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      1 /*
      2  * Copyright 2014 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 SkTextMapStateProc_DEFINED
      9 #define SkTextMapStateProc_DEFINED
     10 
     11 #include "SkPoint.h"
     12 #include "SkMatrix.h"
     13 
     14 class SkTextMapStateProc {
     15 public:
     16     SkTextMapStateProc(const SkMatrix& matrix, const SkPoint& offset, int scalarsPerPosition)
     17         : fMatrix(matrix)
     18         , fProc(matrix.getMapXYProc())
     19         , fOffset(offset)
     20         , fScaleX(fMatrix.getScaleX()) {
     21         SkASSERT(1 == scalarsPerPosition || 2 == scalarsPerPosition);
     22         if (1 == scalarsPerPosition) {
     23             unsigned mtype = fMatrix.getType();
     24             if (mtype & (SkMatrix::kAffine_Mask | SkMatrix::kPerspective_Mask)) {
     25                 fMapCase = kX;
     26             } else {
     27                 // Bake the matrix scale/translation components into fOffset,
     28                 // to expedite proc computations.
     29                 fOffset.set(SkScalarMul(offset.x(), fMatrix.getScaleX()) + fMatrix.getTranslateX(),
     30                             SkScalarMul(offset.y(), fMatrix.getScaleY()) + fMatrix.getTranslateY());
     31 
     32                 if (mtype & SkMatrix::kScale_Mask) {
     33                     fMapCase = kOnlyScaleX;
     34                 } else {
     35                     fMapCase = kOnlyTransX;
     36                 }
     37             }
     38         } else {
     39             fMapCase = kXY;
     40         }
     41     }
     42 
     43     void operator()(const SkScalar pos[], SkPoint* loc) const;
     44 
     45 private:
     46     const SkMatrix& fMatrix;
     47     enum {
     48         kXY,
     49         kOnlyScaleX,
     50         kOnlyTransX,
     51         kX
     52     } fMapCase;
     53     const SkMatrix::MapXYProc fProc;
     54     SkPoint  fOffset; // In kOnly* mode, this includes the matrix translation component.
     55     SkScalar fScaleX; // This is only used by kOnly... cases.
     56 };
     57 
     58 inline void SkTextMapStateProc::operator()(const SkScalar pos[], SkPoint* loc) const {
     59     switch(fMapCase) {
     60     case kXY:
     61         fProc(fMatrix, pos[0] + fOffset.x(), pos[1] + fOffset.y(), loc);
     62         break;
     63     case kOnlyScaleX:
     64         loc->set(SkScalarMul(fScaleX, *pos) + fOffset.x(), fOffset.y());
     65         break;
     66     case kOnlyTransX:
     67         loc->set(*pos + fOffset.x(), fOffset.y());
     68         break;
     69     default:
     70         SkASSERT(false);
     71     case kX:
     72         fProc(fMatrix, *pos + fOffset.x(), fOffset.y(), loc);
     73         break;
     74     }
     75 }
     76 
     77 #endif
     78 
     79