Revert of Analytic AntiAlias for Convex Shapes (patchset #14 id:260001 of https://codereview.chromium.org/2221103002/ )

Reason for revert:
Breaks iOS build.

Original issue's description:
> Implement AnalyticAA for convex shapes.
>
> Design doc: go/analyticAA
>
> A performance test can be found here: https://docs.google.com/a/google.com/spreadsheets/d/1n9LSjFzrQzx0hovFddWey0GSMXNRjl1oFuSypMlHWZk/edit?usp=sharing
>
> Our best case is filling big triangles, which according to our experiment has ~2.9x speedup. Our worst case is filling small ovals/circles, which has a ~1.06x slowdown.
>
> To see how our new algorithm changes the DM images, see: https://x20web.corp.google.com/~liyuqian/dmdiff/index.html
> The most significant changes are in convexpaths and analytic_antialias_convex
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2221103002
>
> Committed: https://skia.googlesource.com/skia/+/7795822807478143120c33228b68d2ab3918af2c

TBR=reed@google.com,caryclark@google.com,liyuqian@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review-Url: https://codereview.chromium.org/2388213003

1 files changed, 36 insertions, 149 deletions

diff --git a/src/core/SkEdgeBuilder.cpp b/src/core/SkEdgeBuilder.cpp
index 1a160882d4..af68e0ff65 100644
--- a/src/core/SkEdgeBuilder.cpp
+++ b/src/core/SkEdgeBuilder.cpp
@@ -7,7 +7,6 @@
 #include "SkEdgeBuilder.h"
 #include "SkPath.h"
 #include "SkEdge.h"
-#include "SkAnalyticEdge.h"
 #include "SkEdgeClipper.h"
 #include "SkLineClipper.h"
 #include "SkGeometry.h"
@@ -63,135 +62,45 @@ SkEdgeBuilder::Combine SkEdgeBuilder::CombineVertical(const SkEdge* edge, SkEdge
     return kNo_Combine;
 }
 
-SkEdgeBuilder::Combine SkEdgeBuilder::CombineVertical(
-        const SkAnalyticEdge* edge, SkAnalyticEdge* last) {
-    SkASSERT(fAnalyticAA);
-    if (last->fCurveCount || last->fDX || edge->fX != last->fX) {
-        return kNo_Combine;
-    }
-    if (edge->fWinding == last->fWinding) {
-        if (edge->fLowerY == last->fUpperY) {
-            last->fUpperY = edge->fUpperY;
-            last->fY = last->fUpperY;
-            return kPartial_Combine;
-        }
-        if (edge->fUpperY == last->fLowerY) {
-            last->fLowerY = edge->fLowerY;
-            return kPartial_Combine;
-        }
-        return kNo_Combine;
-    }
-    if (edge->fUpperY == last->fUpperY) {
-        if (edge->fLowerY == last->fLowerY) {
-            return kTotal_Combine;
-        }
-        if (edge->fLowerY < last->fLowerY) {
-            last->fUpperY = edge->fLowerY;
-            last->fY = last->fUpperY;
-            return kPartial_Combine;
-        }
-        last->fUpperY = last->fLowerY;
-        last->fY = last->fUpperY;
-        last->fLowerY = edge->fLowerY;
-        last->fWinding = edge->fWinding;
-        return kPartial_Combine;
-    }
-    if (edge->fLowerY == last->fLowerY) {
-        if (edge->fUpperY > last->fUpperY) {
-            last->fLowerY = edge->fUpperY;
-            return kPartial_Combine;
-        }
-        last->fLowerY = last->fUpperY;
-        last->fUpperY = edge->fUpperY;
-        last->fY = last->fUpperY;
-        last->fWinding = edge->fWinding;
-        return kPartial_Combine;
-    }
-    return kNo_Combine;
-}
-
-bool SkEdgeBuilder::vertical_line(const SkEdge* edge) {
-    return !edge->fDX && !edge->fCurveCount;
-}
-
-bool SkEdgeBuilder::vertical_line(const SkAnalyticEdge* edge) {
-    SkASSERT(fAnalyticAA);
+static bool vertical_line(const SkEdge* edge) {
     return !edge->fDX && !edge->fCurveCount;
 }
 
 void SkEdgeBuilder::addLine(const SkPoint pts[]) {
-    if (fAnalyticAA) {
-        SkAnalyticEdge* edge = typedAllocThrow<SkAnalyticEdge>(fAlloc);
-        if (edge->setLine(pts[0], pts[1])) {
-            if (vertical_line(edge) && fList.count()) {
-                Combine combine = CombineVertical(edge, (SkAnalyticEdge*)*(fList.end() - 1));
-                if (kNo_Combine != combine) {
-                    if (kTotal_Combine == combine) {
-                        fList.pop();
-                    }
-                    goto unallocate_analytic_edge;
+    SkEdge* edge = typedAllocThrow<SkEdge>(fAlloc);
+    if (edge->setLine(pts[0], pts[1], fShiftUp)) {
+        if (vertical_line(edge) && fList.count()) {
+            Combine combine = CombineVertical(edge, *(fList.end() - 1));
+            if (kNo_Combine != combine) {
+                if (kTotal_Combine == combine) {
+                    fList.pop();
                 }
+                goto unallocate_edge;
             }
-            fList.push(edge);
-        } else {
-unallocate_analytic_edge:
-            ;
-            // TODO: unallocate edge from storage...
         }
+        fList.push(edge);
     } else {
-        SkEdge* edge = typedAllocThrow<SkEdge>(fAlloc);
-        if (edge->setLine(pts[0], pts[1], fShiftUp)) {
-            if (vertical_line(edge) && fList.count()) {
-                Combine combine = CombineVertical(edge, (SkEdge*)*(fList.end() - 1));
-                if (kNo_Combine != combine) {
-                    if (kTotal_Combine == combine) {
-                        fList.pop();
-                    }
-                    goto unallocate_edge;
-                }
-            }
-            fList.push(edge);
-        } else {
 unallocate_edge:
-            ;
-            // TODO: unallocate edge from storage...
-        }
+        ;
+        // TODO: unallocate edge from storage...
     }
 }
 
 void SkEdgeBuilder::addQuad(const SkPoint pts[]) {
-    if (fAnalyticAA) {
-        SkAnalyticQuadraticEdge* edge = typedAllocThrow<SkAnalyticQuadraticEdge>(fAlloc);
-        if (edge->setQuadratic(pts)) {
-            fList.push(edge);
-        } else {
-            // TODO: unallocate edge from storage...
-        }
+    SkQuadraticEdge* edge = typedAllocThrow<SkQuadraticEdge>(fAlloc);
+    if (edge->setQuadratic(pts, fShiftUp)) {
+        fList.push(edge);
     } else {
-        SkQuadraticEdge* edge = typedAllocThrow<SkQuadraticEdge>(fAlloc);
-        if (edge->setQuadratic(pts, fShiftUp)) {
-            fList.push(edge);
-        } else {
-            // TODO: unallocate edge from storage...
-        }
+        // TODO: unallocate edge from storage...
     }
 }
 
 void SkEdgeBuilder::addCubic(const SkPoint pts[]) {
-    if (fAnalyticAA) {
-        SkAnalyticCubicEdge* edge = typedAllocThrow<SkAnalyticCubicEdge>(fAlloc);
-        if (edge->setCubic(pts)) {
-            fList.push(edge);
-        } else {
-            // TODO: unallocate edge from storage...
-        }
+    SkCubicEdge* edge = typedAllocThrow<SkCubicEdge>(fAlloc);
+    if (edge->setCubic(pts, fShiftUp)) {
+        fList.push(edge);
     } else {
-        SkCubicEdge* edge = typedAllocThrow<SkCubicEdge>(fAlloc);
-        if (edge->setCubic(pts, fShiftUp)) {
-            fList.push(edge);
-        } else {
-            // TODO: unallocate edge from storage...
-        }
+        // TODO: unallocate edge from storage...
     }
 }
 
@@ -226,14 +135,7 @@ static void setShiftedClip(SkRect* dst, const SkIRect& src, int shift) {
 }
 
 SkEdgeBuilder::Combine SkEdgeBuilder::checkVertical(const SkEdge* edge, SkEdge** edgePtr) {
-    return !vertical_line(edge) || edgePtr <= (SkEdge**)fEdgeList ? kNo_Combine :
-            CombineVertical(edge, edgePtr[-1]);
-}
-
-SkEdgeBuilder::Combine SkEdgeBuilder::checkVertical(const SkAnalyticEdge* edge,
-        SkAnalyticEdge** edgePtr) {
-    SkASSERT(fAnalyticAA);
-    return !vertical_line(edge) || edgePtr <= (SkAnalyticEdge**)fEdgeList ? kNo_Combine :
+    return !vertical_line(edge) || edgePtr <= fEdgeList ? kNo_Combine :
             CombineVertical(edge, edgePtr[-1]);
 }
 
@@ -250,16 +152,15 @@ int SkEdgeBuilder::buildPoly(const SkPath& path, const SkIRect* iclip, int shift
         // segments.
         maxEdgeCount *= SkLineClipper::kMaxClippedLineSegments;
     }
-    size_t edgeSize = fAnalyticAA ? sizeof(SkAnalyticEdge) : sizeof(SkEdge);
-    size_t maxEdgeSize = maxEdgeCount * edgeSize;
-    size_t maxEdgePtrSize = maxEdgeCount * sizeof(char*);
+    size_t maxEdgeSize = maxEdgeCount * sizeof(SkEdge);
+    size_t maxEdgePtrSize = maxEdgeCount * sizeof(SkEdge*);
 
     // lets store the edges and their pointers in the same block
     char* storage = (char*)fAlloc.allocThrow(maxEdgeSize + maxEdgePtrSize);
-    char* edge = (char*)storage;
-    char** edgePtr = (char**)(storage + maxEdgeSize);
+    SkEdge* edge = reinterpret_cast<SkEdge*>(storage);
+    SkEdge** edgePtr = reinterpret_cast<SkEdge**>(storage + maxEdgeSize);
     // Record the beginning of our pointers, so we can return them to the caller
-    fEdgeList = (void**)edgePtr;
+    fEdgeList = edgePtr;
 
     if (iclip) {
         SkRect clip;
@@ -277,16 +178,10 @@ int SkEdgeBuilder::buildPoly(const SkPath& path, const SkIRect* iclip, int shift
                     int lineCount = SkLineClipper::ClipLine(pts, clip, lines, canCullToTheRight);
                     SkASSERT(lineCount <= SkLineClipper::kMaxClippedLineSegments);
                     for (int i = 0; i < lineCount; i++) {
-                        bool setLineResult = fAnalyticAA ?
-                                ((SkAnalyticEdge*)edge)->setLine(lines[i], lines[i + 1]) :
-                                ((SkEdge*)edge)->setLine(lines[i], lines[i + 1], shiftUp);
-                        if (setLineResult) {
-                            Combine combine = fAnalyticAA ?
-                                    checkVertical((SkAnalyticEdge*)edge, (SkAnalyticEdge**)edgePtr) :
-                                    checkVertical((SkEdge*)edge, (SkEdge**)edgePtr);
+                        if (edge->setLine(lines[i], lines[i + 1], shiftUp)) {
+                            Combine combine = checkVertical(edge, edgePtr);
                             if (kNo_Combine == combine) {
-                                *edgePtr++ = edge;
-                                edge += edgeSize;
+                                *edgePtr++ = edge++;
                             } else if (kTotal_Combine == combine) {
                                 --edgePtr;
                             }
@@ -307,23 +202,16 @@ int SkEdgeBuilder::buildPoly(const SkPath& path, const SkIRect* iclip, int shift
                     // we ignore these, and just get the whole segment from
                     // the corresponding line/quad/cubic verbs
                     break;
-                case SkPath::kLine_Verb: {
-                    bool setLineResult = fAnalyticAA ?
-                            ((SkAnalyticEdge*)edge)->setLine(pts[0], pts[1]) :
-                            ((SkEdge*)edge)->setLine(pts[0], pts[1], shiftUp);
-                    if (setLineResult) {
-                        Combine combine = fAnalyticAA ?
-                                checkVertical((SkAnalyticEdge*)edge, (SkAnalyticEdge**)edgePtr) :
-                                checkVertical((SkEdge*)edge, (SkEdge**)edgePtr);
+                case SkPath::kLine_Verb:
+                    if (edge->setLine(pts[0], pts[1], shiftUp)) {
+                        Combine combine = checkVertical(edge, edgePtr);
                         if (kNo_Combine == combine) {
-                            *edgePtr++ = edge;
-                            edge += edgeSize;
+                            *edgePtr++ = edge++;
                         } else if (kTotal_Combine == combine) {
                             --edgePtr;
                         }
                     }
                     break;
-                }
                 default:
                     SkDEBUGFAIL("unexpected verb");
                     break;
@@ -331,8 +219,8 @@ int SkEdgeBuilder::buildPoly(const SkPath& path, const SkIRect* iclip, int shift
         }
     }
     SkASSERT((char*)edge <= (char*)fEdgeList);
-    SkASSERT(edgePtr - (char**)fEdgeList <= maxEdgeCount);
-    return SkToInt(edgePtr - (char**)fEdgeList);
+    SkASSERT(edgePtr - fEdgeList <= maxEdgeCount);
+    return SkToInt(edgePtr - fEdgeList);
 }
 
 static void handle_quad(SkEdgeBuilder* builder, const SkPoint pts[3]) {
@@ -344,11 +232,10 @@ static void handle_quad(SkEdgeBuilder* builder, const SkPoint pts[3]) {
 }
 
 int SkEdgeBuilder::build(const SkPath& path, const SkIRect* iclip, int shiftUp,
-                         bool canCullToTheRight, bool analyticAA) {
+                         bool canCullToTheRight) {
     fAlloc.reset();
     fList.reset();
     fShiftUp = shiftUp;
-    fAnalyticAA = analyticAA;
 
     if (SkPath::kLine_SegmentMask == path.getSegmentMasks()) {
         return this->buildPoly(path, iclip, shiftUp, canCullToTheRight);