replicant-frameworks_native/include/gui/SurfaceTexture.h
Jamie Gennis 3d8063b02e SurfaceTexture: change onFrameAvailable behavior
This change alters the conditions under which the onFrameAvailable
callback gets called by the C++ SurfaceTexture class.  The new behavior
is to call the callback whenever a frame gets queued that will be
visible to the buffer consumer.  This means that buffers queued in
synchronous mode always trigger the callback, as those buffers will
remain pending until they are consumed.  Buffers queued in asynchronous
mode will only trigger the callback if there was not previously an
unconsumed buffer pending.

The new behavior means that a consumer should perform a draw operation
exactly once for every onFrameAvailable call that it recieves.  This
change also modifies SurfaceFlinger and the SurfaceTexture JNI to
support of the new behavior.

Change-Id: I8b2c6e00961d3d58b11c6af50b555b6e4c5f5b40
2011-06-27 15:45:39 -07:00

383 lines
16 KiB
C++

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef ANDROID_GUI_SURFACETEXTURE_H
#define ANDROID_GUI_SURFACETEXTURE_H
#include <EGL/egl.h>
#include <EGL/eglext.h>
#include <GLES2/gl2.h>
#include <gui/ISurfaceTexture.h>
#include <ui/GraphicBuffer.h>
#include <utils/threads.h>
#include <utils/Vector.h>
#define ANDROID_GRAPHICS_SURFACETEXTURE_JNI_ID "mSurfaceTexture"
namespace android {
// ----------------------------------------------------------------------------
class IGraphicBufferAlloc;
class String8;
class SurfaceTexture : public BnSurfaceTexture {
public:
enum { MIN_UNDEQUEUED_BUFFERS = 2 };
enum {
MIN_ASYNC_BUFFER_SLOTS = MIN_UNDEQUEUED_BUFFERS + 1,
MIN_SYNC_BUFFER_SLOTS = MIN_UNDEQUEUED_BUFFERS
};
enum { NUM_BUFFER_SLOTS = 32 };
struct FrameAvailableListener : public virtual RefBase {
// onFrameAvailable() is called from queueBuffer() each time an
// additional frame becomes available for consumption. This means that
// frames that are queued while in asynchronous mode only trigger the
// callback if no previous frames are pending. Frames queued while in
// synchronous mode always trigger the callback.
//
// This is called without any lock held and can be called concurrently
// by multiple threads.
virtual void onFrameAvailable() = 0;
};
// tex indicates the name OpenGL texture to which images are to be streamed.
// This texture name cannot be changed once the SurfaceTexture is created.
SurfaceTexture(GLuint tex, bool allowSynchronousMode = true);
virtual ~SurfaceTexture();
// setBufferCount updates the number of available buffer slots. After
// calling this all buffer slots are both unallocated and owned by the
// SurfaceTexture object (i.e. they are not owned by the client).
virtual status_t setBufferCount(int bufferCount);
virtual sp<GraphicBuffer> requestBuffer(int buf);
// dequeueBuffer gets the next buffer slot index for the client to use. If a
// buffer slot is available then that slot index is written to the location
// pointed to by the buf argument and a status of OK is returned. If no
// slot is available then a status of -EBUSY is returned and buf is
// unmodified.
virtual status_t dequeueBuffer(int *buf, uint32_t w, uint32_t h,
uint32_t format, uint32_t usage);
// queueBuffer returns a filled buffer to the SurfaceTexture. In addition, a
// timestamp must be provided for the buffer. The timestamp is in
// nanoseconds, and must be monotonically increasing. Its other semantics
// (zero point, etc) are client-dependent and should be documented by the
// client.
virtual status_t queueBuffer(int buf, int64_t timestamp);
virtual void cancelBuffer(int buf);
virtual status_t setCrop(const Rect& reg);
virtual status_t setTransform(uint32_t transform);
virtual int query(int what, int* value);
// setSynchronousMode set whether dequeueBuffer is synchronous or
// asynchronous. In synchronous mode, dequeueBuffer blocks until
// a buffer is available, the currently bound buffer can be dequeued and
// queued buffers will be retired in order.
// The default mode is asynchronous.
virtual status_t setSynchronousMode(bool enabled);
// updateTexImage sets the image contents of the target texture to that of
// the most recently queued buffer.
//
// This call may only be made while the OpenGL ES context to which the
// target texture belongs is bound to the calling thread.
status_t updateTexImage();
// setBufferCountServer set the buffer count. If the client has requested
// a buffer count using setBufferCount, the server-buffer count will
// take effect once the client sets the count back to zero.
status_t setBufferCountServer(int bufferCount);
// getTransformMatrix retrieves the 4x4 texture coordinate transform matrix
// associated with the texture image set by the most recent call to
// updateTexImage.
//
// This transform matrix maps 2D homogeneous texture coordinates of the form
// (s, t, 0, 1) with s and t in the inclusive range [0, 1] to the texture
// coordinate that should be used to sample that location from the texture.
// Sampling the texture outside of the range of this transform is undefined.
//
// This transform is necessary to compensate for transforms that the stream
// content producer may implicitly apply to the content. By forcing users of
// a SurfaceTexture to apply this transform we avoid performing an extra
// copy of the data that would be needed to hide the transform from the
// user.
//
// The matrix is stored in column-major order so that it may be passed
// directly to OpenGL ES via the glLoadMatrixf or glUniformMatrix4fv
// functions.
void getTransformMatrix(float mtx[16]);
// getTimestamp retrieves the timestamp associated with the texture image
// set by the most recent call to updateTexImage.
//
// The timestamp is in nanoseconds, and is monotonically increasing. Its
// other semantics (zero point, etc) are source-dependent and should be
// documented by the source.
int64_t getTimestamp();
// setFrameAvailableListener sets the listener object that will be notified
// when a new frame becomes available.
void setFrameAvailableListener(const sp<FrameAvailableListener>& l);
// getAllocator retrieves the binder object that must be referenced as long
// as the GraphicBuffers dequeued from this SurfaceTexture are referenced.
// Holding this binder reference prevents SurfaceFlinger from freeing the
// buffers before the client is done with them.
sp<IBinder> getAllocator();
// setDefaultBufferSize is used to set the size of buffers returned by
// requestBuffers when a with and height of zero is requested.
// A call to setDefaultBufferSize() may trigger requestBuffers() to
// be called from the client.
status_t setDefaultBufferSize(uint32_t w, uint32_t h);
// getCurrentBuffer returns the buffer associated with the current image.
sp<GraphicBuffer> getCurrentBuffer() const;
// getCurrentTextureTarget returns the texture target of the current
// texture as returned by updateTexImage().
GLenum getCurrentTextureTarget() const;
// getCurrentCrop returns the cropping rectangle of the current buffer
Rect getCurrentCrop() const;
// getCurrentTransform returns the transform of the current buffer
uint32_t getCurrentTransform() const;
// dump our state in a String
void dump(String8& result) const;
void dump(String8& result, const char* prefix, char* buffer, size_t SIZE) const;
protected:
// freeAllBuffers frees the resources (both GraphicBuffer and EGLImage) for
// all slots.
void freeAllBuffers();
static bool isExternalFormat(uint32_t format);
static GLenum getTextureTarget(uint32_t format);
private:
// createImage creates a new EGLImage from a GraphicBuffer.
EGLImageKHR createImage(EGLDisplay dpy,
const sp<GraphicBuffer>& graphicBuffer);
status_t setBufferCountServerLocked(int bufferCount);
// computeCurrentTransformMatrix computes the transform matrix for the
// current texture. It uses mCurrentTransform and the current GraphicBuffer
// to compute this matrix and stores it in mCurrentTransformMatrix.
void computeCurrentTransformMatrix();
enum { INVALID_BUFFER_SLOT = -1 };
struct BufferSlot {
BufferSlot()
: mEglImage(EGL_NO_IMAGE_KHR),
mEglDisplay(EGL_NO_DISPLAY),
mBufferState(BufferSlot::FREE),
mRequestBufferCalled(false),
mTransform(0),
mTimestamp(0) {
mCrop.makeInvalid();
}
// mGraphicBuffer points to the buffer allocated for this slot or is NULL
// if no buffer has been allocated.
sp<GraphicBuffer> mGraphicBuffer;
// mEglImage is the EGLImage created from mGraphicBuffer.
EGLImageKHR mEglImage;
// mEglDisplay is the EGLDisplay used to create mEglImage.
EGLDisplay mEglDisplay;
// BufferState represents the different states in which a buffer slot
// can be.
enum BufferState {
// FREE indicates that the buffer is not currently being used and
// will not be used in the future until it gets dequeued and
// subseqently queued by the client.
FREE = 0,
// DEQUEUED indicates that the buffer has been dequeued by the
// client, but has not yet been queued or canceled. The buffer is
// considered 'owned' by the client, and the server should not use
// it for anything.
//
// Note that when in synchronous-mode (mSynchronousMode == true),
// the buffer that's currently attached to the texture may be
// dequeued by the client. That means that the current buffer can
// be in either the DEQUEUED or QUEUED state. In asynchronous mode,
// however, the current buffer is always in the QUEUED state.
DEQUEUED = 1,
// QUEUED indicates that the buffer has been queued by the client,
// and has not since been made available for the client to dequeue.
// Attaching the buffer to the texture does NOT transition the
// buffer away from the QUEUED state. However, in Synchronous mode
// the current buffer may be dequeued by the client under some
// circumstances. See the note about the current buffer in the
// documentation for DEQUEUED.
QUEUED = 2,
};
// mBufferState is the current state of this buffer slot.
BufferState mBufferState;
// mRequestBufferCalled is used for validating that the client did
// call requestBuffer() when told to do so. Technically this is not
// needed but useful for debugging and catching client bugs.
bool mRequestBufferCalled;
// mCrop is the current crop rectangle for this buffer slot. This gets
// set to mNextCrop each time queueBuffer gets called for this buffer.
Rect mCrop;
// mTransform is the current transform flags for this buffer slot. This
// gets set to mNextTransform each time queueBuffer gets called for this
// slot.
uint32_t mTransform;
// mTimestamp is the current timestamp for this buffer slot. This gets
// to set by queueBuffer each time this slot is queued.
int64_t mTimestamp;
};
// mSlots is the array of buffer slots that must be mirrored on the client
// side. This allows buffer ownership to be transferred between the client
// and server without sending a GraphicBuffer over binder. The entire array
// is initialized to NULL at construction time, and buffers are allocated
// for a slot when requestBuffer is called with that slot's index.
BufferSlot mSlots[NUM_BUFFER_SLOTS];
// mDefaultWidth holds the default width of allocated buffers. It is used
// in requestBuffers() if a width and height of zero is specified.
uint32_t mDefaultWidth;
// mDefaultHeight holds the default height of allocated buffers. It is used
// in requestBuffers() if a width and height of zero is specified.
uint32_t mDefaultHeight;
// mPixelFormat holds the pixel format of allocated buffers. It is used
// in requestBuffers() if a format of zero is specified.
uint32_t mPixelFormat;
// mBufferCount is the number of buffer slots that the client and server
// must maintain. It defaults to MIN_ASYNC_BUFFER_SLOTS and can be changed
// by calling setBufferCount or setBufferCountServer
int mBufferCount;
// mClientBufferCount is the number of buffer slots requested by the client.
// The default is zero, which means the client doesn't care how many buffers
// there is.
int mClientBufferCount;
// mServerBufferCount buffer count requested by the server-side
int mServerBufferCount;
// mCurrentTexture is the buffer slot index of the buffer that is currently
// bound to the OpenGL texture. It is initialized to INVALID_BUFFER_SLOT,
// indicating that no buffer slot is currently bound to the texture. Note,
// however, that a value of INVALID_BUFFER_SLOT does not necessarily mean
// that no buffer is bound to the texture. A call to setBufferCount will
// reset mCurrentTexture to INVALID_BUFFER_SLOT.
int mCurrentTexture;
// mCurrentTextureTarget is the GLES texture target to be used with the
// current texture.
GLenum mCurrentTextureTarget;
// mCurrentTextureBuf is the graphic buffer of the current texture. It's
// possible that this buffer is not associated with any buffer slot, so we
// must track it separately in order to properly use
// IGraphicBufferAlloc::freeAllGraphicBuffersExcept.
sp<GraphicBuffer> mCurrentTextureBuf;
// mCurrentCrop is the crop rectangle that applies to the current texture.
// It gets set to mLastQueuedCrop each time updateTexImage is called.
Rect mCurrentCrop;
// mCurrentTransform is the transform identifier for the current texture. It
// gets set to mLastQueuedTransform each time updateTexImage is called.
uint32_t mCurrentTransform;
// mCurrentTransformMatrix is the transform matrix for the current texture.
// It gets computed by computeTransformMatrix each time updateTexImage is
// called.
float mCurrentTransformMatrix[16];
// mCurrentTimestamp is the timestamp for the current texture. It
// gets set to mLastQueuedTimestamp each time updateTexImage is called.
int64_t mCurrentTimestamp;
// mNextCrop is the crop rectangle that will be used for the next buffer
// that gets queued. It is set by calling setCrop.
Rect mNextCrop;
// mNextTransform is the transform identifier that will be used for the next
// buffer that gets queued. It is set by calling setTransform.
uint32_t mNextTransform;
// mTexName is the name of the OpenGL texture to which streamed images will
// be bound when updateTexImage is called. It is set at construction time
// changed with a call to setTexName.
const GLuint mTexName;
// mGraphicBufferAlloc is the connection to SurfaceFlinger that is used to
// allocate new GraphicBuffer objects.
sp<IGraphicBufferAlloc> mGraphicBufferAlloc;
// mFrameAvailableListener is the listener object that will be called when a
// new frame becomes available. If it is not NULL it will be called from
// queueBuffer.
sp<FrameAvailableListener> mFrameAvailableListener;
// mSynchronousMode whether we're in synchronous mode or not
bool mSynchronousMode;
// mAllowSynchronousMode whether we allow synchronous mode or not
const bool mAllowSynchronousMode;
// mDequeueCondition condition used for dequeueBuffer in synchronous mode
mutable Condition mDequeueCondition;
// mQueue is a FIFO of queued buffers used in synchronous mode
typedef Vector<int> Fifo;
Fifo mQueue;
// mMutex is the mutex used to prevent concurrent access to the member
// variables of SurfaceTexture objects. It must be locked whenever the
// member variables are accessed.
mutable Mutex mMutex;
};
// ----------------------------------------------------------------------------
}; // namespace android
#endif // ANDROID_GUI_SURFACETEXTURE_H