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      1 /*
      2  * Copyright 2013 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #ifndef SkMatrixUtils_DEFINED
      9 #define SkMatrixUtils_DEFINED
     10 
     11 #include "SkPoint.h"
     12 #include "SkSize.h"
     13 
     14 class SkMatrix;
     15 class SkPaint;
     16 
     17 /**
     18  *  Given a matrix, size and paint, return true if the computed dst-rect would
     19  *  align such that there is a 1-to-1 coorspondence between src and dst pixels.
     20  *  This can be called by drawing code to see if drawBitmap can be turned into
     21  *  drawSprite (which is faster).
     22  *
     23  *  The src-rect is defined to be { 0, 0, size.width(), size.height() }
     24  */
     25 bool SkTreatAsSprite(const SkMatrix&, const SkISize& size, const SkPaint& paint);
     26 
     27 /** Decomposes the upper-left 2x2 of the matrix into a rotation (represented by
     28     the cosine and sine of the rotation angle), followed by a non-uniform scale,
     29     followed by another rotation. If there is a reflection, one of the scale
     30     factors will be negative.
     31     Returns true if successful. Returns false if the matrix is degenerate.
     32     */
     33 bool SkDecomposeUpper2x2(const SkMatrix& matrix,
     34                          SkPoint* rotation1,
     35                          SkPoint* scale,
     36                          SkPoint* rotation2);
     37 
     38 #endif
     39