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      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 "MinikinSkia.h"
     24 
     25 namespace android {
     26 
     27 MinikinFontSkia::MinikinFontSkia(SkTypeface *typeface) :
     28     mTypeface(typeface) {
     29 }
     30 
     31 MinikinFontSkia::~MinikinFontSkia() {
     32     SkSafeUnref(mTypeface);
     33 }
     34 
     35 bool MinikinFontSkia::GetGlyph(uint32_t codepoint, uint32_t *glyph) const {
     36     SkPaint paint;
     37     paint.setTypeface(mTypeface);
     38     paint.setTextEncoding(SkPaint::kUTF32_TextEncoding);
     39     uint16_t glyph16;
     40     paint.textToGlyphs(&codepoint, sizeof(codepoint), &glyph16);
     41     *glyph  = glyph16;
     42     return !!glyph16;
     43 }
     44 
     45 static void MinikinFontSkia_SetSkiaPaint(const MinikinFont* font, SkPaint* skPaint, const MinikinPaint& paint) {
     46     skPaint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
     47     skPaint->setTextSize(paint.size);
     48     skPaint->setTextScaleX(paint.scaleX);
     49     skPaint->setTextSkewX(paint.skewX);
     50     MinikinFontSkia::unpackPaintFlags(skPaint, paint.paintFlags);
     51     // Apply font fakery on top of user-supplied flags.
     52     MinikinFontSkia::populateSkPaint(skPaint, font, paint.fakery);
     53 }
     54 
     55 float 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(this, &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 
     68 void 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(this, &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 
     81 bool 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 
     93 SkTypeface *MinikinFontSkia::GetSkTypeface() const {
     94     return mTypeface;
     95 }
     96 
     97 int32_t MinikinFontSkia::GetUniqueId() const {
     98     return mTypeface->uniqueID();
     99 }
    100 
    101 uint32_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 
    113 void 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 void MinikinFontSkia::populateSkPaint(SkPaint* paint, const MinikinFont* font, FontFakery fakery) {
    119     paint->setTypeface(reinterpret_cast<const MinikinFontSkia*>(font)->GetSkTypeface());
    120     paint->setFakeBoldText(paint->isFakeBoldText() || fakery.isFakeBold());
    121     if (fakery.isFakeItalic()) {
    122         paint->setTextSkewX(paint->getTextSkewX() - 0.25f);
    123     }
    124 }
    125 
    126 }
    127