aboutsummaryrefslogtreecommitdiffhomepage
path: root/experimental/svg/model/SkSVGRenderContext.cpp
blob: ee92c47d542ea39744f4487e4007f8a5ed916a7c (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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
/*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "SkCanvas.h"
#include "SkSVGAttribute.h"
#include "SkSVGRenderContext.h"
#include "SkSVGTypes.h"

namespace {

SkScalar length_size_for_type(const SkSize& viewport, SkSVGLengthContext::LengthType t) {
    switch (t) {
    case SkSVGLengthContext::LengthType::kHorizontal:
        return viewport.width();
    case SkSVGLengthContext::LengthType::kVertical:
        return viewport.height();
    case SkSVGLengthContext::LengthType::kOther:
        return SkScalarSqrt(viewport.width() * viewport.height());
    }

    SkASSERT(false);  // Not reached.
    return 0;
}

} // anonymous ns

SkScalar SkSVGLengthContext::resolve(const SkSVGLength& l, LengthType t) const {
    switch (l.unit()) {
    case SkSVGLength::Unit::kNumber:
        // Fall through.
    case SkSVGLength::Unit::kPX:
        return l.value();
    case SkSVGLength::Unit::kPercentage:
        return l.value() * length_size_for_type(fViewport, t) / 100;
    default:
        SkDebugf("unsupported unit type: <%d>\n", l.unit());
        return 0;
    }
}

SkRect SkSVGLengthContext::resolveRect(const SkSVGLength& x, const SkSVGLength& y,
                                       const SkSVGLength& w, const SkSVGLength& h) const {
    return SkRect::MakeXYWH(
        this->resolve(x, SkSVGLengthContext::LengthType::kHorizontal),
        this->resolve(y, SkSVGLengthContext::LengthType::kVertical),
        this->resolve(w, SkSVGLengthContext::LengthType::kHorizontal),
        this->resolve(h, SkSVGLengthContext::LengthType::kVertical));
}

namespace {

SkPaint::Cap toSkCap(const SkSVGLineCap& cap) {
    switch (cap.type()) {
    case SkSVGLineCap::Type::kButt:
        return SkPaint::kButt_Cap;
    case SkSVGLineCap::Type::kRound:
        return SkPaint::kRound_Cap;
    case SkSVGLineCap::Type::kSquare:
        return SkPaint::kSquare_Cap;
    default:
        SkASSERT(false);
        return SkPaint::kButt_Cap;
    }
}

SkPaint::Join toSkJoin(const SkSVGLineJoin& join) {
    switch (join.type()) {
    case SkSVGLineJoin::Type::kMiter:
        return SkPaint::kMiter_Join;
    case SkSVGLineJoin::Type::kRound:
        return SkPaint::kRound_Join;
    case SkSVGLineJoin::Type::kBevel:
        return SkPaint::kBevel_Join;
    default:
        SkASSERT(false);
        return SkPaint::kMiter_Join;
    }
}

void applySvgPaint(const SkSVGPaint& svgPaint, SkPaint* p) {
    switch (svgPaint.type()) {
    case SkSVGPaint::Type::kColor:
        p->setColor(SkColorSetA(svgPaint.color(), p->getAlpha()));
        break;
    case SkSVGPaint::Type::kCurrentColor:
        SkDebugf("unimplemented 'currentColor' paint type");
        // Fall through.
    case SkSVGPaint::Type::kNone:
        // Fall through.
    case SkSVGPaint::Type::kInherit:
        break;
    }
}

// Commit the selected attribute to the paint cache.
template <SkSVGAttribute>
void commitToPaint(const SkSVGPresentationAttributes&,
                   const SkSVGLengthContext&,
                   SkSVGPresentationContext*);

template <>
void commitToPaint<SkSVGAttribute::kFill>(const SkSVGPresentationAttributes& attrs,
                                          const SkSVGLengthContext&,
                                          SkSVGPresentationContext* pctx) {
    applySvgPaint(*attrs.fFill.get(), &pctx->fFillPaint);
}

template <>
void commitToPaint<SkSVGAttribute::kStroke>(const SkSVGPresentationAttributes& attrs,
                                            const SkSVGLengthContext&,
                                            SkSVGPresentationContext* pctx) {
    applySvgPaint(*attrs.fStroke.get(), &pctx->fStrokePaint);
}

template <>
void commitToPaint<SkSVGAttribute::kFillOpacity>(const SkSVGPresentationAttributes& attrs,
                                                 const SkSVGLengthContext&,
                                                 SkSVGPresentationContext* pctx) {
    pctx->fFillPaint.setAlpha(static_cast<uint8_t>(*attrs.fFillOpacity.get() * 255));
}

template <>
void commitToPaint<SkSVGAttribute::kStrokeLineCap>(const SkSVGPresentationAttributes& attrs,
                                                   const SkSVGLengthContext&,
                                                   SkSVGPresentationContext* pctx) {
    const auto& cap = *attrs.fStrokeLineCap.get();
    if (cap.type() != SkSVGLineCap::Type::kInherit) {
        pctx->fStrokePaint.setStrokeCap(toSkCap(cap));
    }
}

template <>
void commitToPaint<SkSVGAttribute::kStrokeLineJoin>(const SkSVGPresentationAttributes& attrs,
                                                    const SkSVGLengthContext&,
                                                    SkSVGPresentationContext* pctx) {
    const auto& join = *attrs.fStrokeLineJoin.get();
    if (join.type() != SkSVGLineJoin::Type::kInherit) {
        pctx->fStrokePaint.setStrokeJoin(toSkJoin(join));
    }
}

template <>
void commitToPaint<SkSVGAttribute::kStrokeOpacity>(const SkSVGPresentationAttributes& attrs,
                                                   const SkSVGLengthContext&,
                                                   SkSVGPresentationContext* pctx) {
    pctx->fStrokePaint.setAlpha(static_cast<uint8_t>(*attrs.fStrokeOpacity.get() * 255));
}

template <>
void commitToPaint<SkSVGAttribute::kStrokeWidth>(const SkSVGPresentationAttributes& attrs,
                                                 const SkSVGLengthContext& lctx,
                                                 SkSVGPresentationContext* pctx) {
    auto strokeWidth = lctx.resolve(*attrs.fStrokeWidth.get(),
                                    SkSVGLengthContext::LengthType::kOther);
    pctx->fStrokePaint.setStrokeWidth(strokeWidth);
}

} // anonymous ns

SkSVGPresentationContext::SkSVGPresentationContext()
    : fInherited(SkSVGPresentationAttributes::MakeInitial()) {

    fFillPaint.setStyle(SkPaint::kFill_Style);
    fStrokePaint.setStyle(SkPaint::kStroke_Style);

    // TODO: drive AA off presentation attrs also (shape-rendering?)
    fFillPaint.setAntiAlias(true);
    fStrokePaint.setAntiAlias(true);

    // Commit initial values to the paint cache.
    SkSVGLengthContext dummy(SkSize::Make(0, 0));
    commitToPaint<SkSVGAttribute::kFill>(fInherited, dummy, this);
    commitToPaint<SkSVGAttribute::kFillOpacity>(fInherited, dummy, this);
    commitToPaint<SkSVGAttribute::kStroke>(fInherited, dummy, this);
    commitToPaint<SkSVGAttribute::kStrokeLineCap>(fInherited, dummy, this);
    commitToPaint<SkSVGAttribute::kStrokeLineJoin>(fInherited, dummy, this);
    commitToPaint<SkSVGAttribute::kStrokeOpacity>(fInherited, dummy, this);
    commitToPaint<SkSVGAttribute::kStrokeWidth>(fInherited, dummy, this);
}

SkSVGRenderContext::SkSVGRenderContext(SkCanvas* canvas,
                                       const SkSVGLengthContext& lctx,
                                       const SkSVGPresentationContext& pctx)
    : fLengthContext(lctx)
    , fPresentationContext(pctx)
    , fCanvas(canvas)
    , fCanvasSaveCount(canvas->getSaveCount()) {}

SkSVGRenderContext::SkSVGRenderContext(const SkSVGRenderContext& other)
    : SkSVGRenderContext(other.fCanvas,
                         *other.fLengthContext,
                         *other.fPresentationContext) {}

SkSVGRenderContext::~SkSVGRenderContext() {
    fCanvas->restoreToCount(fCanvasSaveCount);
}

void SkSVGRenderContext::applyPresentationAttributes(const SkSVGPresentationAttributes& attrs) {

#define ApplyLazyInheritedAttribute(ATTR)                                               \
    do {                                                                                \
        /* All attributes should be defined on the inherited context. */                \
        SkASSERT(fPresentationContext->fInherited.f ## ATTR.isValid());                 \
        const auto* value = attrs.f ## ATTR.getMaybeNull();                             \
        if (value && *value != *fPresentationContext->fInherited.f ## ATTR.get()) {     \
            /* Update the local attribute value */                                      \
            fPresentationContext.writable()->fInherited.f ## ATTR.set(*value);          \
            /* Update the cached paints */                                              \
            commitToPaint<SkSVGAttribute::k ## ATTR>(attrs, *fLengthContext,            \
                                                     fPresentationContext.writable());  \
        }                                                                               \
    } while (false)

    ApplyLazyInheritedAttribute(Fill);
    ApplyLazyInheritedAttribute(FillOpacity);
    ApplyLazyInheritedAttribute(Stroke);
    ApplyLazyInheritedAttribute(StrokeLineCap);
    ApplyLazyInheritedAttribute(StrokeLineJoin);
    ApplyLazyInheritedAttribute(StrokeOpacity);
    ApplyLazyInheritedAttribute(StrokeWidth);

#undef ApplyLazyInheritedAttribute
}

const SkPaint* SkSVGRenderContext::fillPaint() const {
    const SkSVGPaint::Type paintType = fPresentationContext->fInherited.fFill.get()->type();
    return paintType != SkSVGPaint::Type::kNone ? &fPresentationContext->fFillPaint : nullptr;
}

const SkPaint* SkSVGRenderContext::strokePaint() const {
    const SkSVGPaint::Type paintType = fPresentationContext->fInherited.fStroke.get()->type();
    return paintType != SkSVGPaint::Type::kNone ? &fPresentationContext->fStrokePaint : nullptr;
}