Extract most of the mutable state of SkShader into a separate Context object.

src/effects/gradients/SkTwoPointConicalGradient.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTwoPointConicalGradient.h"
 
 static int valid_divide(float numer, float denom, float* ratio) {
@@ skipping 97 matching lines @@
         if (r <= 0) {
             return kDontDrawT;
         }
     }
     return SkFloatToFixed(t);
 }
 
 typedef void (*TwoPointConicalProc)(TwoPtRadial* rec, SkPMColor* dstC,
                                     const SkPMColor* cache, int toggle, int count);
 
+#if 0
 static void twopoint_clamp(TwoPtRadial* rec, SkPMColor* SK_RESTRICT dstC,
                            const SkPMColor* SK_RESTRICT cache, int toggle,
                            int count) {
     for (; count > 0; --count) {
         SkFixed t = rec->nextT();
         if (TwoPtRadial::DontDrawT(t)) {
             *dstC++ = 0;
         } else {
             SkFixed index = SkClampMax(t, 0xFFFF);
             SkASSERT(index <= 0xFFFF);
@@ skipping 30 matching lines @@
             *dstC++ = 0;
         } else {
             SkFixed index = mirror_tileproc(t);
             SkASSERT(index <= 0xFFFF);
             *dstC++ = cache[toggle +
                             (index >> SkGradientShaderBase::kCache32Shift)];
         }
         toggle = next_dither_toggle(toggle);
     }
 }
+#endif
 
 void SkTwoPointConicalGradient::init() {
     fRec.init(fCenter1, fRadius1, fCenter2, fRadius2);
     fPtsToUnit.reset();
 }
 
 /////////////////////////////////////////////////////////////////////
 
 SkTwoPointConicalGradient::SkTwoPointConicalGradient(
         const SkPoint& start, SkScalar startRadius,
         const SkPoint& end, SkScalar endRadius,
         const Descriptor& desc)
     : SkGradientShaderBase(desc),
     fCenter1(start),
     fCenter2(end),
     fRadius1(startRadius),
     fRadius2(endRadius) {
     // this is degenerate, and should be caught by our caller
     SkASSERT(fCenter1 != fCenter2 || fRadius1 != fRadius2);
     this->init();
 }
 
 bool SkTwoPointConicalGradient::isOpaque() const {
     // Because areas outside the cone are left untouched, we cannot treat the
     // shader as opaque even if the gradient itself is opaque.
     // TODO(junov): Compute whether the cone fills the plane crbug.com/222380
     return false;
 }
 
+#if 0
 void SkTwoPointConicalGradient::shadeSpan(int x, int y, SkPMColor* dstCParam,
                                           int count) {
     int toggle = init_dither_toggle(x, y);
 
     SkASSERT(count > 0);
 
     SkPMColor* SK_RESTRICT dstC = dstCParam;
 
     SkMatrix::MapXYProc dstProc = fDstToIndexProc;
 
@@ skipping 53 matching lines @@
 
     // we don't have a span16 proc
     fFlags &= ~kHasSpan16_Flag;
 
     // in general, we might discard based on computed-radius, so clear
     // this flag (todo: sometimes we can detect that we never discard...)
     fFlags &= ~kOpaqueAlpha_Flag;
 
     return true;
 }
+#endif
 
 SkShader::BitmapType SkTwoPointConicalGradient::asABitmap(
     SkBitmap* bitmap, SkMatrix* matrix, SkShader::TileMode* xy) const {
     SkPoint diff = fCenter2 - fCenter1;
     SkScalar diffLen = 0;
 
     if (bitmap) {
         this->getGradientTableBitmap(bitmap);
     }
     if (matrix) {
@@ skipping 448 matching lines @@
     str->appendScalar(fCenter2.fY);
     str->append(") radius2: ");
     str->appendScalar(fRadius2);
     str->append(" ");
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif