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[OS/2] Bug 381333: replace method to scale from font units to pixels. Instead of gfxPangoFonts-like macros use the procedure outlined in the FreeType tutorial. This takes advantage of gfxFloats.

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mozilla@weilbacher.org 2007-08-19 05:36:21 -07:00
Родитель 4e2e66bf62
Коммит d3accf209e
1 изменённых файлов: 22 добавлений и 30 удалений
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52
gfx/thebes/src/gfxOS2Fonts.cpp
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@ -82,18 +82,6 @@ gfxOS2Font::~gfxOS2Font()
mMetrics = nsnull;
}
// rounding and truncation functions for a Freetype floating 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 MOZ_FT_ROUND(x) (((x) + 32) & ~63) // 63 = 2^6 - 1
#define MOZ_FT_TRUNC(x) ((x) >> 6)
#define CONVERT_DESIGN_UNITS_TO_PIXELS(v, s) \
MOZ_FT_TRUNC(MOZ_FT_ROUND(FT_MulFix((v), (s))))
#define CONVERT_DESIGN_UNITS_TO_PIXELS_X(v) \
CONVERT_DESIGN_UNITS_TO_PIXELS(v, face->size->metrics.x_scale)
#define CONVERT_DESIGN_UNITS_TO_PIXELS_Y(v) \
CONVERT_DESIGN_UNITS_TO_PIXELS(v, face->size->metrics.y_scale)
// gfxOS2Font::GetMetrics()
// return the metrics of the current font using the gfxFont metrics structure.
// If the metrics are not available yet, compute them using the FreeType
@ -112,12 +100,16 @@ const gfxFont::Metrics& gfxOS2Font::GetMetrics()
FT_UInt gid; // glyph ID
FT_Face face = cairo_ft_scaled_font_lock_face(CairoScaledFont());
double emUnit = 1.0 * face->units_per_EM;
double xScale = face->size->metrics.x_ppem / emUnit;
double yScale = face->size->metrics.y_ppem / emUnit;
// properties of space
gid = FT_Get_Char_Index(face, ' ');
// load glyph into glyph slot, use no_scale to get font units
FT_Load_Glyph(face, gid, FT_LOAD_NO_SCALE);
// face->glyph->metrics.width doesn't work for spaces, use advance.x instead
mMetrics->spaceWidth = CONVERT_DESIGN_UNITS_TO_PIXELS_X(face->glyph->advance.x);
mMetrics->spaceWidth = face->glyph->advance.x * xScale;
// save the space glyph
mSpaceGlyph = gid;
@ -125,8 +117,8 @@ const gfxFont::Metrics& gfxOS2Font::GetMetrics()
gid = FT_Get_Char_Index(face, 'x'); // select the glyph
if (gid) {
FT_Load_Glyph(face, gid, FT_LOAD_NO_SCALE);
mMetrics->xHeight = CONVERT_DESIGN_UNITS_TO_PIXELS_Y(face->glyph->metrics.height);
mMetrics->aveCharWidth = CONVERT_DESIGN_UNITS_TO_PIXELS_X(face->glyph->metrics.width);
mMetrics->xHeight = face->glyph->metrics.height * yScale;
mMetrics->aveCharWidth = face->glyph->metrics.width * yScale;
} else {
// this font doesn't have an 'x'...
// fake these metrics using a fraction of the font size
@ -145,33 +137,33 @@ const gfxFont::Metrics& gfxOS2Font::GetMetrics()
TT_OS2 *os2 = (TT_OS2 *)FT_Get_Sfnt_Table(face, ft_sfnt_os2);
if (os2 && os2->version != 0xFFFF) { // should be there if not old Mac font
// if we are here we can improve the avgCharWidth
mMetrics->aveCharWidth = CONVERT_DESIGN_UNITS_TO_PIXELS_X(os2->xAvgCharWidth);
mMetrics->aveCharWidth = os2->xAvgCharWidth * xScale;
mMetrics->superscriptOffset = CONVERT_DESIGN_UNITS_TO_PIXELS_Y(os2->ySuperscriptYOffset);
mMetrics->superscriptOffset = os2->ySuperscriptYOffset * yScale;
mMetrics->superscriptOffset = PR_MAX(1, mMetrics->superscriptOffset);
// some fonts have the incorrect sign (from gfxPangoFonts)
mMetrics->subscriptOffset = fabs(CONVERT_DESIGN_UNITS_TO_PIXELS_Y(os2->ySubscriptYOffset));
mMetrics->subscriptOffset = fabs(os2->ySubscriptYOffset * yScale);
mMetrics->subscriptOffset = PR_MAX(1, fabs(mMetrics->subscriptOffset));
mMetrics->strikeoutOffset = CONVERT_DESIGN_UNITS_TO_PIXELS_Y(os2->yStrikeoutPosition);
mMetrics->strikeoutSize = PR_MAX(1, CONVERT_DESIGN_UNITS_TO_PIXELS_Y(os2->yStrikeoutSize));
mMetrics->strikeoutOffset = os2->yStrikeoutPosition * yScale;
mMetrics->strikeoutSize = PR_MAX(1, os2->yStrikeoutSize * yScale);
} else {
// use fractions of emHeight instead of xHeight for these to be more robust
mMetrics->superscriptOffset = mMetrics->emHeight * 0.5;
mMetrics->subscriptOffset = mMetrics->emHeight * 0.2;
mMetrics->strikeoutOffset = mMetrics->emHeight * 0.3;
mMetrics->strikeoutSize = CONVERT_DESIGN_UNITS_TO_PIXELS_Y(face->underline_thickness);
mMetrics->strikeoutSize = face->underline_thickness * yScale;
}
// seems that underlineOffset really has to be negative
mMetrics->underlineOffset = CONVERT_DESIGN_UNITS_TO_PIXELS_Y(face->underline_position);
mMetrics->underlineSize = PR_MAX(1, CONVERT_DESIGN_UNITS_TO_PIXELS_Y(face->underline_thickness));
mMetrics->underlineOffset = face->underline_position * yScale;
mMetrics->underlineSize = PR_MAX(1, face->underline_thickness * yScale);
// descents are negative in FT but Thebes wants them positive
mMetrics->emAscent = CONVERT_DESIGN_UNITS_TO_PIXELS_Y(face->ascender);
mMetrics->emDescent = -CONVERT_DESIGN_UNITS_TO_PIXELS_Y(face->descender);
mMetrics->maxHeight = CONVERT_DESIGN_UNITS_TO_PIXELS_Y(face->height);
mMetrics->maxAscent = CONVERT_DESIGN_UNITS_TO_PIXELS_Y(face->bbox.yMax);
mMetrics->maxDescent = -CONVERT_DESIGN_UNITS_TO_PIXELS_Y(face->bbox.yMin);
mMetrics->maxAdvance = CONVERT_DESIGN_UNITS_TO_PIXELS_X(face->max_advance_width);
mMetrics->emAscent = face->ascender * yScale;
mMetrics->emDescent = -face->descender * yScale;
mMetrics->maxHeight = face->height * yScale;
mMetrics->maxAscent = face->bbox.yMax * yScale;
mMetrics->maxDescent = -face->bbox.yMin * yScale;
mMetrics->maxAdvance = face->max_advance_width * xScale;
// leading are not available directly (only for WinFNTs)
double lineHeight = mMetrics->maxAscent + mMetrics->maxDescent;
if (lineHeight > mMetrics->emHeight) {
@ -577,7 +569,7 @@ void gfxOS2FontGroup::CreateGlyphRunsFT(gfxTextRun *aTextRun, const PRUint8 *aUT
advance = -1; // trigger the missing glyphs case below
} else {
FT_Load_Glyph(face, gid, FT_LOAD_DEFAULT); // load glyph into the slot
advance = MOZ_FT_TRUNC(face->glyph->advance.x) * appUnitsPerDevUnit;
advance = (face->glyph->advance.x >> 6) * appUnitsPerDevUnit;
}
#ifdef DEBUG_thebes_2
printf(" gid=%d, advance=%d (%s)\n", gid, advance,