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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 "SkReadBuffer.h"
     13 #include "SkWriteBuffer.h"
     14 #include "SkMatrix.h"
     15 #include "SkPaint.h"
     16 #include "SkShader.h"
     17 #include "SkValidationUtils.h"
     18 
     19 bool SkTileImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& src,
     20                                       const Context& ctx,
     21                                       SkBitmap* dst, SkIPoint* offset) const {
     22     SkBitmap source = src;
     23     SkImageFilter* input = getInput(0);
     24     SkIPoint srcOffset = SkIPoint::Make(0, 0);
     25     if (input && !input->filterImage(proxy, src, ctx, &source, &srcOffset)) {
     26         return false;
     27     }
     28 
     29     SkRect dstRect;
     30     ctx.ctm().mapRect(&dstRect, fDstRect);
     31     SkIRect dstIRect;
     32     dstRect.roundOut(&dstIRect);
     33     int w = dstIRect.width();
     34     int h = dstIRect.height();
     35     if (!fSrcRect.width() || !fSrcRect.height() || !w || !h) {
     36         return false;
     37     }
     38 
     39     SkRect srcRect;
     40     ctx.ctm().mapRect(&srcRect, fSrcRect);
     41     SkIRect srcIRect;
     42     srcRect.roundOut(&srcIRect);
     43     srcIRect.offset(-srcOffset);
     44     SkBitmap subset;
     45     SkIRect bounds;
     46     source.getBounds(&bounds);
     47 
     48     if (!srcIRect.intersect(bounds)) {
     49         offset->fX = offset->fY = 0;
     50         return true;
     51     } else if (!source.extractSubset(&subset, srcIRect)) {
     52         return false;
     53     }
     54 
     55     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(w, h));
     56     if (NULL == device.get()) {
     57         return false;
     58     }
     59     SkCanvas canvas(device);
     60     SkPaint paint;
     61     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
     62 
     63     SkMatrix shaderMatrix;
     64     shaderMatrix.setTranslate(SkIntToScalar(srcOffset.fX),
     65                               SkIntToScalar(srcOffset.fY));
     66     SkAutoTUnref<SkShader> shader(SkShader::CreateBitmapShader(subset,
     67                                   SkShader::kRepeat_TileMode, SkShader::kRepeat_TileMode,
     68                                   &shaderMatrix));
     69     paint.setShader(shader);
     70     canvas.translate(-dstRect.fLeft, -dstRect.fTop);
     71     canvas.drawRect(dstRect, paint);
     72     *dst = device->accessBitmap(false);
     73     offset->fX = dstIRect.fLeft;
     74     offset->fY = dstIRect.fTop;
     75     return true;
     76 }
     77 
     78 bool SkTileImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
     79                                        SkIRect* dst) const {
     80     SkRect srcRect;
     81     ctm.mapRect(&srcRect, fSrcRect);
     82     SkIRect srcIRect;
     83     srcRect.roundOut(&srcIRect);
     84     srcIRect.join(src);
     85     *dst = srcIRect;
     86     return true;
     87 }
     88 
     89 SkTileImageFilter::SkTileImageFilter(SkReadBuffer& buffer)
     90   : INHERITED(1, buffer) {
     91     buffer.readRect(&fSrcRect);
     92     buffer.readRect(&fDstRect);
     93     buffer.validate(buffer.isValid() && SkIsValidRect(fSrcRect) && SkIsValidRect(fDstRect));
     94 }
     95 
     96 void SkTileImageFilter::flatten(SkWriteBuffer& buffer) const {
     97     this->INHERITED::flatten(buffer);
     98     buffer.writeRect(fSrcRect);
     99     buffer.writeRect(fDstRect);
    100 }
    101