MinikinSkia.cpp revision e95b5850ac2e56330abf68362451e7614b3dfe16 
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(SkTypeface* typeface, SkPaint* skPaint, const MinikinPaint& paint) {
47    skPaint->setTypeface(typeface);
48    skPaint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
49    skPaint->setTextSize(paint.size);
50    skPaint->setTextScaleX(paint.scaleX);
51    skPaint->setTextSkewX(paint.skewX);
52    MinikinFontSkia::unpackPaintFlags(skPaint, paint.paintFlags);
53}
54
55float MinikinFontSkia::GetHorizontalAdvance(uint32_t glyph_id,
56    const MinikinPaint &paint) const {
57    SkPaint skPaint;
58    uint16_t glyph16 = glyph_id;
59    SkScalar skWidth;
60    MinikinFontSkia_SetSkiaPaint(mTypeface, &skPaint, paint);
61    skPaint.getTextWidths(&glyph16, sizeof(glyph16), &skWidth, NULL);
62#ifdef VERBOSE
63    ALOGD("width for typeface %d glyph %d = %f", mTypeface->uniqueID(), glyph_id, skWidth);
64#endif
65    return skWidth;
66}
67
68void MinikinFontSkia::GetBounds(MinikinRect* bounds, uint32_t glyph_id,
69    const MinikinPaint& paint) const {
70    SkPaint skPaint;
71    uint16_t glyph16 = glyph_id;
72    SkRect skBounds;
73    MinikinFontSkia_SetSkiaPaint(mTypeface, &skPaint, paint);
74    skPaint.getTextWidths(&glyph16, sizeof(glyph16), NULL, &skBounds);
75    bounds->mLeft = skBounds.fLeft;
76    bounds->mTop = skBounds.fTop;
77    bounds->mRight = skBounds.fRight;
78    bounds->mBottom = skBounds.fBottom;
79}
80
81bool MinikinFontSkia::GetTable(uint32_t tag, uint8_t *buf, size_t *size) {
82    if (buf == NULL) {
83        const size_t tableSize = mTypeface->getTableSize(tag);
84        *size = tableSize;
85        return tableSize != 0;
86    } else {
87        const size_t actualSize = mTypeface->getTableData(tag, 0, *size, buf);
88        *size = actualSize;
89        return actualSize != 0;
90    }
91}
92
93SkTypeface *MinikinFontSkia::GetSkTypeface() {
94    return mTypeface;
95}
96
97int32_t MinikinFontSkia::GetUniqueId() const {
98    return mTypeface->uniqueID();
99}
100
101uint32_t MinikinFontSkia::packPaintFlags(const SkPaint* paint) {
102    uint32_t flags = paint->getFlags();
103    SkPaint::Hinting hinting = paint->getHinting();
104    // select only flags that might affect text layout
105    flags &= (SkPaint::kAntiAlias_Flag | SkPaint::kFakeBoldText_Flag | SkPaint::kLinearText_Flag |
106            SkPaint::kSubpixelText_Flag | SkPaint::kDevKernText_Flag |
107            SkPaint::kEmbeddedBitmapText_Flag | SkPaint::kAutoHinting_Flag |
108            SkPaint::kVerticalText_Flag);
109    flags |= (hinting << 16);
110    return flags;
111}
112
113void MinikinFontSkia::unpackPaintFlags(SkPaint* paint, uint32_t paintFlags) {
114    paint->setFlags(paintFlags & SkPaint::kAllFlags);
115    paint->setHinting(static_cast<SkPaint::Hinting>(paintFlags >> 16));
116}
117
118}
119