auto import from //branches/cupcake/...@125939
diff --git a/libs/surfaceflinger/BootAnimation.cpp b/libs/surfaceflinger/BootAnimation.cpp
index e9e34c3..d18f59a 100644
--- a/libs/surfaceflinger/BootAnimation.cpp
+++ b/libs/surfaceflinger/BootAnimation.cpp
@@ -36,8 +36,8 @@
 #include <ui/ISurfaceFlingerClient.h>
 #include <ui/EGLNativeWindowSurface.h>
 
-#include <graphics/SkBitmap.h>
-#include <graphics/SkImageDecoder.h>
+#include <core/SkBitmap.h>
+#include <images/SkImageDecoder.h>
 
 #include <GLES/egl.h>
 
diff --git a/libs/surfaceflinger/DisplayHardware/DisplayHardware.cpp b/libs/surfaceflinger/DisplayHardware/DisplayHardware.cpp
index cd72179..19e32ec 100644
--- a/libs/surfaceflinger/DisplayHardware/DisplayHardware.cpp
+++ b/libs/surfaceflinger/DisplayHardware/DisplayHardware.cpp
@@ -250,7 +250,7 @@
 
     mOverlayEngine = NULL;
     if (hw_get_module(OVERLAY_HARDWARE_MODULE_ID, &module) == 0) {
-        overlay_open(module, &mOverlayEngine);
+        overlay_control_open(module, &mOverlayEngine);
     }
 }
 
@@ -266,7 +266,7 @@
     eglMakeCurrent(mDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
     eglTerminate(mDisplay);
     copybit_close(mBlitEngine);
-    overlay_close(mOverlayEngine);
+    overlay_control_close(mOverlayEngine);
 }
 
 void DisplayHardware::releaseScreen() const
diff --git a/libs/surfaceflinger/DisplayHardware/DisplayHardware.h b/libs/surfaceflinger/DisplayHardware/DisplayHardware.h
index de4a2cc..df97b60 100644
--- a/libs/surfaceflinger/DisplayHardware/DisplayHardware.h
+++ b/libs/surfaceflinger/DisplayHardware/DisplayHardware.h
@@ -26,7 +26,7 @@
 
 #include "DisplayHardware/DisplayHardwareBase.h"
 
-struct overlay_device_t;
+struct overlay_control_device_t;
 struct copybit_device_t;
 struct copybit_image_t;
 struct copybit_t;
@@ -78,7 +78,7 @@
     void getDisplaySurface(GGLSurface* fb) const;
     EGLDisplay getEGLDisplay() const { return mDisplay; }
     copybit_device_t* getBlitEngine() const { return mBlitEngine; }
-    overlay_device_t* getOverlayEngine() const { return mOverlayEngine; }
+    overlay_control_device_t* getOverlayEngine() const { return mOverlayEngine; }
     
     Rect bounds() const {
         return Rect(mWidth, mHeight);
@@ -103,7 +103,7 @@
     mutable Region  mDirty;
     sp<EGLDisplaySurface> mDisplaySurface;
     copybit_device_t*     mBlitEngine;
-    overlay_device_t*     mOverlayEngine;
+    overlay_control_device_t* mOverlayEngine;
 };
 
 }; // namespace android
diff --git a/libs/surfaceflinger/Layer.cpp b/libs/surfaceflinger/Layer.cpp
index 8ba0851..f65d669 100644
--- a/libs/surfaceflinger/Layer.cpp
+++ b/libs/surfaceflinger/Layer.cpp
@@ -316,7 +316,7 @@
             if (err == NO_ERROR) {
                 const uint32_t mask = clientBackBufferIndex ? eResizeBuffer1 : eResizeBuffer0;
                 android_atomic_and(~mask, &(lcblk->swapState));
-                // since a buffer became availlable, we can let the client go...
+                // since a buffer became available, we can let the client go...
                 mFlinger->scheduleBroadcast(client);
                 mResizeTransactionDone = true;
 
@@ -511,7 +511,7 @@
             }
             mResizeTransactionDone = false;
             recomputeVisibleRegions = true;
-            invalidate = true;
+            this->contentDirty = true;
         }
     }
 
diff --git a/libs/surfaceflinger/LayerBase.cpp b/libs/surfaceflinger/LayerBase.cpp
index af353e2..bdefba3 100644
--- a/libs/surfaceflinger/LayerBase.cpp
+++ b/libs/surfaceflinger/LayerBase.cpp
@@ -53,14 +53,15 @@
 int32_t LayerBase::sIdentity = 0;
 
 LayerBase::LayerBase(SurfaceFlinger* flinger, DisplayID display)
-    : dpy(display), invalidate(false),
+    : dpy(display), contentDirty(false),
       mFlinger(flinger),
       mTransformed(false),
       mOrientation(0),
       mCanUseCopyBit(false),
       mTransactionFlags(0),
       mPremultipliedAlpha(true),
-      mIdentity(uint32_t(android_atomic_inc(&sIdentity)))
+      mIdentity(uint32_t(android_atomic_inc(&sIdentity))),
+      mInvalidate(0)
 {
     const DisplayHardware& hw(flinger->graphicPlane(0).displayHardware());
     mFlags = hw.getFlags();
@@ -205,7 +206,7 @@
     if (temp.sequence != front.sequence) {
         // invalidate and recompute the visible regions if needed
         flags |= eVisibleRegion;
-        this->invalidate = true;
+        this->contentDirty = true;
     }
     
     // Commit the transaction
@@ -299,12 +300,22 @@
 void LayerBase::unlockPageFlip(
         const Transform& planeTransform, Region& outDirtyRegion)
 {
+    if ((android_atomic_and(~1, &mInvalidate)&1) == 1) {
+        outDirtyRegion.orSelf(visibleRegionScreen);
+    }
 }
 
 void LayerBase::finishPageFlip()
 {
 }
 
+void LayerBase::invalidate()
+{
+    if ((android_atomic_or(1, &mInvalidate)&1) == 0) {
+        mFlinger->signalEvent();
+    }
+}
+
 void LayerBase::drawRegion(const Region& reg) const
 {
     Region::iterator iterator(reg);
diff --git a/libs/surfaceflinger/LayerBase.h b/libs/surfaceflinger/LayerBase.h
index b3f3771..5e14dc8 100644
--- a/libs/surfaceflinger/LayerBase.h
+++ b/libs/surfaceflinger/LayerBase.h
@@ -75,7 +75,7 @@
     virtual ~LayerBase();
     
     DisplayID           dpy;
-    mutable bool        invalidate;
+    mutable bool        contentDirty;
             Region      visibleRegionScreen;
             Region      transparentRegionScreen;
             Region      coveredRegionScreen;
@@ -112,18 +112,87 @@
             Rect visibleBounds() const;
             void drawRegion(const Region& reg) const;
 
+            void invalidate();
+            
+    /**
+     * draw - performs some global clipping optimizations
+     * and calls onDraw().
+     * Typically this method is not overridden, instead implement onDraw()
+     * to perform the actual drawing.  
+     */
     virtual void draw(const Region& clip) const;
+    
+    /**
+     * onDraw - draws the surface.
+     */
     virtual void onDraw(const Region& clip) const = 0;
+    
+    /**
+     * initStates - called just after construction
+     */
     virtual void initStates(uint32_t w, uint32_t h, uint32_t flags);
+    
+    /**
+     * setSizeChanged - called when the *current* state's size is changed.
+     */
     virtual void setSizeChanged(uint32_t w, uint32_t h);
+    
+    /**
+     * doTransaction - process the transaction. This is a good place to figure
+     * out which attributes of the surface have changed.
+     */
     virtual uint32_t doTransaction(uint32_t transactionFlags);
+    
+    /**
+     * setVisibleRegion - called to set the new visible region. This gives
+     * a chance to update the new visible region or record the fact it changed.
+     */
     virtual void setVisibleRegion(const Region& visibleRegion);
+    
+    /**
+     * setCoveredRegion - called when the covered region changes. The covered
+     * region correspond to any area of the surface that is covered 
+     * (transparently or not) by another surface.
+     */
     virtual void setCoveredRegion(const Region& coveredRegion);
+    
+    /**
+     * getPhysicalSize - returns the physical size of the drawing state of
+     * the surface. If the surface is backed by a bitmap, this is the size of
+     * the bitmap (as opposed to the size of the drawing state).
+     */
     virtual Point getPhysicalSize() const;
+    
+    /**
+     * lockPageFlip - called each time the screen is redrawn and returns whether
+     * the visible regions need to be recomputed (this is a fairly heavy
+     * operation, so this should be set only if needed). Typically this is used
+     * to figure out if the content or size of a surface has changed.
+     */
     virtual void lockPageFlip(bool& recomputeVisibleRegions);
+    
+    /**
+     * unlockPageFlip - called each time the screen is redrawn. updates the
+     * final dirty region wrt the planeTransform.
+     * At this point, all visible regions, surface position and size, etc... are
+     * correct.
+     */
     virtual void unlockPageFlip(const Transform& planeTransform, Region& outDirtyRegion);
+    
+    /**
+     * finishPageFlip - called after all surfaces have drawn.
+     */
     virtual void finishPageFlip();
+    
+    /**
+     * needsBlending - true if this surface needs blending
+     */
     virtual bool needsBlending() const  { return false; }
+    
+    /**
+     * isSecure - true if this surface is secure, that is if it prevents a
+     * screenshot to be taken,
+     */
     virtual bool isSecure() const       { return false; }
 
             enum { // flags for doTransaction()
@@ -162,7 +231,6 @@
 
           bool canUseCopybit() const;
           
-          
                 SurfaceFlinger* mFlinger;
                 uint32_t        mFlags;
 
@@ -184,7 +252,10 @@
                 bool            mPremultipliedAlpha;
 
                 // only read
-     const      uint32_t        mIdentity;
+    const       uint32_t        mIdentity;
+     
+                // atomic
+    volatile    int32_t         mInvalidate;
                 
 
 private:
@@ -254,7 +325,7 @@
                 { return INVALID_OPERATION; }
         virtual void postBuffer(ssize_t offset) { }
         virtual void unregisterBuffers() { };
-        virtual sp<Overlay> createOverlay(
+        virtual sp<OverlayRef> createOverlay(
                 uint32_t w, uint32_t h, int32_t format) {
             return NULL;
         };
diff --git a/libs/surfaceflinger/LayerBlur.cpp b/libs/surfaceflinger/LayerBlur.cpp
index e3ae7fb..efadbcf 100644
--- a/libs/surfaceflinger/LayerBlur.cpp
+++ b/libs/surfaceflinger/LayerBlur.cpp
@@ -71,7 +71,7 @@
         mRefreshCache = true;
         mCacheDirty = true;
         flags |= eVisibleRegion;
-        this->invalidate = true;
+        this->contentDirty = true;
     }
     return LayerBase::doTransaction(flags);    
 }
diff --git a/libs/surfaceflinger/LayerBuffer.cpp b/libs/surfaceflinger/LayerBuffer.cpp
index 3861e68..700e4f5 100644
--- a/libs/surfaceflinger/LayerBuffer.cpp
+++ b/libs/surfaceflinger/LayerBuffer.cpp
@@ -46,7 +46,7 @@
 LayerBuffer::LayerBuffer(SurfaceFlinger* flinger, DisplayID display,
         Client* client, int32_t i)
     : LayerBaseClient(flinger, display, client, i),
-    mBuffer(0), mTextureName(-1U), mInvalidate(false), mNeedsBlending(false)
+      mNeedsBlending(false)
 {
 }
 
@@ -57,154 +57,6 @@
         s->disown();
         mClientSurface.clear();
     }
-
-    // this should always be called from the OpenGL thread
-    if (mTextureName != -1U) {
-        //glDeleteTextures(1, &mTextureName);
-        deletedTextures.add(mTextureName);
-    }
-    // to help debugging we set those to zero
-    mWidth = mHeight = 0;
-}
-
-bool LayerBuffer::needsBlending() const
-{
-    Mutex::Autolock _l(mLock);
-    return mNeedsBlending;
-}
-
-void LayerBuffer::onDraw(const Region& clip) const
-{
-    sp<Buffer> buffer(getBuffer());
-    if (UNLIKELY(buffer == 0))  {
-        // nothing to do, we don't have a buffer
-        clearWithOpenGL(clip);
-        return;
-    }
-
-    status_t err = NO_ERROR;
-    NativeBuffer src(buffer->getBuffer());
-    const int can_use_copybit = canUseCopybit();
-
-    if (can_use_copybit)  {
-        //StopWatch watch("MDP");
-
-        const int src_width  = src.crop.r - src.crop.l;
-        const int src_height = src.crop.b - src.crop.t;
-        int W = mTransformedBounds.width();
-        int H = mTransformedBounds.height();
-        if (getOrientation() & Transform::ROT_90) {
-            int t(W); W=H; H=t;
-        }
-
-        /* With LayerBuffer, it is likely that we'll have to rescale the
-         * surface, because this is often used for video playback or
-         * camera-preview. Since we want these operation as fast as possible
-         * we make sure we can use the 2D H/W even if it doesn't support
-         * the requested scale factor, in which case we perform the scaling
-         * in several passes. */
-
-        copybit_device_t* copybit = mFlinger->getBlitEngine();
-        const float min = copybit->get(copybit, COPYBIT_MINIFICATION_LIMIT);
-        const float mag = copybit->get(copybit, COPYBIT_MAGNIFICATION_LIMIT);
-
-        float xscale = 1.0f;
-        if (src_width > W*min)          xscale = 1.0f / min;
-        else if (src_width*mag < W)     xscale = mag;
-
-        float yscale = 1.0f;
-        if (src_height > H*min)         yscale = 1.0f / min;
-        else if (src_height*mag < H)    yscale = mag;
-
-        if (UNLIKELY(xscale!=1.0f || yscale!=1.0f)) {
-            //LOGD("MDP scaling hack w=%d, h=%d, ww=%d, wh=%d, xs=%f, ys=%f",
-            //        src_width, src_height, W, H, xscale, yscale);
-
-            if (UNLIKELY(mTemporaryDealer == 0)) {
-                // allocate a memory-dealer for this the first time
-                mTemporaryDealer = mFlinger->getSurfaceHeapManager()
-                        ->createHeap(ISurfaceComposer::eHardware);
-                mTempBitmap.init(mTemporaryDealer);
-            }
-
-            const int tmp_w = floorf(src_width  * xscale);
-            const int tmp_h = floorf(src_height * yscale);
-            err = mTempBitmap.setBits(tmp_w, tmp_h, 1, src.img.format);
-
-            if (LIKELY(err == NO_ERROR)) {
-                NativeBuffer tmp;
-                mTempBitmap.getBitmapSurface(&tmp.img);
-                tmp.crop.l = 0;
-                tmp.crop.t = 0;
-                tmp.crop.r = tmp.img.w;
-                tmp.crop.b = tmp.img.h;
-
-                region_iterator tmp_it(Region(Rect(tmp.crop.r, tmp.crop.b)));
-                copybit->set_parameter(copybit, COPYBIT_TRANSFORM, 0);
-                copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, 0xFF);
-                copybit->set_parameter(copybit, COPYBIT_DITHER, COPYBIT_DISABLE);
-                err = copybit->stretch(copybit,
-                        &tmp.img, &src.img, &tmp.crop, &src.crop, &tmp_it);
-                src = tmp;
-            }
-        }
-
-        const DisplayHardware& hw(graphicPlane(0).displayHardware());
-        copybit_image_t dst;
-        hw.getDisplaySurface(&dst);
-        const copybit_rect_t& drect
-                = reinterpret_cast<const copybit_rect_t&>(mTransformedBounds);
-        const State& s(drawingState());
-        region_iterator it(clip);
-        copybit->set_parameter(copybit, COPYBIT_TRANSFORM, getOrientation());
-        copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, s.alpha);
-        copybit->set_parameter(copybit, COPYBIT_DITHER,
-                s.flags & ISurfaceComposer::eLayerDither ?
-                        COPYBIT_ENABLE : COPYBIT_DISABLE);
-        err = copybit->stretch(copybit,
-                &dst, &src.img, &drect, &src.crop, &it);
-    }
-
-    if (!can_use_copybit || err) {
-        if (UNLIKELY(mTextureName == -1LU)) {
-            mTextureName = createTexture();
-        }
-        GLuint w = 0;
-        GLuint h = 0;
-        GGLSurface t;
-            t.version = sizeof(GGLSurface);
-            t.width  = src.crop.r;
-            t.height = src.crop.b;
-            t.stride = src.img.w;
-            t.vstride= src.img.h;
-            t.format = src.img.format;
-            t.data = (GGLubyte*)(intptr_t(src.img.base) + src.img.offset);
-        const Region dirty(Rect(t.width, t.height));
-        loadTexture(dirty, mTextureName, t, w, h);
-        drawWithOpenGL(clip, mTextureName, t);
-    }
-}
-
-void LayerBuffer::invalidateLocked()
-{
-    mInvalidate = true;
-    mFlinger->signalEvent();
-}
-
-void LayerBuffer::invalidate()
-{
-    Mutex::Autolock _l(mLock);
-    invalidateLocked();
-}
-
-void LayerBuffer::unlockPageFlip(const Transform& planeTransform,
-        Region& outDirtyRegion)
-{
-    Mutex::Autolock _l(mLock);
-    if (mInvalidate) {
-        mInvalidate = false;
-        outDirtyRegion.orSelf(visibleRegionScreen);
-    }
 }
 
 sp<LayerBuffer::SurfaceBuffer> LayerBuffer::getClientSurface() const
@@ -226,114 +78,106 @@
     return s;
 }
 
+bool LayerBuffer::needsBlending() const {
+    return mNeedsBlending;
+}
 
-status_t LayerBuffer::registerBuffers(int w, int h, int hstride, int vstride,
-            PixelFormat format, const sp<IMemoryHeap>& memoryHeap)
-{
-    if (memoryHeap == NULL) {
-        // this is allowed, but in this case, it is illegal to receive
-        // postBuffer(). The surface just erases the framebuffer with
-        // fully transparent pixels.
-        mHeap.clear();
-        mWidth = w;
-        mHeight = h;
-        mNeedsBlending = false;
-        return NO_ERROR;
-    }
-    
-    status_t err = (memoryHeap->heapID() >= 0) ? NO_ERROR : NO_INIT;
-    if (err != NO_ERROR)
-        return err;
-
-    // TODO: validate format/parameters
-
-    Mutex::Autolock _l(mLock);
-    mHeap = memoryHeap;
-    mWidth = w;
-    mHeight = h;
-    mHStride = hstride;
-    mVStride = vstride;
-    mFormat = format;
-    PixelFormatInfo info;
-    getPixelFormatInfo(format, &info);
-    mNeedsBlending = (info.h_alpha - info.l_alpha) > 0;
-    return NO_ERROR;
+void LayerBuffer::setNeedsBlending(bool blending) {
+    mNeedsBlending = blending;
 }
 
 void LayerBuffer::postBuffer(ssize_t offset)
 {
-    sp<IMemoryHeap> heap;
-    int w, h, hs, vs, f;
-    { // scope for the lock
-        Mutex::Autolock _l(mLock);
-        w = mWidth;
-        h = mHeight;
-        hs= mHStride;
-        vs= mVStride;
-        f = mFormat;
-        heap = mHeap;
-    }
-
-    sp<Buffer> buffer;
-    if (heap != 0) {
-        buffer = new Buffer(heap, offset, w, h, hs, vs, f);
-        if (buffer->getStatus() != NO_ERROR)
-            buffer.clear();
-        setBuffer(buffer);
-        invalidate();
-    }
+    sp<Source> source(getSource());
+    if (source != 0)
+        source->postBuffer(offset);
 }
 
 void LayerBuffer::unregisterBuffers()
 {
-    Mutex::Autolock _l(mLock);
-    mHeap.clear();
-    mBuffer.clear();
-    invalidateLocked();
+    sp<Source> source(getSource());
+    if (source != 0)
+        source->unregisterBuffers();
+    // XXX: clear mSource
 }
 
-sp<Overlay> LayerBuffer::createOverlay(uint32_t w, uint32_t h, int32_t format)
+uint32_t LayerBuffer::doTransaction(uint32_t flags)
 {
-    sp<Overlay> result;
-    Mutex::Autolock _l(mLock);
-    if (mHeap != 0 || mBuffer != 0) {
-        // we're a push surface. error.
-        return result;
-    }
-    
-    overlay_device_t* overlay_dev = mFlinger->getOverlayEngine();
-    if (overlay_dev == NULL) {
-        // overlays not supported
-        return result;
-    }
+    sp<Source> source(getSource());
+    if (source != 0)
+        source->onTransaction(flags);
+    return LayerBase::doTransaction(flags);    
+}
 
-    overlay_t* overlay = overlay_dev->createOverlay(overlay_dev, w, h, format);
-    if (overlay == NULL) {
-        // couldn't create the overlay (no memory? no more overlays?)
-        return result;
+void LayerBuffer::unlockPageFlip(const Transform& planeTransform,
+        Region& outDirtyRegion)
+{
+    // this code-path must be as tight as possible, it's called each time
+    // the screen is composited.
+    sp<Source> source(getSource());
+    if (source != 0)
+        source->onVisibilityResolved(planeTransform);
+    LayerBase::unlockPageFlip(planeTransform, outDirtyRegion);    
+}
+
+void LayerBuffer::onDraw(const Region& clip) const
+{
+    sp<Source> source(getSource());
+    if (LIKELY(source != 0)) {
+        source->onDraw(clip);
+    } else {
+        clearWithOpenGL(clip);
     }
-    
-    /* TODO: implement the real stuff here */
-    
+}
+
+/**
+ * This creates a "buffer" source for this surface
+ */
+status_t LayerBuffer::registerBuffers(int w, int h, int hstride, int vstride,
+        PixelFormat format, const sp<IMemoryHeap>& memoryHeap)
+{
+    Mutex::Autolock _l(mLock);
+    if (mSource != 0)
+        return INVALID_OPERATION;
+
+    sp<BufferSource> source = new BufferSource(*this, w, h,
+            hstride, vstride, format, memoryHeap);
+
+    status_t result = source->getStatus();
+    if (result == NO_ERROR) {
+        mSource = source;
+    }
+    return result;
+}    
+
+/**
+ * This creates an "overlay" source for this surface
+ */
+sp<OverlayRef> LayerBuffer::createOverlay(uint32_t w, uint32_t h, int32_t f)
+{
+    sp<OverlayRef> result;
+    Mutex::Autolock _l(mLock);
+    if (mSource != 0)
+        return result;
+
+    sp<OverlaySource> source = new OverlaySource(*this, &result, w, h, f);
+    if (result != 0) {
+        mSource = source;
+    }
     return result;
 }
 
-sp<LayerBuffer::Buffer> LayerBuffer::getBuffer() const
-{
+sp<LayerBuffer::Source> LayerBuffer::getSource() const {
     Mutex::Autolock _l(mLock);
-    return mBuffer;
+    return mSource;
 }
 
-void LayerBuffer::setBuffer(const sp<LayerBuffer::Buffer>& buffer)
-{
-    Mutex::Autolock _l(mLock);
-    mBuffer = buffer;
-}
-
-// ---------------------------------------------------------------------------
+// ============================================================================
+// LayerBuffer::SurfaceBuffer
+// ============================================================================
 
 LayerBuffer::SurfaceBuffer::SurfaceBuffer(SurfaceID id, LayerBuffer* owner)
-    : LayerBaseClient::Surface(id, owner->getIdentity()), mOwner(owner)
+: LayerBaseClient::Surface(id, owner->getIdentity()), mOwner(owner)
 {
 }
 
@@ -367,9 +211,9 @@
         owner->unregisterBuffers();
 }
 
-sp<Overlay> LayerBuffer::SurfaceBuffer::createOverlay(
+sp<OverlayRef> LayerBuffer::SurfaceBuffer::createOverlay(
         uint32_t w, uint32_t h, int32_t format) {
-    sp<Overlay> result;
+    sp<OverlayRef> result;
     LayerBuffer* owner(getOwner());
     if (owner)
         result = owner->createOverlay(w, h, format);
@@ -382,12 +226,13 @@
     mOwner = 0;
 }
 
-
-// ---------------------------------------------------------------------------
+// ============================================================================
+// LayerBuffer::Buffer
+// ============================================================================
 
 LayerBuffer::Buffer::Buffer(const sp<IMemoryHeap>& heap, ssize_t offset,
         int w, int h, int hs, int vs, int f)
-    : mCount(0), mHeap(heap)
+: mHeap(heap)
 {
     NativeBuffer& src(mNativeBuffer);
     src.crop.l = 0;
@@ -408,5 +253,317 @@
 {
 }
 
+// ============================================================================
+// LayerBuffer::Source
+// LayerBuffer::BufferSource
+// LayerBuffer::OverlaySource
+// ============================================================================
+
+LayerBuffer::Source::Source(LayerBuffer& layer)
+    : mLayer(layer)
+{    
+}
+LayerBuffer::Source::~Source() {    
+}
+void LayerBuffer::Source::onDraw(const Region& clip) const {
+}
+void LayerBuffer::Source::onTransaction(uint32_t flags) {
+}
+void LayerBuffer::Source::onVisibilityResolved(
+        const Transform& planeTransform) {
+}
+void LayerBuffer::Source::postBuffer(ssize_t offset) {
+}
+void LayerBuffer::Source::unregisterBuffers() {
+}
+
+// ---------------------------------------------------------------------------
+
+LayerBuffer::BufferSource::BufferSource(LayerBuffer& layer,
+        int w, int h, int hstride, int vstride,
+        PixelFormat format, const sp<IMemoryHeap>& memoryHeap)
+    : Source(layer), mStatus(NO_ERROR), mTextureName(-1U)
+{
+    if (memoryHeap == NULL) {
+        // this is allowed, but in this case, it is illegal to receive
+        // postBuffer(). The surface just erases the framebuffer with
+        // fully transparent pixels.
+        mHeap.clear();
+        mWidth = w;
+        mHeight = h;
+        mLayer.setNeedsBlending(false);
+        return;
+    }
+
+    status_t err = (memoryHeap->heapID() >= 0) ? NO_ERROR : NO_INIT;
+    if (err != NO_ERROR) {
+        mStatus = err;
+        return;
+    }
+
+    // TODO: validate format/parameters
+    mHeap = memoryHeap;
+    mWidth = w;
+    mHeight = h;
+    mHStride = hstride;
+    mVStride = vstride;
+    mFormat = format;
+    PixelFormatInfo info;
+    getPixelFormatInfo(format, &info);
+    mLayer.setNeedsBlending((info.h_alpha - info.l_alpha) > 0);
+}
+
+LayerBuffer::BufferSource::~BufferSource()
+{    
+    if (mTextureName != -1U) {
+        LayerBase::deletedTextures.add(mTextureName);
+    }
+}
+
+void LayerBuffer::BufferSource::postBuffer(ssize_t offset)
+{    
+    sp<IMemoryHeap> heap;
+    int w, h, hs, vs, f;
+    { // scope for the lock
+        Mutex::Autolock _l(mLock);
+        w = mWidth;
+        h = mHeight;
+        hs= mHStride;
+        vs= mVStride;
+        f = mFormat;
+        heap = mHeap;
+    }
+
+    sp<Buffer> buffer;
+    if (heap != 0) {
+        buffer = new LayerBuffer::Buffer(heap, offset, w, h, hs, vs, f);
+        if (buffer->getStatus() != NO_ERROR)
+            buffer.clear();
+        setBuffer(buffer);
+        mLayer.invalidate();
+    }
+}
+
+void LayerBuffer::BufferSource::unregisterBuffers()
+{
+    Mutex::Autolock _l(mLock);
+    mHeap.clear();
+    mBuffer.clear();
+    mLayer.invalidate();
+}
+
+sp<LayerBuffer::Buffer> LayerBuffer::BufferSource::getBuffer() const
+{
+    Mutex::Autolock _l(mLock);
+    return mBuffer;
+}
+
+void LayerBuffer::BufferSource::setBuffer(const sp<LayerBuffer::Buffer>& buffer)
+{
+    Mutex::Autolock _l(mLock);
+    mBuffer = buffer;
+}
+
+void LayerBuffer::BufferSource::onDraw(const Region& clip) const 
+{
+    sp<Buffer> buffer(getBuffer());
+    if (UNLIKELY(buffer == 0))  {
+        // nothing to do, we don't have a buffer
+        mLayer.clearWithOpenGL(clip);
+        return;
+    }
+
+    status_t err = NO_ERROR;
+    NativeBuffer src(buffer->getBuffer());
+    const Rect& transformedBounds = mLayer.getTransformedBounds();
+    const int can_use_copybit = mLayer.canUseCopybit();
+
+    if (can_use_copybit)  {
+        const int src_width  = src.crop.r - src.crop.l;
+        const int src_height = src.crop.b - src.crop.t;
+        int W = transformedBounds.width();
+        int H = transformedBounds.height();
+        if (mLayer.getOrientation() & Transform::ROT_90) {
+            int t(W); W=H; H=t;
+        }
+
+        /* With LayerBuffer, it is likely that we'll have to rescale the
+         * surface, because this is often used for video playback or
+         * camera-preview. Since we want these operation as fast as possible
+         * we make sure we can use the 2D H/W even if it doesn't support
+         * the requested scale factor, in which case we perform the scaling
+         * in several passes. */
+
+        copybit_device_t* copybit = mLayer.mFlinger->getBlitEngine();
+        const float min = copybit->get(copybit, COPYBIT_MINIFICATION_LIMIT);
+        const float mag = copybit->get(copybit, COPYBIT_MAGNIFICATION_LIMIT);
+
+        float xscale = 1.0f;
+        if (src_width > W*min)          xscale = 1.0f / min;
+        else if (src_width*mag < W)     xscale = mag;
+
+        float yscale = 1.0f;
+        if (src_height > H*min)         yscale = 1.0f / min;
+        else if (src_height*mag < H)    yscale = mag;
+
+        if (UNLIKELY(xscale!=1.0f || yscale!=1.0f)) {
+            if (UNLIKELY(mTemporaryDealer == 0)) {
+                // allocate a memory-dealer for this the first time
+                mTemporaryDealer = mLayer.mFlinger->getSurfaceHeapManager()
+                ->createHeap(ISurfaceComposer::eHardware);
+                mTempBitmap.init(mTemporaryDealer);
+            }
+
+            const int tmp_w = floorf(src_width  * xscale);
+            const int tmp_h = floorf(src_height * yscale);
+            err = mTempBitmap.setBits(tmp_w, tmp_h, 1, src.img.format);
+
+            if (LIKELY(err == NO_ERROR)) {
+                NativeBuffer tmp;
+                mTempBitmap.getBitmapSurface(&tmp.img);
+                tmp.crop.l = 0;
+                tmp.crop.t = 0;
+                tmp.crop.r = tmp.img.w;
+                tmp.crop.b = tmp.img.h;
+
+                region_iterator tmp_it(Region(Rect(tmp.crop.r, tmp.crop.b)));
+                copybit->set_parameter(copybit, COPYBIT_TRANSFORM, 0);
+                copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, 0xFF);
+                copybit->set_parameter(copybit, COPYBIT_DITHER, COPYBIT_DISABLE);
+                err = copybit->stretch(copybit,
+                        &tmp.img, &src.img, &tmp.crop, &src.crop, &tmp_it);
+                src = tmp;
+            }
+        }
+
+        const DisplayHardware& hw(mLayer.graphicPlane(0).displayHardware());
+        copybit_image_t dst;
+        hw.getDisplaySurface(&dst);
+        const copybit_rect_t& drect
+        = reinterpret_cast<const copybit_rect_t&>(transformedBounds);
+        const State& s(mLayer.drawingState());
+        region_iterator it(clip);
+        copybit->set_parameter(copybit, COPYBIT_TRANSFORM, mLayer.getOrientation());
+        copybit->set_parameter(copybit, COPYBIT_PLANE_ALPHA, s.alpha);
+        copybit->set_parameter(copybit, COPYBIT_DITHER,
+                s.flags & ISurfaceComposer::eLayerDither ?
+                        COPYBIT_ENABLE : COPYBIT_DISABLE);
+        err = copybit->stretch(copybit,
+                &dst, &src.img, &drect, &src.crop, &it);
+    }
+
+    if (!can_use_copybit || err) {
+        if (UNLIKELY(mTextureName == -1LU)) {
+            mTextureName = mLayer.createTexture();
+        }
+        GLuint w = 0;
+        GLuint h = 0;
+        GGLSurface t;
+        t.version = sizeof(GGLSurface);
+        t.width  = src.crop.r;
+        t.height = src.crop.b;
+        t.stride = src.img.w;
+        t.vstride= src.img.h;
+        t.format = src.img.format;
+        t.data = (GGLubyte*)(intptr_t(src.img.base) + src.img.offset);
+        const Region dirty(Rect(t.width, t.height));
+        mLayer.loadTexture(dirty, mTextureName, t, w, h);
+        mLayer.drawWithOpenGL(clip, mTextureName, t);
+    }
+}
+
+// ---------------------------------------------------------------------------
+
+LayerBuffer::OverlaySource::OverlaySource(LayerBuffer& layer,
+        sp<OverlayRef>* overlayRef, 
+        uint32_t w, uint32_t h, int32_t format)
+    : Source(layer), mVisibilityChanged(false), mOverlay(0), mOverlayHandle(0)
+{
+    overlay_control_device_t* overlay_dev = mLayer.mFlinger->getOverlayEngine();
+
+    if (overlay_dev == NULL) {
+        // overlays not supported
+        return;
+    }
+
+    overlay_t* overlay = overlay_dev->createOverlay(overlay_dev, w, h, format);
+    if (overlay == NULL) {
+        // couldn't create the overlay (no memory? no more overlays?)
+        return;
+    }
+
+    // enable dithering...
+    overlay_dev->setParameter(overlay_dev, overlay, 
+            OVERLAY_DITHER, OVERLAY_ENABLE);
+
+    mOverlay = overlay;
+    mWidth = overlay->w;
+    mHeight = overlay->h;
+    mFormat = overlay->format; 
+    mWidthStride = overlay->w_stride;
+    mHeightStride = overlay->h_stride;
+
+    mOverlayHandle = overlay->getHandleRef(overlay);
+    
+    // NOTE: here it's okay to acquire a reference to "this"m as long as
+    // the reference is not released before we leave the ctor.
+    sp<OverlayChanel> chanel = new OverlayChanel(this);
+
+    *overlayRef = new OverlayRef(mOverlayHandle, chanel,
+            mWidth, mHeight, mFormat, mWidthStride, mHeightStride);
+}
+
+LayerBuffer::OverlaySource::~OverlaySource()
+{    
+}
+
+void LayerBuffer::OverlaySource::onTransaction(uint32_t flags)
+{
+    const Layer::State& front(mLayer.drawingState());
+    const Layer::State& temp(mLayer.currentState());
+    if (temp.sequence != front.sequence) {
+        mVisibilityChanged = true;
+    }
+}
+
+void LayerBuffer::OverlaySource::onVisibilityResolved(
+        const Transform& planeTransform)
+{
+    // this code-path must be as tight as possible, it's called each time
+    // the screen is composited.
+    if (UNLIKELY(mOverlay != 0)) {
+        if (mVisibilityChanged) {
+            mVisibilityChanged = false;
+            const Rect& bounds = mLayer.getTransformedBounds();
+            int x = bounds.left;
+            int y = bounds.top;
+            int w = bounds.width();
+            int h = bounds.height();
+            
+            // we need a lock here to protect "destroy"
+            Mutex::Autolock _l(mLock);
+            if (mOverlay) {
+                overlay_control_device_t* overlay_dev = 
+                    mLayer.mFlinger->getOverlayEngine();
+                overlay_dev->setPosition(overlay_dev, mOverlay, x,y,w,h);
+                overlay_dev->setParameter(overlay_dev, mOverlay, 
+                        OVERLAY_TRANSFORM, mLayer.getOrientation());
+            }
+        }
+    }
+}
+
+void LayerBuffer::OverlaySource::serverDestroy() 
+{
+    // we need a lock here to protect "onVisibilityResolved"
+    Mutex::Autolock _l(mLock);
+    if (mOverlay) {
+        overlay_control_device_t* overlay_dev = 
+                mLayer.mFlinger->getOverlayEngine();
+        overlay_dev->destroyOverlay(overlay_dev, mOverlay);
+        mOverlay = 0;
+    }
+}
+
 // ---------------------------------------------------------------------------
 }; // namespace android
diff --git a/libs/surfaceflinger/LayerBuffer.h b/libs/surfaceflinger/LayerBuffer.h
index 3e616f2..63ec2cf 100644
--- a/libs/surfaceflinger/LayerBuffer.h
+++ b/libs/surfaceflinger/LayerBuffer.h
@@ -33,10 +33,24 @@
 
 class MemoryDealer;
 class Region;
-class Overlay;
+class OverlayRef;
 
 class LayerBuffer : public LayerBaseClient
 {
+    class Source : public LightRefBase<Source> {
+    public:
+        Source(LayerBuffer& layer);
+        virtual ~Source();
+        virtual void onDraw(const Region& clip) const;
+        virtual void onTransaction(uint32_t flags);
+        virtual void onVisibilityResolved(const Transform& planeTransform);
+        virtual void postBuffer(ssize_t offset);
+        virtual void unregisterBuffers();
+    protected:
+        LayerBuffer& mLayer;
+    };
+
+
 public:
     static const uint32_t typeInfo;
     static const char* const typeID;
@@ -51,39 +65,31 @@
 
     virtual sp<LayerBaseClient::Surface> getSurface() const;
     virtual void onDraw(const Region& clip) const;
+    virtual uint32_t doTransaction(uint32_t flags);
     virtual void unlockPageFlip(const Transform& planeTransform, Region& outDirtyRegion);
 
     status_t registerBuffers(int w, int h, int hstride, int vstride,
             PixelFormat format, const sp<IMemoryHeap>& heap);
     void postBuffer(ssize_t offset);
     void unregisterBuffers();
-    sp<Overlay> createOverlay(uint32_t w, uint32_t h, int32_t format);
-    void invalidate();
-    void invalidateLocked();
+    sp<OverlayRef> createOverlay(uint32_t w, uint32_t h, int32_t format);
+    
+    sp<Source> getSource() const;
+    void setNeedsBlending(bool blending);
+    const Rect& getTransformedBounds() const {
+        return mTransformedBounds;
+    }
 
 private:
-
-    struct NativeBuffer
-    {
+    struct NativeBuffer {
         copybit_image_t   img;
         copybit_rect_t    crop;
     };
 
-    class Buffer
-    {
+    class Buffer : public LightRefBase<Buffer> {
     public:
         Buffer(const sp<IMemoryHeap>& heap, ssize_t offset,
                 int w, int h, int hs, int vs, int f);
-        inline void incStrong(void*) const {
-            android_atomic_inc(&mCount);
-        }
-        inline void decStrong(void*) const {
-            int32_t c = android_atomic_dec(&mCount);
-            //LOGE_IF(c<1, "Buffer::decStrong() called too many times");
-            if (c == 1) {
-                 delete this;
-             }
-        }
         inline status_t getStatus() const {
             return mHeap!=0 ? NO_ERROR : NO_INIT;
         }
@@ -91,15 +97,87 @@
             return mNativeBuffer;
         }
     protected:
+        friend class LightRefBase<Buffer>;
         Buffer& operator = (const Buffer& rhs);
         Buffer(const Buffer& rhs);
         ~Buffer();
-        mutable volatile int32_t mCount;
     private:
         sp<IMemoryHeap>    mHeap;
         NativeBuffer       mNativeBuffer;
     };
 
+    class BufferSource : public Source {
+    public:
+        BufferSource(LayerBuffer& layer,
+                int w, int h, int hstride, int vstride,
+                PixelFormat format, const sp<IMemoryHeap>& heap);
+        virtual ~BufferSource();
+
+        status_t getStatus() const { return mStatus; }
+        sp<Buffer> getBuffer() const;
+        void setBuffer(const sp<Buffer>& buffer);
+
+        virtual void onDraw(const Region& clip) const;
+        virtual void postBuffer(ssize_t offset);
+        virtual void unregisterBuffers();
+    private:
+        mutable Mutex   mLock;
+        sp<IMemoryHeap> mHeap;
+        sp<Buffer>      mBuffer;
+        status_t        mStatus;
+        int             mWidth;
+        int             mHeight;
+        int             mHStride;
+        int             mVStride;
+        int             mFormat;
+        mutable sp<MemoryDealer> mTemporaryDealer;
+        mutable LayerBitmap mTempBitmap;
+        mutable GLuint  mTextureName;
+    };
+    
+    class OverlaySource : public Source {
+    public:
+        OverlaySource(LayerBuffer& layer,
+                sp<OverlayRef>* overlayRef, 
+                uint32_t w, uint32_t h, int32_t format);
+        virtual ~OverlaySource();
+        virtual void onTransaction(uint32_t flags);
+        virtual void onVisibilityResolved(const Transform& planeTransform);
+    private:
+        void serverDestroy(); 
+        class OverlayChanel : public BnOverlay {
+            mutable Mutex mLock;
+            sp<OverlaySource> mSource;
+            virtual void destroy() {
+                sp<OverlaySource> source;
+                { // scope for the lock;
+                    Mutex::Autolock _l(mLock);
+                    source = mSource;
+                    mSource.clear();
+                }
+                if (source != 0) {
+                    source->serverDestroy();
+                }
+            }
+        public:
+            OverlayChanel(const sp<OverlaySource>& source)
+                : mSource(source) {
+            }
+        };
+        friend class OverlayChanel;
+        bool mVisibilityChanged;
+
+        overlay_t* mOverlay;        
+        overlay_handle_t const *mOverlayHandle;
+        uint32_t mWidth;
+        uint32_t mHeight;
+        int32_t mFormat;
+        int32_t mWidthStride;
+        int32_t mHeightStride;
+        mutable Mutex mLock;
+    };
+
+
     class SurfaceBuffer : public LayerBaseClient::Surface
     {
     public:
@@ -109,7 +187,7 @@
                 PixelFormat format, const sp<IMemoryHeap>& heap);
         virtual void postBuffer(ssize_t offset);
         virtual void unregisterBuffers();
-        virtual sp<Overlay> createOverlay(
+        virtual sp<OverlayRef> createOverlay(
                 uint32_t w, uint32_t h, int32_t format);
        void disown();
     private:
@@ -122,24 +200,14 @@
     };
 
     friend class SurfaceFlinger;
-    sp<Buffer> getBuffer() const;
-    void       setBuffer(const sp<Buffer>& buffer);
     sp<SurfaceBuffer>   getClientSurface() const;
 
     mutable Mutex   mLock;
-    sp<IMemoryHeap> mHeap;
-    sp<Buffer>      mBuffer;
-    int             mWidth;
-    int             mHeight;
-    int             mHStride;
-    int             mVStride;
-    int             mFormat;
-    mutable GLuint  mTextureName;
+    sp<Source>      mSource;
+
     bool            mInvalidate;
     bool            mNeedsBlending;
     mutable wp<SurfaceBuffer> mClientSurface;
-    mutable sp<MemoryDealer> mTemporaryDealer;
-    mutable LayerBitmap mTempBitmap;
 };
 
 // ---------------------------------------------------------------------------
diff --git a/libs/surfaceflinger/LayerScreenshot.cpp b/libs/surfaceflinger/LayerScreenshot.cpp
index 9b82bad..3e7132b 100644
--- a/libs/surfaceflinger/LayerScreenshot.cpp
+++ b/libs/surfaceflinger/LayerScreenshot.cpp
@@ -23,7 +23,7 @@
 #include <utils/Errors.h>
 #include <utils/Log.h>
 
-#include <graphics/SkBitmap.h>
+#include <core/SkBitmap.h>
 
 #include <ui/EGLDisplaySurface.h>
 
diff --git a/libs/surfaceflinger/SurfaceFlinger.cpp b/libs/surfaceflinger/SurfaceFlinger.cpp
index e8de21a..4c719e8 100644
--- a/libs/surfaceflinger/SurfaceFlinger.cpp
+++ b/libs/surfaceflinger/SurfaceFlinger.cpp
@@ -231,7 +231,7 @@
     return graphicPlane(0).displayHardware().getBlitEngine();
 }
 
-overlay_device_t* SurfaceFlinger::getOverlayEngine() const
+overlay_control_device_t* SurfaceFlinger::getOverlayEngine() const
 {
     return graphicPlane(0).displayHardware().getOverlayEngine();
 }
@@ -773,12 +773,12 @@
         coveredRegion.andSelf(aboveCoveredLayers);
 
         // compute this layer's dirty region
-        if (layer->invalidate) {
+        if (layer->contentDirty) {
             // we need to invalidate the whole region
             dirty = visibleRegion;
             // as well, as the old visible region
             dirty.orSelf(layer->visibleRegionScreen);
-            layer->invalidate = false;
+            layer->contentDirty = false;
         } else {
             // compute the exposed region
             // dirty = what's visible now - what's wasn't covered before
@@ -1456,7 +1456,7 @@
                     "alpha=0x%02x, flags=0x%08x, tr=[%.2f, %.2f][%.2f, %.2f]\n",
                     layer->getTypeID(), layer,
                     s.z, layer->tx(), layer->ty(), s.w, s.h,
-                    layer->needsBlending(), layer->invalidate,
+                    layer->needsBlending(), layer->contentDirty,
                     s.alpha, s.flags,
                     s.transform[0], s.transform[1],
                     s.transform[2], s.transform[3]);
@@ -1474,22 +1474,6 @@
             }
             result.append(buffer);
             buffer[0] = 0;
-            /*** LayerBuffer ***/
-            LayerBuffer* const lbuf =
-                LayerBase::dynamicCast<LayerBuffer*>((LayerBase*)layer);
-            if (lbuf) {
-                sp<LayerBuffer::Buffer> lbb(lbuf->getBuffer());
-                if (lbb != 0) {
-                    const LayerBuffer::NativeBuffer& nbuf(lbb->getBuffer());
-                    snprintf(buffer, SIZE,
-                            "      "
-                            "mBuffer={w=%u, h=%u, f=%d, offset=%u, base=%p, fd=%d }\n",
-                            nbuf.img.w, nbuf.img.h, nbuf.img.format, nbuf.img.offset,
-                            nbuf.img.base, nbuf.img.fd);
-                }
-            }
-            result.append(buffer);
-            buffer[0] = 0;
             /*** Layer ***/
             Layer* const l = LayerBase::dynamicCast<Layer*>((LayerBase*)layer);
             if (l) {
diff --git a/libs/surfaceflinger/SurfaceFlinger.h b/libs/surfaceflinger/SurfaceFlinger.h
index 92021d0..a242f1a 100644
--- a/libs/surfaceflinger/SurfaceFlinger.h
+++ b/libs/surfaceflinger/SurfaceFlinger.h
@@ -180,7 +180,7 @@
             }
 
             copybit_device_t* getBlitEngine() const;
-            overlay_device_t* getOverlayEngine() const;
+            overlay_control_device_t* getOverlayEngine() const;
             
 private:
     friend class BClient;
@@ -382,24 +382,16 @@
 
 // ---------------------------------------------------------------------------
 
-class FreezeLock {
+class FreezeLock : public LightRefBase<FreezeLock> {
     SurfaceFlinger* mFlinger;
-    mutable volatile int32_t mCount;
 public:
     FreezeLock(SurfaceFlinger* flinger)
-        : mFlinger(flinger), mCount(0) {
+        : mFlinger(flinger) {
         mFlinger->incFreezeCount();
     }
     ~FreezeLock() {
         mFlinger->decFreezeCount();
     }
-    inline void incStrong(void*) const {
-        android_atomic_inc(&mCount);
-    }
-    inline void decStrong(void*) const {
-        if (android_atomic_dec(&mCount) == 1)
-             delete this;
-    }
 };
 
 // ---------------------------------------------------------------------------
diff --git a/libs/surfaceflinger/Transform.h b/libs/surfaceflinger/Transform.h
index 2f617c4..0b4835e 100644
--- a/libs/surfaceflinger/Transform.h
+++ b/libs/surfaceflinger/Transform.h
@@ -25,7 +25,7 @@
 
 #include <GLES/gl.h>
 
-#include <corecg/SkMatrix.h>
+#include <core/SkMatrix.h>
 
 namespace android {