SkDropShadowImageFilter.cpp revision ba6e954140e45e251d67934ed6ad752149fcf72f 
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    buffer.validate(SkScalarIsFinite(fDx) &&
33                    SkScalarIsFinite(fDy) &&
34                    SkScalarIsFinite(fSigma));
35}
36
37void SkDropShadowImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const
38{
39    this->INHERITED::flatten(buffer);
40    buffer.writeScalar(fDx);
41    buffer.writeScalar(fDy);
42    buffer.writeScalar(fSigma);
43    buffer.writeColor(fColor);
44}
45
46bool SkDropShadowImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source, const SkMatrix& matrix, SkBitmap* result, SkIPoint* loc)
47{
48    SkBitmap src = source;
49    if (getInput(0) && !getInput(0)->filterImage(proxy, source, matrix, &src, loc))
50        return false;
51
52    SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(src.width(), src.height()));
53    SkCanvas canvas(device.get());
54
55    SkAutoTUnref<SkImageFilter> blurFilter(new SkBlurImageFilter(fSigma, fSigma));
56    SkAutoTUnref<SkColorFilter> colorFilter(SkColorFilter::CreateModeFilter(fColor, SkXfermode::kSrcIn_Mode));
57    SkPaint paint;
58    paint.setImageFilter(blurFilter.get());
59    paint.setColorFilter(colorFilter.get());
60    paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
61    canvas.drawBitmap(src, fDx, fDy, &paint);
62    canvas.drawBitmap(src, 0, 0);
63    *result = device->accessBitmap(false);
64    return true;
65}
66