API change to allow for NormalSource selection at the user level.

samplecode/SampleLitAtlas.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SampleCode.h"
 #include "SkAnimTimer.h"
 #include "SkView.h"
@@ skipping 114 matching lines @@
             diffMat.setRectToRect(fDiffTex[i], r, SkMatrix::kFill_ScaleToFit);
             normalMat.setRectToRect(fNormTex[i], r, SkMatrix::kFill_ScaleToFit);
 
             SkMatrix m;
             m.setRSXform(xforms[i]);
 
             // TODO: correctly pull out the pure rotation
             SkVector invNormRotation = { m[SkMatrix::kMScaleX], m[SkMatrix::kMSkewY] };
             SkASSERT(SkScalarNearlyEqual(invNormRotation.lengthSqd(), SK_Scalar1));
 
-            paint.setShader(SkLightingShader::Make(fAtlas, fAtlas, fLights,
-                                                   invNormRotation, &diffMat, &normalMat));
+            auto normalSource = SkLightingShader::NormalMapSource::Make(fAtlas, invNormRotation,
+                                                                        &normalMat);
+            paint.setShader(SkLightingShader::Make(fAtlas, fLights, &diffMat,
+                                                   std::move(normalSource)));
 
             canvas->save();
                 canvas->setMatrix(m);
                 canvas->drawRect(r, paint);
             canvas->restore();
         }
 #endif
 
 #ifdef SK_DEBUG
         {
@@ skipping 356 matching lines @@
 private:
     SkAutoTUnref<DrawLitAtlasDrawable> fDrawable;
 
     typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new DrawLitAtlasView; }
 static SkViewRegister reg(MyFactory);