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)));
snprintfcat(char * buf,int off,int size,const char * format,...)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 
doLayout(Layout * layout,const Paint * paint,int bidiFlags,TypefaceImpl * typeface,const uint16_t * buf,size_t start,size_t count,size_t bufSize)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 
xOffsetForTextAlign(Paint * paint,const Layout & layout)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 
hOffsetForTextAlign(Paint * paint,const Layout & layout,const SkPath & path)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