1#include "SkBlurDrawLooper.h"
2#include "SkBlurMaskFilter.h"
3#include "SkCanvas.h"
4#include "SkPaint.h"
5#include "SkMaskFilter.h"
6
7SkBlurDrawLooper::SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy,
8                                   SkColor color)
9    : fDx(dx), fDy(dy), fBlurColor(color)
10{
11    if (radius > 0)
12        fBlur = SkBlurMaskFilter::Create(radius,
13                                         SkBlurMaskFilter::kNormal_BlurStyle);
14    else
15        fBlur = NULL;
16}
17
18SkBlurDrawLooper::SkBlurDrawLooper(SkFlattenableReadBuffer& buffer)
19{
20    fDx = buffer.readScalar();
21    fDy = buffer.readScalar();
22    fBlurColor = buffer.readU32();
23    fBlur = static_cast<SkMaskFilter*>(buffer.readFlattenable());
24}
25
26SkBlurDrawLooper::~SkBlurDrawLooper()
27{
28    fBlur->safeUnref();
29}
30
31void SkBlurDrawLooper::flatten(SkFlattenableWriteBuffer& buffer)
32{
33    buffer.writeScalar(fDx);
34    buffer.writeScalar(fDy);
35    buffer.write32(fBlurColor);
36    buffer.writeFlattenable(fBlur);
37}
38
39void SkBlurDrawLooper::init(SkCanvas* canvas, SkPaint* paint)
40{
41    // we do nothing if a maskfilter is already installed
42    if (paint->getMaskFilter() != NULL)
43        fState = kDone;
44    else
45    {
46        fState = kBeforeEdge;
47        fPaint = paint;
48        fCanvas = canvas;
49        fSaveCount = canvas->getSaveCount();
50    }
51}
52
53bool SkBlurDrawLooper::next()
54{
55    switch (fState) {
56    case kBeforeEdge:
57        fSavedColor = fPaint->getColor();
58        fPaint->setColor(fBlurColor);
59        fPaint->setMaskFilter(fBlur);
60        fCanvas->save(SkCanvas::kMatrix_SaveFlag);
61        fCanvas->translate(fDx, fDy);
62        fState = kAfterEdge;
63        return true;
64    case kAfterEdge:
65        fPaint->setColor(fSavedColor);
66        fPaint->setMaskFilter(NULL);
67        fCanvas->restore(); // to remove the translate we did earlier
68        fState = kDone;
69        return true;
70    default:
71        SkASSERT(kDone == fState);
72        return false;
73    }
74}
75
76void SkBlurDrawLooper::restore()
77{
78    if (kAfterEdge == fState)
79    {
80        fPaint->setColor(fSavedColor);
81        fPaint->setMaskFilter(NULL);
82        fCanvas->restore(); // to remove the translate we did earlier
83        fState = kDone;
84    }
85}
86
87///////////////////////////////////////////////////////////////////////////////
88
89static SkFlattenable::Registrar gReg("SkBlurDrawLooper",
90                                     SkBlurDrawLooper::CreateProc);
91
92