SurfaceTexture.h revision 9d4d6c101d90d4a1d1ca9413cf3eb89d1f1898d6
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 24#include <gui/ISurfaceTexture.h> 25 26#include <ui/GraphicBuffer.h> 27 28#include <utils/threads.h> 29#include <utils/Vector.h> 30 31#define ANDROID_GRAPHICS_SURFACETEXTURE_JNI_ID "mSurfaceTexture" 32 33namespace android { 34// ---------------------------------------------------------------------------- 35 36class IGraphicBufferAlloc; 37 38class SurfaceTexture : public BnSurfaceTexture { 39public: 40 enum { MIN_UNDEQUEUED_BUFFERS = 2 }; 41 enum { MIN_BUFFER_SLOTS = MIN_UNDEQUEUED_BUFFERS + 1 }; 42 enum { NUM_BUFFER_SLOTS = 32 }; 43 44 struct FrameAvailableListener : public virtual RefBase { 45 virtual void onFrameAvailable() = 0; 46 }; 47 48 // tex indicates the name OpenGL texture to which images are to be streamed. 49 // This texture name cannot be changed once the SurfaceTexture is created. 50 SurfaceTexture(GLuint tex); 51 52 virtual ~SurfaceTexture(); 53 54 // setBufferCount updates the number of available buffer slots. After 55 // calling this all buffer slots are both unallocated and owned by the 56 // SurfaceTexture object (i.e. they are not owned by the client). 57 virtual status_t setBufferCount(int bufferCount); 58 59 virtual sp<GraphicBuffer> requestBuffer(int buf, uint32_t w, uint32_t h, 60 uint32_t format, uint32_t usage); 61 62 // dequeueBuffer gets the next buffer slot index for the client to use. If a 63 // buffer slot is available then that slot index is written to the location 64 // pointed to by the buf argument and a status of OK is returned. If no 65 // slot is available then a status of -EBUSY is returned and buf is 66 // unmodified. 67 virtual status_t dequeueBuffer(int *buf); 68 69 virtual status_t queueBuffer(int buf); 70 virtual void cancelBuffer(int buf); 71 virtual status_t setCrop(const Rect& reg); 72 virtual status_t setTransform(uint32_t transform); 73 74 // updateTexImage sets the image contents of the target texture to that of 75 // the most recently queued buffer. 76 // 77 // This call may only be made while the OpenGL ES context to which the 78 // target texture belongs is bound to the calling thread. 79 status_t updateTexImage(); 80 81 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 82 // associated with the texture image set by the most recent call to 83 // updateTexImage. 84 // 85 // This transform matrix maps 2D homogeneous texture coordinates of the form 86 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 87 // coordinate that should be used to sample that location from the texture. 88 // Sampling the texture outside of the range of this transform is undefined. 89 // 90 // This transform is necessary to compensate for transforms that the stream 91 // content producer may implicitly apply to the content. By forcing users of 92 // a SurfaceTexture to apply this transform we avoid performing an extra 93 // copy of the data that would be needed to hide the transform from the 94 // user. 95 // 96 // The matrix is stored in column-major order so that it may be passed 97 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 98 // functions. 99 void getTransformMatrix(float mtx[16]); 100 101 // setFrameAvailableListener sets the listener object that will be notified 102 // when a new frame becomes available. 103 void setFrameAvailableListener(const sp<FrameAvailableListener>& l); 104 105 // getAllocator retrieves the binder object that must be referenced as long 106 // as the GraphicBuffers dequeued from this SurfaceTexture are referenced. 107 // Holding this binder reference prevents SurfaceFlinger from freeing the 108 // buffers before the client is done with them. 109 sp<IBinder> getAllocator(); 110 111private: 112 113 // freeAllBuffers frees the resources (both GraphicBuffer and EGLImage) for 114 // all slots. 115 void freeAllBuffers(); 116 117 // createImage creates a new EGLImage from a GraphicBuffer. 118 EGLImageKHR createImage(EGLDisplay dpy, 119 const sp<GraphicBuffer>& graphicBuffer); 120 121 enum { INVALID_BUFFER_SLOT = -1 }; 122 123 struct BufferSlot { 124 // mGraphicBuffer points to the buffer allocated for this slot or is NULL 125 // if no buffer has been allocated. 126 sp<GraphicBuffer> mGraphicBuffer; 127 128 // mEglImage is the EGLImage created from mGraphicBuffer. 129 EGLImageKHR mEglImage; 130 131 // mEglDisplay is the EGLDisplay used to create mEglImage. 132 EGLDisplay mEglDisplay; 133 134 // mOwnedByClient indicates whether the slot is currently accessible to a 135 // client and should not be used by the SurfaceTexture object. It gets 136 // set to true when dequeueBuffer returns the slot and is reset to false 137 // when the client calls either queueBuffer or cancelBuffer on the slot. 138 bool mOwnedByClient; 139 }; 140 141 // mSlots is the array of buffer slots that must be mirrored on the client 142 // side. This allows buffer ownership to be transferred between the client 143 // and server without sending a GraphicBuffer over binder. The entire array 144 // is initialized to NULL at construction time, and buffers are allocated 145 // for a slot when requestBuffer is called with that slot's index. 146 BufferSlot mSlots[NUM_BUFFER_SLOTS]; 147 148 // mBufferCount is the number of buffer slots that the client and server 149 // must maintain. It defaults to MIN_BUFFER_SLOTS and can be changed by 150 // calling setBufferCount. 151 int mBufferCount; 152 153 // mCurrentTexture is the buffer slot index of the buffer that is currently 154 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 155 // indicating that no buffer slot is currently bound to the texture. Note, 156 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 157 // that no buffer is bound to the texture. A call to setBufferCount will 158 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 159 int mCurrentTexture; 160 161 // mCurrentTextureBuf is the graphic buffer of the current texture. It's 162 // possible that this buffer is not associated with any buffer slot, so we 163 // must track it separately in order to properly use 164 // IGraphicBufferAlloc::freeAllGraphicBuffersExcept. 165 sp<GraphicBuffer> mCurrentTextureBuf; 166 167 // mCurrentCrop is the crop rectangle that applies to the current texture. 168 // It gets set to mLastQueuedCrop each time updateTexImage is called. 169 Rect mCurrentCrop; 170 171 // mCurrentTransform is the transform identifier for the current texture. It 172 // gets set to mLastQueuedTransform each time updateTexImage is called. 173 uint32_t mCurrentTransform; 174 175 // mLastQueued is the buffer slot index of the most recently enqueued buffer. 176 // At construction time it is initialized to INVALID_BUFFER_SLOT, and is 177 // updated each time queueBuffer is called. 178 int mLastQueued; 179 180 // mLastQueuedCrop is the crop rectangle for the buffer that was most 181 // recently queued. This gets set to mNextCrop each time queueBuffer gets 182 // called. 183 Rect mLastQueuedCrop; 184 185 // mLastQueuedTransform is the transform identifier for the buffer that was 186 // most recently queued. This gets set to mNextTransform each time 187 // queueBuffer gets called. 188 uint32_t mLastQueuedTransform; 189 190 // mNextCrop is the crop rectangle that will be used for the next buffer 191 // that gets queued. It is set by calling setCrop. 192 Rect mNextCrop; 193 194 // mNextTransform is the transform identifier that will be used for the next 195 // buffer that gets queued. It is set by calling setTransform. 196 uint32_t mNextTransform; 197 198 // mTexName is the name of the OpenGL texture to which streamed images will 199 // be bound when updateTexImage is called. It is set at construction time 200 // changed with a call to setTexName. 201 const GLuint mTexName; 202 203 // mGraphicBufferAlloc is the connection to SurfaceFlinger that is used to 204 // allocate new GraphicBuffer objects. 205 sp<IGraphicBufferAlloc> mGraphicBufferAlloc; 206 207 // mAllocdBuffers is mirror of the list of buffers that SurfaceFlinger is 208 // referencing. This is kept so that gralloc implementations do not need to 209 // properly handle the case where SurfaceFlinger no longer holds a reference 210 // to a buffer, but other processes do. 211 Vector<sp<GraphicBuffer> > mAllocdBuffers; 212 213 // mFrameAvailableListener is the listener object that will be called when a 214 // new frame becomes available. If it is not NULL it will be called from 215 // queueBuffer. 216 sp<FrameAvailableListener> mFrameAvailableListener; 217 218 // mMutex is the mutex used to prevent concurrent access to the member 219 // variables of SurfaceTexture objects. It must be locked whenever the 220 // member variables are accessed. 221 Mutex mMutex; 222}; 223 224// ---------------------------------------------------------------------------- 225}; // namespace android 226 227#endif // ANDROID_GUI_SURFACETEXTURE_H 228