MinikinSkia.cpp revision b93872ad64afaafa1799a293850f48a96708182e 
1/*
2 * Copyright (C) 2013 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 "MinikinSkia.h"
18
19#include <SkPaint.h>
20#include <SkTypeface.h>
21#include <cutils/log.h>
22
23namespace android {
24
25MinikinFontSkia::MinikinFontSkia(SkTypeface* typeface, const void* fontData, size_t fontSize,
26        int ttcIndex) :
27    MinikinFont(typeface->uniqueID()), mTypeface(typeface), mFontData(fontData),
28    mFontSize(fontSize), mTtcIndex(ttcIndex) {
29}
30
31MinikinFontSkia::~MinikinFontSkia() {
32    SkSafeUnref(mTypeface);
33}
34
35static void MinikinFontSkia_SetSkiaPaint(const MinikinFont* font, SkPaint* skPaint, const MinikinPaint& paint) {
36    skPaint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
37    skPaint->setTextSize(paint.size);
38    skPaint->setTextScaleX(paint.scaleX);
39    skPaint->setTextSkewX(paint.skewX);
40    MinikinFontSkia::unpackPaintFlags(skPaint, paint.paintFlags);
41    // Apply font fakery on top of user-supplied flags.
42    MinikinFontSkia::populateSkPaint(skPaint, font, paint.fakery);
43}
44
45float MinikinFontSkia::GetHorizontalAdvance(uint32_t glyph_id,
46    const MinikinPaint &paint) const {
47    SkPaint skPaint;
48    uint16_t glyph16 = glyph_id;
49    SkScalar skWidth;
50    MinikinFontSkia_SetSkiaPaint(this, &skPaint, paint);
51    skPaint.getTextWidths(&glyph16, sizeof(glyph16), &skWidth, NULL);
52#ifdef VERBOSE
53    ALOGD("width for typeface %d glyph %d = %f", mTypeface->uniqueID(), glyph_id, skWidth);
54#endif
55    return skWidth;
56}
57
58void MinikinFontSkia::GetBounds(MinikinRect* bounds, uint32_t glyph_id,
59    const MinikinPaint& paint) const {
60    SkPaint skPaint;
61    uint16_t glyph16 = glyph_id;
62    SkRect skBounds;
63    MinikinFontSkia_SetSkiaPaint(this, &skPaint, paint);
64    skPaint.getTextWidths(&glyph16, sizeof(glyph16), NULL, &skBounds);
65    bounds->mLeft = skBounds.fLeft;
66    bounds->mTop = skBounds.fTop;
67    bounds->mRight = skBounds.fRight;
68    bounds->mBottom = skBounds.fBottom;
69}
70
71const void* MinikinFontSkia::GetTable(uint32_t tag, size_t* size, MinikinDestroyFunc* destroy) {
72    // we don't have a buffer to the font data, copy to own buffer
73    const size_t tableSize = mTypeface->getTableSize(tag);
74    *size = tableSize;
75    if (tableSize == 0) {
76        return nullptr;
77    }
78    void* buf = malloc(tableSize);
79    if (buf == nullptr) {
80        return nullptr;
81    }
82    mTypeface->getTableData(tag, 0, tableSize, buf);
83    *destroy = free;
84    return buf;
85}
86
87SkTypeface *MinikinFontSkia::GetSkTypeface() const {
88    return mTypeface;
89}
90
91const void* MinikinFontSkia::GetFontData() const {
92    return mFontData;
93}
94
95size_t MinikinFontSkia::GetFontSize() const {
96    return mFontSize;
97}
98
99int MinikinFontSkia::GetFontIndex() const {
100    return mTtcIndex;
101}
102
103uint32_t MinikinFontSkia::packPaintFlags(const SkPaint* paint) {
104    uint32_t flags = paint->getFlags();
105    SkPaint::Hinting hinting = paint->getHinting();
106    // select only flags that might affect text layout
107    flags &= (SkPaint::kAntiAlias_Flag | SkPaint::kFakeBoldText_Flag | SkPaint::kLinearText_Flag |
108            SkPaint::kSubpixelText_Flag | SkPaint::kDevKernText_Flag |
109            SkPaint::kEmbeddedBitmapText_Flag | SkPaint::kAutoHinting_Flag |
110            SkPaint::kVerticalText_Flag);
111    flags |= (hinting << 16);
112    return flags;
113}
114
115void MinikinFontSkia::unpackPaintFlags(SkPaint* paint, uint32_t paintFlags) {
116    paint->setFlags(paintFlags & SkPaint::kAllFlags);
117    paint->setHinting(static_cast<SkPaint::Hinting>(paintFlags >> 16));
118}
119
120void MinikinFontSkia::populateSkPaint(SkPaint* paint, const MinikinFont* font, FontFakery fakery) {
121    paint->setTypeface(reinterpret_cast<const MinikinFontSkia*>(font)->GetSkTypeface());
122    paint->setFakeBoldText(paint->isFakeBoldText() || fakery.isFakeBold());
123    if (fakery.isFakeItalic()) {
124        paint->setTextSkewX(paint->getTextSkewX() - 0.25f);
125    }
126}
127
128}
129