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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
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Add m-esr52 at 52.6.0
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+/* -*- 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:
+ explicit 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);
+
+ // 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();
+
+ RefPtr<gfxFT2FontBase> mGfxFont;
+ FT_Face mFace;
+};
+
+#endif /* GFX_FT2UTILS_H */