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

src/effects/gradients/SkSweepGradient.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 "SkSweepGradient.h"
 
@@ skipping 34 matching lines @@
 SkSweepGradient::SkSweepGradient(SkReadBuffer& buffer)
     : INHERITED(buffer),
       fCenter(buffer.readPoint()) {
 }
 
 void SkSweepGradient::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writePoint(fCenter);
 }
 
+#if 0
 //  returns angle in a circle [0..2PI) -> [0..255]
 static unsigned SkATan2_255(float y, float x) {
     //    static const float g255Over2PI = 255 / (2 * SK_ScalarPI);
     static const float g255Over2PI = 40.584510488433314f;
 
     float result = sk_float_atan2(y, x);
     if (result < 0) {
         result += 2 * SK_ScalarPI;
     }
     SkASSERT(result >= 0);
@@ skipping 84 matching lines @@
             proc(matrix, SkIntToScalar(x) + SK_ScalarHalf,
                          SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
 
             int index = SkATan2_255(srcPt.fY, srcPt.fX);
             index >>= (8 - kCache16Bits);
             *dstC++ = cache[toggle + index];
             toggle = next_dither_toggle16(toggle);
         }
     }
 }
+#endif
 
 /////////////////////////////////////////////////////////////////////
 
 #if SK_SUPPORT_GPU
 
 #include "GrTBackendEffectFactory.h"
 
 class GrGLSweepGradient : public GrGLGradientEffect {
 public:
 
@@ skipping 124 matching lines @@
     str->appendScalar(fCenter.fX);
     str->append(", ");
     str->appendScalar(fCenter.fY);
     str->append(") ");
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif