeBufferLocked(int slotIndex); 283 284 // computeCurrentTransformMatrixLocked computes the transform matrix for the 285 // current texture. It uses mCurrentTransform and the current GraphicBuffer 286 // to compute this matrix and stores it in mCurrentTransformMatrix. 287 // mCurrentTextureBuf must not be NULL. 288 void computeCurrentTransformMatrixLocked(); 289 290 // doGLFenceWaitLocked inserts a wait command into the OpenGL ES command 291 // stream to ensure that it is safe for future OpenGL ES commands to 292 // access the current texture buffer. 293 status_t doGLFenceWaitLocked() const; 294 295 // syncForReleaseLocked performs the synchronization needed to release the 296 // current slot from an OpenGL ES context. If needed it will set the 297 // current slot's fence to guard against a producer accessing the buffer 298 // before the outstanding accesses have completed. 299 status_t syncForReleaseLocked(EGLDisplay dpy); 300 301 // Normally, when we bind a buffer to a texture target, we bind a buffer 302 // that is referenced by an entry in mEglSlots. In some situations we 303 // have a buffer in mCurrentTextureBuf, but no corresponding entry for 304 // it in our slot array. bindUnslottedBuffer handles that situation by 305 // binding the buffer without touching the EglSlots. 306 status_t bindUnslottedBufferLocked(EGLDisplay dpy); 307 308 // returns a graphic buffer used when the texture image has been released 309 static sp<GraphicBuffer> getDebugTexImageBuffer(); 310 311 // The default consumer usage flags that GLConsumer always sets on its 312 // BufferQueue instance; these will be OR:d with any additional flags passed 313 // from the GLConsumer user. In particular, GLConsumer will always 314 // consume buffers as hardware textures. 315 static const uint32_t DEFAULT_USAGE_FLAGS = GraphicBuffer::USAGE_HW_TEXTURE; 316 317 // mCurrentTextureBuf is the graphic buffer of the current texture. It's 318 // possible that this buffer is not associated with any buffer slot, so we 319 // must track it separately in order to support the getCurrentBuffer method. 320 sp<GraphicBuffer> mCurrentTextureBuf; 321 322 // mCurrentCrop is the crop rectangle that applies to the current texture. 323 // It gets set each time updateTexImage is called. 324 Rect mCurrentCrop; 325 326 // mCurrentTransform is the transform identifier for the current texture. It 327 // gets set each time updateTexImage is called. 328 uint32_t mCurrentTransform; 329 330 // mCurrentScalingMode is the scaling mode for the current texture. It gets 331 // set each time updateTexImage is called. 332 uint32_t mCurrentScalingMode; 333 334 // mCurrentFence is the fence received from BufferQueue in updateTexImage. 335 sp<Fence> mCurrentFence; 336 337 // mCurrentTransformMatrix is the transform matrix for the current texture. 338 // It gets computed by computeTransformMatrix each time updateTexImage is 339 // called. 340 float mCurrentTransformMatrix[16]; 341 342 // mCurrentTimestamp is the timestamp for the current texture. It 343 // gets set each time updateTexImage is called. 344 int64_t mCurrentTimestamp; 345 346 // mCurrentFrameNumber is the frame counter for the current texture. 347 // It gets set each time updateTexImage is called. 348 int64_t mCurrentFrameNumber; 349 350 uint32_t mDefaultWidth, mDefaultHeight; 351 352 // mFilteringEnabled indicates whether the transform matrix is computed for 353 // use with bilinear filtering. It defaults to true and is changed by 354 // setFilteringEnabled(). 355 bool mFilteringEnabled; 356 357 // mTexName is the name of the OpenGL texture to which streamed images will 358 // be bound when updateTexImage is called. It is set at construction time 359 // and can be changed with a call to attachToContext. 360 uint32_t mTexName; 361 362 // mUseFenceSync indicates whether creation of the EGL_KHR_fence_sync 363 // extension should be used to prevent buffers from being dequeued before 364 // it's safe for them to be written. It gets set at construction time and 365 // never changes. 366 const bool mUseFenceSync; 367 368 // mTexTarget is the GL texture target with which the GL texture object is 369 // associated. It is set in the constructor and never changed. It is 370 // almost always GL_TEXTURE_EXTERNAL_OES except for one use case in Android 371 // Browser. In that case it is set to GL_TEXTURE_2D to allow 372 // glCopyTexSubImage to read from the texture. This is a hack to work 373 // around a GL driver limitation on the number of FBO attachments, which the 374 // browser's tile cache exceeds. 375 const uint32_t mTexTarget; 376 377 // EGLSlot contains the information and object references that 378 // GLConsumer maintains about a BufferQueue buffer slot. 379 struct EglSlot { 380 EglSlot() 381 : mEglImage(EGL_NO_IMAGE_KHR), 382 mEglFence(EGL_NO_SYNC_KHR) { 383 } 384 385 // mEglImage is the EGLImage created from mGraphicBuffer. 386 EGLImageKHR mEglImage; 387 388 // mCropRect is the crop rectangle passed to EGL when mEglImage was 389 // created. 390 Rect mCropRect; 391 392 // mFence is the EGL sync object that must signal before the buffer 393 // associated with this buffer slot may be dequeued. It is initialized 394 // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based 395 // on a compile-time option) set to a new sync object in updateTexImage. 396 EGLSyncKHR mEglFence; 397 }; 398 399 // mEglDisplay is the EGLDisplay with which this GLConsumer is currently 400 // associated. It is intialized to EGL_NO_DISPLAY and gets set to the 401 // current display when updateTexImage is called for the first time and when 402 // attachToContext is called. 403 EGLDisplay mEglDisplay; 404 405 // mEglContext is the OpenGL ES context with which this GLConsumer is 406 // currently associated. It is initialized to EGL_NO_CONTEXT and gets set 407 // to the current GL context when updateTexImage is called for the first 408 // time and when attachToContext is called. 409 EGLContext mEglContext; 410 411 // mEGLSlots stores the buffers that have been allocated by the BufferQueue 412 // for each buffer slot. It is initialized to null pointers, and gets 413 // filled in with the result of BufferQueue::acquire when the 414 // client dequeues a buffer from a 415 // slot that has not yet been used. The buffer allocated to a slot will also 416 // be replaced if the requested buffer usage or geometry differs from that 417 // of the buffer allocated to a slot. 418 EglSlot mEglSlots[BufferQueue::NUM_BUFFER_SLOTS]; 419 420 // mCurrentTexture is the buffer slot index of the buffer that is currently 421 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 422 // indicating that no buffer slot is currently bound to the texture. Note, 423 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 424 // that no buffer is bound to the texture. A call to setBufferCount will 425 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 426 int mCurrentTexture; 427 428 // mAttached indicates whether the ConsumerBase is currently attached to 429 // an OpenGL ES context. For legacy reasons, this is initialized to true, 430 // indicating that the ConsumerBase is considered to be attached to 431 // whatever context is current at the time of the first updateTexImage call. 432 // It is set to false by detachFromContext, and then set to true again by 433 // attachToContext. 434 bool mAttached; 435 436 // protects static initialization 437 static Mutex sStaticInitLock; 438 439 // mReleasedTexImageBuffer is a dummy buffer used when in single buffer 440 // mode and releaseTexImage() has been called 441 static sp<GraphicBuffer> sReleasedTexImageBuffer; 442}; 443 444// ---------------------------------------------------------------------------- 445}; // namespace android 446 447#endif // ANDROID_GUI_CONSUMER_H 448