SkDropShadowImageFilter.cpp revision 24ddde97581624777feebc9e95ae558282f95d4c 
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 "SkDropShadowImageFilter.h"
9
10#include "SkBitmap.h"
11#include "SkBlurImageFilter.h"
12#include "SkCanvas.h"
13#include "SkColorMatrixFilter.h"
14#include "SkDevice.h"
15#include "SkFlattenableBuffers.h"
16
17SkDropShadowImageFilter::SkDropShadowImageFilter(SkScalar dx, SkScalar dy, SkScalar sigma, SkColor color, SkImageFilter* input)
18    : SkImageFilter(input)
19    , fDx(dx)
20    , fDy(dy)
21    , fSigma(sigma)
22    , fColor(color)
23{
24}
25
26SkDropShadowImageFilter::SkDropShadowImageFilter(SkFlattenableReadBuffer& buffer) : INHERITED(buffer)
27{
28    fDx = buffer.readScalar();
29    fDy = buffer.readScalar();
30    fSigma = buffer.readScalar();
31    fColor = buffer.readColor();
32}
33
34void SkDropShadowImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const
35{
36    this->INHERITED::flatten(buffer);
37    buffer.writeScalar(fDx);
38    buffer.writeScalar(fDy);
39    buffer.writeScalar(fSigma);
40    buffer.writeColor(fColor);
41}
42
43bool SkDropShadowImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source, const SkMatrix& matrix, SkBitmap* result, SkIPoint* loc)
44{
45    SkBitmap src = source;
46    if (getInput(0) && !getInput(0)->filterImage(proxy, source, matrix, &src, loc))
47        return false;
48
49    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(src.width(), src.height()));
50    SkCanvas canvas(device.get());
51
52    SkAutoTUnref<SkImageFilter> blurFilter(new SkBlurImageFilter(fSigma, fSigma));
53    SkAutoTUnref<SkColorFilter> colorFilter(SkColorFilter::CreateModeFilter(fColor, SkXfermode::kSrcIn_Mode));
54    SkPaint paint;
55    paint.setImageFilter(blurFilter.get());
56    paint.setColorFilter(colorFilter.get());
57    paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
58    canvas.drawBitmap(src, fDx, fDy, &paint);
59    canvas.drawBitmap(src, 0, 0);
60    *result = device->accessBitmap(false);
61    return true;
62}
63