libs/hwui/jni/text/TextShaper.cpp

/*
 * Copyright (C) 2020 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.
 */

#undef LOG_TAG
#define LOG_TAG "TextShaper"

#include "graphics_jni_helpers.h"
#include <nativehelper/ScopedStringChars.h>
#include <nativehelper/ScopedPrimitiveArray.h>
#include <set>
#include <algorithm>

#include "SkPaint.h"
#include "SkTypeface.h"
#include <hwui/MinikinSkia.h>
#include <hwui/MinikinUtils.h>
#include <hwui/Paint.h>
#include <minikin/MinikinPaint.h>
#include <minikin/MinikinFont.h>

namespace android {

struct LayoutWrapper {
    LayoutWrapper(minikin::Layout&& layout, float ascent, float descent)
        : layout(std::move(layout)), ascent(ascent), descent(descent)  {}
    minikin::Layout layout;
    float ascent;
    float descent;
};

static void releaseLayout(jlong ptr) {
    delete reinterpret_cast<LayoutWrapper*>(ptr);
}

static jlong shapeTextRun(const uint16_t* text, int textSize, int start, int count,
    int contextStart, int contextCount, minikin::Bidi bidiFlags,
    const Paint& paint, const Typeface* typeface) {

    minikin::MinikinPaint minikinPaint = MinikinUtils::prepareMinikinPaint(&paint, typeface);

    minikin::Layout layout = MinikinUtils::doLayout(&paint, bidiFlags, typeface,
        text, textSize, start, count, contextStart, contextCount, nullptr);

    std::set<const minikin::Font*> seenFonts;
    float overallAscent = 0;
    float overallDescent = 0;
    for (int i = 0; i < layout.nGlyphs(); ++i) {
        const minikin::Font* font = layout.getFont(i);
        if (seenFonts.find(font) != seenFonts.end()) continue;
        minikin::MinikinExtent extent = {};
        font->typeface()->GetFontExtent(&extent, minikinPaint, layout.getFakery(i));
        overallAscent = std::min(overallAscent, extent.ascent);
        overallDescent = std::max(overallDescent, extent.descent);
    }

    std::unique_ptr<LayoutWrapper> ptr = std::make_unique<LayoutWrapper>(
        std::move(layout), overallAscent, overallDescent
    );

    return reinterpret_cast<jlong>(ptr.release());
}

static jlong TextShaper_shapeTextRunChars(JNIEnv *env, jobject, jcharArray charArray,
    jint start, jint count, jint contextStart, jint contextCount, jboolean isRtl,
    jlong paintPtr) {
    ScopedCharArrayRO text(env, charArray);
    Paint* paint = reinterpret_cast<Paint*>(paintPtr);
    const Typeface* typeface = paint->getAndroidTypeface();
    const minikin::Bidi bidiFlags = isRtl ? minikin::Bidi::FORCE_RTL : minikin::Bidi::FORCE_LTR;
    return shapeTextRun(
        text.get(), text.size(),
        start, count,
        contextStart, contextCount,
        bidiFlags,
        *paint, typeface);

}

static jlong TextShaper_shapeTextRunString(JNIEnv *env, jobject, jstring string,
    jint start, jint count, jint contextStart, jint contextCount, jboolean isRtl,
    jlong paintPtr) {
    ScopedStringChars text(env, string);
    Paint* paint = reinterpret_cast<Paint*>(paintPtr);
    const Typeface* typeface = paint->getAndroidTypeface();
    const minikin::Bidi bidiFlags = isRtl ? minikin::Bidi::FORCE_RTL : minikin::Bidi::FORCE_LTR;
    return shapeTextRun(
        text.get(), text.size(),
        start, count,
        contextStart, contextCount,
        bidiFlags,
        *paint, typeface);
}

// CriticalNative
static jint TextShaper_Result_getGlyphCount(CRITICAL_JNI_PARAMS_COMMA jlong ptr) {
    const LayoutWrapper* layout = reinterpret_cast<LayoutWrapper*>(ptr);
    return layout->layout.nGlyphs();
}

// CriticalNative
static jfloat TextShaper_Result_getTotalAdvance(CRITICAL_JNI_PARAMS_COMMA jlong ptr) {
    const LayoutWrapper* layout = reinterpret_cast<LayoutWrapper*>(ptr);
    return layout->layout.getAdvance();
}

// CriticalNative
static jfloat TextShaper_Result_getAscent(CRITICAL_JNI_PARAMS_COMMA jlong ptr) {
    const LayoutWrapper* layout = reinterpret_cast<LayoutWrapper*>(ptr);
    return layout->ascent;
}

// CriticalNative
static jfloat TextShaper_Result_getDescent(CRITICAL_JNI_PARAMS_COMMA jlong ptr) {
    const LayoutWrapper* layout = reinterpret_cast<LayoutWrapper*>(ptr);
    return layout->descent;
}

// CriticalNative
static jint TextShaper_Result_getGlyphId(CRITICAL_JNI_PARAMS_COMMA jlong ptr, jint i) {
    const LayoutWrapper* layout = reinterpret_cast<LayoutWrapper*>(ptr);
    return layout->layout.getGlyphId(i);
}

// CriticalNative
static jfloat TextShaper_Result_getX(CRITICAL_JNI_PARAMS_COMMA jlong ptr, jint i) {
    const LayoutWrapper* layout = reinterpret_cast<LayoutWrapper*>(ptr);
    return layout->layout.getX(i);
}

// CriticalNative
static jfloat TextShaper_Result_getY(CRITICAL_JNI_PARAMS_COMMA jlong ptr, jint i) {
    const LayoutWrapper* layout = reinterpret_cast<LayoutWrapper*>(ptr);
    return layout->layout.getY(i);
}

// CriticalNative
static jlong TextShaper_Result_getFont(CRITICAL_JNI_PARAMS_COMMA jlong ptr, jint i) {
    const LayoutWrapper* layout = reinterpret_cast<LayoutWrapper*>(ptr);
    return reinterpret_cast<jlong>(layout->layout.getFont(i));
}

// CriticalNative
static jlong TextShaper_Result_nReleaseFunc(CRITICAL_JNI_PARAMS) {
    return reinterpret_cast<jlong>(releaseLayout);
}

static const JNINativeMethod gMethods[] = {
    // Fast Natives
    {"nativeShapeTextRun", "("
        "[C"  // text
        "I"  // start
        "I"  // count
        "I"  // contextStart
        "I"  // contextCount
        "Z"  // isRtl
        "J)"  // paint
        "J",  // LayoutPtr
        (void*) TextShaper_shapeTextRunChars},

    {"nativeShapeTextRun", "("
        "Ljava/lang/String;"  // text
        "I"  // start
        "I"  // count
        "I"  // contextStart
        "I"  // contextCount
        "Z"  // isRtl
        "J)"  // paint
        "J",  // LayoutPtr
        (void*) TextShaper_shapeTextRunString},

};

static const JNINativeMethod gResultMethods[] = {
    { "nGetGlyphCount", "(J)I", (void*)TextShaper_Result_getGlyphCount },
    { "nGetTotalAdvance", "(J)F", (void*)TextShaper_Result_getTotalAdvance },
    { "nGetAscent", "(J)F", (void*)TextShaper_Result_getAscent },
    { "nGetDescent", "(J)F", (void*)TextShaper_Result_getDescent },
    { "nGetGlyphId", "(JI)I", (void*)TextShaper_Result_getGlyphId },
    { "nGetX", "(JI)F", (void*)TextShaper_Result_getX },
    { "nGetY", "(JI)F", (void*)TextShaper_Result_getY },
    { "nGetFont", "(JI)J", (void*)TextShaper_Result_getFont },
    { "nReleaseFunc", "()J", (void*)TextShaper_Result_nReleaseFunc },
};

int register_android_graphics_text_TextShaper(JNIEnv* env) {
    return RegisterMethodsOrDie(env, "android/graphics/text/TextShaper", gMethods,
                                NELEM(gMethods))
        + RegisterMethodsOrDie(env, "android/graphics/text/PositionedGlyphs",
            gResultMethods, NELEM(gResultMethods));
}

}