WIP RasterCanvasLayerAllocator

src/core/SkCanvas.cpp

Index: src/core/SkCanvas.cpp
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 4150a9a55b663584879600346610b2d042259824..90b1562ac56afe6382a4e4ff0c1a8934293bd722 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -25,6 +25,7 @@
 #include "SkPaintPriv.h"
 #include "SkPatchUtils.h"
 #include "SkPicture.h"
+#include "SkRasterCanvasLayerAllocator.h"
 #include "SkRasterClip.h"
 #include "SkReadPixelsRec.h"
 #include "SkRRect.h"
@@ -196,6 +197,8 @@ struct DeviceCM {
     SkRasterClip        fClip;
     SkPaint*            fPaint; // may be null (in the future)
     const SkMatrix*     fMatrix;
+    SkRasterCanvasLayerAllocator* fAllocator;
+    void*               fNativeContext;
     SkMatrix            fMatrixStorage;
     SkMatrix            fStashedMatrix; // original CTM; used by imagefilter in saveLayer
     const bool          fDeviceIsBitmapDevice;
@@ -204,6 +207,8 @@ struct DeviceCM {
              bool conservativeRasterClip, bool deviceIsBitmapDevice, const SkMatrix& stashed)
         : fNext(nullptr)
         , fClip(conservativeRasterClip)
+        , fAllocator(nullptr)
+        , fNativeContext(nullptr)
         , fStashedMatrix(stashed)
         , fDeviceIsBitmapDevice(deviceIsBitmapDevice)
     {
@@ -217,6 +222,10 @@ struct DeviceCM {
 
     ~DeviceCM() {
         if (fDevice) {
+            if (fAllocator) {
+                fAllocator->free(fDevice->accessBitmap(false).getPixels(),
+                                 fNativeContext);
+            }
             fDevice->onDetachFromCanvas();
             fDevice->unref();
         }
@@ -643,7 +652,8 @@ void SkCanvas::resetForNextPicture(const SkIRect& bounds) {
     static_cast<SkBitmapDevice*>(fMCRec->fLayer->fDevice)->setNewSize(bounds.size());
 }
 
-SkBaseDevice* SkCanvas::init(SkBaseDevice* device, InitFlags flags) {
+SkBaseDevice* SkCanvas::init(SkBaseDevice* device, InitFlags flags,
+                             sk_sp<SkRasterCanvasLayerAllocator> allocator) {
     if (device && device->forceConservativeRasterClip()) {
         flags = InitFlags(flags | kConservativeRasterClip_InitFlag);
     }
@@ -672,6 +682,8 @@ SkBaseDevice* SkCanvas::init(SkBaseDevice* device, InitFlags flags) {
     fMCRec->fTopLayer = fMCRec->fLayer;
 
     fSurfaceBase = nullptr;
+    fAllocator = allocator;
+    fMCRec->fLayer->fAllocator = allocator.get();
 
     if (device) {
         // The root device and the canvas should always have the same pixel geometry
@@ -690,7 +702,7 @@ SkCanvas::SkCanvas()
 {
     inc_canvas();
 
-    this->init(nullptr, kDefault_InitFlags);
+    this->init(nullptr, kDefault_InitFlags, nullptr);
 }
 
 static SkBitmap make_nopixels(int width, int height) {
@@ -720,7 +732,7 @@ SkCanvas::SkCanvas(int width, int height, const SkSurfaceProps* props)
     inc_canvas();
 
     this->init(new SkNoPixelsBitmapDevice(SkIRect::MakeWH(width, height), fProps),
-               kDefault_InitFlags)->unref();
+               kDefault_InitFlags, nullptr)->unref();
 }
 
 SkCanvas::SkCanvas(const SkIRect& bounds, InitFlags flags)
@@ -730,7 +742,8 @@ SkCanvas::SkCanvas(const SkIRect& bounds, InitFlags flags)
 {
     inc_canvas();
 
-    this->init(new SkNoPixelsBitmapDevice(bounds, fProps), flags)->unref();
+    this->init(new SkNoPixelsBitmapDevice(bounds, fProps), flags,
+               nullptr)->unref();
 }
 
 SkCanvas::SkCanvas(SkBaseDevice* device)
@@ -740,7 +753,7 @@ SkCanvas::SkCanvas(SkBaseDevice* device)
 {
     inc_canvas();
 
-    this->init(device, kDefault_InitFlags);
+    this->init(device, kDefault_InitFlags, nullptr);
 }
 
 SkCanvas::SkCanvas(SkBaseDevice* device, InitFlags flags)
@@ -750,7 +763,7 @@ SkCanvas::SkCanvas(SkBaseDevice* device, InitFlags flags)
 {
     inc_canvas();
 
-    this->init(device, flags);
+    this->init(device, flags, nullptr);
 }
 
 SkCanvas::SkCanvas(const SkBitmap& bitmap, const SkSurfaceProps& props)
@@ -761,7 +774,7 @@ SkCanvas::SkCanvas(const SkBitmap& bitmap, const SkSurfaceProps& props)
     inc_canvas();
 
     SkAutoTUnref<SkBaseDevice> device(new SkBitmapDevice(bitmap, fProps));
-    this->init(device, kDefault_InitFlags);
+    this->init(device, kDefault_InitFlags, nullptr);
 }
 
 SkCanvas::SkCanvas(const SkBitmap& bitmap)
@@ -772,7 +785,22 @@ SkCanvas::SkCanvas(const SkBitmap& bitmap)
     inc_canvas();
 
     SkAutoTUnref<SkBaseDevice> device(new SkBitmapDevice(bitmap, fProps));
-    this->init(device, kDefault_InitFlags);
+    this->init(device, kDefault_InitFlags, nullptr);
+}
+
+SkCanvas::SkCanvas(const SkBitmap& bitmap,
+                   sk_sp<SkRasterCanvasLayerAllocator> allocator)
+    : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage))
+    , fProps(SkSurfaceProps::kLegacyFontHost_InitType)
+    , fConservativeRasterClip(false)
+{
+    inc_canvas();
+
+    SkAutoTUnref<SkBaseDevice> device(new SkBitmapDevice(bitmap, fProps));
+    this->init(device, kDefault_InitFlags, allocator);
+    // TODO(tomhudson): this is circuitous, wasteful, and ugly to boot
+    this->fMCRec->fLayer->fNativeContext =
+        allocator->getNativeContext(this->accessTopLayerPixels(nullptr, nullptr));
 }
 
 SkCanvas::~SkCanvas() {
@@ -1275,7 +1303,7 @@ void SkCanvas::internalSaveLayer(const SaveLayerRec& rec, SaveLayerStrategy stra
         const SkBaseDevice::TileUsage usage = SkBaseDevice::kNever_TileUsage;
         const SkBaseDevice::CreateInfo createInfo = SkBaseDevice::CreateInfo(info, usage, geo,
                                                                             preserveLCDText, false);
-        SkBaseDevice* newDev = device->onCreateDevice(createInfo, paint);
+        SkBaseDevice* newDev = device->onCreateDevice(createInfo, paint, fAllocator.get());
         if (nullptr == newDev) {
             // If onCreateDevice didn't succeed, try raster (e.g. PDF couldn't handle the paint)
             const SkSurfaceProps surfaceProps(fProps.flags(), createInfo.fPixelGeometry);
@@ -1300,6 +1328,10 @@ void SkCanvas::internalSaveLayer(const SaveLayerRec& rec, SaveLayerStrategy stra
     device->unref();
 
     layer->fNext = fMCRec->fTopLayer;
+    layer->fAllocator = fAllocator.get();
+    layer->fNativeContext = fAllocator
+        ? fAllocator->getNativeContext(device->accessBitmap(false).getPixels())
+        : nullptr;
     fMCRec->fLayer = layer;
     fMCRec->fTopLayer = layer;    // this field is NOT an owner of layer
 }
@@ -1324,6 +1356,7 @@ void SkCanvas::internalRestore() {
 
     // reserve our layer (if any)
     DeviceCM* layer = fMCRec->fLayer;   // may be null
+
     // now detach it from fMCRec so we can pop(). Gets freed after its drawn
     fMCRec->fLayer = nullptr;
 
@@ -1337,6 +1370,7 @@ void SkCanvas::internalRestore() {
         recorder will have already recorded the restore).
     */
     if (layer) {
+        SkASSERT(layer->fAllocator == fAllocator.get());
         if (layer->fNext) {
             const SkIPoint& origin = layer->fDevice->getOrigin();
             this->internalDrawDevice(layer->fDevice, origin.x(), origin.y(),
@@ -1767,6 +1801,11 @@ void SkCanvas::replayClips(ClipVisitor* visitor) const {
     }
 }
 
+void* SkCanvas::getTopLayerNative() const {
+    return fMCRec->fLayer->fNativeContext;
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 
 bool SkCanvas::isClipEmpty() const {