commit 51c5678f258736736c4a5d48d4e82c73be225428
author caryclark <caryclark@google.com> Mon Nov 07 05:09:28 2016 -0800
committer Commit bot <commit-bot@chromium.org> Mon Nov 07 05:09:28 2016 -0800
tree fd9c8b36f3e4d384e881e608835b107f4613d281
parent ad512797c9405f78b080a1d24cd98f465b9879dd

use reversePathTo in place of addPathReverse

Path ops was using addPathReverse, instead of reversePathTo.
The former adds a moveTo always, and the latter requires
that the caller add the moveTo if needed.

Simplify the reversePathTo implementation.

R=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2481463002

Committed: https://skia.googlesource.com/skia/+/d8db392be9dd1887df04b10b5670991d6b098c17
Review-Url: https://codereview.chromium.org/2481463002

src/core/SkPath.cpp

diff --git a/src/core/SkPath.cpp b/src/core/SkPath.cpp
index c1b6327..8241c10 100644
--- a/src/core/SkPath.cpp
+++ b/src/core/SkPath.cpp
@@ -1567,49 +1567,41 @@
 
 // ignore the last point of the 1st contour
 void SkPath::reversePathTo(const SkPath& path) {
-    int i, vcount = path.fPathRef->countVerbs();
-    // exit early if the path is empty, or just has a moveTo.
-    if (vcount < 2) {
+    const uint8_t* verbs = path.fPathRef->verbsMemBegin(); // points at the last verb
+    if (!verbs) {  // empty path returns nullptr
         return;
     }
+    const uint8_t* verbsEnd = path.fPathRef->verbs() - 1; // points just past the first verb
+    SkASSERT(verbsEnd[0] == kMove_Verb);
+    const SkPoint*  pts = path.fPathRef->pointsEnd() - 1;
+    const SkScalar* conicWeights = path.fPathRef->conicWeightsEnd();
 
-    SkPathRef::Editor(&fPathRef, vcount, path.countPoints());
-
-    const uint8_t*  verbs = path.fPathRef->verbs();
-    const SkPoint*  pts = path.fPathRef->points();
-    const SkScalar* conicWeights = path.fPathRef->conicWeights();
-
-    SkASSERT(verbs[~0] == kMove_Verb);
-    for (i = 1; i < vcount; ++i) {
-        unsigned v = verbs[~i];
-        int n = pts_in_verb(v);
-        if (n == 0) {
-            break;
-        }
-        pts += n;
-        conicWeights += (SkPath::kConic_Verb == v);
-    }
-
-    while (--i > 0) {
-        switch (verbs[~i]) {
+    while (verbs < verbsEnd) {
+        uint8_t v = *verbs++;
+        pts -= pts_in_verb(v);
+        switch (v) {
+            case kMove_Verb:
+                // if the path has multiple contours, stop after reversing the last
+                return;
             case kLine_Verb:
-                this->lineTo(pts[-1].fX, pts[-1].fY);
+                this->lineTo(pts[0]);
                 break;
             case kQuad_Verb:
-                this->quadTo(pts[-1].fX, pts[-1].fY, pts[-2].fX, pts[-2].fY);
+                this->quadTo(pts[1], pts[0]);
                 break;
             case kConic_Verb:
-                this->conicTo(pts[-1], pts[-2], *--conicWeights);
+                this->conicTo(pts[1], pts[0], *--conicWeights);
                 break;
             case kCubic_Verb:
-                this->cubicTo(pts[-1].fX, pts[-1].fY, pts[-2].fX, pts[-2].fY,
-                              pts[-3].fX, pts[-3].fY);
+                this->cubicTo(pts[2], pts[1], pts[0]);
+                break;
+            case kClose_Verb:
+                SkASSERT(verbs - path.fPathRef->verbsMemBegin() == 1);
                 break;
             default:
                 SkDEBUGFAIL("bad verb");
                 break;
         }
-        pts -= pts_in_verb(verbs[~i]);
     }
 }
 

src/pathops/SkOpBuilder.cpp

diff --git a/src/pathops/SkOpBuilder.cpp b/src/pathops/SkOpBuilder.cpp
index 011d6a6..075520d 100644
--- a/src/pathops/SkOpBuilder.cpp
+++ b/src/pathops/SkOpBuilder.cpp
@@ -25,7 +25,17 @@
     return true;
 }
 
-bool FixWinding(SkPath* path) {
+void SkOpBuilder::ReversePath(SkPath* path) {
+    SkPath temp;
+    SkPoint lastPt;
+    SkAssertResult(path->getLastPt(&lastPt));
+    temp.moveTo(lastPt);
+    temp.reversePathTo(*path);
+    temp.close();
+    *path = temp;
+}
+
+bool SkOpBuilder::FixWinding(SkPath* path) {
     SkPath::FillType fillType = path->getFillType();
     if (fillType == SkPath::kInverseEvenOdd_FillType) {
         fillType = SkPath::kInverseWinding_FillType;
@@ -35,9 +45,7 @@
     SkPathPriv::FirstDirection dir;
     if (one_contour(*path) && SkPathPriv::CheapComputeFirstDirection(*path, &dir)) {
         if (dir != SkPathPriv::kCCW_FirstDirection) {
-            SkPath temp;
-            temp.reverseAddPath(*path);
-            *path = temp;
+            ReversePath(path);
         }
         path->setFillType(fillType);
         return true;
@@ -133,9 +141,7 @@
             if (firstDir == SkPathPriv::kUnknown_FirstDirection) {
                 firstDir = dir;
             } else if (firstDir != dir) {
-                SkPath temp;
-                temp.reverseAddPath(*test);
-                *test = temp;
+                ReversePath(test);
             }
             continue;
         }

src/pathops/SkPathWriter.cpp

diff --git a/src/pathops/SkPathWriter.cpp b/src/pathops/SkPathWriter.cpp
index c94809e..9893a50 100644
--- a/src/pathops/SkPathWriter.cpp
+++ b/src/pathops/SkPathWriter.cpp
@@ -306,7 +306,7 @@
                         first ? SkPath::kAppend_AddPathMode : SkPath::kExtend_AddPathMode);
             } else {
                 SkASSERT(!first);
-                fPathPtr->reverseAddPath(contour);
+                fPathPtr->reversePathTo(contour);
             }
             if (first) {
                 first = false;