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      1 /*
      2  * Copyright (C) 2014 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "MinikinUtils.h"
     18 
     19 #include <string>
     20 
     21 #include <log/log.h>
     22 
     23 #include "Paint.h"
     24 #include "SkPathMeasure.h"
     25 #include "Typeface.h"
     26 
     27 namespace android {
     28 
     29 minikin::FontStyle MinikinUtils::prepareMinikinPaint(minikin::MinikinPaint* minikinPaint,
     30         const Paint* paint, Typeface* typeface) {
     31     const Typeface* resolvedFace = Typeface::resolveDefault(typeface);
     32     minikin::FontStyle resolved = resolvedFace->fStyle;
     33 
     34     /* Prepare minikin FontStyle */
     35     minikin::FontVariant minikinVariant = (paint->getFontVariant() == minikin::VARIANT_ELEGANT) ?
     36             minikin::VARIANT_ELEGANT : minikin::VARIANT_COMPACT;
     37     const uint32_t langListId = paint->getMinikinLangListId();
     38     minikin::FontStyle minikinStyle(langListId, minikinVariant, resolved.getWeight(),
     39             resolved.getItalic());
     40 
     41     /* Prepare minikin Paint */
     42     // Note: it would be nice to handle fractional size values (it would improve smooth zoom
     43     // behavior), but historically size has been treated as an int.
     44     // TODO: explore whether to enable fractional sizes, possibly when linear text flag is set.
     45     minikinPaint->size = (int)paint->getTextSize();
     46     minikinPaint->scaleX = paint->getTextScaleX();
     47     minikinPaint->skewX = paint->getTextSkewX();
     48     minikinPaint->letterSpacing = paint->getLetterSpacing();
     49     minikinPaint->wordSpacing = paint->getWordSpacing();
     50     minikinPaint->paintFlags = MinikinFontSkia::packPaintFlags(paint);
     51     minikinPaint->fontFeatureSettings = paint->getFontFeatureSettings();
     52     minikinPaint->hyphenEdit = minikin::HyphenEdit(paint->getHyphenEdit());
     53     return minikinStyle;
     54 }
     55 
     56 minikin::Layout MinikinUtils::doLayout(const Paint* paint, int bidiFlags,
     57         Typeface* typeface, const uint16_t* buf, size_t start, size_t count,
     58         size_t bufSize) {
     59     minikin::MinikinPaint minikinPaint;
     60     minikin::FontStyle minikinStyle = prepareMinikinPaint(&minikinPaint, paint, typeface);
     61     minikin::Layout layout;
     62     layout.doLayout(buf, start, count, bufSize, bidiFlags, minikinStyle, minikinPaint,
     63             Typeface::resolveDefault(typeface)->fFontCollection);
     64     return layout;
     65 }
     66 
     67 float MinikinUtils::measureText(const Paint* paint, int bidiFlags, Typeface* typeface,
     68         const uint16_t* buf, size_t start, size_t count, size_t bufSize, float *advances) {
     69     minikin::MinikinPaint minikinPaint;
     70     minikin::FontStyle minikinStyle = prepareMinikinPaint(&minikinPaint, paint, typeface);
     71     Typeface* resolvedTypeface = Typeface::resolveDefault(typeface);
     72     return minikin::Layout::measureText(buf, start, count, bufSize, bidiFlags, minikinStyle,
     73             minikinPaint, resolvedTypeface->fFontCollection, advances);
     74 }
     75 
     76 bool MinikinUtils::hasVariationSelector(Typeface* typeface, uint32_t codepoint, uint32_t vs) {
     77     const Typeface* resolvedFace = Typeface::resolveDefault(typeface);
     78     return resolvedFace->fFontCollection->hasVariationSelector(codepoint, vs);
     79 }
     80 
     81 float MinikinUtils::xOffsetForTextAlign(Paint* paint, const minikin::Layout& layout) {
     82     switch (paint->getTextAlign()) {
     83         case Paint::kCenter_Align:
     84             return layout.getAdvance() * -0.5f;
     85             break;
     86         case Paint::kRight_Align:
     87             return -layout.getAdvance();
     88             break;
     89         default:
     90             break;
     91     }
     92     return 0;
     93 }
     94 
     95 float MinikinUtils::hOffsetForTextAlign(Paint* paint, const minikin::Layout& layout,
     96         const SkPath& path) {
     97     float align = 0;
     98     switch (paint->getTextAlign()) {
     99         case Paint::kCenter_Align:
    100             align = -0.5f;
    101             break;
    102         case Paint::kRight_Align:
    103             align = -1;
    104             break;
    105         default:
    106             return 0;
    107     }
    108     SkPathMeasure measure(path, false);
    109     return align * (layout.getAdvance() - measure.getLength());
    110 }
    111 
    112 }
    113