added the notion of fixed-size buffers

the new native_window_set_buffers_geometry allows
to specify a size and format for all buffers to be
dequeued. the buffer will be scalled to the window's
size.

Change-Id: I2c378b85c88d29cdd827a5f319d5c704d79ba381

11 files changed, 273 insertions, 93 deletions

diff --git a/include/private/surfaceflinger/SharedBufferStack.h b/include/private/surfaceflinger/SharedBufferStack.h
index de54870..ea8391d 100644
--- a/include/private/surfaceflinger/SharedBufferStack.h
+++ b/include/private/surfaceflinger/SharedBufferStack.h
@@ -279,7 +279,8 @@ public:
     ssize_t retireAndLock();
     status_t unlock(int buffer);
     void setStatus(status_t status);
-    status_t reallocate();
+    status_t reallocateAll();
+    status_t reallocateAllExcept(int buffer);
     status_t assertReallocate(int buffer);
     int32_t getQueuedCount() const;
     Region getDirtyRegion(int buffer) const;
diff --git a/include/surfaceflinger/ISurface.h b/include/surfaceflinger/ISurface.h
index 9476686..18e7950 100644
--- a/include/surfaceflinger/ISurface.h
+++ b/include/surfaceflinger/ISurface.h
@@ -53,7 +53,8 @@ protected:
 public: 
     DECLARE_META_INTERFACE(Surface);
 
-    virtual sp<GraphicBuffer> requestBuffer(int bufferIdx, int usage) = 0; 
+    virtual sp<GraphicBuffer> requestBuffer(int bufferIdx,
+            uint32_t w, uint32_t h, uint32_t format, uint32_t usage) = 0;
     virtual status_t setBufferCount(int bufferCount) = 0;
     
     class BufferHeap {
diff --git a/include/surfaceflinger/Surface.h b/include/surfaceflinger/Surface.h
index e4d60af..77e4a61 100644
--- a/include/surfaceflinger/Surface.h
+++ b/include/surfaceflinger/Surface.h
@@ -36,6 +36,7 @@ namespace android {
 
 // ---------------------------------------------------------------------------
 
+class GraphicBuffer;
 class GraphicBufferMapper;
 class IOMX;
 class Rect;
@@ -213,12 +214,14 @@ private:
     int  dispatch_disconnect(va_list args);
     int  dispatch_crop(va_list args);
     int  dispatch_set_buffer_count(va_list args);
+    int  dispatch_set_buffers_geometry(va_list args);
     
     void setUsage(uint32_t reqUsage);
     int  connect(int api);
     int  disconnect(int api);
     int  crop(Rect const* rect);
     int  setBufferCount(int bufferCount);
+    int  setBuffersGeometry(int w, int h, int format);
 
     /*
      *  private stuff...
@@ -231,12 +234,34 @@ private:
     inline const GraphicBufferMapper& getBufferMapper() const { return mBufferMapper; }
     inline GraphicBufferMapper& getBufferMapper() { return mBufferMapper; }
 
-    status_t getBufferLocked(int index, int usage);
+    status_t getBufferLocked(int index,
+            uint32_t w, uint32_t h, uint32_t format, uint32_t usage);
     int getBufferIndex(const sp<GraphicBuffer>& buffer) const;
 
-    uint32_t getUsage() const;
-    int      getConnectedApi() const;
+    int getConnectedApi() const;
     
+    bool needNewBuffer(int bufIdx,
+            uint32_t *pWidth, uint32_t *pHeight,
+            uint32_t *pFormat, uint32_t *pUsage) const;
+
+    class BufferInfo {
+        uint32_t mWidth;
+        uint32_t mHeight;
+        uint32_t mFormat;
+        uint32_t mUsage;
+        mutable uint32_t mDirty;
+        enum {
+            GEOMETRY = 0x01
+        };
+    public:
+        BufferInfo();
+        void set(uint32_t w, uint32_t h, uint32_t format);
+        void set(uint32_t usage);
+        void get(uint32_t *pWidth, uint32_t *pHeight,
+                uint32_t *pFormat, uint32_t *pUsage) const;
+        bool validateBuffer(const sp<GraphicBuffer>& buffer) const;
+    };
+
     // constants
     sp<SurfaceComposerClient>   mClient;
     sp<ISurface>                mSurface;
@@ -249,13 +274,12 @@ private:
 
     // protected by mSurfaceLock
     Rect                        mSwapRectangle;
-    uint32_t                    mUsage;
     int                         mConnected;
     Rect                        mNextBufferCrop;
+    BufferInfo                  mBufferInfo;
     
     // protected by mSurfaceLock. These are also used from lock/unlock
     // but in that case, they must be called form the same thread.
-    sp<GraphicBuffer>           mBuffers[2];
     mutable Region              mDirtyRegion;
 
     // must be used from the lock/unlock thread
@@ -264,6 +288,9 @@ private:
     mutable Region              mOldDirtyRegion;
     bool                        mReserved;
 
+    // only used from dequeueBuffer()
+    Vector< sp<GraphicBuffer> > mBuffers;
+
     // query() must be called from dequeueBuffer() thread
     uint32_t                    mWidth;
     uint32_t                    mHeight;
diff --git a/include/ui/egl/android_natives.h b/include/ui/egl/android_natives.h
index b44901f..171f3df 100644
--- a/include/ui/egl/android_natives.h
+++ b/include/ui/egl/android_natives.h
@@ -82,6 +82,7 @@ enum {
     NATIVE_WINDOW_DISCONNECT,
     NATIVE_WINDOW_SET_CROP,
     NATIVE_WINDOW_SET_BUFFER_COUNT,
+    NATIVE_WINDOW_SET_BUFFERS_GEOMETRY,
 };
 
 /* parameter for NATIVE_WINDOW_[DIS]CONNECT */
@@ -192,6 +193,7 @@ typedef struct android_native_window_t
      *     NATIVE_WINDOW_DISCONNECT
      *     NATIVE_WINDOW_SET_CROP
      *     NATIVE_WINDOW_SET_BUFFER_COUNT
+     *     NATIVE_WINDOW_SET_BUFFERS_GEOMETRY
      *  
      */
     
@@ -273,6 +275,25 @@ static inline int native_window_set_buffer_count(
     return window->perform(window, NATIVE_WINDOW_SET_BUFFER_COUNT, bufferCount);
 }
 
+/*
+ * native_window_set_buffers_geometry(..., int w, int h, int format)
+ * All buffers dequeued after this call will have the geometry specified.
+ * In particular, all buffers will have a fixed-size, independent form the
+ * native-window size. They will be appropriately scaled to the window-size
+ * upon composition.
+ *
+ * If all parameters are 0, the normal behavior is restored. That is,
+ * dequeued buffers following this call will be sized to the window's size.
+ *
+ */
+static inline int native_window_set_buffers_geometry(
+        android_native_window_t* window,
+        int w, int h, int format)
+{
+    return window->perform(window, NATIVE_WINDOW_SET_BUFFERS_GEOMETRY,
+            w, h, format);
+}
+
 // ---------------------------------------------------------------------------
 
 /* FIXME: this is legacy for pixmaps */
diff --git a/libs/surfaceflinger/Layer.cpp b/libs/surfaceflinger/Layer.cpp
index 621b7e3..84584aa 100644
--- a/libs/surfaceflinger/Layer.cpp
+++ b/libs/surfaceflinger/Layer.cpp
@@ -55,7 +55,8 @@ Layer::Layer(SurfaceFlinger* flinger, DisplayID display,
         mNeedsBlending(true),
         mNeedsDithering(false),
         mTextureManager(mFlags),
-        mBufferManager(mTextureManager)
+        mBufferManager(mTextureManager),
+        mWidth(0), mHeight(0), mFixedSize(false)
 {
     // no OpenGL operation is possible here, since we might not be
     // in the OpenGL thread.
@@ -227,10 +228,18 @@ status_t Layer::setBufferCount(int bufferCount)
     return err;
 }
 
-sp<GraphicBuffer> Layer::requestBuffer(int index, int usage)
+sp<GraphicBuffer> Layer::requestBuffer(int index,
+        uint32_t reqWidth, uint32_t reqHeight, uint32_t reqFormat,
+        uint32_t usage)
 {
     sp<GraphicBuffer> buffer;
 
+    if ((reqWidth | reqHeight | reqFormat) < 0)
+        return buffer;
+
+    if ((!reqWidth && reqHeight) || (reqWidth && !reqHeight))
+        return buffer;
+
     // this ensures our client doesn't go away while we're accessing
     // the shared area.
     sp<Client> ourClient(client.promote());
@@ -256,23 +265,33 @@ sp<GraphicBuffer> Layer::requestBuffer(int index, int usage)
         return buffer;
     }
 
-    uint32_t w, h;
+    uint32_t w, h, f;
     { // scope for the lock
         Mutex::Autolock _l(mLock);
-        w = mWidth;
-        h = mHeight;
+        const bool fixedSizeChanged = mFixedSize != (reqWidth && reqHeight);
+        const bool formatChanged    = mReqFormat != reqFormat;
+        mReqWidth  = reqWidth;
+        mReqHeight = reqHeight;
+        mReqFormat = reqFormat;
+        mFixedSize = reqWidth && reqHeight;
+        w = reqWidth  ? reqWidth  : mWidth;
+        h = reqHeight ? reqHeight : mHeight;
+        f = reqFormat ? reqFormat : mFormat;
         buffer = mBufferManager.detachBuffer(index);
+        if (fixedSizeChanged || formatChanged) {
+            lcblk->reallocateAllExcept(index);
+        }
     }
 
     const uint32_t effectiveUsage = getEffectiveUsage(usage);
     if (buffer!=0 && buffer->getStrongCount() == 1) {
-        err = buffer->reallocate(w, h, mFormat, effectiveUsage);
+        err = buffer->reallocate(w, h, f, effectiveUsage);
     } else {
         // here we have to reallocate a new buffer because we could have a
         // client in our process with a reference to it (eg: status bar),
         // and we can't release the handle under its feet.
         buffer.clear();
-        buffer = new GraphicBuffer(w, h, mFormat, effectiveUsage);
+        buffer = new GraphicBuffer(w, h, f, effectiveUsage);
         err = buffer->initCheck();
     }
 
@@ -288,12 +307,7 @@ sp<GraphicBuffer> Layer::requestBuffer(int index, int usage)
 
     if (err == NO_ERROR && buffer->handle != 0) {
         Mutex::Autolock _l(mLock);
-        if (mWidth && mHeight) {
-            mBufferManager.attachBuffer(index, buffer);
-        } else {
-            // oops we got killed while we were allocating the buffer
-            buffer.clear();
-        }
+        mBufferManager.attachBuffer(index, buffer);
     }
     return buffer;
 }
@@ -330,39 +344,46 @@ uint32_t Layer::doTransaction(uint32_t flags)
     const Layer::State& front(drawingState());
     const Layer::State& temp(currentState());
 
-    if ((front.requested_w != temp.requested_w) || 
-        (front.requested_h != temp.requested_h)) {
+    const bool sizeChanged = (front.requested_w != temp.requested_w) ||
+            (front.requested_h != temp.requested_h);
+
+    if (sizeChanged) {
         // the size changed, we need to ask our client to request a new buffer
         LOGD_IF(DEBUG_RESIZE,
-                    "resize (layer=%p), requested (%dx%d), drawing (%d,%d)",
-                    this, 
-                    int(temp.requested_w), int(temp.requested_h),
-                    int(front.requested_w), int(front.requested_h));
-
-        // we're being resized and there is a freeze display request,
-        // acquire a freeze lock, so that the screen stays put
-        // until we've redrawn at the new size; this is to avoid
-        // glitches upon orientation changes.
-        if (mFlinger->hasFreezeRequest()) {
-            // if the surface is hidden, don't try to acquire the
-            // freeze lock, since hidden surfaces may never redraw
-            if (!(front.flags & ISurfaceComposer::eLayerHidden)) {
-                mFreezeLock = mFlinger->getFreezeLock();
+                "resize (layer=%p), requested (%dx%d), drawing (%d,%d)",
+                this,
+                int(temp.requested_w), int(temp.requested_h),
+                int(front.requested_w), int(front.requested_h));
+
+        if (!isFixedSize()) {
+            // we're being resized and there is a freeze display request,
+            // acquire a freeze lock, so that the screen stays put
+            // until we've redrawn at the new size; this is to avoid
+            // glitches upon orientation changes.
+            if (mFlinger->hasFreezeRequest()) {
+                // if the surface is hidden, don't try to acquire the
+                // freeze lock, since hidden surfaces may never redraw
+                if (!(front.flags & ISurfaceComposer::eLayerHidden)) {
+                    mFreezeLock = mFlinger->getFreezeLock();
+                }
             }
-        }
 
-        // this will make sure LayerBase::doTransaction doesn't update
-        // the drawing state's size
-        Layer::State& editDraw(mDrawingState);
-        editDraw.requested_w = temp.requested_w;
-        editDraw.requested_h = temp.requested_h;
+            // this will make sure LayerBase::doTransaction doesn't update
+            // the drawing state's size
+            Layer::State& editDraw(mDrawingState);
+            editDraw.requested_w = temp.requested_w;
+            editDraw.requested_h = temp.requested_h;
 
-        // record the new size, form this point on, when the client request a
-        // buffer, it'll get the new size.
-        setDrawingSize(temp.requested_w, temp.requested_h);
+            // record the new size, form this point on, when the client request
+            // a buffer, it'll get the new size.
+            setBufferSize(temp.requested_w, temp.requested_h);
 
-        // all buffers need reallocation
-        lcblk->reallocate();
+            // all buffers need reallocation
+            lcblk->reallocateAll();
+        } else {
+            // record the new size
+            setBufferSize(temp.requested_w, temp.requested_h);
+        }
     }
 
     if (temp.sequence != front.sequence) {
@@ -376,12 +397,17 @@ uint32_t Layer::doTransaction(uint32_t flags)
     return LayerBase::doTransaction(flags);
 }
 
-void Layer::setDrawingSize(uint32_t w, uint32_t h) {
+void Layer::setBufferSize(uint32_t w, uint32_t h) {
     Mutex::Autolock _l(mLock);
     mWidth = w;
     mHeight = h;
 }
 
+bool Layer::isFixedSize() const {
+    Mutex::Autolock _l(mLock);
+    return mFixedSize;
+}
+
 // ----------------------------------------------------------------------------
 // pageflip handling...
 // ----------------------------------------------------------------------------
@@ -677,7 +703,8 @@ Layer::SurfaceLayer::~SurfaceLayer()
 {
 }
 
-sp<GraphicBuffer> Layer::SurfaceLayer::requestBuffer(int index, int usage)
+sp<GraphicBuffer> Layer::SurfaceLayer::requestBuffer(int index,
+        uint32_t w, uint32_t h, uint32_t format, uint32_t usage)
 {
     sp<GraphicBuffer> buffer;
     sp<Layer> owner(getOwner());
@@ -687,7 +714,7 @@ sp<GraphicBuffer> Layer::SurfaceLayer::requestBuffer(int index, int usage)
          * as it could cause a dead-lock, since it may have to wait
          * on conditions updated my the main thread.
          */
-        buffer = owner->requestBuffer(index, usage);
+        buffer = owner->requestBuffer(index, w, h, format, usage);
     }
     return buffer;
 }
diff --git a/libs/surfaceflinger/Layer.h b/libs/surfaceflinger/Layer.h
index 247748b..10b5910 100644
--- a/libs/surfaceflinger/Layer.h
+++ b/libs/surfaceflinger/Layer.h
@@ -57,7 +57,8 @@ public:
     status_t setBuffers(uint32_t w, uint32_t h, 
             PixelFormat format, uint32_t flags=0);
 
-    void setDrawingSize(uint32_t w, uint32_t h);
+    void setBufferSize(uint32_t w, uint32_t h);
+    bool isFixedSize() const;
 
     virtual void onDraw(const Region& clip) const;
     virtual uint32_t doTransaction(uint32_t transactionFlags);
@@ -88,7 +89,8 @@ private:
 
     uint32_t getEffectiveUsage(uint32_t usage) const;
 
-    sp<GraphicBuffer> requestBuffer(int index, int usage);
+    sp<GraphicBuffer> requestBuffer(int bufferIdx,
+            uint32_t w, uint32_t h, uint32_t format, uint32_t usage);
     status_t setBufferCount(int bufferCount);
 
     class SurfaceLayer : public LayerBaseClient::Surface {
@@ -97,7 +99,8 @@ private:
                 SurfaceID id, const sp<Layer>& owner);
         ~SurfaceLayer();
     private:
-        virtual sp<GraphicBuffer> requestBuffer(int index, int usage);
+        virtual sp<GraphicBuffer> requestBuffer(int bufferIdx,
+                uint32_t w, uint32_t h, uint32_t format, uint32_t usage);
         virtual status_t setBufferCount(int bufferCount);
         sp<Layer> getOwner() const {
             return static_cast<Layer*>(Surface::getOwner().get());
@@ -181,6 +184,10 @@ private:
             mutable Mutex mLock;
             uint32_t    mWidth;
             uint32_t    mHeight;
+            uint32_t    mReqWidth;
+            uint32_t    mReqHeight;
+            uint32_t    mReqFormat;
+            bool        mFixedSize;
 };
 
 // ---------------------------------------------------------------------------
diff --git a/libs/surfaceflinger/LayerBase.cpp b/libs/surfaceflinger/LayerBase.cpp
index 63b9520..51673ff 100644
--- a/libs/surfaceflinger/LayerBase.cpp
+++ b/libs/surfaceflinger/LayerBase.cpp
@@ -616,7 +616,8 @@ status_t LayerBaseClient::Surface::onTransact(
     return BnSurface::onTransact(code, data, reply, flags);
 }
 
-sp<GraphicBuffer> LayerBaseClient::Surface::requestBuffer(int index, int usage) 
+sp<GraphicBuffer> LayerBaseClient::Surface::requestBuffer(int bufferIdx,
+        uint32_t w, uint32_t h, uint32_t format, uint32_t usage)
 {
     return NULL; 
 }
diff --git a/libs/surfaceflinger/LayerBase.h b/libs/surfaceflinger/LayerBase.h
index 53b848f..569b0ff 100644
--- a/libs/surfaceflinger/LayerBase.h
+++ b/libs/surfaceflinger/LayerBase.h
@@ -301,7 +301,8 @@ public:
         sp<LayerBaseClient> getOwner() const;
 
     private:
-        virtual sp<GraphicBuffer> requestBuffer(int index, int usage);
+        virtual sp<GraphicBuffer> requestBuffer(int bufferIdx,
+                uint32_t w, uint32_t h, uint32_t format, uint32_t usage);
         virtual status_t setBufferCount(int bufferCount);
 
         virtual status_t registerBuffers(const ISurface::BufferHeap& buffers); 
diff --git a/libs/surfaceflinger_client/ISurface.cpp b/libs/surfaceflinger_client/ISurface.cpp
index c5d0c0e..7049d9e 100644
--- a/libs/surfaceflinger_client/ISurface.cpp
+++ b/libs/surfaceflinger_client/ISurface.cpp
@@ -71,11 +71,15 @@ public:
     {
     }
 
-    virtual sp<GraphicBuffer> requestBuffer(int bufferIdx, int usage)
+    virtual sp<GraphicBuffer> requestBuffer(int bufferIdx,
+            uint32_t w, uint32_t h, uint32_t format, uint32_t usage)
     {
         Parcel data, reply;
         data.writeInterfaceToken(ISurface::getInterfaceDescriptor());
         data.writeInt32(bufferIdx);
+        data.writeInt32(w);
+        data.writeInt32(h);
+        data.writeInt32(format);
         data.writeInt32(usage);
         remote()->transact(REQUEST_BUFFER, data, &reply);
         sp<GraphicBuffer> buffer = new GraphicBuffer();
@@ -150,8 +154,11 @@ status_t BnSurface::onTransact(
         case REQUEST_BUFFER: {
             CHECK_INTERFACE(ISurface, data, reply);
             int bufferIdx = data.readInt32();
-            int usage = data.readInt32();
-            sp<GraphicBuffer> buffer(requestBuffer(bufferIdx, usage));
+            uint32_t w = data.readInt32();
+            uint32_t h = data.readInt32();
+            uint32_t format = data.readInt32();
+            uint32_t usage = data.readInt32();
+            sp<GraphicBuffer> buffer(requestBuffer(bufferIdx, w, h, format, usage));
             if (buffer == NULL)
                 return BAD_VALUE;
             return reply->write(*buffer);
diff --git a/libs/surfaceflinger_client/SharedBufferStack.cpp b/libs/surfaceflinger_client/SharedBufferStack.cpp
index 8681b59..b4522598 100644
--- a/libs/surfaceflinger_client/SharedBufferStack.cpp
+++ b/libs/surfaceflinger_client/SharedBufferStack.cpp
@@ -527,13 +527,25 @@ void SharedBufferServer::setStatus(status_t status)
     }
 }
 
-status_t SharedBufferServer::reallocate()
+status_t SharedBufferServer::reallocateAll()
 {
     RWLock::AutoRLock _l(mLock);
 
     SharedBufferStack& stack( *mSharedStack );
     uint32_t mask = mBufferList.getMask();
-    android_atomic_or(mask, &stack.reallocMask); 
+    android_atomic_or(mask, &stack.reallocMask);
+    return NO_ERROR;
+}
+
+status_t SharedBufferServer::reallocateAllExcept(int buffer)
+{
+    RWLock::AutoRLock _l(mLock);
+
+    SharedBufferStack& stack( *mSharedStack );
+    BufferList temp(mBufferList);
+    temp.remove(buffer);
+    uint32_t mask = temp.getMask();
+    android_atomic_or(mask, &stack.reallocMask);
     return NO_ERROR;
 }
 
diff --git a/libs/surfaceflinger_client/Surface.cpp b/libs/surfaceflinger_client/Surface.cpp
index 5f42af0..71504fa 100644
--- a/libs/surfaceflinger_client/Surface.cpp
+++ b/libs/surfaceflinger_client/Surface.cpp
@@ -349,15 +349,18 @@ void Surface::init()
     const_cast<int&>(android_native_window_t::maxSwapInterval) = 1;
     const_cast<uint32_t&>(android_native_window_t::flags) = 0;
     // be default we request a hardware surface
-    mUsage = GRALLOC_USAGE_HW_RENDER;
     mConnected = 0;
+    // two buffers by default
+    mBuffers.setCapacity(2);
+    mBuffers.insertAt(0, 2);
 }
 
 Surface::~Surface()
 {
     // this is a client-side operation, the surface is destroyed, unmap
     // its buffers in this process.
-    for (int i=0 ; i<2 ; i++) {
+    size_t size = mBuffers.size();
+    for (size_t i=0 ; i<size ; i++) {
         if (mBuffers[i] != 0 && mBuffers[i]->handle != 0) {
             getBufferMapper().unregisterBuffer(mBuffers[i]->handle);
         }
@@ -365,6 +368,7 @@ Surface::~Surface()
 
     // clear all references and trigger an IPC now, to make sure things
     // happen without delay, since these resources are quite heavy.
+    mBuffers.clear();
     mClient.clear();
     mSurface.clear();
     delete mSharedBufferClient;
@@ -463,6 +467,22 @@ int Surface::perform(android_native_window_t* window,
 
 // ----------------------------------------------------------------------------
 
+bool Surface::needNewBuffer(int bufIdx,
+        uint32_t *pWidth, uint32_t *pHeight,
+        uint32_t *pFormat, uint32_t *pUsage) const
+{
+    Mutex::Autolock _l(mSurfaceLock);
+
+    // Always call needNewBuffer(), since it clears the needed buffers flags
+    bool needNewBuffer = mSharedBufferClient->needNewBuffer(bufIdx);
+    bool validBuffer = mBufferInfo.validateBuffer(mBuffers[bufIdx]);
+    bool newNeewBuffer = needNewBuffer || !validBuffer;
+    if (newNeewBuffer) {
+        mBufferInfo.get(pWidth, pHeight, pFormat, pUsage);
+    }
+    return newNeewBuffer;
+}
+
 int Surface::dequeueBuffer(android_native_buffer_t** buffer)
 {
     sp<SurfaceComposerClient> client(getClient());
@@ -476,27 +496,28 @@ int Surface::dequeueBuffer(android_native_buffer_t** buffer)
         return bufIdx;
     }
 
-    // below we make sure we AT LEAST have the usage flags we want
-    const uint32_t usage(getUsage());
-    const sp<GraphicBuffer>& backBuffer(mBuffers[bufIdx]);
+    // grow the buffer array if needed
+    const size_t size = mBuffers.size();
+    const size_t needed = bufIdx+1;
+    if (size < needed) {
+        mBuffers.insertAt(size, needed-size);
+    }
 
-    // Always call needNewBuffer(), since it clears the needed buffers flags
-    bool needNewBuffer = mSharedBufferClient->needNewBuffer(bufIdx);
-    if (backBuffer == 0 || 
-        ((uint32_t(backBuffer->usage) & usage) != usage) ||
-        needNewBuffer)
-    {
-        err = getBufferLocked(bufIdx, usage);
-        LOGE_IF(err, "getBufferLocked(%ld, %08x) failed (%s)",
-                bufIdx, usage, strerror(-err));
+    uint32_t w, h, format, usage;
+    if (needNewBuffer(bufIdx, &w, &h, &format, &usage)) {
+        err = getBufferLocked(bufIdx, w, h, format, usage);
+        LOGE_IF(err, "getBufferLocked(%ld, %u, %u, %u, %08x) failed (%s)",
+                bufIdx, w, h, format, usage, strerror(-err));
         if (err == NO_ERROR) {
             // reset the width/height with the what we get from the buffer
+            const sp<GraphicBuffer>& backBuffer(mBuffers[bufIdx]);
             mWidth  = uint32_t(backBuffer->width);
             mHeight = uint32_t(backBuffer->height);
         }
     }
 
     // if we still don't have a buffer here, we probably ran out of memory
+    const sp<GraphicBuffer>& backBuffer(mBuffers[bufIdx]);
     if (!err && backBuffer==0) {
         err = NO_MEMORY;
     }
@@ -614,12 +635,17 @@ int Surface::dispatch_set_buffer_count(va_list args) {
     size_t bufferCount = va_arg(args, size_t);
     return setBufferCount(bufferCount);
 }
-
+int Surface::dispatch_set_buffers_geometry(va_list args) {
+    int w = va_arg(args, int);
+    int h = va_arg(args, int);
+    int f = va_arg(args, int);
+    return setBuffersGeometry(w, h, f);
+}
 
 void Surface::setUsage(uint32_t reqUsage)
 {
     Mutex::Autolock _l(mSurfaceLock);
-    mUsage = reqUsage;
+    mBufferInfo.set(reqUsage);
 }
 
 int Surface::connect(int api)
@@ -660,18 +686,6 @@ int Surface::disconnect(int api)
     return err;
 }
 
-uint32_t Surface::getUsage() const
-{
-    Mutex::Autolock _l(mSurfaceLock);
-    return mUsage;
-}
-
-int Surface::getConnectedApi() const
-{
-    Mutex::Autolock _l(mSurfaceLock);
-    return mConnected;
-}
-
 int Surface::crop(Rect const* rect)
 {
     Mutex::Autolock _l(mSurfaceLock);
@@ -700,6 +714,26 @@ int Surface::setBufferCount(int bufferCount)
     return err;
 }
 
+int Surface::setBuffersGeometry(int w, int h, int format)
+{
+    if (w<0 || h<0 || format<0)
+        return BAD_VALUE;
+
+    if ((w && !h) || (!w && h))
+        return BAD_VALUE;
+
+    Mutex::Autolock _l(mSurfaceLock);
+    mBufferInfo.set(w, h, format);
+    return NO_ERROR;
+}
+
+// ----------------------------------------------------------------------------
+
+int Surface::getConnectedApi() const
+{
+    Mutex::Autolock _l(mSurfaceLock);
+    return mConnected;
+}
 
 // ----------------------------------------------------------------------------
 
@@ -830,7 +864,8 @@ int Surface::getBufferIndex(const sp<GraphicBuffer>& buffer) const
     return buffer->getIndex();
 }
 
-status_t Surface::getBufferLocked(int index, int usage)
+status_t Surface::getBufferLocked(int index,
+        uint32_t w, uint32_t h, uint32_t format, uint32_t usage)
 {
     sp<ISurface> s(mSurface);
     if (s == 0) return NO_INIT;
@@ -838,20 +873,21 @@ status_t Surface::getBufferLocked(int index, int usage)
     status_t err = NO_MEMORY;
 
     // free the current buffer
-    sp<GraphicBuffer>& currentBuffer(mBuffers[index]);
+    sp<GraphicBuffer>& currentBuffer(mBuffers.editItemAt(index));
     if (currentBuffer != 0) {
         getBufferMapper().unregisterBuffer(currentBuffer->handle);
         currentBuffer.clear();
     }
 
-    sp<GraphicBuffer> buffer = s->requestBuffer(index, usage);
+    sp<GraphicBuffer> buffer = s->requestBuffer(index, w, h, format, usage);
     LOGE_IF(buffer==0,
             "ISurface::getBuffer(%d, %08x) returned NULL",
             index, usage);
     if (buffer != 0) { // this should never happen by construction
         LOGE_IF(buffer->handle == NULL, 
-                "Surface (identity=%d) requestBuffer(%d, %08x) returned"
-                "a buffer with a null handle", mIdentity, index, usage);
+                "Surface (identity=%d) requestBuffer(%d, %u, %u, %u, %08x) "
+                "returned a buffer with a null handle",
+                mIdentity, index, w, h, format, usage);
         err = mSharedBufferClient->getStatus();
         LOGE_IF(err,  "Surface (identity=%d) state = %d", mIdentity, err);
         if (!err && buffer->handle != NULL) {
@@ -869,5 +905,44 @@ status_t Surface::getBufferLocked(int index, int usage)
     return err; 
 }
 
+// ----------------------------------------------------------------------------
+Surface::BufferInfo::BufferInfo()
+    : mWidth(0), mHeight(0), mFormat(0),
+      mUsage(GRALLOC_USAGE_HW_RENDER), mDirty(0)
+{
+}
+
+void Surface::BufferInfo::set(uint32_t w, uint32_t h, uint32_t format) {
+    if ((mWidth != w) || (mHeight != h) || (mFormat != format)) {
+        mWidth = w;
+        mHeight = h;
+        mFormat = format;
+        mDirty |= GEOMETRY;
+    }
+}
+
+void Surface::BufferInfo::set(uint32_t usage) {
+    mUsage = usage;
+}
+
+void Surface::BufferInfo::get(uint32_t *pWidth, uint32_t *pHeight,
+        uint32_t *pFormat, uint32_t *pUsage) const {
+    *pWidth  = mWidth;
+    *pHeight = mHeight;
+    *pFormat = mFormat;
+    *pUsage  = mUsage;
+}
+
+bool Surface::BufferInfo::validateBuffer(const sp<GraphicBuffer>& buffer) const {
+    // make sure we AT LEAST have the usage flags we want
+    if (mDirty || buffer==0 ||
+            ((buffer->usage & mUsage) != mUsage)) {
+        mDirty = 0;
+        return false;
+    }
+    return true;
+}
+
+// ----------------------------------------------------------------------------
 }; // namespace android