[PDF] Fix clipping in xfermode improvement.

src/pdf/SkPDFDevice.cpp

Index: src/pdf/SkPDFDevice.cpp
diff --git a/src/pdf/SkPDFDevice.cpp b/src/pdf/SkPDFDevice.cpp
index cdfec330f0888330d7ae6ff1e055019fa597e851..6625a8e701c10c7db14558d4b2a2bee321f0e40f 100644
--- a/src/pdf/SkPDFDevice.cpp
+++ b/src/pdf/SkPDFDevice.cpp
@@ -1912,8 +1912,10 @@ void SkPDFDevice::finishContentEntry(SkXfermode::Mode xfermode,
     ContentEntry* contentEntries = getContentEntries()->get();
     SkASSERT(dst);
     SkASSERT(!contentEntries->fNext.get());
-    // We have to make a copy of these here because changing the current
-    // content into a form-xobject will destroy them.
+    // Changing the current content into a form-xobject will destroy the clip
+    // objects which is fine since the xobject will already be clipped. However
+    // if source has shape, we need to clip it too, so a copy of the clip is
+    // saved.
     SkClipStack clipStack = contentEntries->fState.fClipStack;
     SkRegion clipRegion = contentEntries->fState.fClipRegion;
 
@@ -1930,7 +1932,8 @@ void SkPDFDevice::finishContentEntry(SkXfermode::Mode xfermode,
         // reduces to Dst.
         if (shape == NULL || xfermode == SkXfermode::kDstOut_Mode ||
                 xfermode == SkXfermode::kSrcATop_Mode) {
-            ScopedContentEntry content(this, &clipStack, clipRegion, identity,
+            ScopedContentEntry content(this, &fExistingClipStack,
+                                       fExistingClipRegion, identity,
                                        stockPaint);
             SkPDFUtils::DrawFormXObject(this->addXObjectResource(dst),
                                         &content.entry()->fContent);
@@ -1951,7 +1954,7 @@ void SkPDFDevice::finishContentEntry(SkXfermode::Mode xfermode,
         // the non-transparent parts of the device and the outlines (shape) of
         // all images and devices drawn.
         drawFormXObjectWithMask(addXObjectResource(srcFormXObject.get()), dst,
-                                &clipStack, clipRegion,
+                                &fExistingClipStack, fExistingClipRegion,
                                 SkXfermode::kSrcOver_Mode, true);
     } else {
         SkAutoTUnref<SkPDFFormXObject> dstMaskStorage;
@@ -1970,16 +1973,17 @@ void SkPDFDevice::finishContentEntry(SkXfermode::Mode xfermode,
             dstMaskStorage.reset(createFormXObjectFromDevice());
             dstMask = dstMaskStorage.get();
         }
-        drawFormXObjectWithMask(addXObjectResource(dst), dstMask, &clipStack,
-                                clipRegion, SkXfermode::kSrcOver_Mode, true);
+        drawFormXObjectWithMask(addXObjectResource(dst), dstMask,
+                                &fExistingClipStack, fExistingClipRegion,
+                                SkXfermode::kSrcOver_Mode, true);
     }
 
     if (xfermode == SkXfermode::kClear_Mode) {
         return;
     } else if (xfermode == SkXfermode::kSrc_Mode ||
             xfermode == SkXfermode::kDstATop_Mode) {
-        ScopedContentEntry content(this, &clipStack, clipRegion, identity,
-                                   stockPaint);
+        ScopedContentEntry content(this, &fExistingClipStack,
+                                   fExistingClipRegion, identity, stockPaint);
         if (content.entry()) {
             SkPDFUtils::DrawFormXObject(
                     this->addXObjectResource(srcFormXObject.get()),
@@ -1989,8 +1993,8 @@ void SkPDFDevice::finishContentEntry(SkXfermode::Mode xfermode,
             return;
         }
     } else if (xfermode == SkXfermode::kSrcATop_Mode) {
-        ScopedContentEntry content(this, &clipStack, clipRegion, identity,
-                                   stockPaint);
+        ScopedContentEntry content(this, &fExistingClipStack,
+                                   fExistingClipRegion, identity, stockPaint);
         if (content.entry()) {
             SkPDFUtils::DrawFormXObject(this->addXObjectResource(dst),
                                         &content.entry()->fContent);
@@ -2005,30 +2009,24 @@ void SkPDFDevice::finishContentEntry(SkXfermode::Mode xfermode,
              xfermode == SkXfermode::kDstATop_Mode ||
              xfermode == SkXfermode::kModulate_Mode);
 
-    ScopedContentEntry inShapeContentEntry(this, &fExistingClipStack,

[vandebo (ex-Chrome), 2013/12/17 23:11:03]

This was dead code - inShapeContentEntry is not used.

-                                           fExistingClipRegion, identity,
-                                           stockPaint);
-    if (!inShapeContentEntry.entry()) {

[vandebo (ex-Chrome), 2013/12/17 23:11:03]

This can't be true because fExistingClipRegion is not empty and xfermode is
SrcOver.

-        return;
-    }
-
     if (xfermode == SkXfermode::kSrcIn_Mode ||
             xfermode == SkXfermode::kSrcOut_Mode ||
             xfermode == SkXfermode::kSrcATop_Mode) {
         drawFormXObjectWithMask(addXObjectResource(srcFormXObject.get()), dst,
-                                &clipStack, clipRegion,
+                                &fExistingClipStack, fExistingClipRegion,
                                 SkXfermode::kSrcOver_Mode,
                                 xfermode == SkXfermode::kSrcOut_Mode);
     } else {
         SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode;
         if (xfermode == SkXfermode::kModulate_Mode) {
             drawFormXObjectWithMask(addXObjectResource(srcFormXObject.get()),
-                                    dst, &clipStack, clipRegion,
+                                    dst, &fExistingClipStack,
+                                    fExistingClipRegion,
                                     SkXfermode::kSrcOver_Mode, false);
             mode = SkXfermode::kMultiply_Mode;
         }
         drawFormXObjectWithMask(addXObjectResource(dst), srcFormXObject.get(),
-                                &clipStack, clipRegion, mode,
+                                &fExistingClipStack, fExistingClipRegion, mode,
                                 xfermode == SkXfermode::kDstOut_Mode);
     }
 }