enable conservative raster clipping

src/core/SkCanvas.cpp

Index: src/core/SkCanvas.cpp
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 7d71ffb13bdd573ea0b014e66975e4c81de9393b..895d36fe8c57d696a1effcff290fcd7608ed1a0d 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -627,7 +627,13 @@ void SkCanvas::resetForNextPicture(const SkIRect& bounds) {
 }
 
 SkBaseDevice* SkCanvas::init(SkBaseDevice* device, InitFlags flags) {
-    fConservativeRasterClip = SkToBool(flags & kConservativeRasterClip_InitFlag);
+    if (device && device->forceConservativeRasterClip()) {
+        flags = InitFlags(flags | kConservativeRasterClip_InitFlag);
+    }

[robertphillips, 2015/11/20 19:45:47]

Why don't we just do this inside the above else:

*const_cast<bool*>(&fConservativeRasterClip) = true;

?

[reed1, 2015/11/20 20:46:34]

doesn't seem smaller or clearer (to me) since it presumes that no one else will
ever look at flags (since it will now be "out of date" with the true sense...
(assuming your proposal is to replace the bit-or with assign=true)

+    // Since init() is only called once by our constructors, it is safe to perform this
+    // const-cast.
+    *const_cast<bool*>(&fConservativeRasterClip) = SkToBool(flags & kConservativeRasterClip_InitFlag);
+
     fCachedLocalClipBounds.setEmpty();
     fCachedLocalClipBoundsDirty = true;
     fAllowSoftClip = true;
@@ -652,9 +658,6 @@ SkBaseDevice* SkCanvas::init(SkBaseDevice* device, InitFlags flags) {
     if (device) {
         // The root device and the canvas should always have the same pixel geometry
         SkASSERT(fProps.pixelGeometry() == device->surfaceProps().pixelGeometry());
-        if (device->forceConservativeRasterClip()) {
-            fConservativeRasterClip = true;
-        }
         device->onAttachToCanvas(this);
         fMCRec->fLayer->fDevice = SkRef(device);
         fMCRec->fRasterClip.setRect(device->getGlobalBounds());
@@ -665,6 +668,7 @@ SkBaseDevice* SkCanvas::init(SkBaseDevice* device, InitFlags flags) {
 SkCanvas::SkCanvas()
     : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage))
     , fProps(SkSurfaceProps::kLegacyFontHost_InitType)
+    , fConservativeRasterClip(false)
 {
     inc_canvas();
 
@@ -693,6 +697,7 @@ private:
 SkCanvas::SkCanvas(int width, int height, const SkSurfaceProps* props)
     : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage))
     , fProps(SkSurfacePropsCopyOrDefault(props))
+    , fConservativeRasterClip(false)
 {
     inc_canvas();
 
@@ -703,6 +708,7 @@ SkCanvas::SkCanvas(int width, int height, const SkSurfaceProps* props)
 SkCanvas::SkCanvas(const SkIRect& bounds, InitFlags flags)
     : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage))
     , fProps(SkSurfaceProps::kLegacyFontHost_InitType)
+    , fConservativeRasterClip(false)
 {
     inc_canvas();
 
@@ -712,6 +718,7 @@ SkCanvas::SkCanvas(const SkIRect& bounds, InitFlags flags)
 SkCanvas::SkCanvas(SkBaseDevice* device)
     : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage))
     , fProps(device->surfaceProps())
+    , fConservativeRasterClip(false)
 {
     inc_canvas();
 
@@ -721,6 +728,7 @@ SkCanvas::SkCanvas(SkBaseDevice* device)
 SkCanvas::SkCanvas(SkBaseDevice* device, InitFlags flags)
     : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage))
     , fProps(device->surfaceProps())
+    , fConservativeRasterClip(false)
 {
     inc_canvas();
 
@@ -730,6 +738,7 @@ SkCanvas::SkCanvas(SkBaseDevice* device, InitFlags flags)
 SkCanvas::SkCanvas(const SkBitmap& bitmap, const SkSurfaceProps& props)
     : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage))
     , fProps(props)
+    , fConservativeRasterClip(false)
 {
     inc_canvas();
 
@@ -740,6 +749,7 @@ SkCanvas::SkCanvas(const SkBitmap& bitmap, const SkSurfaceProps& props)
 SkCanvas::SkCanvas(const SkBitmap& bitmap)
     : fMCStack(sizeof(MCRec), fMCRecStorage, sizeof(fMCRecStorage))
     , fProps(SkSurfaceProps::kLegacyFontHost_InitType)
+    , fConservativeRasterClip(false)
 {
     inc_canvas();