Make GrShape capable of representing inverse filled rrects.

src/gpu/GrShape.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrShape.h"
 
 GrShape& GrShape::operator=(const GrShape& that) {
     bool wasPath = Type::kPath == fType;
     fStyle = that.fStyle;
     fType = that.fType;
     switch (fType) {
         case Type::kEmpty:
             if (wasPath) {
                 fPath.reset();
             }
             break;
         case Type::kRRect:
             if (wasPath) {
                 fPath.reset();
             }
             fRRect = that.fRRect;
             fRRectDir = that.fRRectDir;
             fRRectStart = that.fRRectStart;
+            fRRectIsInverted = that.fRRectIsInverted;
             break;
         case Type::kPath:
             if (wasPath) {
                 *fPath.get() = *that.fPath.get();
             } else {
                 fPath.set(*that.fPath.get());
             }
             break;
     }
     fInheritedKey.reset(that.fInheritedKey.count());
@@ skipping 27 matching lines @@
 int GrShape::unstyledKeySize() const {
     if (fInheritedKey.count()) {
         return fInheritedKey.count();
     }
     switch (fType) {
         case Type::kEmpty:
             return 1;
         case Type::kRRect:
             SkASSERT(!fInheritedKey.count());
             SkASSERT(0 == SkRRect::kSizeInMemory % sizeof(uint32_t));
-            // + 1 for the direction + start index.
+            // + 1 for the direction, start index, and inverseness.
             return SkRRect::kSizeInMemory / sizeof(uint32_t) + 1;
         case Type::kPath:
             if (fPath.get()->isVolatile()) {
                 return -1;
             } else {
-                return 1;
+                // The key is the path ID and fill type.
+                return 2;
             }
     }
     SkFAIL("Should never get here.");
     return 0;
 }
 
 void GrShape::writeUnstyledKey(uint32_t* key) const {
     SkASSERT(this->unstyledKeySize());
     SkDEBUGCODE(uint32_t* origKey = key;)
     if (fInheritedKey.count()) {
         memcpy(key, fInheritedKey.get(), sizeof(uint32_t) * fInheritedKey.count());
         SkDEBUGCODE(key += fInheritedKey.count();)
     } else {
         switch (fType) {
             case Type::kEmpty:
                 *key++ = 1;
                 break;
             case Type::kRRect:
                 fRRect.writeToMemory(key);
                 key += SkRRect::kSizeInMemory / sizeof(uint32_t);
                 *key = (fRRectDir == SkPath::kCCW_Direction) ? (1 << 31) : 0;
+                *key |= fRRectIsInverted ? (1 << 30) : 0;
                 *key++ |= fRRectStart;
                 SkASSERT(fRRectStart < 8);
                 break;
             case Type::kPath:
                 SkASSERT(!fPath.get()->isVolatile());
                 *key++ = fPath.get()->getGenerationID();
+                // We could canonicalize the fill rule for paths that don't differentiate between
+                // even/odd or winding fill (e.g. convex).
+                *key++ = fPath.get()->getFillType();
                 break;
         }
     }
     SkASSERT(key - origKey == this->unstyledKeySize());
 }
 
 void GrShape::setInheritedKey(const GrShape &parent, GrStyle::Apply apply, SkScalar scale) {
     SkASSERT(!fInheritedKey.count());
     // If the output shape turns out to be simple, then we will just use its geometric key
     if (Type::kPath == fType) {
@@ skipping 38 matching lines @@
                           styleKeyFlags);
     }
 }
 
 GrShape::GrShape(const GrShape& that) : fType(that.fType), fStyle(that.fStyle) {
     switch (fType) {
         case Type::kEmpty:
             return;
         case Type::kRRect:
             fRRect = that.fRRect;
+            fRRectDir = that.fRRectDir;
+            fRRectStart = that.fRRectStart;
+            fRRectIsInverted = that.fRRectIsInverted;
             return;
         case Type::kPath:
             fPath.set(*that.fPath.get());
             return;
     }
     fInheritedKey.reset(that.fInheritedKey.count());
     memcpy(fInheritedKey.get(), that.fInheritedKey.get(),
            sizeof(uint32_t) * fInheritedKey.count());
 }
 
@@ skipping 47 matching lines @@
                 // The intermediate shape may not be a general path. If we we're just applying
                 // the path effect then attemptToReduceFromPath would catch it. This means that
                 // when we subsequently applied the remaining strokeRec we would have a non-path
                 // parent shape that would be used to determine the the stroked path's key.
                 // We detect that case here and change parentForKey to a temporary that represents
                 // the simpler shape so that applying both path effect and the strokerec all at
                 // once produces the same key.
                 SkRRect rrect;
                 SkPath::Direction dir;
                 unsigned start;
+                bool inverted;
                 Type parentType = AttemptToReduceFromPathImpl(*fPath.get(), &rrect, &dir, &start,
-                                                              nullptr, strokeRec);
+                                                              &inverted, nullptr, strokeRec);
                 switch (parentType) {
                     case Type::kEmpty:
                         tmpParent.init();
                         parentForKey = tmpParent.get();
                         break;
                     case Type::kRRect:
-                        tmpParent.init(rrect, dir, start, GrStyle(strokeRec, nullptr));
+                        tmpParent.init(rrect, dir, start, inverted, GrStyle(strokeRec, nullptr));
                         parentForKey = tmpParent.get();
                     case Type::kPath:
                         break;
                 }
                 SkAssertResult(strokeRec.applyToPath(fPath.get(), *fPath.get()));
             } else {
                 fStyle = GrStyle(strokeRec, nullptr);
             }
         } else {
             fStyle = GrStyle(strokeRec, nullptr);
@@ skipping 10 matching lines @@
         SkASSERT(parent.fStyle.applies());
         SkASSERT(!parent.fStyle.pathEffect());
         SkAssertResult(parent.fStyle.applyToPath(fPath.get(), &fillOrHairline, *srcForParentStyle,
                                                  scale));
         fStyle.resetToInitStyle(fillOrHairline);
     }
     this->attemptToReduceFromPath();
     this->setInheritedKey(*parentForKey, apply, scale);
 }
 
+static inline bool rrect_path_is_inverse_filled(const SkPath& path, const SkStrokeRec& strokeRec,
+                                                const SkPathEffect* pe) {
+    // Dashing doesn't use the path fill type. Dashing only works with stroking
+    if (pe && pe->asADash(nullptr)) {
+        pe = nullptr;
+    }
+
+    SkStrokeRec::Style style = strokeRec.getStyle();
+    if (!pe && (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style)) {
+        // stroking ignores the path fill rule.
+        return false;
+    }
+    return path.isInverseFillType();
+}
+
 GrShape::Type GrShape::AttemptToReduceFromPathImpl(const SkPath& path, SkRRect* rrect,
                                                    SkPath::Direction* rrectDir,
                                                    unsigned* rrectStart,
+                                                   bool* rrectIsInverted,
                                                    const SkPathEffect* pe,
                                                    const SkStrokeRec& strokeRec) {
     if (path.isEmpty()) {
         return Type::kEmpty;
     }
     if (path.isRRect(rrect, rrectDir, rrectStart)) {
         // Currently SkPath does not acknowledge that empty, rect, or oval subtypes as rrects.
         SkASSERT(!rrect->isEmpty());
         SkASSERT(rrect->getType() != SkRRect::kRect_Type);
         SkASSERT(rrect->getType() != SkRRect::kOval_Type);
         if (!pe) {
             *rrectStart = DefaultRRectDirAndStartIndex(*rrect, false, rrectDir);
         }
+        *rrectIsInverted = rrect_path_is_inverse_filled(path, strokeRec, pe);
         return Type::kRRect;
     }
     SkRect rect;
     if (path.isOval(&rect, rrectDir, rrectStart)) {
         rrect->setOval(rect);
         if (!pe) {
             *rrectDir = kDefaultRRectDir;
             *rrectStart = kDefaultRRectStart;
         } else {
             // convert from oval indexing to rrect indexiing.
             *rrectStart *= 2;
         }
+        *rrectIsInverted = rrect_path_is_inverse_filled(path, strokeRec, pe);
         return Type::kRRect;
     }
     // When there is a path effect we restrict rect detection to the narrower API that
     // gives us the starting position. Otherwise, we will retry with the more aggressive isRect().
     if (SkPathPriv::IsSimpleClosedRect(path, &rect, rrectDir, rrectStart)) {
         if (!pe) {
             *rrectDir = kDefaultRRectDir;
             *rrectStart = kDefaultRRectStart;
         } else {
             // convert from rect indexing to rrect indexiing.
             *rrectStart *= 2;
         }
         rrect->setRect(rect);
+        *rrectIsInverted = rrect_path_is_inverse_filled(path, strokeRec, pe);
         return Type::kRRect;
     }
     if (!pe) {
         bool closed;
         if (path.isRect(&rect, &closed, nullptr)) {
             if (closed || strokeRec.isFillStyle()) {
                 rrect->setRect(rect);
                 // Since there is no path effect the dir and start index is immaterial.
                 *rrectDir = kDefaultRRectDir;
                 *rrectStart = kDefaultRRectStart;
+                *rrectIsInverted = rrect_path_is_inverse_filled(path, strokeRec, pe);
                 return Type::kRRect;
             }
         }
     }
     return Type::kPath;
 }