SurfaceTexture.h revision eae59d2ea77ef57aab203fb185a880ce37ac38d6
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 BufferQueue { 43public: 44 45 // SurfaceTexture constructs a new SurfaceTexture object. tex indicates the 46 // name of the OpenGL ES texture to which images are to be streamed. This 47 // texture name cannot be changed once the SurfaceTexture is created. 48 // allowSynchronousMode specifies whether or not synchronous mode can be 49 // enabled. texTarget specifies the OpenGL ES texture target to which the 50 // texture will be bound in updateTexImage. useFenceSync specifies whether 51 // fences should be used to synchronize access to buffers if that behavior 52 // is enabled at compile-time. 53 SurfaceTexture(GLuint tex, bool allowSynchronousMode = true, 54 GLenum texTarget = GL_TEXTURE_EXTERNAL_OES, bool useFenceSync = true); 55 56 virtual ~SurfaceTexture(); 57 58 59 60 // updateTexImage sets the image contents of the target texture to that of 61 // the most recently queued buffer. 62 // 63 // This call may only be made while the OpenGL ES context to which the 64 // target texture belongs is bound to the calling thread. 65 status_t updateTexImage(); 66 67 // setBufferCountServer set the buffer count. If the client has requested 68 // a buffer count using setBufferCount, the server-buffer count will 69 // take effect once the client sets the count back to zero. 70 status_t setBufferCountServer(int bufferCount); 71 72 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 73 // associated with the texture image set by the most recent call to 74 // updateTexImage. 75 // 76 // This transform matrix maps 2D homogeneous texture coordinates of the form 77 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 78 // coordinate that should be used to sample that location from the texture. 79 // Sampling the texture outside of the range of this transform is undefined. 80 // 81 // This transform is necessary to compensate for transforms that the stream 82 // content producer may implicitly apply to the content. By forcing users of 83 // a SurfaceTexture to apply this transform we avoid performing an extra 84 // copy of the data that would be needed to hide the transform from the 85 // user. 86 // 87 // The matrix is stored in column-major order so that it may be passed 88 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 89 // functions. 90 void getTransformMatrix(float mtx[16]); 91 92 // getTimestamp retrieves the timestamp associated with the texture image 93 // set by the most recent call to updateTexImage. 94 // 95 // The timestamp is in nanoseconds, and is monotonically increasing. Its 96 // other semantics (zero point, etc) are source-dependent and should be 97 // documented by the source. 98 int64_t getTimestamp(); 99 100 // setFrameAvailableListener sets the listener object that will be notified 101 // when a new frame becomes available. 102 void setFrameAvailableListener(const sp<FrameAvailableListener>& listener); 103 104 // getAllocator retrieves the binder object that must be referenced as long 105 // as the GraphicBuffers dequeued from this SurfaceTexture are referenced. 106 // Holding this binder reference prevents SurfaceFlinger from freeing the 107 // buffers before the client is done with them. 108 sp<IBinder> getAllocator(); 109 110 // setDefaultBufferSize is used to set the size of buffers returned by 111 // requestBuffers when a with and height of zero is requested. 112 // A call to setDefaultBufferSize() may trigger requestBuffers() to 113 // be called from the client. 114 // The width and height parameters must be no greater than the minimum of 115 // GL_MAX_VIEWPORT_DIMS and GL_MAX_TEXTURE_SIZE (see: glGetIntegerv). 116 // An error due to invalid dimensions might not be reported until 117 // updateTexImage() is called. 118 status_t setDefaultBufferSize(uint32_t width, uint32_t height); 119 120 // getCurrentBuffer returns the buffer associated with the current image. 121 sp<GraphicBuffer> getCurrentBuffer() const; 122 123 // getCurrentTextureTarget returns the texture target of the current 124 // texture as returned by updateTexImage(). 125 GLenum getCurrentTextureTarget() const; 126 127 // getCurrentCrop returns the cropping rectangle of the current buffer 128 Rect getCurrentCrop() const; 129 130 // getCurrentTransform returns the transform of the current buffer 131 uint32_t getCurrentTransform() const; 132 133 // getCurrentScalingMode returns the scaling mode of the current buffer 134 uint32_t getCurrentScalingMode() const; 135 136 // isSynchronousMode returns whether the SurfaceTexture is currently in 137 // synchronous mode. 138 bool isSynchronousMode() const; 139 140 // abandon frees all the buffers and puts the SurfaceTexture into the 141 // 'abandoned' state. Once put in this state the SurfaceTexture can never 142 // leave it. When in the 'abandoned' state, all methods of the 143 // ISurfaceTexture interface will fail with the NO_INIT error. 144 // 145 // Note that while calling this method causes all the buffers to be freed 146 // from the perspective of the the SurfaceTexture, if there are additional 147 // references on the buffers (e.g. if a buffer is referenced by a client or 148 // by OpenGL ES as a texture) then those buffer will remain allocated. 149 void abandon(); 150 151 // set the name of the SurfaceTexture that will be used to identify it in 152 // log messages. 153 void setName(const String8& name); 154 155 // dump our state in a String 156 virtual void dump(String8& result) const; 157 virtual void dump(String8& result, const char* prefix, char* buffer, size_t SIZE) const; 158 159protected: 160 161 static bool isExternalFormat(uint32_t format); 162 163private: 164 165 // createImage creates a new EGLImage from a GraphicBuffer. 166 EGLImageKHR createImage(EGLDisplay dpy, 167 const sp<GraphicBuffer>& graphicBuffer); 168 169 // computeCurrentTransformMatrix computes the transform matrix for the 170 // current texture. It uses mCurrentTransform and the current GraphicBuffer 171 // to compute this matrix and stores it in mCurrentTransformMatrix. 172 void computeCurrentTransformMatrix(); 173 174 // mCurrentTextureBuf is the graphic buffer of the current texture. It's 175 // possible that this buffer is not associated with any buffer slot, so we 176 // must track it separately in order to support the getCurrentBuffer method. 177 sp<GraphicBuffer> mCurrentTextureBuf; 178 179 // mCurrentCrop is the crop rectangle that applies to the current texture. 180 // It gets set each time updateTexImage is called. 181 Rect mCurrentCrop; 182 183 // mCurrentTransform is the transform identifier for the current texture. It 184 // gets set each time updateTexImage is called. 185 uint32_t mCurrentTransform; 186 187 // mCurrentScalingMode is the scaling mode for the current texture. It gets 188 // set to each time updateTexImage is called. 189 uint32_t mCurrentScalingMode; 190 191 // mCurrentTransformMatrix is the transform matrix for the current texture. 192 // It gets computed by computeTransformMatrix each time updateTexImage is 193 // called. 194 float mCurrentTransformMatrix[16]; 195 196 // mCurrentTimestamp is the timestamp for the current texture. It 197 // gets set each time updateTexImage is called. 198 int64_t mCurrentTimestamp; 199 200 // mTexName is the name of the OpenGL texture to which streamed images will 201 // be bound when updateTexImage is called. It is set at construction time 202 // changed with a call to setTexName. 203 const GLuint mTexName; 204 205 // mUseFenceSync indicates whether creation of the EGL_KHR_fence_sync 206 // extension should be used to prevent buffers from being dequeued before 207 // it's safe for them to be written. It gets set at construction time and 208 // never changes. 209 const bool mUseFenceSync; 210 211 // mTexTarget is the GL texture target with which the GL texture object is 212 // associated. It is set in the constructor and never changed. It is 213 // almost always GL_TEXTURE_EXTERNAL_OES except for one use case in Android 214 // Browser. In that case it is set to GL_TEXTURE_2D to allow 215 // glCopyTexSubImage to read from the texture. This is a hack to work 216 // around a GL driver limitation on the number of FBO attachments, which the 217 // browser's tile cache exceeds. 218 const GLenum mTexTarget; 219 220 // SurfaceTexture maintains EGL information about GraphicBuffers that corresponds 221 // directly with BufferQueue's buffers 222 struct EGLSlot { 223 EGLSlot() 224 : mEglImage(EGL_NO_IMAGE_KHR), 225 mEglDisplay(EGL_NO_DISPLAY), 226 mFence(EGL_NO_SYNC_KHR) { 227 } 228 229 sp<GraphicBuffer> mGraphicBuffer; 230 231 // mEglImage is the EGLImage created from mGraphicBuffer. 232 EGLImageKHR mEglImage; 233 234 // mEglDisplay is the EGLDisplay used to create mEglImage. 235 EGLDisplay mEglDisplay; 236 237 // mFence is the EGL sync object that must signal before the buffer 238 // associated with this buffer slot may be dequeued. It is initialized 239 // to EGL_NO_SYNC_KHR when the buffer is created and (optionally, based 240 // on a compile-time option) set to a new sync object in updateTexImage. 241 EGLSyncKHR mFence; 242 }; 243 244 EGLSlot mEGLSlots[NUM_BUFFER_SLOTS]; 245 246 // mAbandoned indicates that the BufferQueue will no longer be used to 247 // consume images buffers pushed to it using the ISurfaceTexture interface. 248 // It is initialized to false, and set to true in the abandon method. A 249 // BufferQueue that has been abandoned will return the NO_INIT error from 250 // all ISurfaceTexture methods capable of returning an error. 251 bool mAbandoned; 252 253 // mName is a string used to identify the SurfaceTexture in log messages. 254 // It can be set by the setName method. 255 String8 mName; 256 257 // mMutex is the mutex used to prevent concurrent access to the member 258 // variables of SurfaceTexture objects. It must be locked whenever the 259 // member variables are accessed. 260 mutable Mutex mMutex; 261 262 // mCurrentTexture is the buffer slot index of the buffer that is currently 263 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 264 // indicating that no buffer slot is currently bound to the texture. Note, 265 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 266 // that no buffer is bound to the texture. A call to setBufferCount will 267 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 268 int mCurrentTexture; 269 270}; 271 272// ---------------------------------------------------------------------------- 273}; // namespace android 274 275#endif // ANDROID_GUI_SURFACETEXTURE_H 276