xref: /frameworks/minikin/libs/minikin/FontFamily.cpp

/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#define LOG_TAG "Minikin"

#include <cutils/log.h>
#include <stdlib.h>
#include <stdint.h>
#include <utils/UniquePtr.h>
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_TRUETYPE_TABLES_H
#include <minikin/AnalyzeStyle.h>
#include <minikin/FontFamily.h>

using std::vector;

namespace android {

bool FontFamily::addFont(FT_Face typeface) {
    const uint32_t os2Tag = FT_MAKE_TAG('O', 'S', '/', '2');
    FT_ULong os2Size = 0;
    FT_Error error = FT_Load_Sfnt_Table(typeface, os2Tag, 0, NULL, &os2Size);
    if (error != 0) return false;
    UniquePtr<uint8_t[]> os2Data(new uint8_t[os2Size]);
    error = FT_Load_Sfnt_Table(typeface, os2Tag, 0, os2Data.get(), &os2Size);
    if (error != 0) return false;
    int weight;
    bool italic;
    if (analyzeStyle(os2Data.get(), os2Size, &weight, &italic)) {
        //ALOGD("analyzed weight = %d, italic = %s", weight, italic ? "true" : "false");
        FontStyle style(weight, italic);
        addFont(typeface, style);
        return true;
    } else {
        ALOGD("failed to analyze style");
    }
    return false;
}

void FontFamily::addFont(FT_Face typeface, FontStyle style) {
    mFonts.push_back(Font(typeface, style));
    ALOGD("added font, mFonts.size() = %d", mFonts.size());
}

// Compute a matching metric between two styles - 0 is an exact match
int computeMatch(FontStyle style1, FontStyle style2) {
    if (style1 == style2) return 0;
    int score = abs(style1.getWeight() - style2.getWeight());
    if (style1.getItalic() != style2.getItalic()) {
        score += 2;
    }
    return score;
}

FT_Face FontFamily::getClosestMatch(FontStyle style) const {
    const Font* bestFont = NULL;
    int bestMatch = 0;
    for (size_t i = 0; i < mFonts.size(); i++) {
        const Font& font = mFonts[i];
        int match = computeMatch(font.style, style);
        if (i == 0 || match < bestMatch) {
            bestFont = &font;
            bestMatch = match;
        }
    }
    return bestFont == NULL ? NULL : bestFont->typeface;
}

size_t FontFamily::getNumFonts() const {
    return mFonts.size();
}

FT_Face FontFamily::getFont(size_t index) const {
    return mFonts[index].typeface;
}

FontStyle FontFamily::getStyle(size_t index) const {
    return mFonts[index].style;
}

}  // namespace android