aboutsummaryrefslogtreecommitdiffstats
path: root/src/effects/SkBlurMaskFilter.cpp
blob: b74cd99bcf40fc165cf2bc602bfa9e8ca3fb8f21 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
/* libs/graphics/effects/SkBlurMaskFilter.cpp
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License"); 
** you may not use this file except in compliance with the License. 
** You may obtain a copy of the License at 
**
**     http://www.apache.org/licenses/LICENSE-2.0 
**
** Unless required by applicable law or agreed to in writing, software 
** distributed under the License is distributed on an "AS IS" BASIS, 
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
** See the License for the specific language governing permissions and 
** limitations under the License.
*/

#include "SkBlurMaskFilter.h"
#include "SkBlurMask.h"
#include "SkBuffer.h"
#include "SkMaskFilter.h"

class SkBlurMaskFilterImpl : public SkMaskFilter {
public:
    SkBlurMaskFilterImpl(SkScalar radius, SkBlurMaskFilter::BlurStyle style);

    // overrides from SkMaskFilter
    virtual SkMask::Format getFormat();
    virtual bool filterMask(SkMask* dst, const SkMask& src, const SkMatrix& matrix, SkIPoint* margin);

    // overrides from SkFlattenable
    // This method is not exported to java.
    virtual Factory getFactory();
    // This method is not exported to java.
    virtual void flatten(SkFlattenableWriteBuffer&);

    static SkFlattenable* CreateProc(SkFlattenableReadBuffer&);

private:
    SkScalar                    fRadius;
    SkBlurMaskFilter::BlurStyle fBlurStyle;

    SkBlurMaskFilterImpl(SkFlattenableReadBuffer&);
    
    typedef SkMaskFilter INHERITED;
};

SkMaskFilter* SkBlurMaskFilter::Create(SkScalar radius, SkBlurMaskFilter::BlurStyle style)
{
    if (radius <= 0 || (unsigned)style >= SkBlurMaskFilter::kBlurStyleCount)
        return NULL;

    return SkNEW_ARGS(SkBlurMaskFilterImpl, (radius, style));
}

/////////////////////////////////////////////////////////////////////////////////////////////////////////

SkBlurMaskFilterImpl::SkBlurMaskFilterImpl(SkScalar radius, SkBlurMaskFilter::BlurStyle style)
    : fRadius(radius), fBlurStyle(style)
{
#if 0
    fGamma = NULL;
    if (gammaScale)
    {
        fGamma = new U8[256];
        if (gammaScale > 0)
            SkBlurMask::BuildSqrGamma(fGamma, gammaScale);
        else
            SkBlurMask::BuildSqrtGamma(fGamma, -gammaScale);
    }
#endif
    SkASSERT(radius >= 0);
    SkASSERT((unsigned)style < SkBlurMaskFilter::kBlurStyleCount);
}

SkMask::Format SkBlurMaskFilterImpl::getFormat()
{
    return SkMask::kA8_Format;
}

bool SkBlurMaskFilterImpl::filterMask(SkMask* dst, const SkMask& src, const SkMatrix& matrix, SkIPoint* margin)
{
    SkScalar radius = matrix.mapRadius(fRadius);
    // To avoid unseemly allocation requests (esp. for finite platforms like
    // handset) we limit the radius so something manageable. (as opposed to
    // a request like 10,000)
    static const SkScalar MAX_RADIUS = SkIntToScalar(128);
    radius = SkMinScalar(radius, MAX_RADIUS);

    if (SkBlurMask::Blur(dst, src, radius, (SkBlurMask::Style)fBlurStyle))
    {
        if (margin) {
            // we need to integralize radius for our margin, so take the ceil
            // just to be safe.
            margin->set(SkScalarCeil(radius), SkScalarCeil(radius));
        }
        return true;
    }
    return false;
}

SkFlattenable* SkBlurMaskFilterImpl::CreateProc(SkFlattenableReadBuffer& buffer)
{
    return SkNEW_ARGS(SkBlurMaskFilterImpl, (buffer));
}

SkFlattenable::Factory SkBlurMaskFilterImpl::getFactory()
{
    return CreateProc;
}

SkBlurMaskFilterImpl::SkBlurMaskFilterImpl(SkFlattenableReadBuffer& buffer) : SkMaskFilter(buffer)
{
    fRadius = buffer.readScalar();
    fBlurStyle = (SkBlurMaskFilter::BlurStyle)buffer.readS32();
    SkASSERT(fRadius >= 0);
    SkASSERT((unsigned)fBlurStyle < SkBlurMaskFilter::kBlurStyleCount);
}

void SkBlurMaskFilterImpl::flatten(SkFlattenableWriteBuffer& buffer)
{
    this->INHERITED::flatten(buffer);
    buffer.writeScalar(fRadius);
    buffer.write32(fBlurStyle);
}

///////////////////////////////////////////////////////////////////////////////

static SkFlattenable::Registrar gReg("SkBlurMaskFilter",
                                     SkBlurMaskFilterImpl::CreateProc);