GLConsumer.h revision ab57491de3a89a2d454d3060d36adef71741a7ae
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. If the constructor with 60 // the tex parameter is used, tex indicates the name of the OpenGL ES 61 // texture to which images are to be streamed. texTarget specifies the 62 // OpenGL ES texture target to which the texture will be bound in 63 // updateTexImage. useFenceSync specifies whether fences should be used to 64 // synchronize access to buffers if that behavior is enabled at 65 // compile-time. 66 // 67 // A GLConsumer may be detached from one OpenGL ES context and then 68 // attached to a different context using the detachFromContext and 69 // attachToContext methods, respectively. The intention of these methods is 70 // purely to allow a GLConsumer to be transferred from one consumer 71 // context to another. If such a transfer is not needed there is no 72 // requirement that either of these methods be called. 73 // 74 // If the constructor with the tex parameter is used, the GLConsumer is 75 // created in a state where it is considered attached to an OpenGL ES 76 // context for the purposes of the attachToContext and detachFromContext 77 // methods. However, despite being considered "attached" to a context, the 78 // specific OpenGL ES context doesn't get latched until the first call to 79 // updateTexImage. After that point, all calls to updateTexImage must be 80 // made with the same OpenGL ES context current. 81 // 82 // If the constructor without the tex parameter is used, the GLConsumer is 83 // created in a detached state, and attachToContext must be called before 84 // calls to updateTexImage. 85 GLConsumer(const sp<IGraphicBufferConsumer>& bq, 86 uint32_t tex, uint32_t texureTarget, bool useFenceSync, 87 bool isControlledByApp); 88 89 GLConsumer(const sp<IGraphicBufferConsumer>& bq, uint32_t texureTarget, 90 bool useFenceSync, bool isControlledByApp); 91 92 // updateTexImage acquires the most recently queued buffer, and sets the 93 // image contents of the target texture to it. 94 // 95 // This call may only be made while the OpenGL ES context to which the 96 // target texture belongs is bound to the calling thread. 97 // 98 // This calls doGLFenceWait to ensure proper synchronization. 99 status_t updateTexImage(); 100 101 // releaseTexImage releases the texture acquired in updateTexImage(). 102 // This is intended to be used in single buffer mode. 103 // 104 // This call may only be made while the OpenGL ES context to which the 105 // target texture belongs is bound to the calling thread. 106 status_t releaseTexImage(); 107 108 // setReleaseFence stores a fence that will signal when the current buffer 109 // is no longer being read. This fence will be returned to the producer 110 // when the current buffer is released by updateTexImage(). Multiple 111 // fences can be set for a given buffer; they will be merged into a single 112 // union fence. 113 void setReleaseFence(const sp<Fence>& fence); 114 115 // setDefaultMaxBufferCount sets the default limit on the maximum number 116 // of buffers that will be allocated at one time. The image producer may 117 // override the limit. 118 status_t setDefaultMaxBufferCount(int bufferCount); 119 120 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 121 // associated with the texture image set by the most recent call to 122 // updateTexImage. 123 // 124 // This transform matrix maps 2D homogeneous texture coordinates of the form 125 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 126 // coordinate that should be used to sample that location from the texture. 127 // Sampling the texture outside of the range of this transform is undefined. 128 // 129 // This transform is necessary to compensate for transforms that the stream 130 // content producer may implicitly apply to the content. By forcing users of 131 // a GLConsumer to apply this transform we avoid performing an extra 132 // copy of the data that would be needed to hide the transform from the 133 // user. 134 // 135 // The matrix is stored in column-major order so that it may be passed 136 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 137 // functions. 138 void getTransformMatrix(float mtx[16]); 139 140 // getTimestamp retrieves the timestamp associated with the texture image 141 // set by the most recent call to updateTexImage. 142 // 143 // The timestamp is in nanoseconds, and is monotonically increasing. Its 144 // other semantics (zero point, etc) are source-dependent and should be 145 // documented by the source. 146 int64_t getTimestamp(); 147 148 // getFrameNumber retrieves the frame number associated with the texture 149 // image set by the most recent call to updateTexImage. 150 // 151 // The frame number is an incrementing counter set to 0 at the creation of 152 // the BufferQueue associated with this consumer. 153 int64_t getFrameNumber(); 154 155 // setDefaultBufferSize is used to set the size of buffers returned by 156 // requestBuffers when a with and height of zero is requested. 157 // A call to setDefaultBufferSize() may trigger requestBuffers() to 158 // be called from the client. 159 // The width and height parameters must be no greater than the minimum of 160 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 161 // An error due to invalid dimensions might not be reported until 162 // updateTexImage() is called. 163 status_t setDefaultBufferSize(uint32_t width, uint32_t height); 164 165 // setFilteringEnabled sets whether the transform matrix should be computed 166 // for use with bilinear filtering. 167 void setFilteringEnabled(bool enabled); 168 169 // getCurrentBuffer returns the buffer associated with the current image. 170 sp<GraphicBuffer> getCurrentBuffer() const; 171 172 // getCurrentTextureTarget returns the texture target of the current 173 // texture as returned by updateTexImage(). 174 uint32_t getCurrentTextureTarget() const; 175 176 // getCurrentCrop returns the cropping rectangle of the current buffer. 177 Rect getCurrentCrop() const; 178 179 // getCurrentTransform returns the transform of the current buffer. 180 uint32_t getCurrentTransform() const; 181 182 // getCurrentScalingMode returns the scaling mode of the current buffer. 183 uint32_t getCurrentScalingMode() const; 184 185 // getCurrentFence returns the fence indicating when the current buffer is 186 // ready to be read from. 187 sp<Fence> getCurrentFence() const; 188 189 // doGLFenceWait inserts a wait command into the OpenGL ES command stream 190 // to ensure that it is safe for future OpenGL ES commands to access the 191 // current texture buffer. 192 status_t doGLFenceWait() const; 193 194 // set the name of the GLConsumer 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); 203 204 // detachFromContext detaches the GLConsumer from the calling thread's 205 // current OpenGL ES context. This context must be the same as the context 206 // that was current for previous calls to updateTexImage. 207 // 208 // Detaching a GLConsumer from an OpenGL ES context will result in the 209 // deletion of the OpenGL ES texture object into which the images were being 210 // streamed. After a GLConsumer has been detached from the OpenGL ES 211 // context calls to updateTexImage will fail returning INVALID_OPERATION 212 // until the GLConsumer is attached to a new OpenGL ES context using the 213 // attachToContext method. 214 status_t detachFromContext(); 215 216 // attachToContext attaches a GLConsumer that is currently in the 217 // 'detached' state to the current OpenGL ES context. A GLConsumer is 218 // in the 'detached' state iff detachFromContext has successfully been 219 // called and no calls to attachToContext have succeeded since the last 220 // detachFromContext call. Calls to attachToContext made on a 221 // GLConsumer that is not in the 'detached' state will result in an 222 // INVALID_OPERATION error. 223 // 224 // The tex argument specifies the OpenGL ES texture object name in the 225 // new context into which the image contents will be streamed. A successful 226 // call to attachToContext will result in this texture object being bound to 227 // the texture target and populated with the image contents that were 228 // current at the time of the last call to detachFromContext. 229 status_t attachToContext(uint32_t tex); 230 231protected: 232 233 // abandonLocked overrides the ConsumerBase method to clear 234 // mCurrentTextureBuf in addition to the ConsumerBase behavior. 235 virtual void abandonLocked(); 236 237 // dumpLocked overrides the ConsumerBase method to dump GLConsumer- 238 // specific info in addition to the ConsumerBase behavior. 239 virtual void dumpLocked(String8& result, const char* prefix) const; 240 241 // acquireBufferLocked overrides the ConsumerBase method to update the 242 // mEglSlots array in addition to the ConsumerBase behavior. 243 virtual status_t acquireBufferLocked(BufferQueue::BufferItem *item, 244 nsecs_t presentWhen); 245 246 // releaseBufferLocked overrides the ConsumerBase method to update the 247 // mEglSlots array in addition to the ConsumerBase. 248 virtual status_t releaseBufferLocked(int slot, 249 const sp<GraphicBuffer> graphicBuffer, 250 EGLDisplay display, EGLSyncKHR eglFence); 251 252 status_t releaseBufferLocked(int slot, 253 const sp<GraphicBuffer> graphicBuffer, EGLSyncKHR eglFence) { 254 return releaseBufferLocked(slot, graphicBuffer, mEglDisplay, eglFence); 255 } 256 257 static bool isExternalFormat(uint32_t format); 258 259 // This releases the buffer in the slot referenced by mCurrentTexture, 260 // then updates state to refer to the BufferItem, which must be a 261 // newly-acquired buffer. 262 status_t updateAndReleaseLocked(const BufferQueue::BufferItem& item); 263 264 // Binds mTexName and the current buffer to mTexTarget. Uses 265 // mCurrentTexture if it's set, mCurrentTextureBuf if not. If the 266 // bind succeeds, this calls doGLFenceWait. 267 status_t bindTextureImageLocked(); 268 269 // Gets the current EGLDisplay and EGLContext values, and compares them 270 // to mEglDisplay and mEglContext. If the fields have been previously 271 // set, the values must match; if not, the fields are set to the current 272 // values. 273 // The contextCheck argument is used to ensure that a GL context is 274 // properly set; when set to false, the check is not performed. 275 status_t checkAndUpdateEglStateLocked(bool contextCheck = false); 276 277private: 278 // createImage creates a new EGLImage from a GraphicBuffer. 279 EGLImageKHR createImage(EGLDisplay dpy, 280 const sp<GraphicBuffer>& graphicBuffer, const Rect& crop); 281 282 // freeBufferLocked frees up the given buffer slot. If the slot has been 283 // initialized this will release the reference to the GraphicBuffer in that 284 // slot and destroy the EGLImage in that slot. Otherwise it has no effect. 285 // 286 // This method must be called with mMutex locked. 287 virtual void freeBufferLocked(int slotIndex); 288 289 // computeCurrentTransformMatrixLocked computes the transform matrix for the 290 // current texture. It uses mCurrentTransform and the current GraphicBuffer 291 // to compute this matrix and stores it in mCurrentTransformMatrix. 292 // mCurrentTextureBuf must not be NULL. 293 void computeCurrentTransformMatrixLocked(); 294 295 // doGLFenceWaitLocked inserts a wait command into the OpenGL ES command 296 // stream to ensure that it is safe for future OpenGL ES commands to 297 // access the current texture buffer. 298 status_t doGLFenceWaitLocked() const; 299 300 // syncForReleaseLocked performs the synchronization needed to release the 301 // current slot from an OpenGL ES context. If needed it will set the 302 // current slot's fence to guard against a producer accessing the buffer 303 // before the outstanding accesses have completed. 304 status_t syncForReleaseLocked(EGLDisplay dpy); 305 306 // Normally, when we bind a buffer to a texture target, we bind a buffer 307 // that is referenced by an entry in mEglSlots. In some situations we 308 // have a buffer in mCurrentTextureBuf, but no corresponding entry for 309 // it in our slot array. bindUnslottedBuffer handles that situation by 310 // binding the buffer without touching the EglSlots. 311 status_t bindUnslottedBufferLocked(EGLDisplay dpy); 312 313 // returns a graphic buffer used when the texture image has been released 314 static sp<GraphicBuffer> getDebugTexImageBuffer(); 315 316 // The default consumer usage flags that GLConsumer always sets on its 317 // BufferQueue instance; these will be OR:d with any additional flags passed 318 // from the GLConsumer user. In particular, GLConsumer will always 319 // consume buffers as hardware textures. 320 static const uint32_t DEFAULT_USAGE_FLAGS = GraphicBuffer::USAGE_HW_TEXTURE; 321 322 // mCurrentTextureBuf is the graphic buffer of the current texture. It's 323 // possible that this buffer is not associated with any buffer slot, so we 324 // must track it separately in order to support the getCurrentBuffer method. 325 sp<GraphicBuffer> mCurrentTextureBuf; 326 327 // mCurrentCrop is the crop rectangle that applies to the current texture. 328 // It gets set each time updateTexImage is called. 329 Rect mCurrentCrop; 330 331 // mCurrentTransform is the transform identifier for the current texture. It 332 // gets set each time updateTexImage is called. 333 uint32_t mCurrentTransform; 334 335 // mCurrentScalingMode is the scaling mode for the current texture. It gets 336 // set each time updateTexImage is called. 337 uint32_t mCurrentScalingMode; 338 339 // mCurrentFence is the fence received from BufferQueue in updateTexImage. 340 sp<Fence> mCurrentFence; 341 342 // mCurrentTransformMatrix is the transform matrix for the current texture. 343 // It gets computed by computeTransformMatrix each time updateTexImage is 344 // called. 345 float mCurrentTransformMatrix[16]; 346 347 // mCurrentTimestamp is the timestamp for the current texture. It 348 // gets set each time updateTexImage is called. 349 int64_t mCurrentTimestamp; 350 351 // mCurrentFrameNumber is the frame counter for the current texture. 352 // It gets set each time updateTexImage is called. 353 int64_t mCurrentFrameNumber; 354 355 uint32_t mDefaultWidth, mDefaultHeight; 356 357 // mFilteringEnabled indicates whether the transform matrix is computed for 358 // use with bilinear filtering. It defaults to true and is changed by 359 // setFilteringEnabled(). 360 bool mFilteringEnabled; 361 362 // mTexName is the name of the OpenGL texture to which streamed images will 363 // be bound when updateTexImage is called. It is set at construction time 364 // and can be changed with a call to attachToContext. 365 uint32_t mTexName; 366 367 // mUseFenceSync indicates whether creation of the EGL_KHR_fence_sync 368 // extension should be used to prevent buffers from being dequeued before 369 // it's safe for them to be written. It gets set at construction time and 370 // never changes. 371 const bool mUseFenceSync; 372 373 // mTexTarget is the GL texture target with which the GL texture object is 374 // associated. It is set in the constructor and never changed. It is 375 // almost always GL_TEXTURE_EXTERNAL_OES except for one use case in Android 376 // Browser. In that case it is set to GL_TEXTURE_2D to allow 377 // glCopyTexSubImage to read from the texture. This is a hack to work 378 // around a GL driver limitation on the number of FBO attachments, which the 379 // browser's tile cache exceeds. 380 const uint32_t mTexTarget; 381 382 // EGLSlot contains the information and object references that 383 // GLConsumer maintains about a BufferQueue buffer slot. 384 struct EglSlot { 385 EglSlot() 386 : mEglImage(EGL_NO_IMAGE_KHR), 387 mEglFence(EGL_NO_SYNC_KHR) { 388 } 389 390 // mEglImage is the EGLImage created from mGraphicBuffer. 391 EGLImageKHR mEglImage; 392 393 // mCropRect is the crop rectangle passed to EGL when mEglImage was 394 // created. 395 Rect mCropRect; 396 397 // mFence is the EGL sync object that must signal before the buffer 398 // associated with this buffer slot may be dequeued. It is initialized 399 // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based 400 // on a compile-time option) set to a new sync object in updateTexImage. 401 EGLSyncKHR mEglFence; 402 }; 403 404 // mEglDisplay is the EGLDisplay with which this GLConsumer is currently 405 // associated. It is intialized to EGL_NO_DISPLAY and gets set to the 406 // current display when updateTexImage is called for the first time and when 407 // attachToContext is called. 408 EGLDisplay mEglDisplay; 409 410 // mEglContext is the OpenGL ES context with which this GLConsumer is 411 // currently associated. It is initialized to EGL_NO_CONTEXT and gets set 412 // to the current GL context when updateTexImage is called for the first 413 // time and when attachToContext is called. 414 EGLContext mEglContext; 415 416 // mEGLSlots stores the buffers that have been allocated by the BufferQueue 417 // for each buffer slot. It is initialized to null pointers, and gets 418 // filled in with the result of BufferQueue::acquire when the 419 // client dequeues a buffer from a 420 // slot that has not yet been used. The buffer allocated to a slot will also 421 // be replaced if the requested buffer usage or geometry differs from that 422 // of the buffer allocated to a slot. 423 EglSlot mEglSlots[BufferQueue::NUM_BUFFER_SLOTS]; 424 425 // mCurrentTexture is the buffer slot index of the buffer that is currently 426 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 427 // indicating that no buffer slot is currently bound to the texture. Note, 428 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 429 // that no buffer is bound to the texture. A call to setBufferCount will 430 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 431 int mCurrentTexture; 432 433 // mAttached indicates whether the ConsumerBase is currently attached to 434 // an OpenGL ES context. For legacy reasons, this is initialized to true, 435 // indicating that the ConsumerBase is considered to be attached to 436 // whatever context is current at the time of the first updateTexImage call. 437 // It is set to false by detachFromContext, and then set to true again by 438 // attachToContext. 439 bool mAttached; 440 441 // protects static initialization 442 static Mutex sStaticInitLock; 443 444 // mReleasedTexImageBuffer is a dummy buffer used when in single buffer 445 // mode and releaseTexImage() has been called 446 static sp<GraphicBuffer> sReleasedTexImageBuffer; 447}; 448 449// ---------------------------------------------------------------------------- 450}; // namespace android 451 452#endif // ANDROID_GUI_CONSUMER_H 453