MinikinSkia.cpp revision 0627ec08dcc2e87c17e9b85f045dfb27dc4884b3 
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 <SkTypeface.h>
18#include <SkPaint.h>
19
20#define LOG_TAG "Minikin"
21#include <cutils/log.h>
22
23#include <minikin/MinikinFont.h>
24#include "MinikinSkia.h"
25
26namespace android {
27
28MinikinFontSkia::MinikinFontSkia(SkTypeface *typeface) :
29    mTypeface(typeface) {
30}
31
32MinikinFontSkia::~MinikinFontSkia() {
33    SkSafeUnref(mTypeface);
34}
35
36bool MinikinFontSkia::GetGlyph(uint32_t codepoint, uint32_t *glyph) const {
37    SkPaint paint;
38    paint.setTypeface(mTypeface);
39    paint.setTextEncoding(SkPaint::kUTF32_TextEncoding);
40    uint16_t glyph16;
41    paint.textToGlyphs(&codepoint, sizeof(codepoint), &glyph16);
42    *glyph  = glyph16;
43    return !!glyph;
44}
45
46static void MinikinFontSkia_SetSkiaPaint(const MinikinFont* font, SkPaint* skPaint, const MinikinPaint& paint) {
47    skPaint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
48    skPaint->setTextSize(paint.size);
49    skPaint->setTextScaleX(paint.scaleX);
50    skPaint->setTextSkewX(paint.skewX);
51    MinikinFontSkia::unpackPaintFlags(skPaint, paint.paintFlags);
52    // Apply font fakery on top of user-supplied flags.
53    MinikinFontSkia::populateSkPaint(skPaint, font, paint.fakery);
54}
55
56float MinikinFontSkia::GetHorizontalAdvance(uint32_t glyph_id,
57    const MinikinPaint &paint) const {
58    SkPaint skPaint;
59    uint16_t glyph16 = glyph_id;
60    SkScalar skWidth;
61    MinikinFontSkia_SetSkiaPaint(this, &skPaint, paint);
62    skPaint.getTextWidths(&glyph16, sizeof(glyph16), &skWidth, NULL);
63#ifdef VERBOSE
64    ALOGD("width for typeface %d glyph %d = %f", mTypeface->uniqueID(), glyph_id, skWidth);
65#endif
66    return skWidth;
67}
68
69void MinikinFontSkia::GetBounds(MinikinRect* bounds, uint32_t glyph_id,
70    const MinikinPaint& paint) const {
71    SkPaint skPaint;
72    uint16_t glyph16 = glyph_id;
73    SkRect skBounds;
74    MinikinFontSkia_SetSkiaPaint(this, &skPaint, paint);
75    skPaint.getTextWidths(&glyph16, sizeof(glyph16), NULL, &skBounds);
76    bounds->mLeft = skBounds.fLeft;
77    bounds->mTop = skBounds.fTop;
78    bounds->mRight = skBounds.fRight;
79    bounds->mBottom = skBounds.fBottom;
80}
81
82bool MinikinFontSkia::GetTable(uint32_t tag, uint8_t *buf, size_t *size) {
83    if (buf == NULL) {
84        const size_t tableSize = mTypeface->getTableSize(tag);
85        *size = tableSize;
86        return tableSize != 0;
87    } else {
88        const size_t actualSize = mTypeface->getTableData(tag, 0, *size, buf);
89        *size = actualSize;
90        return actualSize != 0;
91    }
92}
93
94SkTypeface *MinikinFontSkia::GetSkTypeface() const {
95    return mTypeface;
96}
97
98int32_t MinikinFontSkia::GetUniqueId() const {
99    return mTypeface->uniqueID();
100}
101
102uint32_t MinikinFontSkia::packPaintFlags(const SkPaint* paint) {
103    uint32_t flags = paint->getFlags();
104    SkPaint::Hinting hinting = paint->getHinting();
105    // select only flags that might affect text layout
106    flags &= (SkPaint::kAntiAlias_Flag | SkPaint::kFakeBoldText_Flag | SkPaint::kLinearText_Flag |
107            SkPaint::kSubpixelText_Flag | SkPaint::kDevKernText_Flag |
108            SkPaint::kEmbeddedBitmapText_Flag | SkPaint::kAutoHinting_Flag |
109            SkPaint::kVerticalText_Flag);
110    flags |= (hinting << 16);
111    return flags;
112}
113
114void MinikinFontSkia::unpackPaintFlags(SkPaint* paint, uint32_t paintFlags) {
115    paint->setFlags(paintFlags & SkPaint::kAllFlags);
116    paint->setHinting(static_cast<SkPaint::Hinting>(paintFlags >> 16));
117}
118
119void MinikinFontSkia::populateSkPaint(SkPaint* paint, const MinikinFont* font, FontFakery fakery) {
120    paint->setTypeface(reinterpret_cast<const MinikinFontSkia*>(font)->GetSkTypeface());
121    paint->setFakeBoldText(paint->isFakeBoldText() || fakery.isFakeBold());
122    if (fakery.isFakeItalic()) {
123        paint->setTextSkewX(paint->getTextSkewX() - 0.25f);
124    }
125}
126
127}
128