simplify making translate only invmatrix

src/core/SkBitmapProcState.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkBitmapProcState.h"
 #include "SkColorPriv.h"
 #include "SkFilterProc.h"
@@ skipping 161 matching lines @@
                                                             invScaleX,
                                                             invScaleY,
                                                             fScaledBitmap);
         }
         fScaledBitmap.lockPixels();
 
         fBitmap = &fScaledBitmap;
 
         // set the inv matrix type to translate-only;
 
-        fInvMatrix.setTranslate( 1/fInvMatrix.getScaleX() * fInvMatrix.getTranslateX(),
-                                 1/fInvMatrix.getScaleY() * fInvMatrix.getTranslateY() );
+        fInvMatrix.setTranslate(fInvMatrix.getTranslateX() / fInvMatrix.getScaleX(),
+                                fInvMatrix.getTranslateY() / fInvMatrix.getScaleY());
 
         // no need for any further filtering; we just did it!
 
         fFilterLevel = SkPaint::kNone_FilterLevel;
 
         return;
     }
 
     /*
      *  If we get here, the caller has requested either Med or High filter-level
@@ skipping 754 matching lines @@
     } else {
         size >>= 2;
     }
 
     if (fFilterLevel != SkPaint::kNone_FilterLevel) {
         size >>= 1;
     }
 
     return size;
 }