GLConsumer.h revision b6a0ca7276017ac6d2e846a857d663941a5bd382
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#include <GLES2/gl2.h> 23#include <GLES2/gl2ext.h> 24 25#include <gui/IGraphicBufferProducer.h> 26#include <gui/BufferQueue.h> 27#include <gui/ConsumerBase.h> 28 29#include <ui/GraphicBuffer.h> 30 31#include <utils/String8.h> 32#include <utils/Vector.h> 33#include <utils/threads.h> 34 35#define ANDROID_GRAPHICS_SURFACETEXTURE_JNI_ID "mSurfaceTexture" 36#define ANDROID_GRAPHICS_FRAMEAVAILABLELISTENER_JNI_ID \ 37 "mFrameAvailableListener" 38 39namespace android { 40// ---------------------------------------------------------------------------- 41 42 43class String8; 44 45/* 46 * GLConsumer consumes buffers of graphics data from a BufferQueue, 47 * and makes them available to OpenGL as a texture. 48 * 49 * A typical usage pattern is to set up the GLConsumer with the 50 * desired options, and call updateTexImage() when a new frame is desired. 51 * If a new frame is available, the texture will be updated. If not, 52 * the previous contents are retained. 53 * 54 * By default, the texture is attached to the GL_TEXTURE_EXTERNAL_OES 55 * texture target, in the EGL context of the first thread that calls 56 * updateTexImage(). 57 * 58 * This class was previously called SurfaceTexture. 59 */ 60class GLConsumer : public ConsumerBase { 61public: 62 typedef ConsumerBase::FrameAvailableListener FrameAvailableListener; 63 64 // GLConsumer constructs a new GLConsumer object. tex indicates the 65 // name of the OpenGL ES texture to which images are to be streamed. 66 // allowSynchronousMode specifies whether or not synchronous mode can be 67 // enabled. texTarget specifies the OpenGL ES texture target to which the 68 // texture will be bound in updateTexImage. useFenceSync specifies whether 69 // fences should be used to synchronize access to buffers if that behavior 70 // is enabled at compile-time. A custom bufferQueue can be specified 71 // if behavior for queue/dequeue/connect etc needs to be customized. 72 // Otherwise a default BufferQueue will be created and used. 73 // 74 // For legacy reasons, the GLConsumer is created in a state where it is 75 // considered attached to an OpenGL ES context for the purposes of the 76 // attachToContext and detachFromContext methods. However, despite being 77 // considered "attached" to a context, the specific OpenGL ES context 78 // doesn't get latched until the first call to updateTexImage. After that 79 // point, all calls to updateTexImage must be made with the same OpenGL ES 80 // context current. 81 // 82 // A GLConsumer 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 GLConsumer 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 GLConsumer(const sp<BufferQueue>& bq, 89 GLuint tex, GLenum texTarget = GL_TEXTURE_EXTERNAL_OES, 90 bool useFenceSync = true); 91 GLConsumer(GLuint tex, bool allowSynchronousMode = true, 92 GLenum texTarget = GL_TEXTURE_EXTERNAL_OES, bool useFenceSync = true, 93 const sp<BufferQueue> &bufferQueue = 0); 94 95 // updateTexImage acquires the most recently queued buffer, and sets the 96 // image contents of the target texture to it. 97 // 98 // This call may only be made while the OpenGL ES context to which the 99 // target texture belongs is bound to the calling thread. 100 // 101 // This calls doGLFenceWait to ensure proper synchronization. 102 status_t updateTexImage(); 103 104 // setReleaseFence stores a fence that will signal when the current buffer 105 // is no longer being read. This fence will be returned to the producer 106 // when the current buffer is released by updateTexImage(). Multiple 107 // fences can be set for a given buffer; they will be merged into a single 108 // union fence. 109 void setReleaseFence(const sp<Fence>& fence); 110 111 // setDefaultMaxBufferCount sets the default limit on the maximum number 112 // of buffers that will be allocated at one time. The image producer may 113 // override the limit. 114 status_t setDefaultMaxBufferCount(int bufferCount); 115 116 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 117 // associated with the texture image set by the most recent call to 118 // updateTexImage. 119 // 120 // This transform matrix maps 2D homogeneous texture coordinates of the form 121 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 122 // coordinate that should be used to sample that location from the texture. 123 // Sampling the texture outside of the range of this transform is undefined. 124 // 125 // This transform is necessary to compensate for transforms that the stream 126 // content producer may implicitly apply to the content. By forcing users of 127 // a GLConsumer to apply this transform we avoid performing an extra 128 // copy of the data that would be needed to hide the transform from the 129 // user. 130 // 131 // The matrix is stored in column-major order so that it may be passed 132 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 133 // functions. 134 void getTransformMatrix(float mtx[16]); 135 136 // getTimestamp retrieves the timestamp associated with the texture image 137 // set by the most recent call to updateTexImage. 138 // 139 // The timestamp is in nanoseconds, and is monotonically increasing. Its 140 // other semantics (zero point, etc) are source-dependent and should be 141 // documented by the source. 142 int64_t getTimestamp(); 143 144 // setDefaultBufferSize is used to set the size of buffers returned by 145 // requestBuffers when a with and height of zero is requested. 146 // A call to setDefaultBufferSize() may trigger requestBuffers() to 147 // be called from the client. 148 // The width and height parameters must be no greater than the minimum of 149 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 150 // An error due to invalid dimensions might not be reported until 151 // updateTexImage() is called. 152 status_t setDefaultBufferSize(uint32_t width, uint32_t height); 153 154 // setFilteringEnabled sets whether the transform matrix should be computed 155 // for use with bilinear filtering. 156 void setFilteringEnabled(bool enabled); 157 158 // getCurrentBuffer returns the buffer associated with the current image. 159 sp<GraphicBuffer> getCurrentBuffer() const; 160 161 // getCurrentTextureTarget returns the texture target of the current 162 // texture as returned by updateTexImage(). 163 GLenum getCurrentTextureTarget() const; 164 165 // getCurrentCrop returns the cropping rectangle of the current buffer. 166 Rect getCurrentCrop() const; 167 168 // getCurrentTransform returns the transform of the current buffer. 169 uint32_t getCurrentTransform() const; 170 171 // getCurrentScalingMode returns the scaling mode of the current buffer. 172 uint32_t getCurrentScalingMode() const; 173 174 // getCurrentFence returns the fence indicating when the current buffer is 175 // ready to be read from. 176 sp<Fence> getCurrentFence() const; 177 178 // doGLFenceWait inserts a wait command into the OpenGL ES command stream 179 // to ensure that it is safe for future OpenGL ES commands to access the 180 // current texture buffer. 181 status_t doGLFenceWait() const; 182 183 // isSynchronousMode returns whether the GLConsumer is currently in 184 // synchronous mode. 185 bool isSynchronousMode() const; 186 187 // set the name of the GLConsumer that will be used to identify it in 188 // log messages. 189 void setName(const String8& name); 190 191 // These functions call the corresponding BufferQueue implementation 192 // so the refactoring can proceed smoothly 193 status_t setDefaultBufferFormat(uint32_t defaultFormat); 194 status_t setConsumerUsageBits(uint32_t usage); 195 status_t setTransformHint(uint32_t hint); 196 virtual status_t setSynchronousMode(bool enabled); 197 198 // getBufferQueue returns the BufferQueue object to which this 199 // GLConsumer is connected. 200 sp<BufferQueue> getBufferQueue() const { 201 return mBufferQueue; 202 } 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(GLuint 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, char* buffer, 240 size_t size) const; 241 242 // acquireBufferLocked overrides the ConsumerBase method to update the 243 // mEglSlots array in addition to the ConsumerBase behavior. 244 virtual status_t acquireBufferLocked(BufferQueue::BufferItem *item); 245 246 // releaseBufferLocked overrides the ConsumerBase method to update the 247 // mEglSlots array in addition to the ConsumerBase. 248 virtual status_t releaseBufferLocked(int buf, EGLDisplay display, 249 EGLSyncKHR eglFence); 250 251 status_t releaseBufferLocked(int buf, EGLSyncKHR eglFence) { 252 return releaseBufferLocked(buf, mEglDisplay, eglFence); 253 } 254 255 static bool isExternalFormat(uint32_t format); 256 257 // This releases the buffer in the slot referenced by mCurrentTexture, 258 // then updates state to refer to the BufferItem, which must be a 259 // newly-acquired buffer. 260 status_t releaseAndUpdateLocked(const BufferQueue::BufferItem& item); 261 262 // Binds mTexName and the current buffer to mTexTarget. Uses 263 // mCurrentTexture if it's set, mCurrentTextureBuf if not. If the 264 // bind succeeds, this calls doGLFenceWait. 265 status_t bindTextureImageLocked(); 266 267 // Gets the current EGLDisplay and EGLContext values, and compares them 268 // to mEglDisplay and mEglContext. If the fields have been previously 269 // set, the values must match; if not, the fields are set to the current 270 // values. 271 status_t checkAndUpdateEglStateLocked(); 272 273private: 274 // createImage creates a new EGLImage from a GraphicBuffer. 275 EGLImageKHR createImage(EGLDisplay dpy, 276 const sp<GraphicBuffer>& graphicBuffer); 277 278 // freeBufferLocked frees up the given buffer slot. If the slot has been 279 // initialized this will release the reference to the GraphicBuffer in that 280 // slot and destroy the EGLImage in that slot. Otherwise it has no effect. 281 // 282 // This method must be called with mMutex locked. 283 virtual void freeBufferLocked(int slotIndex); 284 285 // computeCurrentTransformMatrixLocked computes the transform matrix for the 286 // current texture. It uses mCurrentTransform and the current GraphicBuffer 287 // to compute this matrix and stores it in mCurrentTransformMatrix. 288 // mCurrentTextureBuf must not be NULL. 289 void computeCurrentTransformMatrixLocked(); 290 291 // doGLFenceWaitLocked inserts a wait command into the OpenGL ES command 292 // stream to ensure that it is safe for future OpenGL ES commands to 293 // access the current texture buffer. 294 status_t doGLFenceWaitLocked() const; 295 296 // syncForReleaseLocked performs the synchronization needed to release the 297 // current slot from an OpenGL ES context. If needed it will set the 298 // current slot's fence to guard against a producer accessing the buffer 299 // before the outstanding accesses have completed. 300 status_t syncForReleaseLocked(EGLDisplay dpy); 301 302 // Normally, when we bind a buffer to a texture target, we bind a buffer 303 // that is referenced by an entry in mEglSlots. In some situations we 304 // have a buffer in mCurrentTextureBuf, but no corresponding entry for 305 // it in our slot array. bindUnslottedBuffer handles that situation by 306 // binding the buffer without touching the EglSlots. 307 status_t bindUnslottedBufferLocked(EGLDisplay dpy); 308 309 // The default consumer usage flags that GLConsumer always sets on its 310 // BufferQueue instance; these will be OR:d with any additional flags passed 311 // from the GLConsumer user. In particular, GLConsumer will always 312 // consume buffers as hardware textures. 313 static const uint32_t DEFAULT_USAGE_FLAGS = GraphicBuffer::USAGE_HW_TEXTURE; 314 315 // mCurrentTextureBuf is the graphic buffer of the current texture. It's 316 // possible that this buffer is not associated with any buffer slot, so we 317 // must track it separately in order to support the getCurrentBuffer method. 318 sp<GraphicBuffer> mCurrentTextureBuf; 319 320 // mCurrentCrop is the crop rectangle that applies to the current texture. 321 // It gets set each time updateTexImage is called. 322 Rect mCurrentCrop; 323 324 // mCurrentTransform is the transform identifier for the current texture. It 325 // gets set each time updateTexImage is called. 326 uint32_t mCurrentTransform; 327 328 // mCurrentScalingMode is the scaling mode for the current texture. It gets 329 // set each time updateTexImage is called. 330 uint32_t mCurrentScalingMode; 331 332 // mCurrentFence is the fence received from BufferQueue in updateTexImage. 333 sp<Fence> mCurrentFence; 334 335 // mCurrentTransformMatrix is the transform matrix for the current texture. 336 // It gets computed by computeTransformMatrix each time updateTexImage is 337 // called. 338 float mCurrentTransformMatrix[16]; 339 340 // mCurrentTimestamp is the timestamp for the current texture. It 341 // gets set each time updateTexImage is called. 342 int64_t mCurrentTimestamp; 343 344 uint32_t mDefaultWidth, mDefaultHeight; 345 346 // mFilteringEnabled indicates whether the transform matrix is computed for 347 // use with bilinear filtering. It defaults to true and is changed by 348 // setFilteringEnabled(). 349 bool mFilteringEnabled; 350 351 // mTexName is the name of the OpenGL texture to which streamed images will 352 // be bound when updateTexImage is called. It is set at construction time 353 // and can be changed with a call to attachToContext. 354 GLuint mTexName; 355 356 // mUseFenceSync indicates whether creation of the EGL_KHR_fence_sync 357 // extension should be used to prevent buffers from being dequeued before 358 // it's safe for them to be written. It gets set at construction time and 359 // never changes. 360 const bool mUseFenceSync; 361 362 // mTexTarget is the GL texture target with which the GL texture object is 363 // associated. It is set in the constructor and never changed. It is 364 // almost always GL_TEXTURE_EXTERNAL_OES except for one use case in Android 365 // Browser. In that case it is set to GL_TEXTURE_2D to allow 366 // glCopyTexSubImage to read from the texture. This is a hack to work 367 // around a GL driver limitation on the number of FBO attachments, which the 368 // browser's tile cache exceeds. 369 const GLenum mTexTarget; 370 371 // EGLSlot contains the information and object references that 372 // GLConsumer maintains about a BufferQueue buffer slot. 373 struct EglSlot { 374 EglSlot() 375 : mEglImage(EGL_NO_IMAGE_KHR), 376 mEglFence(EGL_NO_SYNC_KHR) { 377 } 378 379 // mEglImage is the EGLImage created from mGraphicBuffer. 380 EGLImageKHR mEglImage; 381 382 // mFence is the EGL sync object that must signal before the buffer 383 // associated with this buffer slot may be dequeued. It is initialized 384 // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based 385 // on a compile-time option) set to a new sync object in updateTexImage. 386 EGLSyncKHR mEglFence; 387 }; 388 389 // mEglDisplay is the EGLDisplay with which this GLConsumer is currently 390 // associated. It is intialized to EGL_NO_DISPLAY and gets set to the 391 // current display when updateTexImage is called for the first time and when 392 // attachToContext is called. 393 EGLDisplay mEglDisplay; 394 395 // mEglContext is the OpenGL ES context with which this GLConsumer is 396 // currently associated. It is initialized to EGL_NO_CONTEXT and gets set 397 // to the current GL context when updateTexImage is called for the first 398 // time and when attachToContext is called. 399 EGLContext mEglContext; 400 401 // mEGLSlots stores the buffers that have been allocated by the BufferQueue 402 // for each buffer slot. It is initialized to null pointers, and gets 403 // filled in with the result of BufferQueue::acquire when the 404 // client dequeues a buffer from a 405 // slot that has not yet been used. The buffer allocated to a slot will also 406 // be replaced if the requested buffer usage or geometry differs from that 407 // of the buffer allocated to a slot. 408 EglSlot mEglSlots[BufferQueue::NUM_BUFFER_SLOTS]; 409 410 // mCurrentTexture is the buffer slot index of the buffer that is currently 411 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 412 // indicating that no buffer slot is currently bound to the texture. Note, 413 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 414 // that no buffer is bound to the texture. A call to setBufferCount will 415 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 416 int mCurrentTexture; 417 418 // mAttached indicates whether the ConsumerBase is currently attached to 419 // an OpenGL ES context. For legacy reasons, this is initialized to true, 420 // indicating that the ConsumerBase is considered to be attached to 421 // whatever context is current at the time of the first updateTexImage call. 422 // It is set to false by detachFromContext, and then set to true again by 423 // attachToContext. 424 bool mAttached; 425}; 426 427// ---------------------------------------------------------------------------- 428}; // namespace android 429 430#endif // ANDROID_GUI_CONSUMER_H 431