SurfaceTexture.h revision c4d4aeab52435c177ded6abdd578fec8191f0f5d
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_BUFFER_SLOTS = 3 }; 41 enum { NUM_BUFFER_SLOTS = 32 }; 42 43 struct FrameAvailableListener : public virtual RefBase { 44 virtual void onFrameAvailable() = 0; 45 }; 46 47 // tex indicates the name OpenGL texture to which images are to be streamed. 48 // This texture name cannot be changed once the SurfaceTexture is created. 49 SurfaceTexture(GLuint tex); 50 51 virtual ~SurfaceTexture(); 52 53 // setBufferCount updates the number of available buffer slots. After 54 // calling this all buffer slots are both unallocated and owned by the 55 // SurfaceTexture object (i.e. they are not owned by the client). 56 virtual status_t setBufferCount(int bufferCount); 57 58 virtual sp<GraphicBuffer> requestBuffer(int buf, uint32_t w, uint32_t h, 59 uint32_t format, uint32_t usage); 60 61 // dequeueBuffer gets the next buffer slot index for the client to use. If a 62 // buffer slot is available then that slot index is written to the location 63 // pointed to by the buf argument and a status of OK is returned. If no 64 // slot is available then a status of -EBUSY is returned and buf is 65 // unmodified. 66 virtual status_t dequeueBuffer(int *buf); 67 68 virtual status_t queueBuffer(int buf); 69 virtual void cancelBuffer(int buf); 70 virtual status_t setCrop(const Rect& reg); 71 virtual status_t setTransform(uint32_t transform); 72 73 // updateTexImage sets the image contents of the target texture to that of 74 // the most recently queued buffer. 75 // 76 // This call may only be made while the OpenGL ES context to which the 77 // target texture belongs is bound to the calling thread. 78 status_t updateTexImage(); 79 80 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 81 // associated with the texture image set by the most recent call to 82 // updateTexImage. 83 // 84 // This transform matrix maps 2D homogeneous texture coordinates of the form 85 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 86 // coordinate that should be used to sample that location from the texture. 87 // Sampling the texture outside of the range of this transform is undefined. 88 // 89 // This transform is necessary to compensate for transforms that the stream 90 // content producer may implicitly apply to the content. By forcing users of 91 // a SurfaceTexture to apply this transform we avoid performing an extra 92 // copy of the data that would be needed to hide the transform from the 93 // user. 94 // 95 // The matrix is stored in column-major order so that it may be passed 96 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 97 // functions. 98 void getTransformMatrix(float mtx[16]); 99 100 // setFrameAvailableListener sets the listener object that will be notified 101 // when a new frame becomes available. 102 void setFrameAvailableListener(const sp<FrameAvailableListener>& l); 103 104private: 105 106 // freeAllBuffers frees the resources (both GraphicBuffer and EGLImage) for 107 // all slots. 108 void freeAllBuffers(); 109 110 // createImage creates a new EGLImage from a GraphicBuffer. 111 EGLImageKHR createImage(EGLDisplay dpy, 112 const sp<GraphicBuffer>& graphicBuffer); 113 114 enum { INVALID_BUFFER_SLOT = -1 }; 115 116 struct BufferSlot { 117 // mGraphicBuffer points to the buffer allocated for this slot or is NULL 118 // if no buffer has been allocated. 119 sp<GraphicBuffer> mGraphicBuffer; 120 121 // mEglImage is the EGLImage created from mGraphicBuffer. 122 EGLImageKHR mEglImage; 123 124 // mEglDisplay is the EGLDisplay used to create mEglImage. 125 EGLDisplay mEglDisplay; 126 127 // mOwnedByClient indicates whether the slot is currently accessible to a 128 // client and should not be used by the SurfaceTexture object. It gets 129 // set to true when dequeueBuffer returns the slot and is reset to false 130 // when the client calls either queueBuffer or cancelBuffer on the slot. 131 bool mOwnedByClient; 132 }; 133 134 // mSlots is the array of buffer slots that must be mirrored on the client 135 // side. This allows buffer ownership to be transferred between the client 136 // and server without sending a GraphicBuffer over binder. The entire array 137 // is initialized to NULL at construction time, and buffers are allocated 138 // for a slot when requestBuffer is called with that slot's index. 139 BufferSlot mSlots[NUM_BUFFER_SLOTS]; 140 141 // mBufferCount is the number of buffer slots that the client and server 142 // must maintain. It defaults to MIN_BUFFER_SLOTS and can be changed by 143 // calling setBufferCount. 144 int mBufferCount; 145 146 // mCurrentTexture is the buffer slot index of the buffer that is currently 147 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 148 // indicating that no buffer slot is currently bound to the texture. Note, 149 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 150 // that no buffer is bound to the texture. A call to setBufferCount will 151 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 152 int mCurrentTexture; 153 154 // mCurrentTextureBuf is the graphic buffer of the current texture. It's 155 // possible that this buffer is not associated with any buffer slot, so we 156 // must track it separately in order to properly use 157 // IGraphicBufferAlloc::freeAllGraphicBuffersExcept. 158 sp<GraphicBuffer> mCurrentTextureBuf; 159 160 // mCurrentCrop is the crop rectangle that applies to the current texture. 161 // It gets set to mLastQueuedCrop each time updateTexImage is called. 162 Rect mCurrentCrop; 163 164 // mCurrentTransform is the transform identifier for the current texture. It 165 // gets set to mLastQueuedTransform each time updateTexImage is called. 166 uint32_t mCurrentTransform; 167 168 // mLastQueued is the buffer slot index of the most recently enqueued buffer. 169 // At construction time it is initialized to INVALID_BUFFER_SLOT, and is 170 // updated each time queueBuffer is called. 171 int mLastQueued; 172 173 // mLastQueuedCrop is the crop rectangle for the buffer that was most 174 // recently queued. This gets set to mNextCrop each time queueBuffer gets 175 // called. 176 Rect mLastQueuedCrop; 177 178 // mLastQueuedTransform is the transform identifier for the buffer that was 179 // most recently queued. This gets set to mNextTransform each time 180 // queueBuffer gets called. 181 uint32_t mLastQueuedTransform; 182 183 // mNextCrop is the crop rectangle that will be used for the next buffer 184 // that gets queued. It is set by calling setCrop. 185 Rect mNextCrop; 186 187 // mNextTransform is the transform identifier that will be used for the next 188 // buffer that gets queued. It is set by calling setTransform. 189 uint32_t mNextTransform; 190 191 // mTexName is the name of the OpenGL texture to which streamed images will 192 // be bound when updateTexImage is called. It is set at construction time 193 // changed with a call to setTexName. 194 const GLuint mTexName; 195 196 // mGraphicBufferAlloc is the connection to SurfaceFlinger that is used to 197 // allocate new GraphicBuffer objects. 198 sp<IGraphicBufferAlloc> mGraphicBufferAlloc; 199 200 // mAllocdBuffers is mirror of the list of buffers that SurfaceFlinger is 201 // referencing. This is kept so that gralloc implementations do not need to 202 // properly handle the case where SurfaceFlinger no longer holds a reference 203 // to a buffer, but other processes do. 204 Vector<sp<GraphicBuffer> > mAllocdBuffers; 205 206 // mFrameAvailableListener is the listener object that will be called when a 207 // new frame becomes available. If it is not NULL it will be called from 208 // queueBuffer. 209 sp<FrameAvailableListener> mFrameAvailableListener; 210 211 // mMutex is the mutex used to prevent concurrent access to the member 212 // variables of SurfaceTexture objects. It must be locked whenever the 213 // member variables are accessed. 214 Mutex mMutex; 215}; 216 217// ---------------------------------------------------------------------------- 218}; // namespace android 219 220#endif // ANDROID_GUI_SURFACETEXTURE_H 221