GLConsumer.h revision c5d7b7d323bba8772a9005f7d300ad983a04733a
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(GLuint tex, bool allowSynchronousMode = true, 89 GLenum texTarget = GL_TEXTURE_EXTERNAL_OES, bool useFenceSync = true, 90 const sp<BufferQueue> &bufferQueue = 0); 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 // setReleaseFence stores a fence that will signal when the current buffer 102 // is no longer being read. This fence will be returned to the producer 103 // when the current buffer is released by updateTexImage(). Multiple 104 // fences can be set for a given buffer; they will be merged into a single 105 // union fence. 106 void setReleaseFence(const sp<Fence>& fence); 107 108 // setDefaultMaxBufferCount sets the default limit on the maximum number 109 // of buffers that will be allocated at one time. The image producer may 110 // override the limit. 111 status_t setDefaultMaxBufferCount(int bufferCount); 112 113 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 114 // associated with the texture image set by the most recent call to 115 // updateTexImage. 116 // 117 // This transform matrix maps 2D homogeneous texture coordinates of the form 118 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 119 // coordinate that should be used to sample that location from the texture. 120 // Sampling the texture outside of the range of this transform is undefined. 121 // 122 // This transform is necessary to compensate for transforms that the stream 123 // content producer may implicitly apply to the content. By forcing users of 124 // a GLConsumer to apply this transform we avoid performing an extra 125 // copy of the data that would be needed to hide the transform from the 126 // user. 127 // 128 // The matrix is stored in column-major order so that it may be passed 129 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 130 // functions. 131 void getTransformMatrix(float mtx[16]); 132 133 // getTimestamp retrieves the timestamp associated with the texture image 134 // set by the most recent call to updateTexImage. 135 // 136 // The timestamp is in nanoseconds, and is monotonically increasing. Its 137 // other semantics (zero point, etc) are source-dependent and should be 138 // documented by the source. 139 int64_t getTimestamp(); 140 141 // setDefaultBufferSize is used to set the size of buffers returned by 142 // requestBuffers when a with and height of zero is requested. 143 // A call to setDefaultBufferSize() may trigger requestBuffers() to 144 // be called from the client. 145 // The width and height parameters must be no greater than the minimum of 146 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 147 // An error due to invalid dimensions might not be reported until 148 // updateTexImage() is called. 149 status_t setDefaultBufferSize(uint32_t width, uint32_t height); 150 151 // setFilteringEnabled sets whether the transform matrix should be computed 152 // for use with bilinear filtering. 153 void setFilteringEnabled(bool enabled); 154 155 // getCurrentBuffer returns the buffer associated with the current image. 156 sp<GraphicBuffer> getCurrentBuffer() const; 157 158 // getCurrentTextureTarget returns the texture target of the current 159 // texture as returned by updateTexImage(). 160 GLenum getCurrentTextureTarget() const; 161 162 // getCurrentCrop returns the cropping rectangle of the current buffer. 163 Rect getCurrentCrop() const; 164 165 // getCurrentTransform returns the transform of the current buffer. 166 uint32_t getCurrentTransform() const; 167 168 // getCurrentScalingMode returns the scaling mode of the current buffer. 169 uint32_t getCurrentScalingMode() const; 170 171 // getCurrentFence returns the fence indicating when the current buffer is 172 // ready to be read from. 173 sp<Fence> getCurrentFence() const; 174 175 // doGLFenceWait inserts a wait command into the OpenGL ES command stream 176 // to ensure that it is safe for future OpenGL ES commands to access the 177 // current texture buffer. 178 status_t doGLFenceWait() const; 179 180 // isSynchronousMode returns whether the GLConsumer is currently in 181 // synchronous mode. 182 bool isSynchronousMode() const; 183 184 // set the name of the GLConsumer that will be used to identify it in 185 // log messages. 186 void setName(const String8& name); 187 188 // These functions call the corresponding BufferQueue implementation 189 // so the refactoring can proceed smoothly 190 status_t setDefaultBufferFormat(uint32_t defaultFormat); 191 status_t setConsumerUsageBits(uint32_t usage); 192 status_t setTransformHint(uint32_t hint); 193 virtual status_t setSynchronousMode(bool enabled); 194 195 // getBufferQueue returns the BufferQueue object to which this 196 // GLConsumer is connected. 197 sp<BufferQueue> getBufferQueue() const { 198 return mBufferQueue; 199 } 200 201 // detachFromContext detaches the GLConsumer from the calling thread's 202 // current OpenGL ES context. This context must be the same as the context 203 // that was current for previous calls to updateTexImage. 204 // 205 // Detaching a GLConsumer from an OpenGL ES context will result in the 206 // deletion of the OpenGL ES texture object into which the images were being 207 // streamed. After a GLConsumer has been detached from the OpenGL ES 208 // context calls to updateTexImage will fail returning INVALID_OPERATION 209 // until the GLConsumer is attached to a new OpenGL ES context using the 210 // attachToContext method. 211 status_t detachFromContext(); 212 213 // attachToContext attaches a GLConsumer that is currently in the 214 // 'detached' state to the current OpenGL ES context. A GLConsumer is 215 // in the 'detached' state iff detachFromContext has successfully been 216 // called and no calls to attachToContext have succeeded since the last 217 // detachFromContext call. Calls to attachToContext made on a 218 // GLConsumer that is not in the 'detached' state will result in an 219 // INVALID_OPERATION error. 220 // 221 // The tex argument specifies the OpenGL ES texture object name in the 222 // new context into which the image contents will be streamed. A successful 223 // call to attachToContext will result in this texture object being bound to 224 // the texture target and populated with the image contents that were 225 // current at the time of the last call to detachFromContext. 226 status_t attachToContext(GLuint tex); 227 228protected: 229 230 // abandonLocked overrides the ConsumerBase method to clear 231 // mCurrentTextureBuf in addition to the ConsumerBase behavior. 232 virtual void abandonLocked(); 233 234 // dumpLocked overrides the ConsumerBase method to dump GLConsumer- 235 // specific info in addition to the ConsumerBase behavior. 236 virtual void dumpLocked(String8& result, const char* prefix) const; 237 238 // acquireBufferLocked overrides the ConsumerBase method to update the 239 // mEglSlots array in addition to the ConsumerBase behavior. 240 virtual status_t acquireBufferLocked(BufferQueue::BufferItem *item); 241 242 // releaseBufferLocked overrides the ConsumerBase method to update the 243 // mEglSlots array in addition to the ConsumerBase. 244 virtual status_t releaseBufferLocked(int slot, 245 const sp<GraphicBuffer> graphicBuffer, 246 EGLDisplay display, EGLSyncKHR eglFence); 247 248 status_t releaseBufferLocked(int slot, 249 const sp<GraphicBuffer> graphicBuffer, EGLSyncKHR eglFence) { 250 return releaseBufferLocked(slot, graphicBuffer, mEglDisplay, eglFence); 251 } 252 253 static bool isExternalFormat(uint32_t format); 254 255 // This releases the buffer in the slot referenced by mCurrentTexture, 256 // then updates state to refer to the BufferItem, which must be a 257 // newly-acquired buffer. 258 status_t releaseAndUpdateLocked(const BufferQueue::BufferItem& item); 259 260 // Binds mTexName and the current buffer to mTexTarget. Uses 261 // mCurrentTexture if it's set, mCurrentTextureBuf if not. If the 262 // bind succeeds, this calls doGLFenceWait. 263 status_t bindTextureImageLocked(); 264 265 // Gets the current EGLDisplay and EGLContext values, and compares them 266 // to mEglDisplay and mEglContext. If the fields have been previously 267 // set, the values must match; if not, the fields are set to the current 268 // values. 269 status_t checkAndUpdateEglStateLocked(); 270 271private: 272 // createImage creates a new EGLImage from a GraphicBuffer. 273 EGLImageKHR createImage(EGLDisplay dpy, 274 const sp<GraphicBuffer>& graphicBuffer); 275 276 // freeBufferLocked frees up the given buffer slot. If the slot has been 277 // initialized this will release the reference to the GraphicBuffer in that 278 // slot and destroy the EGLImage in that slot. Otherwise it has no effect. 279 // 280 // This method must be called with mMutex locked. 281 virtual void freeBufferLocked(int slotIndex); 282 283 // computeCurrentTransformMatrixLocked computes the transform matrix for the 284 // current texture. It uses mCurrentTransform and the current GraphicBuffer 285 // to compute this matrix and stores it in mCurrentTransformMatrix. 286 // mCurrentTextureBuf must not be NULL. 287 void computeCurrentTransformMatrixLocked(); 288 289 // doGLFenceWaitLocked inserts a wait command into the OpenGL ES command 290 // stream to ensure that it is safe for future OpenGL ES commands to 291 // access the current texture buffer. 292 status_t doGLFenceWaitLocked() const; 293 294 // syncForReleaseLocked performs the synchronization needed to release the 295 // current slot from an OpenGL ES context. If needed it will set the 296 // current slot's fence to guard against a producer accessing the buffer 297 // before the outstanding accesses have completed. 298 status_t syncForReleaseLocked(EGLDisplay dpy); 299 300 // Normally, when we bind a buffer to a texture target, we bind a buffer 301 // that is referenced by an entry in mEglSlots. In some situations we 302 // have a buffer in mCurrentTextureBuf, but no corresponding entry for 303 // it in our slot array. bindUnslottedBuffer handles that situation by 304 // binding the buffer without touching the EglSlots. 305 status_t bindUnslottedBufferLocked(EGLDisplay dpy); 306 307 // The default consumer usage flags that GLConsumer always sets on its 308 // BufferQueue instance; these will be OR:d with any additional flags passed 309 // from the GLConsumer user. In particular, GLConsumer will always 310 // consume buffers as hardware textures. 311 static const uint32_t DEFAULT_USAGE_FLAGS = GraphicBuffer::USAGE_HW_TEXTURE; 312 313 // mCurrentTextureBuf is the graphic buffer of the current texture. It's 314 // possible that this buffer is not associated with any buffer slot, so we 315 // must track it separately in order to support the getCurrentBuffer method. 316 sp<GraphicBuffer> mCurrentTextureBuf; 317 318 // mCurrentCrop is the crop rectangle that applies to the current texture. 319 // It gets set each time updateTexImage is called. 320 Rect mCurrentCrop; 321 322 // mCurrentTransform is the transform identifier for the current texture. It 323 // gets set each time updateTexImage is called. 324 uint32_t mCurrentTransform; 325 326 // mCurrentScalingMode is the scaling mode for the current texture. It gets 327 // set each time updateTexImage is called. 328 uint32_t mCurrentScalingMode; 329 330 // mCurrentFence is the fence received from BufferQueue in updateTexImage. 331 sp<Fence> mCurrentFence; 332 333 // mCurrentTransformMatrix is the transform matrix for the current texture. 334 // It gets computed by computeTransformMatrix each time updateTexImage is 335 // called. 336 float mCurrentTransformMatrix[16]; 337 338 // mCurrentTimestamp is the timestamp for the current texture. It 339 // gets set each time updateTexImage is called. 340 int64_t mCurrentTimestamp; 341 342 uint32_t mDefaultWidth, mDefaultHeight; 343 344 // mFilteringEnabled indicates whether the transform matrix is computed for 345 // use with bilinear filtering. It defaults to true and is changed by 346 // setFilteringEnabled(). 347 bool mFilteringEnabled; 348 349 // mTexName is the name of the OpenGL texture to which streamed images will 350 // be bound when updateTexImage is called. It is set at construction time 351 // and can be changed with a call to attachToContext. 352 GLuint mTexName; 353 354 // mUseFenceSync indicates whether creation of the EGL_KHR_fence_sync 355 // extension should be used to prevent buffers from being dequeued before 356 // it's safe for them to be written. It gets set at construction time and 357 // never changes. 358 const bool mUseFenceSync; 359 360 // mTexTarget is the GL texture target with which the GL texture object is 361 // associated. It is set in the constructor and never changed. It is 362 // almost always GL_TEXTURE_EXTERNAL_OES except for one use case in Android 363 // Browser. In that case it is set to GL_TEXTURE_2D to allow 364 // glCopyTexSubImage to read from the texture. This is a hack to work 365 // around a GL driver limitation on the number of FBO attachments, which the 366 // browser's tile cache exceeds. 367 const GLenum mTexTarget; 368 369 // EGLSlot contains the information and object references that 370 // GLConsumer maintains about a BufferQueue buffer slot. 371 struct EglSlot { 372 EglSlot() 373 : mEglImage(EGL_NO_IMAGE_KHR), 374 mEglFence(EGL_NO_SYNC_KHR) { 375 } 376 377 // mEglImage is the EGLImage created from mGraphicBuffer. 378 EGLImageKHR mEglImage; 379 380 // mFence is the EGL sync object that must signal before the buffer 381 // associated with this buffer slot may be dequeued. It is initialized 382 // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based 383 // on a compile-time option) set to a new sync object in updateTexImage. 384 EGLSyncKHR mEglFence; 385 }; 386 387 // mEglDisplay is the EGLDisplay with which this GLConsumer is currently 388 // associated. It is intialized to EGL_NO_DISPLAY and gets set to the 389 // current display when updateTexImage is called for the first time and when 390 // attachToContext is called. 391 EGLDisplay mEglDisplay; 392 393 // mEglContext is the OpenGL ES context with which this GLConsumer is 394 // currently associated. It is initialized to EGL_NO_CONTEXT and gets set 395 // to the current GL context when updateTexImage is called for the first 396 // time and when attachToContext is called. 397 EGLContext mEglContext; 398 399 // mEGLSlots stores the buffers that have been allocated by the BufferQueue 400 // for each buffer slot. It is initialized to null pointers, and gets 401 // filled in with the result of BufferQueue::acquire when the 402 // client dequeues a buffer from a 403 // slot that has not yet been used. The buffer allocated to a slot will also 404 // be replaced if the requested buffer usage or geometry differs from that 405 // of the buffer allocated to a slot. 406 EglSlot mEglSlots[BufferQueue::NUM_BUFFER_SLOTS]; 407 408 // mCurrentTexture is the buffer slot index of the buffer that is currently 409 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 410 // indicating that no buffer slot is currently bound to the texture. Note, 411 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 412 // that no buffer is bound to the texture. A call to setBufferCount will 413 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 414 int mCurrentTexture; 415 416 // mAttached indicates whether the ConsumerBase is currently attached to 417 // an OpenGL ES context. For legacy reasons, this is initialized to true, 418 // indicating that the ConsumerBase is considered to be attached to 419 // whatever context is current at the time of the first updateTexImage call. 420 // It is set to false by detachFromContext, and then set to true again by 421 // attachToContext. 422 bool mAttached; 423}; 424 425// ---------------------------------------------------------------------------- 426}; // namespace android 427 428#endif // ANDROID_GUI_CONSUMER_H 429