[WIP] Add Context to SkDrawLooper.

src/effects/SkLayerDrawLooper.cpp

Index: src/effects/SkLayerDrawLooper.cpp
diff --git a/src/effects/SkLayerDrawLooper.cpp b/src/effects/SkLayerDrawLooper.cpp
index 6c7c3cef0cb04f2529fc3e21fd5688d3a7b19fed..bb1b887fa8b987984f57f9725d3e2d9b7289ec9d 100644
--- a/src/effects/SkLayerDrawLooper.cpp
+++ b/src/effects/SkLayerDrawLooper.cpp
@@ -25,8 +25,7 @@ SkLayerDrawLooper::LayerInfo::LayerInfo() {
 SkLayerDrawLooper::SkLayerDrawLooper()
         : fRecs(NULL),
           fTopRec(NULL),
-          fCount(0),
-          fCurrRec(NULL) {
+          fCount(0) {
 }
 
 SkLayerDrawLooper::~SkLayerDrawLooper() {
@@ -76,9 +75,11 @@ SkPaint* SkLayerDrawLooper::addLayerOnTop(const LayerInfo& info) {
     return &rec->fPaint;
 }
 
-void SkLayerDrawLooper::init(SkCanvas* canvas) {
-    fCurrRec = fRecs;
+SkLayerDrawLooper::DrawContext* SkLayerDrawLooper::init(SkCanvas* canvas)
+        const {
+    SkLayerDrawLooperContext* context = new SkLayerDrawLooperContext(this);

[scroggo, 2014/02/06 17:57:13]

SkNEW_ARGS

     canvas->save(SkCanvas::kMatrix_SaveFlag);
+    return context;
 }
 
 static SkColor xferColor(SkColor src, SkColor dst, SkXfermode::Mode mode) {
@@ -96,6 +97,9 @@ static SkColor xferColor(SkColor src, SkColor dst, SkXfermode::Mode mode) {
     }
 }
 
+SkLayerDrawLooper::SkLayerDrawLooperContext::SkLayerDrawLooperContext(
+    const SkLayerDrawLooper* looper) : fCurrRec(looper->fRecs) {}
+
 // Even with kEntirePaint_Bits, we always ensure that the master paint's
 // text-encoding is respected, since that controls how we interpret the
 // text/length parameters of a draw[Pos]Text call.
@@ -170,22 +174,28 @@ static void postTranslate(SkCanvas* canvas, SkScalar dx, SkScalar dy) {
     canvas->setMatrix(m);
 }
 
-bool SkLayerDrawLooper::next(SkCanvas* canvas, SkPaint* paint) {
+bool SkLayerDrawLooper::next_internal(SkCanvas* canvas, SkPaint* paint,
+                                      SkDrawLooper::DrawContext* context) const {
+    SkLayerDrawLooperContext* layerContext =
+        static_cast<SkLayerDrawLooperContext*>(context);
+
     canvas->restore();
-    if (NULL == fCurrRec) {
+    if (NULL == layerContext->fCurrRec) {
         return false;
     }
 
-    ApplyInfo(paint, fCurrRec->fPaint, fCurrRec->fInfo);
+    ApplyInfo(paint, layerContext->fCurrRec->fPaint,
+              layerContext->fCurrRec->fInfo);
 
     canvas->save(SkCanvas::kMatrix_SaveFlag);
-    if (fCurrRec->fInfo.fPostTranslate) {
-        postTranslate(canvas, fCurrRec->fInfo.fOffset.fX,
-                      fCurrRec->fInfo.fOffset.fY);
+    if (layerContext->fCurrRec->fInfo.fPostTranslate) {
+        postTranslate(canvas, layerContext->fCurrRec->fInfo.fOffset.fX,
+                      layerContext->fCurrRec->fInfo.fOffset.fY);
     } else {
-        canvas->translate(fCurrRec->fInfo.fOffset.fX, fCurrRec->fInfo.fOffset.fY);
+        canvas->translate(layerContext->fCurrRec->fInfo.fOffset.fX,
+                          layerContext->fCurrRec->fInfo.fOffset.fY);
     }
-    fCurrRec = fCurrRec->fNext;
+    layerContext->fCurrRec = layerContext->fCurrRec->fNext;
 
     return true;
 }
@@ -225,8 +235,7 @@ SkLayerDrawLooper::SkLayerDrawLooper(SkReadBuffer& buffer)
         : INHERITED(buffer),
           fRecs(NULL),
           fTopRec(NULL),
-          fCount(0),
-          fCurrRec(NULL) {
+          fCount(0) {
     int count = buffer.readInt();
 
     for (int i = 0; i < count; i++) {