Create helper functions to use in computeInvariantOutput calls

src/effects/SkMagnifierImageFilter.cpp

 /*
  * Copyright 2012 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 "SkBitmap.h"
 #include "SkMagnifierImageFilter.h"
 #include "SkColorPriv.h"
@@ skipping 210 matching lines @@
     return (this->texture(0) == s.texture(0) &&
             this->fXOffset == s.fXOffset &&
             this->fYOffset == s.fYOffset &&
             this->fXInvZoom == s.fXInvZoom &&
             this->fYInvZoom == s.fYInvZoom &&
             this->fXInvInset == s.fXInvInset &&
             this->fYInvInset == s.fYInvInset);
 }
 
 void GrMagnifierEffect::onComputeInvariantOutput(InvariantOutput* inout) const {
     this->updateInvariantOutputForModulation(inout);

[bsalomon, 2014/10/10 19:48:16]

do we still want this function?

[egdaniel, 2014/10/13 16:44:57]

So the basic structure of this function is:

if(texture.isOpaque())
 mulByOpaqueColor();
else
 mulByUnknownColor();


This pattern is repeated in all our SingleTextureEffects so I feel like there is
still value to the function.

-    inout->fIsSingleComponent = false;
 }
 
 #endif
 
 ////////////////////////////////////////////////////////////////////////////////
 
 SkImageFilter* SkMagnifierImageFilter::Create(const SkRect& srcRect, SkScalar inset,
                                               SkImageFilter* input) {
     
     if (!SkScalarIsFinite(inset) || !SkIsValidRect(srcRect)) {
@@ skipping 123 matching lines @@
 
             int x_val = SkPin32(SkScalarFloorToInt(x_interp), 0, width - 1);
             int y_val = SkPin32(SkScalarFloorToInt(y_interp), 0, height - 1);
 
             *dptr = sptr[y_val * width + x_val];
             dptr++;
         }
     }
     return true;
 }