SkPDF: simplify PathOp code, emit empty clips.

BUG=skia:772685
Change-Id: Ia658551cadcfeb2777f4a6727b48ec9d9fc22dd8
Reviewed-on: https://skia-review.googlesource.com/113462
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Hal Canary <halcanary@google.com>

1 files changed, 12 insertions, 54 deletions

diff --git a/src/pdf/SkPDFDevice.cpp b/src/pdf/SkPDFDevice.cpp
index 91f170d194..01bd0a661e 100644
--- a/src/pdf/SkPDFDevice.cpp
+++ b/src/pdf/SkPDFDevice.cpp
@@ -209,8 +209,7 @@ public:
         fEntries[0].fClipStack = existingClipStack;
     }
 
-    void updateClip(const SkClipStack& clipStack,
-                    const SkPoint& translation, const SkRect& bounds);
+    void updateClip(const SkClipStack& clipStack, const SkIRect& bounds);
     void updateMatrix(const SkMatrix& matrix);
     void updateDrawingState(const SkPDFDevice::GraphicStateEntry& state);
 
@@ -283,56 +282,11 @@ bool apply_clip(SkClipOp op, const SkPath& u, const SkPath& v, SkPath* r)  {
     }
 }
 
-/* Uses Path Ops to calculate a vector SkPath clip from a clip stack.
- * Returns true if successful, or false if not successful.
- * If successful, the resulting clip is stored in outClipPath.
- * If not successful, outClipPath is undefined, and a fallback method
- * should be used.
- */
-static bool get_clip_stack_path(const SkMatrix& transform,
-                                const SkClipStack& clipStack,
-                                const SkRect& bounds,
-                                SkPath* outClipPath) {
-    outClipPath->reset();
-    outClipPath->setFillType(SkPath::kInverseWinding_FillType);
-
-    const SkClipStack::Element* clipEntry;
-    SkClipStack::Iter iter;
-    iter.reset(clipStack, SkClipStack::Iter::kBottom_IterStart);
-    for (clipEntry = iter.next(); clipEntry; clipEntry = iter.next()) {
-        SkPath entryPath;
-        if (SkClipStack::Element::DeviceSpaceType::kEmpty == clipEntry->getDeviceSpaceType()) {
-            outClipPath->reset();
-            outClipPath->setFillType(SkPath::kInverseWinding_FillType);
-            continue;
-        } else {
-            clipEntry->asDeviceSpacePath(&entryPath);
-        }
-        entryPath.transform(transform);
-        if (!apply_clip(clipEntry->getOp(), *outClipPath, entryPath, outClipPath)) {
-            return false;
-        }
-    }
-
-    if (outClipPath->isInverseFillType()) {
-        // The bounds are slightly outset to ensure this is correct in the
-        // face of floating-point accuracy and possible SkRegion bitmap
-        // approximations.
-        SkRect clipBounds = bounds;
-        clipBounds.outset(SK_Scalar1, SK_Scalar1);
-        if (!calculate_inverse_path(clipBounds, *outClipPath, outClipPath)) {
-            return false;
-        }
-    }
-    return true;
-}
-
 // TODO(vandebo): Take advantage of SkClipStack::getSaveCount(), the PDF
 // graphic state stack, and the fact that we can know all the clips used
 // on the page to optimize this.
 void GraphicStackState::updateClip(const SkClipStack& clipStack,
-                                   const SkPoint& translation,
-                                   const SkRect& bounds) {
+                                   const SkIRect& bounds) {
     if (clipStack == currentEntry()->fClipStack) {
         return;
     }
@@ -347,11 +301,16 @@ void GraphicStackState::updateClip(const SkClipStack& clipStack,
 
     currentEntry()->fClipStack = clipStack;
 
-    SkMatrix transform;
-    transform.setTranslate(translation.fX, translation.fY);
-
     SkPath clipPath;
-    if (get_clip_stack_path(transform, clipStack, bounds, &clipPath)) {
+    (void)clipStack.asPath(&clipPath);
+
+    // The bounds are slightly outset to ensure this is correct in the
+    // face of floating-point accuracy and possible SkRegion bitmap
+    // approximations.
+    SkPath clipBoundsPath;
+    clipBoundsPath.addRect(SkRect::Make(bounds.makeOutset(1, 1)));
+
+    if (Op(clipPath, clipBoundsPath, kIntersect_SkPathOp, &clipPath)) {
         SkPDFUtils::EmitPath(clipPath, SkPaint::kFill_Style, fContentStream);
         SkPath::FillType clipFill = clipPath.getFillType();
         NOT_IMPLEMENTED(clipFill == SkPath::kInverseEvenOdd_FillType, false);
@@ -1776,8 +1735,7 @@ std::unique_ptr<SkStreamAsset> SkPDFDevice::content() const {
 
     GraphicStackState gsState(fExistingClipStack, &buffer);
     for (const auto& entry : fContentEntries) {
-        gsState.updateClip(entry.fState.fClipStack,
-                {0, 0}, SkRect::Make(this->bounds()));
+        gsState.updateClip(entry.fState.fClipStack, this->bounds());
         gsState.updateMatrix(entry.fState.fMatrix);
         gsState.updateDrawingState(entry.fState);