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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 #define LOG_TAG "Minikin"
     18 #include <cutils/log.h>
     19 #include <string>
     20 
     21 #include "SkPathMeasure.h"
     22 #include "Paint.h"
     23 #include "TypefaceImpl.h"
     24 
     25 #include "MinikinUtils.h"
     26 
     27 namespace android {
     28 
     29 // Do an sprintf starting at offset n, abort on overflow
     30 static int snprintfcat(char* buf, int off, int size, const char* format, ...)
     31         __attribute__((__format__(__printf__, 4, 5)));
     32 static int snprintfcat(char* buf, int off, int size, const char* format, ...) {
     33     va_list args;
     34     va_start(args, format);
     35     int n = vsnprintf(buf + off, size - off, format, args);
     36     LOG_ALWAYS_FATAL_IF(n >= size - off, "String overflow in setting layout properties");
     37     va_end(args);
     38     return off + n;
     39 }
     40 
     41 void MinikinUtils::doLayout(Layout* layout, const Paint* paint, int bidiFlags, TypefaceImpl* typeface,
     42         const uint16_t* buf, size_t start, size_t count, size_t bufSize) {
     43     TypefaceImpl* resolvedFace = TypefaceImpl_resolveDefault(typeface);
     44     layout->setFontCollection(resolvedFace->fFontCollection);
     45     FontStyle resolved = resolvedFace->fStyle;
     46 
     47     /* Prepare minikin FontStyle */
     48     std::string lang = paint->getTextLocale();
     49     FontLanguage minikinLang(lang.c_str(), lang.size());
     50     FontVariant minikinVariant = (paint->getFontVariant() == VARIANT_ELEGANT) ? VARIANT_ELEGANT
     51             : VARIANT_COMPACT;
     52     FontStyle minikinStyle(minikinLang, minikinVariant, resolved.getWeight(), resolved.getItalic());
     53 
     54     /* Prepare minikin Paint */
     55     MinikinPaint minikinPaint;
     56     minikinPaint.size = (int)/*WHY?!*/paint->getTextSize();
     57     minikinPaint.scaleX = paint->getTextScaleX();
     58     minikinPaint.skewX = paint->getTextSkewX();
     59     minikinPaint.letterSpacing = paint->getLetterSpacing();
     60     minikinPaint.paintFlags = MinikinFontSkia::packPaintFlags(paint);
     61     minikinPaint.fontFeatureSettings = paint->getFontFeatureSettings();
     62 
     63     layout->doLayout(buf, start, count, bufSize, bidiFlags, minikinStyle, minikinPaint);
     64 }
     65 
     66 float MinikinUtils::xOffsetForTextAlign(Paint* paint, const Layout& layout) {
     67     switch (paint->getTextAlign()) {
     68         case Paint::kCenter_Align:
     69             return layout.getAdvance() * -0.5f;
     70             break;
     71         case Paint::kRight_Align:
     72             return -layout.getAdvance();
     73             break;
     74         default:
     75             break;
     76     }
     77     return 0;
     78 }
     79 
     80 float MinikinUtils::hOffsetForTextAlign(Paint* paint, const Layout& layout, const SkPath& path) {
     81     float align = 0;
     82     switch (paint->getTextAlign()) {
     83         case Paint::kCenter_Align:
     84             align = -0.5f;
     85             break;
     86         case Paint::kRight_Align:
     87             align = -1;
     88             break;
     89         default:
     90             return 0;
     91     }
     92     SkPathMeasure measure(path, false);
     93     return align * (layout.getAdvance() - measure.getLength());
     94 }
     95 
     96 }
     97