SurfaceTexture.h revision f238e28500ca756fbd9e323f728ce7c8dda59475
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 30#define ANDROID_GRAPHICS_SURFACETEXTURE_JNI_ID "mSurfaceTexture" 31 32namespace android { 33// ---------------------------------------------------------------------------- 34 35class SurfaceTexture : public BnSurfaceTexture { 36public: 37 enum { MIN_BUFFER_SLOTS = 3 }; 38 enum { NUM_BUFFER_SLOTS = 32 }; 39 40 // tex indicates the name OpenGL texture to which images are to be streamed. 41 // This texture name cannot be changed once the SurfaceTexture is created. 42 SurfaceTexture(GLuint tex); 43 44 virtual ~SurfaceTexture(); 45 46 // setBufferCount updates the number of available buffer slots. After 47 // calling this all buffer slots are both unallocated and owned by the 48 // SurfaceTexture object (i.e. they are not owned by the client). 49 virtual status_t setBufferCount(int bufferCount); 50 51 virtual sp<GraphicBuffer> requestBuffer(int buf, uint32_t w, uint32_t h, 52 uint32_t format, uint32_t usage); 53 54 // dequeueBuffer gets the next buffer slot index for the client to use. If a 55 // buffer slot is available then that slot index is written to the location 56 // pointed to by the buf argument and a status of OK is returned. If no 57 // slot is available then a status of -EBUSY is returned and buf is 58 // unmodified. 59 virtual status_t dequeueBuffer(int *buf); 60 61 virtual status_t queueBuffer(int buf); 62 virtual void cancelBuffer(int buf); 63 virtual status_t setCrop(const Rect& reg); 64 virtual status_t setTransform(uint32_t transform); 65 66 // updateTexImage sets the image contents of the target texture to that of 67 // the most recently queued buffer. 68 // 69 // This call may only be made while the OpenGL ES context to which the 70 // target texture belongs is bound to the calling thread. 71 status_t updateTexImage(); 72 73 // getTransformMatrix retrieves the 4x4 texture coordinate transform matrix 74 // associated with the texture image set by the most recent call to 75 // updateTexImage. 76 // 77 // This transform matrix maps 2D homogeneous texture coordinates of the form 78 // (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture 79 // coordinate that should be used to sample that location from the texture. 80 // Sampling the texture outside of the range of this transform is undefined. 81 // 82 // This transform is necessary to compensate for transforms that the stream 83 // content producer may implicitly apply to the content. By forcing users of 84 // a SurfaceTexture to apply this transform we avoid performing an extra 85 // copy of the data that would be needed to hide the transform from the 86 // user. 87 // 88 // The matrix is stored in column-major order so that it may be passed 89 // directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv 90 // functions. 91 void getTransformMatrix(float mtx[16]); 92 93private: 94 95 // freeAllBuffers frees the resources (both GraphicBuffer and EGLImage) for 96 // all slots. 97 void freeAllBuffers(); 98 99 // createImage creates a new EGLImage from a GraphicBuffer. 100 EGLImageKHR createImage(EGLDisplay dpy, 101 const sp<GraphicBuffer>& graphicBuffer); 102 103 enum { INVALID_BUFFER_SLOT = -1 }; 104 105 struct BufferSlot { 106 // mGraphicBuffer points to the buffer allocated for this slot or is NULL 107 // if no buffer has been allocated. 108 sp<GraphicBuffer> mGraphicBuffer; 109 110 // mEglImage is the EGLImage created from mGraphicBuffer. 111 EGLImageKHR mEglImage; 112 113 // mEglDisplay is the EGLDisplay used to create mEglImage. 114 EGLDisplay mEglDisplay; 115 116 // mOwnedByClient indicates whether the slot is currently accessible to a 117 // client and should not be used by the SurfaceTexture object. It gets 118 // set to true when dequeueBuffer returns the slot and is reset to false 119 // when the client calls either queueBuffer or cancelBuffer on the slot. 120 bool mOwnedByClient; 121 }; 122 123 // mSlots is the array of buffer slots that must be mirrored on the client 124 // side. This allows buffer ownership to be transferred between the client 125 // and server without sending a GraphicBuffer over binder. The entire array 126 // is initialized to NULL at construction time, and buffers are allocated 127 // for a slot when requestBuffer is called with that slot's index. 128 BufferSlot mSlots[NUM_BUFFER_SLOTS]; 129 130 // mBufferCount is the number of buffer slots that the client and server 131 // must maintain. It defaults to MIN_BUFFER_SLOTS and can be changed by 132 // calling setBufferCount. 133 int mBufferCount; 134 135 // mCurrentTexture is the buffer slot index of the buffer that is currently 136 // bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT, 137 // indicating that no buffer slot is currently bound to the texture. Note, 138 // however, that a value of INVALID_BUFFER_SLOT does not necessarily mean 139 // that no buffer is bound to the texture. A call to setBufferCount will 140 // reset mCurrentTexture to INVALID_BUFFER_SLOT. 141 int mCurrentTexture; 142 143 // mCurrentCrop is the crop rectangle that applies to the current texture. 144 // It gets set to mLastQueuedCrop each time updateTexImage is called. 145 Rect mCurrentCrop; 146 147 // mCurrentTransform is the transform identifier for the current texture. It 148 // gets set to mLastQueuedTransform each time updateTexImage is called. 149 uint32_t mCurrentTransform; 150 151 // mLastQueued is the buffer slot index of the most recently enqueued buffer. 152 // At construction time it is initialized to INVALID_BUFFER_SLOT, and is 153 // updated each time queueBuffer is called. 154 int mLastQueued; 155 156 // mLastQueuedCrop is the crop rectangle for the buffer that was most 157 // recently queued. This gets set to mNextCrop each time queueBuffer gets 158 // called. 159 Rect mLastQueuedCrop; 160 161 // mLastQueuedTransform is the transform identifier for the buffer that was 162 // most recently queued. This gets set to mNextTransform each time 163 // queueBuffer gets called. 164 uint32_t mLastQueuedTransform; 165 166 // mNextCrop is the crop rectangle that will be used for the next buffer 167 // that gets queued. It is set by calling setCrop. 168 Rect mNextCrop; 169 170 // mNextTransform is the transform identifier that will be used for the next 171 // buffer that gets queued. It is set by calling setTransform. 172 uint32_t mNextTransform; 173 174 // mTexName is the name of the OpenGL texture to which streamed images will 175 // be bound when updateTexImage is called. It is set at construction time 176 // changed with a call to setTexName. 177 const GLuint mTexName; 178 179 // mMutex is the mutex used to prevent concurrent access to the member 180 // variables of SurfaceTexture objects. It must be locked whenever the 181 // member variables are accessed. 182 Mutex mMutex; 183}; 184 185// ---------------------------------------------------------------------------- 186}; // namespace android 187 188#endif // ANDROID_GUI_SURFACETEXTURE_H 189