Expose FillBounds to allow GrPictureUtils::CollectLayers to be layered on top of it

src/core/SkRecordDraw.h

Index: src/core/SkRecordDraw.h
diff --git a/src/core/SkRecordDraw.h b/src/core/SkRecordDraw.h
index f3f00881ea69b2cb1be5892c6935a2b5d16df577..c38447b1ed10b7e096ae1792d6526c999bc0d18c 100644
--- a/src/core/SkRecordDraw.h
+++ b/src/core/SkRecordDraw.h
@@ -12,6 +12,7 @@
 #include "SkCanvas.h"
 #include "SkDrawPictureCallback.h"
 #include "SkMatrix.h"
+#include "SkPatchUtils.h"
 #include "SkRecord.h"
 
 // Fill a BBH to be used by SkRecordDraw to accelerate playback.
@@ -74,6 +75,278 @@ private:
     typedef Draw INHERITED;
 };
 
+// This is an SkRecord visitor that fills an SkBBoxHierarchy.
+//
+// The interesting part here is how to calculate bounds for ops which don't
+// have intrinsic bounds.  What is the bounds of a Save or a Translate?
+//
+// We answer this by thinking about a particular definition of bounds: if I
+// don't execute this op, pixels in this rectangle might draw incorrectly.  So
+// the bounds of a Save, a Translate, a Restore, etc. are the union of the
+// bounds of Draw* ops that they might have an effect on.  For any given
+// Save/Restore block, the bounds of the Save, the Restore, and any other
+// non-drawing ("control") ops inside are exactly the union of the bounds of
+// the drawing ops inside that block.
+//
+// To implement this, we keep a stack of active Save blocks.  As we consume ops
+// inside the Save/Restore block, drawing ops are unioned with the bounds of
+// the block, and control ops are stashed away for later.  When we finish the
+// block with a Restore, our bounds are complete, and we go back and fill them
+// in for all the control ops we stashed away.
+class FillBounds : SkNoncopyable {
+public:
+    FillBounds(const SkRect& cullRect, const SkRecord& record, SkBBoxHierarchy* bbh);
+
+    void setCurrentOp(unsigned currentOp) { fCurrentOp = currentOp; }
+    void cleanUp();
+
+    template <typename T> void operator()(const T& op) {
+        this->updateCTM(op);
+        this->updateClipBounds(op);
+        this->trackBounds(op);
+    }
+
+    // In FillBounds, SkRect are in local coordinates, Bounds are translated back to identity space.
+    typedef SkRect Bounds;
+
+    unsigned currentOp() const { return fCurrentOp;  }
+    const SkMatrix& ctm() const { return *fCTM; }
+    const Bounds& currentClipBounds() const { return fCurrentClipBounds; }
+
+    Bounds adjustAndMap(SkRect rect, const SkPaint* paint) const;
+    const Bounds& getBounds(unsigned index) const { return fBounds[index]; }
+
+private:
+    struct SaveBounds {
+        int controlOps;        // Number of control ops in this Save block, including the Save.
+        Bounds bounds;         // Bounds of everything in the block.
+        const SkPaint* paint;  // Unowned.  If set, adjusts the bounds of all ops in this block.
+    };
+
+    static void AdjustTextForFontMetrics(SkRect* rect, const SkPaint& paint);
+
+    template <typename T> void updateCTM(const T&) {}
+    template <typename T> void updateClipBounds(const T&) {}
+    template <typename T> void trackBounds(const T& op) {
+        fBounds[fCurrentOp] = this->bounds(op);
+        this->updateSaveBounds(fBounds[fCurrentOp]);
+    }
+    template <typename T> Bounds bounds(const T&) const;
+
+    void updateClipBoundsForClipOp(const SkIRect& devBounds);
+
+    void pushSaveBlock(const SkPaint* paint);
+    Bounds popSaveBlock();
+    void pushControl();
+    void popControl(const Bounds& bounds);
+    void updateSaveBounds(const Bounds& bounds);
+
+    bool adjustForSaveLayerPaints(SkRect* rect, int savesToIgnore = 0) const;
+
+    const unsigned int fNumRecords;
+
+    // The BBH being filled in
+    SkBBoxHierarchy* fBBH;
+
+    // We do not guarantee anything for operations outside of the cull rect
+    const SkRect fCullRect;
+
+    // Conservative identity-space bounds for each op in the SkRecord.
+    SkAutoTMalloc<Bounds> fBounds;
+
+    // We walk fCurrentOp through the SkRecord, as we go using updateCTM()
+    // and updateClipBounds() to maintain the exact CTM (fCTM) and conservative
+    // identity-space bounds of the current clip (fCurrentClipBounds).
+    unsigned fCurrentOp;
+    const SkMatrix* fCTM;
+    Bounds fCurrentClipBounds;
+
+    // Used to track the bounds of Save/Restore blocks and the control ops inside them.
+    SkTDArray<SaveBounds> fSaveStack;
+    SkTDArray<unsigned>   fControlIndices;
+};
+
+// Only Restore and SetMatrix change the CTM.
+template <> inline void FillBounds::updateCTM(const Restore& op)   { fCTM = &op.matrix; }
+template <> inline void FillBounds::updateCTM(const SetMatrix& op) { fCTM = &op.matrix; }
+
+// Clip{Path,RRect,Rect,Region} obviously change the clip.  They all know their bounds already.
+template <> inline void FillBounds::updateClipBounds(const ClipPath&   op) { this->updateClipBoundsForClipOp(op.devBounds); }
+template <> inline void FillBounds::updateClipBounds(const ClipRRect&  op) { this->updateClipBoundsForClipOp(op.devBounds); }
+template <> inline void FillBounds::updateClipBounds(const ClipRect&   op) { this->updateClipBoundsForClipOp(op.devBounds); }
+template <> inline void FillBounds::updateClipBounds(const ClipRegion& op) { this->updateClipBoundsForClipOp(op.devBounds); }
+
+// Restore holds the devBounds for the clip after the {save,saveLayer}/restore block completes.
+template <> inline void FillBounds::updateClipBounds(const Restore& op) {
+    // This is just like the clip ops above, but we need to skip the effects (if any) of our
+    // paired saveLayer (if it is one); it has not yet been popped off the save stack.  Our
+    // devBounds reflect the state of the world after the saveLayer/restore block is done,
+    // so they are not affected by the saveLayer's paint.
+    const int kSavesToIgnore = 1;
+    Bounds clip = SkRect::Make(op.devBounds);
+    fCurrentClipBounds =
+        this->adjustForSaveLayerPaints(&clip, kSavesToIgnore) ? clip : fCullRect;
+}
+
+// We also take advantage of SaveLayer bounds when present to further cut the clip down.
+template <> inline void FillBounds::updateClipBounds(const SaveLayer& op)  {
+    if (op.bounds) {
+        // adjustAndMap() intersects these layer bounds with the previous clip for us.
+        fCurrentClipBounds = this->adjustAndMap(*op.bounds, op.paint);
+    }
+}
+
+template <> inline void FillBounds::trackBounds(const Save&)          { this->pushSaveBlock(NULL); }
+template <> inline void FillBounds::trackBounds(const SaveLayer& op)  { this->pushSaveBlock(op.paint); }
+template <> inline void FillBounds::trackBounds(const Restore&) { fBounds[fCurrentOp] = this->popSaveBlock(); }
+
+template <> inline void FillBounds::trackBounds(const SetMatrix&)         { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const ClipRect&)          { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const ClipRRect&)         { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const ClipPath&)          { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const ClipRegion&)        { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const PushCull&)          { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const PopCull&)           { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const BeginCommentGroup&) { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const AddComment&)        { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const EndCommentGroup&)   { this->pushControl(); }
+template <> inline void FillBounds::trackBounds(const DrawData&)          { this->pushControl(); }
+
+// FIXME: this method could use better bounds
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawText&) const { return fCurrentClipBounds; }
+
+template <> inline FillBounds::Bounds FillBounds::bounds(const Clear&) const { return fCullRect; }      // Ignores the clip.
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawPaint&) const { return fCurrentClipBounds; }
+template <> inline FillBounds::Bounds FillBounds::bounds(const NoOp&)  const { return Bounds::MakeEmpty(); }    // NoOps don't draw.
+
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawSprite& op) const {
+    // Ignores the matrix.
+    const SkBitmap& bm = op.bitmap;
+    return Bounds::MakeXYWH(SkIntToScalar(op.left), SkIntToScalar(op.top), 
+                            SkIntToScalar(bm.width()), SkIntToScalar(bm.height()));
+}
+
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawRect& op) const { return this->adjustAndMap(op.rect, &op.paint); }
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawOval& op) const { return this->adjustAndMap(op.oval, &op.paint); }
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawRRect& op) const {
+    return this->adjustAndMap(op.rrect.rect(), &op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawDRRect& op) const {
+    return this->adjustAndMap(op.outer.rect(), &op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawImage& op) const {
+    const SkImage* image = op.image;
+    SkRect rect = SkRect::MakeXYWH(SkIntToScalar(op.left), SkIntToScalar(op.top), 
+                                   SkIntToScalar(image->width()), SkIntToScalar(image->height()));
+
+    return this->adjustAndMap(rect, op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawImageRect& op) const {
+    return this->adjustAndMap(op.dst, op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawBitmapRectToRect& op) const {
+    return this->adjustAndMap(op.dst, op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawBitmapNine& op) const {
+    return this->adjustAndMap(op.dst, op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawBitmap& op) const {
+    const SkBitmap& bm = op.bitmap;
+    return this->adjustAndMap(SkRect::MakeXYWH(SkIntToScalar(op.left), 
+                                               SkIntToScalar(op.top), 
+                                               SkIntToScalar(bm.width()), 
+                                               SkIntToScalar(bm.height())),
+                              op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawBitmapMatrix& op) const {
+    const SkBitmap& bm = op.bitmap;
+    SkRect dst = SkRect::MakeWH(SkIntToScalar(bm.width()), 
+                                SkIntToScalar(bm.height()));
+    op.matrix.mapRect(&dst);
+    return this->adjustAndMap(dst, op.paint);
+}
+
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawPath& op) const {
+    return op.path.isInverseFillType() ? fCurrentClipBounds
+                                       : this->adjustAndMap(op.path.getBounds(), &op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawPoints& op) const {
+    SkRect dst;
+    dst.set(op.pts, op.count);
+
+    // Pad the bounding box a little to make sure hairline points' bounds aren't empty.
+    SkScalar stroke = SkMaxScalar(op.paint.getStrokeWidth(), 0.01f);
+    dst.outset(stroke/2, stroke/2);
+
+    return this->adjustAndMap(dst, &op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawPatch& op) const {
+    SkRect dst;
+    dst.set(op.cubics, SkPatchUtils::kNumCtrlPts);
+    return this->adjustAndMap(dst, &op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawVertices& op) const {
+    SkRect dst;
+    dst.set(op.vertices, op.vertexCount);
+    return this->adjustAndMap(dst, &op.paint);
+}
+
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawPicture& op) const {
+    SkRect dst = op.picture->cullRect();
+    if (op.matrix) {
+        op.matrix->mapRect(&dst);
+    }
+    return this->adjustAndMap(dst, op.paint);
+}
+
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawPosText& op) const {
+    const int N = op.paint.countText(op.text, op.byteLength);
+    if (N == 0) {
+        return Bounds::MakeEmpty();
+    }
+
+    SkRect dst;
+    dst.set(op.pos, N);
+    AdjustTextForFontMetrics(&dst, op.paint);
+    return this->adjustAndMap(dst, &op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawPosTextH& op) const {
+    const int N = op.paint.countText(op.text, op.byteLength);
+    if (N == 0) {
+        return Bounds::MakeEmpty();
+    }
+
+    SkScalar left = op.xpos[0], right = op.xpos[0];
+    for (int i = 1; i < N; i++) {
+        left  = SkMinScalar(left,  op.xpos[i]);
+        right = SkMaxScalar(right, op.xpos[i]);
+    }
+    SkRect dst = { left, op.y, right, op.y };
+    AdjustTextForFontMetrics(&dst, op.paint);
+    return this->adjustAndMap(dst, &op.paint);
+}
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawTextOnPath& op) const {
+    SkRect dst = op.path.getBounds();
+
+    // Pad all sides by the maximum padding in any direction we'd normally apply.
+    SkRect pad = { 0, 0, 0, 0};
+    AdjustTextForFontMetrics(&pad, op.paint);
+
+    // That maximum padding happens to always be the right pad today.
+    SkASSERT(pad.fLeft == -pad.fRight);
+    SkASSERT(pad.fTop  == -pad.fBottom);
+    SkASSERT(pad.fRight > pad.fBottom);
+    dst.outset(pad.fRight, pad.fRight);
+
+    return this->adjustAndMap(dst, &op.paint);
+}
+
+template <> inline FillBounds::Bounds FillBounds::bounds(const DrawTextBlob& op) const {
+    SkRect dst = op.blob->bounds();
+    dst.offset(op.x, op.y);
+    return this->adjustAndMap(dst, &op.paint);
+}
+
 }  // namespace SkRecords
 
 #endif//SkRecordDraw_DEFINED