gfxDWriteFonts.h - mozsearch

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-

 * 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/. */

#ifndef GFX_WINDOWSDWRITEFONTS_H

#define GFX_WINDOWSDWRITEFONTS_H

#include "mozilla/Atomics.h"

#include "mozilla/MemoryReporting.h"

#include "mozilla/UniquePtr.h"

#include <dwrite_1.h>

#include "gfxFont.h"

#include "gfxUserFontSet.h"

#include "nsTHashMap.h"

#include "nsHashKeys.h"

#include "mozilla/gfx/gfxVars.h"

#include "mozilla/gfx/UnscaledFontDWrite.h"

/**

 * \brief Class representing a font face for a font entry.

*/

class gfxDWriteFont final : public gfxFont {

 public:

  gfxDWriteFont(const RefPtr<mozilla::gfx::UnscaledFontDWrite>& aUnscaledFont,

                gfxFontEntry* aFontEntry, const gfxFontStyle* aFontStyle,

                RefPtr<IDWriteFontFace> aFontFace = nullptr,

                AntialiasOption = kAntialiasDefault);

  static bool InitDWriteSupport();

  // These Update functions update gfxVars with font settings, they must only be

  // called in the parent process.

  static void UpdateSystemTextVars();

  static void UpdateClearTypeVars();

  static void SystemTextQualityChanged();

  gfxFont* CopyWithAntialiasOption(AntialiasOption anAAOption) const override;

  bool AllowSubpixelAA() const override { return mAllowManualShowGlyphs; }

  bool IsValid() const;

  IDWriteFontFace* GetFontFace();

  /* override Measure to add padding for antialiasing */

  RunMetrics Measure(const gfxTextRun* aTextRun, uint32_t aStart, uint32_t aEnd,

                     BoundingBoxType aBoundingBoxType,

                     DrawTarget* aDrawTargetForTightBoundingBox,

                     Spacing* aSpacing,

                     mozilla::gfx::ShapedTextFlags aOrientation) override;

  bool ProvidesGlyphWidths() const override;

  int32_t GetGlyphWidth(uint16_t aGID) override;

  bool GetGlyphBounds(uint16_t aGID, gfxRect* aBounds, bool aTight) override;

  void AddSizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf,

                              FontCacheSizes* aSizes) const override;

  void AddSizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf,

                              FontCacheSizes* aSizes) const override;

  FontType GetType() const override { return FONT_TYPE_DWRITE; }

  already_AddRefed<mozilla::gfx::ScaledFont> GetScaledFont(

      const TextRunDrawParams& aRunParams) override;

  bool ShouldRoundXOffset(cairo_t* aCairo) const override;

 protected:

  ~gfxDWriteFont() override;

  const Metrics& GetHorizontalMetrics() const override { return mMetrics; }

  bool GetFakeMetricsForArialBlack(DWRITE_FONT_METRICS* aFontMetrics);

  void ComputeMetrics(AntialiasOption anAAOption);

  bool HasBitmapStrikeForSize(uint32_t aSize);

  gfxFloat MeasureGlyphWidth(uint16_t aGlyph);

  DWRITE_MEASURING_MODE GetMeasuringMode() const;

  static mozilla::Atomic<bool> sForceGDIClassicEnabled;

  bool GetForceGDIClassic() const;

  RefPtr<IDWriteFontFace> mFontFace;

  RefPtr<IDWriteFontFace1> mFontFace1;  // may be unavailable on older DWrite

  Metrics mMetrics;

  // cache of glyph widths in 16.16 fixed-point pixels

  mozilla::UniquePtr<nsTHashMap<nsUint32HashKey, int32_t>> mGlyphWidths;

  bool mUseSubpixelPositions;

  bool mAllowManualShowGlyphs;

  // Used to record the sUseClearType setting at the time mAzureScaledFont

  // was set up, so we can tell if it's stale and needs to be re-created.

  mozilla::Atomic<bool> mAzureScaledFontUsedClearType;

  // Cache the GDI version of the ScaledFont so that font keys and other

  // meta-data can remain stable even if there is thrashing between GDI and

  // non-GDI usage.

  mozilla::Atomic<mozilla::gfx::ScaledFont*> mAzureScaledFontGDI;

  bool UsingClearType() {

    return mozilla::gfx::gfxVars::SystemTextQuality() == CLEARTYPE_QUALITY;

};

#endif