MinikinUtils.cpp revision afbd0f1fef46ef0ddf633dfde0de724db3da1405 
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
27namespace android {
28
29FontStyle MinikinUtils::prepareMinikinPaint(MinikinPaint* minikinPaint, FontCollection** pFont,
30        const Paint* paint, TypefaceImpl* typeface) {
31    const TypefaceImpl* resolvedFace = TypefaceImpl_resolveDefault(typeface);
32    *pFont = resolvedFace->fFontCollection;
33    FontStyle resolved = resolvedFace->fStyle;
34
35    /* Prepare minikin FontStyle */
36    FontVariant minikinVariant = (paint->getFontVariant() == VARIANT_ELEGANT) ? VARIANT_ELEGANT
37            : VARIANT_COMPACT;
38    const uint32_t langListId = paint->getMinikinLangListId();
39    FontStyle minikinStyle(langListId, minikinVariant, resolved.getWeight(), 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->paintFlags = MinikinFontSkia::packPaintFlags(paint);
50    minikinPaint->fontFeatureSettings = paint->getFontFeatureSettings();
51    minikinPaint->hyphenEdit = HyphenEdit(paint->getHyphenEdit());
52    return minikinStyle;
53}
54
55void MinikinUtils::doLayout(Layout* layout, const Paint* paint, int bidiFlags,
56        TypefaceImpl* typeface, const uint16_t* buf, size_t start, size_t count,
57        size_t bufSize) {
58    FontCollection *font;
59    MinikinPaint minikinPaint;
60    FontStyle minikinStyle = prepareMinikinPaint(&minikinPaint, &font, paint, typeface);
61    layout->setFontCollection(font);
62    layout->doLayout(buf, start, count, bufSize, bidiFlags, minikinStyle, minikinPaint);
63}
64
65float MinikinUtils::measureText(const Paint* paint, int bidiFlags, TypefaceImpl* typeface,
66        const uint16_t* buf, size_t start, size_t count, size_t bufSize, float *advances) {
67    FontCollection *font;
68    MinikinPaint minikinPaint;
69    FontStyle minikinStyle = prepareMinikinPaint(&minikinPaint, &font, paint, typeface);
70    return Layout::measureText(buf, start, count, bufSize, bidiFlags, minikinStyle, minikinPaint,
71            font, advances);
72}
73
74bool MinikinUtils::hasVariationSelector(TypefaceImpl* typeface, uint32_t codepoint, uint32_t vs) {
75    const TypefaceImpl* resolvedFace = TypefaceImpl_resolveDefault(typeface);
76    return resolvedFace->fFontCollection->hasVariationSelector(codepoint, vs);
77}
78
79float MinikinUtils::xOffsetForTextAlign(Paint* paint, const Layout& layout) {
80    switch (paint->getTextAlign()) {
81        case Paint::kCenter_Align:
82            return layout.getAdvance() * -0.5f;
83            break;
84        case Paint::kRight_Align:
85            return -layout.getAdvance();
86            break;
87        default:
88            break;
89    }
90    return 0;
91}
92
93float MinikinUtils::hOffsetForTextAlign(Paint* paint, const Layout& layout, const SkPath& path) {
94    float align = 0;
95    switch (paint->getTextAlign()) {
96        case Paint::kCenter_Align:
97            align = -0.5f;
98            break;
99        case Paint::kRight_Align:
100            align = -1;
101            break;
102        default:
103            return 0;
104    }
105    SkPathMeasure measure(path, false);
106    return align * (layout.getAdvance() - measure.getLength());
107}
108
109}
110