mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-12-02 18:08:58 +00:00
97 lines
3.4 KiB
C++
97 lines
3.4 KiB
C++
/* -*- 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;
|
|
|
|
class gfxFT2LockedFace {
|
|
public:
|
|
gfxFT2LockedFace(gfxFT2FontBase *aFont) :
|
|
mGfxFont(aFont),
|
|
mFace(cairo_ft_scaled_font_lock_face(aFont->CairoScaledFont()))
|
|
{ }
|
|
~gfxFT2LockedFace()
|
|
{
|
|
if (mFace) {
|
|
cairo_ft_scaled_font_unlock_face(mGfxFont->CairoScaledFont());
|
|
}
|
|
}
|
|
|
|
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);
|
|
|
|
void GetMetrics(gfxFont::Metrics* aMetrics, uint32_t* aSpaceGlyph);
|
|
|
|
bool GetFontTable(uint32_t aTag, FallibleTArray<uint8_t>& aBuffer);
|
|
|
|
// A scale factor for use in converting horizontal metrics from font units
|
|
// to pixels.
|
|
gfxFloat XScale()
|
|
{
|
|
if (MOZ_UNLIKELY(!mFace))
|
|
return 0.0;
|
|
|
|
const FT_Size_Metrics& ftMetrics = mFace->size->metrics;
|
|
|
|
if (FT_IS_SCALABLE(mFace)) {
|
|
// Prefer FT_Size_Metrics::x_scale to x_ppem as x_ppem does not
|
|
// have subpixel accuracy.
|
|
//
|
|
// FT_Size_Metrics::x_scale is in 16.16 fixed point format. Its
|
|
// (fractional) value is a factor that converts vertical metrics
|
|
// from design units to units of 1/64 pixels, so that the result
|
|
// may be interpreted as pixels in 26.6 fixed point format.
|
|
return FLOAT_FROM_26_6(FLOAT_FROM_16_16(ftMetrics.x_scale));
|
|
}
|
|
|
|
// Not scalable.
|
|
// FT_Size_Metrics doc says x_scale is "only relevant for scalable
|
|
// font formats".
|
|
return gfxFloat(ftMetrics.x_ppem) / gfxFloat(mFace->units_per_EM);
|
|
}
|
|
|
|
protected:
|
|
/**
|
|
* Get extents for a simple character representable by a single glyph.
|
|
* The return value is the glyph id of that glyph or zero if no such glyph
|
|
* exists. aExtents is only set when this returns a non-zero glyph id.
|
|
*/
|
|
uint32_t GetCharExtents(char aChar, cairo_text_extents_t* aExtents);
|
|
|
|
typedef FT_UInt (*CharVariantFunction)(FT_Face face,
|
|
FT_ULong charcode,
|
|
FT_ULong variantSelector);
|
|
CharVariantFunction FindCharVariantFunction();
|
|
|
|
nsRefPtr<gfxFT2FontBase> mGfxFont;
|
|
FT_Face mFace;
|
|
};
|
|
|
|
#endif /* GFX_FT2UTILS_H */
|