/* -*- 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/. */

#ifndef GFX_FT2UTILS_H

#define GFX_FT2UTILS_H

#include "cairo-ft.h"

#include "gfxFT2FontBase.h"

#include "mozilla/Likely.h"

// Rounding and truncation functions for a FreeType fixed point number 

// (FT26Dot6) stored in a 32bit integer with high 26 bits for the integer

// part and low 6 bits for the fractional part. 

#define FLOAT_FROM_26_6(x) ((x) / 64.0)

#define FLOAT_FROM_16_16(x) ((x) / 65536.0)

#define ROUND_26_6_TO_INT(x) ((x) >= 0 ?  ((32 + (x)) >> 6) \

                                       : -((32 - (x)) >> 6))

typedef struct FT_FaceRec_* FT_Face;

/**

 * BEWARE: Recursively locking with gfxFT2LockedFace is not supported.

 * Do not instantiate gfxFT2LockedFace within the scope of another instance.

 * Do not attempt to call into Cairo within the scope of gfxFT2LockedFace,

 * as that may accidentally try to re-lock the face within Cairo itself

 * and thus deadlock.

 */

class MOZ_STACK_CLASS gfxFT2LockedFace {

public:

    explicit gfxFT2LockedFace(gfxFT2FontBase *aFont) :

        mGfxFont(aFont),

        mFace(cairo_ft_scaled_font_lock_face(aFont->GetCairoScaledFont()))

    { }

    ~gfxFT2LockedFace()

    {

        if (mFace) {

            cairo_ft_scaled_font_unlock_face(mGfxFont->GetCairoScaledFont());

        }

    }

    FT_Face get() { return mFace; };

    /**

     * Get the glyph id for a Unicode character representable by a single

     * glyph, or return zero if there is no such glyph.  This does no caching,

     * so you probably want gfxFcFont::GetGlyph.

     */

    uint32_t GetGlyph(uint32_t aCharCode);

    /**

     * Returns 0 if there is no variation selector cmap subtable.

     */

    uint32_t GetUVSGlyph(uint32_t aCharCode, uint32_t aVariantSelector);

protected:

    typedef FT_UInt (*CharVariantFunction)(FT_Face  face,

                                           FT_ULong charcode,

                                           FT_ULong variantSelector);

    CharVariantFunction FindCharVariantFunction();

    gfxFT2FontBase* MOZ_NON_OWNING_REF mGfxFont; // owned by caller

    FT_Face mFace;

};

// A couple of FreeType-based utilities shared by gfxFontconfigFontEntry

// and FT2FontEntry.

typedef struct FT_MM_Var_ FT_MM_Var;

class gfxFT2Utils {

public:

    static void

    GetVariationAxes(const FT_MM_Var* aMMVar,

                     nsTArray<gfxFontVariationAxis>& aAxes);

    static void

    GetVariationInstances(gfxFontEntry* aFontEntry,

                          const FT_MM_Var* aMMVar,

                          nsTArray<gfxFontVariationInstance>& aInstances);

};

#endif /* GFX_FT2UTILS_H */