Revert of Speeup hairline curves (quads and cubics)

src/core/SkScan_Hairline.cpp

Index: src/core/SkScan_Hairline.cpp
diff --git a/src/core/SkScan_Hairline.cpp b/src/core/SkScan_Hairline.cpp
index 2ec051f8abb1758b8f700aaf90a3145e679f77a3..0f2308b1f79df7279c5bde4c11585e0430a68e63 100644
--- a/src/core/SkScan_Hairline.cpp
+++ b/src/core/SkScan_Hairline.cpp
@@ -1,9 +1,11 @@
+
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+
 
 #include "SkScan.h"
 #include "SkBlitter.h"
@@ -190,10 +192,6 @@
 
 #include "SkPath.h"
 #include "SkGeometry.h"
-#include "SkNx.h"
-
-#define kMaxCubicSubdivideLevel 6
-#define kMaxQuadSubdivideLevel  5
 
 static int compute_int_quad_dist(const SkPoint pts[3]) {
     // compute the vector between the control point ([1]) and the middle of the
@@ -216,9 +214,6 @@
 
 static void hairquad(const SkPoint pts[3], const SkRegion* clip,
                      SkBlitter* blitter, int level, SkScan::HairRgnProc lineproc) {
-    SkASSERT(level <= kMaxQuadSubdivideLevel);
-
-#ifdef SK_SUPPORT_LEGACY_BLITANTIH2V2
     if (level > 0) {
         SkPoint tmp[5];
 
@@ -229,113 +224,10 @@
         SkPoint tmp[] = { pts[0], pts[2] };
         lineproc(tmp, 2, clip, blitter);
     }
-#else
-    SkPoint coeff[3];
-    SkQuadToCoeff(pts, coeff);
-
-    const int lines = 1 << level;
-    Sk2s t(0);
-    Sk2s dt(SK_Scalar1 / lines);
-
-    SkPoint tmp[(1 << kMaxQuadSubdivideLevel) + 1];
-    SkASSERT((unsigned)lines < SK_ARRAY_COUNT(tmp));
-
-    tmp[0] = pts[0];
-    Sk2s A = Sk2s::Load(&coeff[0].fX);
-    Sk2s B = Sk2s::Load(&coeff[1].fX);
-    Sk2s C = Sk2s::Load(&coeff[2].fX);
-    for (int i = 1; i < lines; ++i) {
-        t += dt;
-        ((A * t + B) * t + C).store(&tmp[i].fX);
-    }
-    tmp[lines] = pts[2];
-    lineproc(tmp, lines + 1, clip, blitter);
-#endif
-}
-
-#ifndef SK_SUPPORT_LEGACY_BLITANTIH2V2
-static inline Sk2s abs(const Sk2s& value) {
-    return Sk2s::Max(value, -value);
-}
-
-static inline SkScalar max_component(const Sk2s& value) {
-    SkScalar components[2];
-    value.store(components);
-    return SkTMax(components[0], components[1]);
-}
-
-static inline int compute_cubic_segs(const SkPoint pts[4]) {
-    Sk2s p0 = from_point(pts[0]);
-    Sk2s p1 = from_point(pts[1]);
-    Sk2s p2 = from_point(pts[2]);
-    Sk2s p3 = from_point(pts[3]);
-
-    const Sk2s oneThird(1.0f / 3.0f);
-    const Sk2s twoThird(2.0f / 3.0f);
-
-    Sk2s p13 = oneThird * p3 + twoThird * p0;
-    Sk2s p23 = oneThird * p0 + twoThird * p3;
-
-    SkScalar diff = max_component(Sk2s::Max(abs(p1 - p13), abs(p2 - p23)));
-    SkScalar tol = SK_Scalar1 / 8;
-
-    for (int i = 0; i < kMaxCubicSubdivideLevel; ++i) {
-        if (diff < tol) {
-            return 1 << i;
-        }
-        tol *= 4;
-    }
-    return 1 << kMaxCubicSubdivideLevel;
-}
-
-static bool lt_90(SkPoint p0, SkPoint pivot, SkPoint p2) {
-    return SkVector::DotProduct(p0 - pivot, p2 - pivot) >= 0;
-}
-
-// The off-curve points are "inside" the limits of the on-curve pts
-static bool quick_cubic_niceness_check(const SkPoint pts[4]) {
-    return lt_90(pts[1], pts[0], pts[3]) &&
-           lt_90(pts[2], pts[0], pts[3]) &&
-           lt_90(pts[1], pts[3], pts[0]) &&
-           lt_90(pts[2], pts[3], pts[0]);
-}
-
-static void hair_cubic(const SkPoint pts[4], const SkRegion* clip, SkBlitter* blitter,
-                       SkScan::HairRgnProc lineproc) {
-    const int lines = compute_cubic_segs(pts);
-    SkASSERT(lines > 0);
-    if (1 == lines) {
-        SkPoint tmp[2] = { pts[0], pts[3] };
-        lineproc(tmp, 2, clip, blitter);
-        return;
-    }
-
-    SkPoint coeff[4];
-    SkCubicToCoeff(pts, coeff);
-    
-    const Sk2s dt(SK_Scalar1 / lines);
-    Sk2s t(0);
-
-    SkPoint tmp[(1 << kMaxCubicSubdivideLevel) + 1];
-    SkASSERT((unsigned)lines < SK_ARRAY_COUNT(tmp));
-
-    tmp[0] = pts[0];
-    Sk2s A = Sk2s::Load(&coeff[0].fX);
-    Sk2s B = Sk2s::Load(&coeff[1].fX);
-    Sk2s C = Sk2s::Load(&coeff[2].fX);
-    Sk2s D = Sk2s::Load(&coeff[3].fX);
-    for (int i = 1; i < lines; ++i) {
-        t += dt;
-        (((A * t + B) * t + C) * t + D).store(&tmp[i].fX);
-    }
-    tmp[lines] = pts[3];
-    lineproc(tmp, lines + 1, clip, blitter);
-}
-#endif
-
-static inline void haircubic(const SkPoint pts[4], const SkRegion* clip,
+}
+
+static void haircubic(const SkPoint pts[4], const SkRegion* clip,
                       SkBlitter* blitter, int level, SkScan::HairRgnProc lineproc) {
-#ifdef SK_SUPPORT_LEGACY_BLITANTIH2V2
     if (level > 0) {
         SkPoint tmp[7];
 
@@ -346,20 +238,10 @@
         SkPoint tmp[] = { pts[0], pts[3] };
         lineproc(tmp, 2, clip, blitter);
     }
-#else
-    if (quick_cubic_niceness_check(pts)) {
-        hair_cubic(pts, clip, blitter, lineproc);
-    } else {
-        SkPoint  tmp[13];
-        SkScalar tValues[3];
-
-        int count = SkChopCubicAtMaxCurvature(pts, tmp, tValues);
-        for (int i = 0; i < count; i++) {
-            hair_cubic(&tmp[i * 3], clip, blitter, lineproc);
-        }
-    }
-#endif
-}
+}
+
+#define kMaxCubicSubdivideLevel 6
+#define kMaxQuadSubdivideLevel  5
 
 static int compute_quad_level(const SkPoint pts[3]) {
     int d = compute_int_quad_dist(pts);
@@ -429,9 +311,9 @@
                 }
                 break;
             }
-            case SkPath::kCubic_Verb: {
+            case SkPath::kCubic_Verb:
                 haircubic(pts, clip, blitter, kMaxCubicSubdivideLevel, lineproc);
-            } break;
+                break;
             case SkPath::kClose_Verb:
                 break;
             case SkPath::kDone_Verb: