1/*
2 * Copyright 2006 The Android Open Source Project
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 "SkEmbossMaskFilter.h"
9#include "SkBlurMaskFilter.h"
10#include "SkBlurMask.h"
11#include "SkEmbossMask.h"
12#include "SkReadBuffer.h"
13#include "SkWriteBuffer.h"
14#include "SkString.h"
15
16SkEmbossMaskFilter* SkEmbossMaskFilter::Create(SkScalar blurSigma, const Light& light) {
17    return SkNEW_ARGS(SkEmbossMaskFilter, (blurSigma, light));
18}
19
20static inline int pin2byte(int n) {
21    if (n < 0) {
22        n = 0;
23    } else if (n > 0xFF) {
24        n = 0xFF;
25    }
26    return n;
27}
28
29SkMaskFilter* SkBlurMaskFilter::CreateEmboss(const SkScalar direction[3],
30                                             SkScalar ambient, SkScalar specular,
31                                             SkScalar blurRadius) {
32    return SkBlurMaskFilter::CreateEmboss(SkBlurMask::ConvertRadiusToSigma(blurRadius),
33                                          direction, ambient, specular);
34}
35
36SkMaskFilter* SkBlurMaskFilter::CreateEmboss(SkScalar blurSigma, const SkScalar direction[3],
37                                             SkScalar ambient, SkScalar specular) {
38    if (direction == NULL) {
39        return NULL;
40    }
41
42    // ambient should be 0...1 as a scalar
43    int am = pin2byte(SkScalarToFixed(ambient) >> 8);
44
45    // specular should be 0..15.99 as a scalar
46    int sp = pin2byte(SkScalarToFixed(specular) >> 12);
47
48    SkEmbossMaskFilter::Light   light;
49
50    memcpy(light.fDirection, direction, sizeof(light.fDirection));
51    light.fAmbient = SkToU8(am);
52    light.fSpecular = SkToU8(sp);
53
54    return SkEmbossMaskFilter::Create(blurSigma, light);
55}
56
57///////////////////////////////////////////////////////////////////////////////
58
59static void normalize(SkScalar v[3]) {
60    SkScalar mag = SkScalarSquare(v[0]) + SkScalarSquare(v[1]) + SkScalarSquare(v[2]);
61    mag = SkScalarSqrt(mag);
62
63    for (int i = 0; i < 3; i++) {
64        v[i] /= mag;
65    }
66}
67
68SkEmbossMaskFilter::SkEmbossMaskFilter(SkScalar blurSigma, const Light& light)
69    : fLight(light), fBlurSigma(blurSigma) {
70    normalize(fLight.fDirection);
71}
72
73SkMask::Format SkEmbossMaskFilter::getFormat() const {
74    return SkMask::k3D_Format;
75}
76
77bool SkEmbossMaskFilter::filterMask(SkMask* dst, const SkMask& src,
78                                    const SkMatrix& matrix, SkIPoint* margin) const {
79    SkScalar sigma = matrix.mapRadius(fBlurSigma);
80
81    if (!SkBlurMask::BoxBlur(dst, src, sigma, kInner_SkBlurStyle, kLow_SkBlurQuality)) {
82        return false;
83    }
84
85    dst->fFormat = SkMask::k3D_Format;
86    if (margin) {
87        margin->set(SkScalarCeilToInt(3*sigma), SkScalarCeilToInt(3*sigma));
88    }
89
90    if (src.fImage == NULL) {
91        return true;
92    }
93
94    // create a larger buffer for the other two channels (should force fBlur to do this for us)
95
96    {
97        uint8_t* alphaPlane = dst->fImage;
98        size_t   planeSize = dst->computeImageSize();
99        if (0 == planeSize) {
100            return false;   // too big to allocate, abort
101        }
102        dst->fImage = SkMask::AllocImage(planeSize * 3);
103        memcpy(dst->fImage, alphaPlane, planeSize);
104        SkMask::FreeImage(alphaPlane);
105    }
106
107    // run the light direction through the matrix...
108    Light   light = fLight;
109    matrix.mapVectors((SkVector*)(void*)light.fDirection,
110                      (SkVector*)(void*)fLight.fDirection, 1);
111
112    // now restore the length of the XY component
113    // cast to SkVector so we can call setLength (this double cast silences alias warnings)
114    SkVector* vec = (SkVector*)(void*)light.fDirection;
115    vec->setLength(light.fDirection[0],
116                   light.fDirection[1],
117                   SkPoint::Length(fLight.fDirection[0], fLight.fDirection[1]));
118
119    SkEmbossMask::Emboss(dst, light);
120
121    // restore original alpha
122    memcpy(dst->fImage, src.fImage, src.computeImageSize());
123
124    return true;
125}
126
127SkFlattenable* SkEmbossMaskFilter::CreateProc(SkReadBuffer& buffer) {
128    Light light;
129    if (buffer.readByteArray(&light, sizeof(Light))) {
130        light.fPad = 0; // for the font-cache lookup to be clean
131        const SkScalar sigma = buffer.readScalar();
132        return Create(sigma, light);
133    }
134    return NULL;
135}
136
137void SkEmbossMaskFilter::flatten(SkWriteBuffer& buffer) const {
138    Light tmpLight = fLight;
139    tmpLight.fPad = 0;    // for the font-cache lookup to be clean
140    buffer.writeByteArray(&tmpLight, sizeof(tmpLight));
141    buffer.writeScalar(fBlurSigma);
142}
143
144#ifndef SK_IGNORE_TO_STRING
145void SkEmbossMaskFilter::toString(SkString* str) const {
146    str->append("SkEmbossMaskFilter: (");
147
148    str->append("direction: (");
149    str->appendScalar(fLight.fDirection[0]);
150    str->append(", ");
151    str->appendScalar(fLight.fDirection[1]);
152    str->append(", ");
153    str->appendScalar(fLight.fDirection[2]);
154    str->append(") ");
155
156    str->appendf("ambient: %d specular: %d ",
157        fLight.fAmbient, fLight.fSpecular);
158
159    str->append("blurSigma: ");
160    str->appendScalar(fBlurSigma);
161    str->append(")");
162}
163#endif
164