MinikinSkia.cpp revision 296bf8c55aaba0025f3e5b904fda3b6e15686753 
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    mTypeface(typeface), mFontData(fontData), mFontSize(fontSize), mTtcIndex(ttcIndex) {
28}
29
30MinikinFontSkia::~MinikinFontSkia() {
31    SkSafeUnref(mTypeface);
32}
33
34static void MinikinFontSkia_SetSkiaPaint(const MinikinFont* font, SkPaint* skPaint, const MinikinPaint& paint) {
35    skPaint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
36    skPaint->setTextSize(paint.size);
37    skPaint->setTextScaleX(paint.scaleX);
38    skPaint->setTextSkewX(paint.skewX);
39    MinikinFontSkia::unpackPaintFlags(skPaint, paint.paintFlags);
40    // Apply font fakery on top of user-supplied flags.
41    MinikinFontSkia::populateSkPaint(skPaint, font, paint.fakery);
42}
43
44float MinikinFontSkia::GetHorizontalAdvance(uint32_t glyph_id,
45    const MinikinPaint &paint) const {
46    SkPaint skPaint;
47    uint16_t glyph16 = glyph_id;
48    SkScalar skWidth;
49    MinikinFontSkia_SetSkiaPaint(this, &skPaint, paint);
50    skPaint.getTextWidths(&glyph16, sizeof(glyph16), &skWidth, NULL);
51#ifdef VERBOSE
52    ALOGD("width for typeface %d glyph %d = %f", mTypeface->uniqueID(), glyph_id, skWidth);
53#endif
54    return skWidth;
55}
56
57void MinikinFontSkia::GetBounds(MinikinRect* bounds, uint32_t glyph_id,
58    const MinikinPaint& paint) const {
59    SkPaint skPaint;
60    uint16_t glyph16 = glyph_id;
61    SkRect skBounds;
62    MinikinFontSkia_SetSkiaPaint(this, &skPaint, paint);
63    skPaint.getTextWidths(&glyph16, sizeof(glyph16), NULL, &skBounds);
64    bounds->mLeft = skBounds.fLeft;
65    bounds->mTop = skBounds.fTop;
66    bounds->mRight = skBounds.fRight;
67    bounds->mBottom = skBounds.fBottom;
68}
69
70const void* MinikinFontSkia::GetTable(uint32_t tag, size_t* size, MinikinDestroyFunc* destroy) {
71    // we don't have a buffer to the font data, copy to own buffer
72    const size_t tableSize = mTypeface->getTableSize(tag);
73    *size = tableSize;
74    if (tableSize == 0) {
75        return nullptr;
76    }
77    void* buf = malloc(tableSize);
78    if (buf == nullptr) {
79        return nullptr;
80    }
81    mTypeface->getTableData(tag, 0, tableSize, buf);
82    *destroy = free;
83    return buf;
84}
85
86SkTypeface *MinikinFontSkia::GetSkTypeface() const {
87    return mTypeface;
88}
89
90const void* MinikinFontSkia::GetFontData() const {
91    return mFontData;
92}
93
94size_t MinikinFontSkia::GetFontSize() const {
95    return mFontSize;
96}
97
98int MinikinFontSkia::GetFontIndex() const {
99    return mTtcIndex;
100}
101
102int32_t MinikinFontSkia::GetUniqueId() const {
103    return mTypeface->uniqueID();
104}
105
106uint32_t MinikinFontSkia::packPaintFlags(const SkPaint* paint) {
107    uint32_t flags = paint->getFlags();
108    SkPaint::Hinting hinting = paint->getHinting();
109    // select only flags that might affect text layout
110    flags &= (SkPaint::kAntiAlias_Flag | SkPaint::kFakeBoldText_Flag | SkPaint::kLinearText_Flag |
111            SkPaint::kSubpixelText_Flag | SkPaint::kDevKernText_Flag |
112            SkPaint::kEmbeddedBitmapText_Flag | SkPaint::kAutoHinting_Flag |
113            SkPaint::kVerticalText_Flag);
114    flags |= (hinting << 16);
115    return flags;
116}
117
118void MinikinFontSkia::unpackPaintFlags(SkPaint* paint, uint32_t paintFlags) {
119    paint->setFlags(paintFlags & SkPaint::kAllFlags);
120    paint->setHinting(static_cast<SkPaint::Hinting>(paintFlags >> 16));
121}
122
123void MinikinFontSkia::populateSkPaint(SkPaint* paint, const MinikinFont* font, FontFakery fakery) {
124    paint->setTypeface(reinterpret_cast<const MinikinFontSkia*>(font)->GetSkTypeface());
125    paint->setFakeBoldText(paint->isFakeBoldText() || fakery.isFakeBold());
126    if (fakery.isFakeItalic()) {
127        paint->setTextSkewX(paint->getTextSkewX() - 0.25f);
128    }
129}
130
131}
132