gecko-dev/gfx/thebes/gfxGlyphExtents.cpp

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "gfxGlyphExtents.h"
#include "gfxTextRun.h"

using namespace mozilla;

#ifdef DEBUG_roc
#define DEBUG_TEXT_RUN_STORAGE_METRICS
#endif

#ifdef DEBUG_TEXT_RUN_STORAGE_METRICS
extern uint32_t gTextRunStorageHighWaterMark;
extern uint32_t gTextRunStorage;
extern uint32_t gFontCount;
extern uint32_t gGlyphExtentsCount;
extern uint32_t gGlyphExtentsWidthsTotalSize;
extern uint32_t gGlyphExtentsSetupEagerSimple;
extern uint32_t gGlyphExtentsSetupEagerTight;
extern uint32_t gGlyphExtentsSetupLazyTight;
extern uint32_t gGlyphExtentsSetupFallBackToTight;
#endif

gfxGlyphExtents::~gfxGlyphExtents()
{
#ifdef DEBUG_TEXT_RUN_STORAGE_METRICS
    gGlyphExtentsWidthsTotalSize +=
        mContainedGlyphWidths.SizeOfExcludingThis(&FontCacheMallocSizeOf);
    gGlyphExtentsCount++;
#endif
    MOZ_COUNT_DTOR(gfxGlyphExtents);
}

bool
gfxGlyphExtents::GetTightGlyphExtentsAppUnits(gfxFont* aFont,
    DrawTarget* aDrawTarget, uint32_t aGlyphID, gfxRect* aExtents)
{
    HashEntry *entry = mTightGlyphExtents.GetEntry(aGlyphID);
    if (!entry) {
        // Some functions higher up in the call chain deliberately pass in a
        // nullptr DrawTarget, e.g. GetBaselinePosition() passes nullptr to
        // gfxTextRun::MeasureText() and that nullptr reaches here.
        if (!aDrawTarget) {
            NS_WARNING("Could not get glyph extents (no aDrawTarget)");
            return false;
        }

        if (aFont->SetupCairoFont(aDrawTarget)) {
#ifdef DEBUG_TEXT_RUN_STORAGE_METRICS
            ++gGlyphExtentsSetupLazyTight;
#endif
            aFont->SetupGlyphExtents(aDrawTarget, aGlyphID, true, this);
            entry = mTightGlyphExtents.GetEntry(aGlyphID);
        }
        if (!entry) {
            NS_WARNING("Could not get glyph extents");
            return false;
        }
    }

    *aExtents = gfxRect(entry->x, entry->y, entry->width, entry->height);
    return true;
}

gfxGlyphExtents::GlyphWidths::~GlyphWidths()
{
    uint32_t i, count = mBlocks.Length();
    for (i = 0; i < count; ++i) {
        uintptr_t bits = mBlocks[i];
        if (bits && !(bits & 0x1)) {
            delete[] reinterpret_cast<uint16_t *>(bits);
        }
    }
}

uint32_t
gfxGlyphExtents::GlyphWidths::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
{
    uint32_t i;
    uint32_t size = mBlocks.ShallowSizeOfExcludingThis(aMallocSizeOf);
    for (i = 0; i < mBlocks.Length(); ++i) {
        uintptr_t bits = mBlocks[i];
        if (bits && !(bits & 0x1)) {
            size += aMallocSizeOf(reinterpret_cast<void*>(bits));
        }
    }
    return size;
}

void
gfxGlyphExtents::GlyphWidths::Set(uint32_t aGlyphID, uint16_t aWidth)
{
    uint32_t block = aGlyphID >> BLOCK_SIZE_BITS;
    uint32_t len = mBlocks.Length();
    if (block >= len) {
        uintptr_t *elems = mBlocks.AppendElements(block + 1 - len);
        if (!elems)
            return;
        memset(elems, 0, sizeof(uintptr_t)*(block + 1 - len));
    }

    uintptr_t bits = mBlocks[block];
    uint32_t glyphOffset = aGlyphID & (BLOCK_SIZE - 1);
    if (!bits) {
        mBlocks[block] = MakeSingle(glyphOffset, aWidth);
        return;
    }

    uint16_t *newBlock;
    if (bits & 0x1) {
        // Expand the block to a real block. We could avoid this by checking
        // glyphOffset == GetGlyphOffset(bits), but that never happens so don't bother
        newBlock = new uint16_t[BLOCK_SIZE];
        if (!newBlock)
            return;
        uint32_t i;
        for (i = 0; i < BLOCK_SIZE; ++i) {
            newBlock[i] = INVALID_WIDTH;
        }
        newBlock[GetGlyphOffset(bits)] = GetWidth(bits);
        mBlocks[block] = reinterpret_cast<uintptr_t>(newBlock);
    } else {
        newBlock = reinterpret_cast<uint16_t *>(bits);
    }
    newBlock[glyphOffset] = aWidth;
}

void
gfxGlyphExtents::SetTightGlyphExtents(uint32_t aGlyphID, const gfxRect& aExtentsAppUnits)
{
    HashEntry *entry = mTightGlyphExtents.PutEntry(aGlyphID);
    if (!entry)
        return;
    entry->x = aExtentsAppUnits.X();
    entry->y = aExtentsAppUnits.Y();
    entry->width = aExtentsAppUnits.Width();
    entry->height = aExtentsAppUnits.Height();
}

size_t
gfxGlyphExtents::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
{
    return mContainedGlyphWidths.SizeOfExcludingThis(aMallocSizeOf) +
        mTightGlyphExtents.ShallowSizeOfExcludingThis(aMallocSizeOf);
}

size_t
gfxGlyphExtents::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
{
    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
}