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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 #include "SkTileImageFilter.h"
      9 #include "SkBitmap.h"
     10 #include "SkCanvas.h"
     11 #include "SkDevice.h"
     12 #include "SkFlattenableBuffers.h"
     13 #include "SkMatrix.h"
     14 #include "SkPaint.h"
     15 #include "SkShader.h"
     16 #include "SkValidationUtils.h"
     17 
     18 bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm,
     19                                       SkBitmap* dst, SkIPoint* offset) {
     20     SkBitmap source = src;
     21     SkImageFilter* input = getInput(0);
     22     SkIPoint localOffset = SkIPoint::Make(0, 0);
     23     if (input && !input->filterImage(proxy, src, ctm, &source, &localOffset)) {
     24         return false;
     25     }
     26 
     27     SkRect dstRect;
     28     ctm.mapRect(&dstRect, fDstRect);
     29     int w = SkScalarCeilToInt(dstRect.width());
     30     int h = SkScalarCeilToInt(dstRect.height());
     31     if (!fSrcRect.width() || !fSrcRect.height() || !w || !h) {
     32         return false;
     33     }
     34 
     35     SkRect srcRect;
     36     ctm.mapRect(&srcRect, fSrcRect);
     37     SkIRect srcIRect;
     38     srcRect.roundOut(&srcIRect);
     39     SkBitmap subset;
     40     SkIRect bounds;
     41     source.getBounds(&bounds);
     42     if (!srcIRect.intersect(bounds)) {
     43         return true;
     44     } else if (!source.extractSubset(&subset, srcIRect)) {
     45         return false;
     46     }
     47 
     48     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(w, h));
     49     if (NULL == device.get()) {
     50         return false;
     51     }
     52     SkCanvas canvas(device);
     53     SkPaint paint;
     54     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
     55 
     56     SkAutoTUnref<SkShader> shader(SkShader::CreateBitmapShader(subset,
     57                                   SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode));
     58     paint.setShader(shader);
     59     dstRect.offset(SkIntToScalar(localOffset.fX), SkIntToScalar(localOffset.fY));
     60     canvas.drawRect(dstRect, paint);
     61     *dst = device->accessBitmap(false);
     62     return true;
     63 }
     64 
     65 SkTileImageFilter::SkTileImageFilter(SkFlattenableReadBuffer& buffer)
     66   : INHERITED(1, buffer) {
     67     buffer.readRect(&fSrcRect);
     68     buffer.readRect(&fDstRect);
     69     buffer.validate(buffer.isValid() && SkIsValidRect(fSrcRect) && SkIsValidRect(fDstRect));
     70 }
     71 
     72 void SkTileImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
     73     this->INHERITED::flatten(buffer);
     74     buffer.writeRect(fSrcRect);
     75     buffer.writeRect(fDstRect);
     76 }
     77