Gradient shaders: make fPtsToUnit const, pre-cache getType().

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"
 
+static SkMatrix translate(SkScalar dx, SkScalar dy) {
+    SkMatrix matrix;
+    matrix.setTranslate(dx, dy);
+    return matrix;
+}
+
 SkSweepGradient::SkSweepGradient(SkScalar cx, SkScalar cy, const Descriptor& desc)
-    : SkGradientShaderBase(desc)
+    : SkGradientShaderBase(desc, translate(-cx, -cy))
     , fCenter(SkPoint::Make(cx, cy))
 {
-    fPtsToUnit.setTranslate(-cx, -cy);
-
     // overwrite the tilemode to a canonical value (since sweep ignores it)
     fTileMode = SkShader::kClamp_TileMode;
 }
 
 SkShader::BitmapType SkSweepGradient::asABitmap(SkBitmap* bitmap,
     SkMatrix* matrix, SkShader::TileMode* xy) const {
     if (bitmap) {
         this->getGradientTableBitmap(bitmap);
     }
     if (matrix) {
@@ skipping 302 matching lines @@
     str->appendScalar(fCenter.fX);
     str->append(", ");
     str->appendScalar(fCenter.fY);
     str->append(") ");
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif