Add asADash entry point into SkPathEffect to allow extracting Dash info from PathEffects

src/effects/SkDashPathEffect.cpp

Index: src/effects/SkDashPathEffect.cpp
diff --git a/src/effects/SkDashPathEffect.cpp b/src/effects/SkDashPathEffect.cpp
index 58706c5b78f52d55bbead6d4f7a8f3634bd838c6..cab90736c4fc20aceef8becd50c2fdbd473da05d 100644
--- a/src/effects/SkDashPathEffect.cpp
+++ b/src/effects/SkDashPathEffect.cpp
@@ -34,20 +34,10 @@ static SkScalar FindFirstInterval(const SkScalar intervals[], SkScalar phase,
     return intervals[0];
 }
 
-SkDashPathEffect::SkDashPathEffect(const SkScalar intervals[], int count,
-                                   SkScalar phase, bool scaleToFit)
-        : fScaleToFit(scaleToFit) {
-    SkASSERT(intervals);
-    SkASSERT(count > 1 && SkAlign2(count) == count);
-
-    fIntervals = (SkScalar*)sk_malloc_throw(sizeof(SkScalar) * count);
-    fCount = count;
-
+void SkDashPathEffect::setInternalMembers(SkScalar phase) {
     SkScalar len = 0;
-    for (int i = 0; i < count; i++) {
-        SkASSERT(intervals[i] >= 0);
-        fIntervals[i] = intervals[i];
-        len += intervals[i];
+    for (int i = 0; i < fCount; i++) {
+        len += fIntervals[i];
     }
     fIntervalLength = len;
 
@@ -75,8 +65,10 @@ SkDashPathEffect::SkDashPathEffect(const SkScalar intervals[], int count,
         }
         SkASSERT(phase >= 0 && phase < len);
 
-        fInitialDashLength = FindFirstInterval(intervals, phase,
-                                               &fInitialDashIndex, count);
+        fPhase = phase;
+
+        fInitialDashLength = FindFirstInterval(fIntervals, fPhase,
+                                               &fInitialDashIndex, fCount);
 
         SkASSERT(fInitialDashLength >= 0);
         SkASSERT(fInitialDashIndex >= 0 && fInitialDashIndex < fCount);
@@ -85,6 +77,22 @@ SkDashPathEffect::SkDashPathEffect(const SkScalar intervals[], int count,
     }
 }
 
+SkDashPathEffect::SkDashPathEffect(const SkScalar intervals[], int count,
+                                   SkScalar phase, bool scaleToFit)
+        : fScaleToFit(scaleToFit) {
+    SkASSERT(intervals);
+    SkASSERT(count > 1 && SkAlign2(count) == count);
+
+    fIntervals = (SkScalar*)sk_malloc_throw(sizeof(SkScalar) * count);
+    fCount = count;
+    for (int i = 0; i < count; i++) {
+        SkASSERT(intervals[i] >= 0);
+        fIntervals[i] = intervals[i];
+    }
+
+    this->setInternalMembers(phase);
+}
+
 SkDashPathEffect::~SkDashPathEffect() {
     sk_free(fIntervals);
 }
@@ -529,15 +537,35 @@ bool SkDashPathEffect::asPoints(PointData* results,
     return true;
 }
 
+SkPathEffect::DashType SkDashPathEffect::asADash(DashInfo* info) const {
+    if (info) {
+       if (info->fCount >= fCount) {
+            if (info->fIntervals) {
+                memcpy(info->fIntervals, fIntervals, fCount * sizeof(SkScalar));
+            }
+       }
+       info->fCount = fCount;
+       info->fPhase = fPhase;
+       info->fScaleToFit = fScaleToFit;
+    }
+    return kDash_DashType;
+}
+
+#define NEW_FLATTEN_VERSION 123
+
 SkFlattenable::Factory SkDashPathEffect::getFactory() const {
     return CreateProc;
 }
 
 void SkDashPathEffect::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
-    buffer.writeInt(fInitialDashIndex);
-    buffer.writeScalar(fInitialDashLength);
-    buffer.writeScalar(fIntervalLength);
+    if (buffer.pictureVersion() < NEW_FLATTEN_VERSION) {

[bsalomon, 2014/03/28 14:57:22]

Do we need this? Will we ever write an old picture format? I think we only care
about reading old ones.

+        buffer.writeInt(fInitialDashIndex);
+        buffer.writeScalar(fInitialDashLength);
+        buffer.writeScalar(fIntervalLength);
+    } else {
+        buffer.writeScalar(fPhase);
+    }
     buffer.writeBool(fScaleToFit);
     buffer.writeScalarArray(fIntervals, fCount);
 }
@@ -547,9 +575,14 @@ SkFlattenable* SkDashPathEffect::CreateProc(SkReadBuffer& buffer) {
 }
 
 SkDashPathEffect::SkDashPathEffect(SkReadBuffer& buffer) : INHERITED(buffer) {
-    fInitialDashIndex = buffer.readInt();
-    fInitialDashLength = buffer.readScalar();
-    fIntervalLength = buffer.readScalar();
+    if (buffer.pictureVersion() < NEW_FLATTEN_VERSION) {
+        fInitialDashIndex = buffer.readInt();
+        fInitialDashLength = buffer.readScalar();
+        fIntervalLength = buffer.readScalar();
+    } else {
+        fPhase = buffer.readScalar();
+    }
+
     fScaleToFit = buffer.readBool();
 
     fCount = buffer.getArrayCount();
@@ -560,4 +593,14 @@ SkDashPathEffect::SkDashPathEffect(SkReadBuffer& buffer) : INHERITED(buffer) {
     } else {
         fIntervals = NULL;
     }
+
+    if (buffer.pictureVersion() < NEW_FLATTEN_VERSION) {
+        fPhase = 0.0;
+        for (int i = 0; i < fInitialDashIndex; ++i) {
+            fPhase += fIntervals[i];
+        }
+        fPhase += fInitialDashLength;
+    } else {
+        this->setInternalMembers(fPhase);
+    }
 }