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/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkSGText.h"
#include "SkCanvas.h"
#include "SkPaint.h"
#include "SkPath.h"
#include "SkTArray.h"
#include "SkTextBlob.h"
#include "SkTypeface.h"
namespace sksg {
sk_sp<Text> Text::Make(sk_sp<SkTypeface> tf, const SkString& text) {
return sk_sp<Text>(new Text(std::move(tf), text));
}
Text::Text(sk_sp<SkTypeface> tf, const SkString& text)
: fTypeface(std::move(tf))
, fText(text) {}
Text::~Text() = default;
SkPoint Text::alignedPosition(SkScalar advance) const {
auto aligned = fPosition;
switch (fAlign) {
case SkPaint::kLeft_Align:
break;
case SkPaint::kCenter_Align:
aligned.offset(-advance / 2, 0);
break;
case SkPaint::kRight_Align:
aligned.offset(-advance, 0);
break;
}
return aligned;
}
SkRect Text::onRevalidate(InvalidationController*, const SkMatrix&) {
// TODO: we could potentially track invals which don't require rebuilding the blob.
SkPaint font;
font.setFlags(fFlags);
font.setTypeface(fTypeface);
font.setTextSize(fSize);
font.setTextScaleX(fScaleX);
font.setTextSkewX(fSkewX);
font.setHinting(fHinting);
// N.B.: fAlign is applied externally (in alignedPosition()), because
// 1) SkTextBlob has some trouble computing accurate bounds with alignment.
// 2) SkPaint::Align is slated for deprecation.
// First, convert to glyphIDs.
font.setTextEncoding(SkPaint::kUTF8_TextEncoding);
SkSTArray<256, SkGlyphID, true> glyphs;
glyphs.reset(font.textToGlyphs(fText.c_str(), fText.size(), nullptr));
SkAssertResult(font.textToGlyphs(fText.c_str(), fText.size(), glyphs.begin()) == glyphs.count());
font.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
// Next, build the cached blob.
SkTextBlobBuilder builder;
const auto& buf = builder.allocRun(font, glyphs.count(), 0, 0, nullptr);
if (!buf.glyphs) {
fBlob.reset();
return SkRect::MakeEmpty();
}
memcpy(buf.glyphs, glyphs.begin(), glyphs.count() * sizeof(SkGlyphID));
fBlob = builder.make();
if (!fBlob) {
return SkRect::MakeEmpty();
}
const auto& bounds = fBlob->bounds();
const auto aligned_pos = this->alignedPosition(bounds.width());
return bounds.makeOffset(aligned_pos.x(), aligned_pos.y());
}
void Text::onDraw(SkCanvas* canvas, const SkPaint& paint) const {
const auto aligned_pos = this->alignedPosition(this->bounds().width());
canvas->drawTextBlob(fBlob, aligned_pos.x(), aligned_pos.y(), paint);
}
SkPath Text::onAsPath() const {
// TODO
return SkPath();
}
void Text::onClip(SkCanvas* canvas, bool antiAlias) const {
canvas->clipPath(this->asPath(), antiAlias);
}
} // namespace sksg
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