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      1 /*
      2  * Copyright 2011 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 #include "SkBitmapProcShader.h"
      9 
     10 #include "SkArenaAlloc.h"
     11 #include "SkBitmapProcState.h"
     12 #include "SkBitmapProvider.h"
     13 #include "SkPM4fPriv.h"
     14 #include "SkXfermodePriv.h"
     15 
     16 static bool only_scale_and_translate(const SkMatrix& matrix) {
     17     unsigned mask = SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask;
     18     return (matrix.getType() & ~mask) == 0;
     19 }
     20 
     21 class BitmapProcInfoContext : public SkShaderBase::Context {
     22 public:
     23     // The info has been allocated elsewhere, but we are responsible for calling its destructor.
     24     BitmapProcInfoContext(const SkShaderBase& shader, const SkShaderBase::ContextRec& rec,
     25                             SkBitmapProcInfo* info)
     26         : INHERITED(shader, rec)
     27         , fInfo(info)
     28     {
     29         fFlags = 0;
     30         if (fInfo->fPixmap.isOpaque() && (255 == this->getPaintAlpha())) {
     31             fFlags |= SkShaderBase::kOpaqueAlpha_Flag;
     32         }
     33 
     34         if (1 == fInfo->fPixmap.height() && only_scale_and_translate(this->getTotalInverse())) {
     35             fFlags |= SkShaderBase::kConstInY32_Flag;
     36         }
     37     }
     38 
     39     uint32_t getFlags() const override { return fFlags; }
     40 
     41 private:
     42     SkBitmapProcInfo*   fInfo;
     43     uint32_t            fFlags;
     44 
     45     typedef SkShaderBase::Context INHERITED;
     46 };
     47 
     48 ///////////////////////////////////////////////////////////////////////////////////////////////////
     49 
     50 class BitmapProcShaderContext : public BitmapProcInfoContext {
     51 public:
     52     BitmapProcShaderContext(const SkShaderBase& shader, const SkShaderBase::ContextRec& rec,
     53                             SkBitmapProcState* state)
     54         : INHERITED(shader, rec, state)
     55         , fState(state)
     56     {}
     57 
     58     void shadeSpan(int x, int y, SkPMColor dstC[], int count) override {
     59         const SkBitmapProcState& state = *fState;
     60         if (state.getShaderProc32()) {
     61             state.getShaderProc32()(&state, x, y, dstC, count);
     62             return;
     63         }
     64 
     65         const int BUF_MAX = 128;
     66         uint32_t buffer[BUF_MAX];
     67         SkBitmapProcState::MatrixProc   mproc = state.getMatrixProc();
     68         SkBitmapProcState::SampleProc32 sproc = state.getSampleProc32();
     69         const int max = state.maxCountForBufferSize(sizeof(buffer[0]) * BUF_MAX);
     70 
     71         SkASSERT(state.fPixmap.addr());
     72 
     73         for (;;) {
     74             int n = SkTMin(count, max);
     75             SkASSERT(n > 0 && n < BUF_MAX*2);
     76             mproc(state, buffer, n, x, y);
     77             sproc(state, buffer, n, dstC);
     78 
     79             if ((count -= n) == 0) {
     80                 break;
     81             }
     82             SkASSERT(count > 0);
     83             x += n;
     84             dstC += n;
     85         }
     86     }
     87 
     88 private:
     89     SkBitmapProcState*  fState;
     90 
     91     typedef BitmapProcInfoContext INHERITED;
     92 };
     93 
     94 ///////////////////////////////////////////////////////////////////////////////////////////////////
     95 
     96 SkShaderBase::Context* SkBitmapProcLegacyShader::MakeContext(
     97     const SkShaderBase& shader, TileMode tmx, TileMode tmy,
     98     const SkBitmapProvider& provider, const ContextRec& rec, SkArenaAlloc* alloc)
     99 {
    100     SkMatrix totalInverse;
    101     // Do this first, so we know the matrix can be inverted.
    102     if (!shader.computeTotalInverse(*rec.fMatrix, rec.fLocalMatrix, &totalInverse)) {
    103         return nullptr;
    104     }
    105 
    106     SkBitmapProcState* state = alloc->make<SkBitmapProcState>(provider, tmx, tmy);
    107     if (!state->setup(totalInverse, *rec.fPaint)) {
    108         return nullptr;
    109     }
    110     return alloc->make<BitmapProcShaderContext>(shader, rec, state);
    111 }
    112