1/*
2 * Copyright 2018 Google Inc.
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 "SkSGText.h"
9
10#include "SkCanvas.h"
11#include "SkPaint.h"
12#include "SkPath.h"
13#include "SkTArray.h"
14#include "SkTextBlob.h"
15#include "SkTypeface.h"
16
17namespace sksg {
18
19sk_sp<Text> Text::Make(sk_sp<SkTypeface> tf, const SkString& text) {
20    return sk_sp<Text>(new Text(std::move(tf), text));
21}
22
23Text::Text(sk_sp<SkTypeface> tf, const SkString& text)
24    : fTypeface(std::move(tf))
25    , fText(text) {}
26
27Text::~Text() = default;
28
29SkRect Text::onRevalidate(InvalidationController*, const SkMatrix&) {
30    // TODO: we could potentially track invals which don't require rebuilding the blob.
31
32    SkPaint font;
33    font.setFlags(fFlags);
34    font.setTypeface(fTypeface);
35    font.setTextSize(fSize);
36    font.setTextScaleX(fScaleX);
37    font.setTextSkewX(fSkewX);
38    font.setTextAlign(fAlign);
39    font.setHinting(fHinting);
40
41    // First, convert to glyphIDs.
42    font.setTextEncoding(SkPaint::kUTF8_TextEncoding);
43    SkSTArray<256, SkGlyphID, true> glyphs;
44    glyphs.reset(font.textToGlyphs(fText.c_str(), fText.size(), nullptr));
45    SkAssertResult(font.textToGlyphs(fText.c_str(), fText.size(), glyphs.begin()) == glyphs.count());
46    font.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
47
48    // Next, build the cached blob.
49    SkTextBlobBuilder builder;
50    const auto& buf = builder.allocRun(font, glyphs.count(), 0, 0, nullptr);
51    if (!buf.glyphs) {
52        fBlob.reset();
53        return SkRect::MakeEmpty();
54    }
55
56    memcpy(buf.glyphs, glyphs.begin(), glyphs.count() * sizeof(SkGlyphID));
57
58    fBlob = builder.make();
59    return fBlob
60        ? fBlob->bounds().makeOffset(fPosition.x(), fPosition.y())
61        : SkRect::MakeEmpty();
62}
63
64void Text::onDraw(SkCanvas* canvas, const SkPaint& paint) const {
65    canvas->drawTextBlob(fBlob, fPosition.x(), fPosition.y(), paint);
66}
67
68SkPath Text::onAsPath() const {
69    // TODO
70    return SkPath();
71}
72
73void Text::onClip(SkCanvas* canvas, bool antiAlias) const {
74    canvas->clipPath(this->asPath(), antiAlias);
75}
76
77} // namespace sksg
78