Start using type traits in src/record instead of macros.

src/record/SkRecordOpts.cpp

Index: src/record/SkRecordOpts.cpp
diff --git a/src/record/SkRecordOpts.cpp b/src/record/SkRecordOpts.cpp
index 4b35b33a3c20683ff1601879bf0504718c328a06..5b537de040120a7238ec2dbc95256eeabd51a027 100644
--- a/src/record/SkRecordOpts.cpp
+++ b/src/record/SkRecordOpts.cpp
@@ -7,6 +7,7 @@
 
 #include "SkRecordOpts.h"
 
+#include "SkRecordTraits.h"
 #include "SkRecords.h"
 #include "SkTDArray.h"
 
@@ -40,9 +41,28 @@ public:
     explicit SaveRestoreNooper(SkRecord* record)
         : Common(record), fSave(kInactive), fChanged(false) {}
 
-    // Most drawing commands reset to inactive state without nooping anything.
+    // Drawing commands reset state to inactive without nooping.
     template <typename T>
-    void operator()(T*) { fSave = kInactive; }
+    SK_WHEN(SkRecords::IsDraw<T>, void) operator()(T*) { fSave = kInactive; }
+
+    // Most non-drawing commands can be ignored.
+    template <typename T>
+    SK_WHEN(!SkRecords::IsDraw<T>, void) operator()(T*) {}
+
+    void operator()(SkRecords::Save* r) {
+        fSave = SkCanvas::kMatrixClip_SaveFlag == r->flags ? this->index() : kInactive;
+    }
+
+    void operator()(SkRecords::Restore* r) {
+        if (fSave != kInactive) {
+            // Remove everything between the save and restore, inclusive on both sides.
+            fChanged = true;
+            for (unsigned i = fSave; i <= this->index(); i++) {
+                fRecord->replace<SkRecords::NoOp>(i);
+            }
+            fSave = kInactive;
+        }
+    }
 
     bool changed() const { return fChanged; }
 
@@ -52,39 +72,6 @@ private:
     bool fChanged;
 };
 
-// If the command doesn't draw anything, that doesn't reset the state back to inactive.
-// TODO(mtklein): do this with some sort of template-based trait mechanism instead of macros
-#define DOESNT_DRAW(T) template <> void SaveRestoreNooper::operator()(SkRecords::T*) {}
-DOESNT_DRAW(NoOp)
-DOESNT_DRAW(Concat)
-DOESNT_DRAW(SetMatrix)
-DOESNT_DRAW(ClipRect)
-DOESNT_DRAW(ClipRRect)
-DOESNT_DRAW(ClipPath)
-DOESNT_DRAW(ClipRegion)
-DOESNT_DRAW(PairedPushCull)
-DOESNT_DRAW(PushCull)
-DOESNT_DRAW(PopCull)
-#undef DOESNT_DRAW
-
-template <>
-void SaveRestoreNooper::operator()(SkRecords::Save* r) {
-    fSave = SkCanvas::kMatrixClip_SaveFlag == r->flags ? this->index() : kInactive;
-}
-
-template <>
-void SaveRestoreNooper::operator()(SkRecords::Restore* r) {
-    if (fSave != kInactive) {
-        // Remove everything between the save and restore, inclusive on both sides.
-        fChanged = true;
-        for (unsigned i = fSave; i <= this->index(); i++) {
-            fRecord->replace<SkRecords::NoOp>(i);
-        }
-        fSave = kInactive;
-    }
-}
-
-
 // Tries to replace PushCull with PairedPushCull, which lets us skip to the paired PopCull
 // when the canvas can quickReject the cull rect.
 class CullAnnotator : public Common {
@@ -92,8 +79,24 @@ public:
     explicit CullAnnotator(SkRecord* record) : Common(record) {}
 
     // Do nothing to most ops.
-    template <typename T>
-    void operator()(T*) {}
+    template <typename T> void operator()(T*) {}
+
+    void operator()(SkRecords::PushCull* push) {
+        Pair pair = { this->index(), push };
+        fPushStack.push(pair);
+    }
+
+    void operator()(SkRecords::PopCull* pop) {
+        Pair push = fPushStack.top();
+        fPushStack.pop();
+
+        SkASSERT(this->index() > push.index);
+        unsigned skip = this->index() - push.index;
+
+        SkRecords::Adopted<SkRecords::PushCull> adopted(push.command);
+        SkNEW_PLACEMENT_ARGS(fRecord->replace<SkRecords::PairedPushCull>(push.index, adopted),
+                             SkRecords::PairedPushCull, (&adopted, skip));
+    }
 
 private:
     struct Pair {
@@ -104,68 +107,46 @@ private:
     SkTDArray<Pair> fPushStack;
 };
 
-template <>
-void CullAnnotator::operator()(SkRecords::PushCull* push) {
-    Pair pair = { this->index(), push };
-    fPushStack.push(pair);
-}
-
-template <>
-void CullAnnotator::operator()(SkRecords::PopCull* pop) {
-    Pair push = fPushStack.top();
-    fPushStack.pop();
-
-    SkASSERT(this->index() > push.index);
-    unsigned skip = this->index() - push.index;
-
-    SkRecords::Adopted<SkRecords::PushCull> adopted(push.command);
-    SkNEW_PLACEMENT_ARGS(fRecord->replace<SkRecords::PairedPushCull>(push.index, adopted),
-                         SkRecords::PairedPushCull, (&adopted, skip));
-}
-
 // Replaces DrawPosText with DrawPosTextH when all Y coordinates are equal.
 class StrengthReducer : public Common {
 public:
     explicit StrengthReducer(SkRecord* record) : Common(record) {}
 
     // Do nothing to most ops.
-    template <typename T>
-    void operator()(T*) {}
-};
+    template <typename T> void operator()(T*) {}
 
-template <>
-void StrengthReducer::operator()(SkRecords::DrawPosText* r) {
-    const unsigned points = r->paint.countText(r->text, r->byteLength);
-    if (points == 0) {
-        // No point (ha!).
-        return;
-    }
-
-    const SkScalar firstY = r->pos[0].fY;
-    for (unsigned i = 1; i < points; i++) {
-        if (r->pos[i].fY != firstY) {
-            // Needs the full strength of DrawPosText.
+    void operator()(SkRecords::DrawPosText* r) {
+        const unsigned points = r->paint.countText(r->text, r->byteLength);
+        if (points == 0) {
+            // No point (ha!).
             return;
         }
-    }
-    // All ys are the same.  We can replace DrawPosText with DrawPosTextH.
-
-    // r->pos is points SkPoints, [(x,y),(x,y),(x,y),(x,y), ... ].
-    // We're going to squint and look at that as 2*points SkScalars, [x,y,x,y,x,y,x,y, ...].
-    // Then we'll rearrange things so all the xs are in order up front, clobbering the ys.
-    SK_COMPILE_ASSERT(sizeof(SkPoint) == 2 * sizeof(SkScalar), SquintingIsNotSafe);
-    SkScalar* scalars = &r->pos[0].fX;
-    for (unsigned i = 0; i < 2*points; i += 2) {
-        scalars[i/2] = scalars[i];
-    }
 
-    // Extend lifetime of r to the end of the method so we can copy its parts.
-    SkRecords::Adopted<SkRecords::DrawPosText> adopted(r);
-    SkNEW_PLACEMENT_ARGS(fRecord->replace<SkRecords::DrawPosTextH>(this->index(), adopted),
-                         SkRecords::DrawPosTextH,
-                         (r->text, r->byteLength, scalars, firstY, r->paint));
-}
+        const SkScalar firstY = r->pos[0].fY;
+        for (unsigned i = 1; i < points; i++) {
+            if (r->pos[i].fY != firstY) {
+                // Needs the full strength of DrawPosText.
+                return;
+            }
+        }
+        // All ys are the same.  We can replace DrawPosText with DrawPosTextH.
+
+        // r->pos is points SkPoints, [(x,y),(x,y),(x,y),(x,y), ... ].
+        // We're going to squint and look at that as 2*points SkScalars, [x,y,x,y,x,y,x,y, ...].
+        // Then we'll rearrange things so all the xs are in order up front, clobbering the ys.
+        SK_COMPILE_ASSERT(sizeof(SkPoint) == 2 * sizeof(SkScalar), SquintingIsNotSafe);
+        SkScalar* scalars = &r->pos[0].fX;
+        for (unsigned i = 0; i < 2*points; i += 2) {
+            scalars[i/2] = scalars[i];
+        }
 
+        // Extend lifetime of r to the end of the method so we can copy its parts.
+        SkRecords::Adopted<SkRecords::DrawPosText> adopted(r);
+        SkNEW_PLACEMENT_ARGS(fRecord->replace<SkRecords::DrawPosTextH>(this->index(), adopted),
+                             SkRecords::DrawPosTextH,
+                             (r->text, r->byteLength, scalars, firstY, r->paint));
+    }
+};
 
 // Tries to replace DrawPosTextH with BoundedDrawPosTextH, which knows conservative upper and lower
 // bounds to use with SkCanvas::quickRejectY.
@@ -174,37 +155,37 @@ public:
     explicit TextBounder(SkRecord* record) : Common(record) {}
 
     // Do nothing to most ops.
-    template <typename T>
-    void operator()(T*) {}
-};
+    template <typename T> void operator()(T*) {}
 
-template <>
-void TextBounder::operator()(SkRecords::DrawPosTextH* r) {
-    // If we're drawing vertical text, none of the checks we're about to do make any sense.
-    // We'll need to call SkPaint::computeFastBounds() later, so bail if that's not possible.
-    if (r->paint.isVerticalText() || !r->paint.canComputeFastBounds()) {
-        return;
+    void operator()(SkRecords::DrawPosTextH* r) {
+        // If we're drawing vertical text, none of the checks we're about to do make any sense.
+        // We'll need to call SkPaint::computeFastBounds() later, so bail if that's not possible.
+        if (r->paint.isVerticalText() || !r->paint.canComputeFastBounds()) {
+            return;
+        }
+
+        // Rather than checking the top and bottom font metrics, we guess.  Actually looking up the
+        // top and bottom metrics is slow, and this overapproximation should be good enough.
+        const SkScalar buffer = r->paint.getTextSize() * 1.5f;
+        SkDEBUGCODE(SkPaint::FontMetrics metrics;)
+        SkDEBUGCODE(r->paint.getFontMetrics(&metrics);)
+        SkASSERT(-buffer <= metrics.fTop);
+        SkASSERT(+buffer >= metrics.fBottom);
+
+        // Let the paint adjust the text bounds.  We don't care about left and right here, so we use
+        // 0 and 1 respectively just so the bounds rectangle isn't empty.
+        SkRect bounds;
+        bounds.set(0, r->y - buffer, SK_Scalar1, r->y + buffer);
+        SkRect adjusted = r->paint.computeFastBounds(bounds, &bounds);
+
+        SkRecords::Adopted<SkRecords::DrawPosTextH> adopted(r);
+        SkNEW_PLACEMENT_ARGS(
+                fRecord->replace<SkRecords::BoundedDrawPosTextH>(this->index(), adopted),
+                SkRecords::BoundedDrawPosTextH,
+                (&adopted, adjusted.fTop, adjusted.fBottom));
     }
+};
 
-    // Rather than checking the top and bottom font metrics, we guess.  Actually looking up the
-    // top and bottom metrics is slow, and this overapproximation should be good enough.
-    const SkScalar buffer = r->paint.getTextSize() * 1.5f;
-    SkDEBUGCODE(SkPaint::FontMetrics metrics;)
-    SkDEBUGCODE(r->paint.getFontMetrics(&metrics);)
-    SkASSERT(-buffer <= metrics.fTop);
-    SkASSERT(+buffer >= metrics.fBottom);
-
-    // Let the paint adjust the text bounds.  We don't care about left and right here, so we use
-    // 0 and 1 respectively just so the bounds rectangle isn't empty.
-    SkRect bounds;
-    bounds.set(0, r->y - buffer, SK_Scalar1, r->y + buffer);
-    SkRect adjusted = r->paint.computeFastBounds(bounds, &bounds);
-
-    SkRecords::Adopted<SkRecords::DrawPosTextH> adopted(r);
-    SkNEW_PLACEMENT_ARGS(fRecord->replace<SkRecords::BoundedDrawPosTextH>(this->index(), adopted),
-                         SkRecords::BoundedDrawPosTextH,
-                         (&adopted, adjusted.fTop, adjusted.fBottom));
-}
 
 template <typename Pass>
 static void run_pass(Pass& pass, SkRecord* record) {