aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/effects/SkEmbossMaskFilter.cpp
blob: 4caef9ef0ba8349cf6a14e23736f983425bee26c (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
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
/*
 * Copyright 2006 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkEmbossMaskFilter.h"
#include "SkBlurMaskFilter.h"
#include "SkBlurMask.h"
#include "SkEmbossMask.h"
#include "SkReadBuffer.h"
#include "SkWriteBuffer.h"
#include "SkString.h"

sk_sp<SkMaskFilter> SkEmbossMaskFilter::Make(SkScalar blurSigma, const Light& light) {
    return sk_sp<SkMaskFilter>(new SkEmbossMaskFilter(blurSigma, light));
}

#ifdef SK_SUPPORT_LEGACY_EMBOSSMASKFILTER
sk_sp<SkMaskFilter> SkBlurMaskFilter::MakeEmboss(SkScalar blurSigma, const SkScalar direction[3],
                                                 SkScalar ambient, SkScalar specular) {
    if (direction == nullptr) {
        return nullptr;
    }

    SkEmbossMaskFilter::Light   light;

    memcpy(light.fDirection, direction, sizeof(light.fDirection));
    // ambient should be 0...1 as a scalar
    light.fAmbient = SkUnitScalarClampToByte(ambient);
    // specular should be 0..15.99 as a scalar
    static const SkScalar kSpecularMultiplier = SkIntToScalar(255) / 16;
    light.fSpecular = static_cast<U8CPU>(SkScalarPin(specular, 0, 16) * kSpecularMultiplier + 0.5);

    return SkEmbossMaskFilter::Make(blurSigma, light);
}
#endif

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

static void normalize(SkScalar v[3]) {
    SkScalar mag = SkScalarSquare(v[0]) + SkScalarSquare(v[1]) + SkScalarSquare(v[2]);
    mag = SkScalarSqrt(mag);

    for (int i = 0; i < 3; i++) {
        v[i] /= mag;
    }
}

SkEmbossMaskFilter::SkEmbossMaskFilter(SkScalar blurSigma, const Light& light)
    : fLight(light), fBlurSigma(blurSigma) {
    normalize(fLight.fDirection);
}

SkMask::Format SkEmbossMaskFilter::getFormat() const {
    return SkMask::k3D_Format;
}

bool SkEmbossMaskFilter::filterMask(SkMask* dst, const SkMask& src,
                                    const SkMatrix& matrix, SkIPoint* margin) const {
    SkScalar sigma = matrix.mapRadius(fBlurSigma);

    if (!SkBlurMask::BoxBlur(dst, src, sigma, kInner_SkBlurStyle, kLow_SkBlurQuality)) {
        return false;
    }

    dst->fFormat = SkMask::k3D_Format;
    if (margin) {
        margin->set(SkScalarCeilToInt(3*sigma), SkScalarCeilToInt(3*sigma));
    }

    if (src.fImage == nullptr) {
        return true;
    }

    // create a larger buffer for the other two channels (should force fBlur to do this for us)

    {
        uint8_t* alphaPlane = dst->fImage;
        size_t   planeSize = dst->computeImageSize();
        if (0 == planeSize) {
            return false;   // too big to allocate, abort
        }
        dst->fImage = SkMask::AllocImage(planeSize * 3);
        memcpy(dst->fImage, alphaPlane, planeSize);
        SkMask::FreeImage(alphaPlane);
    }

    // run the light direction through the matrix...
    Light   light = fLight;
    matrix.mapVectors((SkVector*)(void*)light.fDirection,
                      (SkVector*)(void*)fLight.fDirection, 1);

    // now restore the length of the XY component
    // cast to SkVector so we can call setLength (this double cast silences alias warnings)
    SkVector* vec = (SkVector*)(void*)light.fDirection;
    vec->setLength(light.fDirection[0],
                   light.fDirection[1],
                   SkPoint::Length(fLight.fDirection[0], fLight.fDirection[1]));

    SkEmbossMask::Emboss(dst, light);

    // restore original alpha
    memcpy(dst->fImage, src.fImage, src.computeImageSize());

    return true;
}

sk_sp<SkFlattenable> SkEmbossMaskFilter::CreateProc(SkReadBuffer& buffer) {
    Light light;
    if (buffer.readByteArray(&light, sizeof(Light))) {
        light.fPad = 0; // for the font-cache lookup to be clean
        const SkScalar sigma = buffer.readScalar();
        return Make(sigma, light);
    }
    return nullptr;
}

void SkEmbossMaskFilter::flatten(SkWriteBuffer& buffer) const {
    Light tmpLight = fLight;
    tmpLight.fPad = 0;    // for the font-cache lookup to be clean
    buffer.writeByteArray(&tmpLight, sizeof(tmpLight));
    buffer.writeScalar(fBlurSigma);
}

#ifndef SK_IGNORE_TO_STRING
void SkEmbossMaskFilter::toString(SkString* str) const {
    str->append("SkEmbossMaskFilter: (");

    str->append("direction: (");
    str->appendScalar(fLight.fDirection[0]);
    str->append(", ");
    str->appendScalar(fLight.fDirection[1]);
    str->append(", ");
    str->appendScalar(fLight.fDirection[2]);
    str->append(") ");

    str->appendf("ambient: %d specular: %d ",
        fLight.fAmbient, fLight.fSpecular);

    str->append("blurSigma: ");
    str->appendScalar(fBlurSigma);
    str->append(")");
}
#endif