HarfBuzzFaceCairo.cpp [plain text]
#include "config.h"
#include "HarfBuzzFace.h"
#include "CairoUtilities.h"
#include "Font.h"
#include "FontPlatformData.h"
#include "GlyphBuffer.h"
#include "HarfBuzzShaper.h"
#include "TextEncoding.h"
#include <cairo-ft.h>
#include <cairo.h>
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_TRUETYPE_TABLES_H
#include <hb.h>
#include <wtf/text/CString.h>
#include <wtf/text/StringView.h>
namespace WebCore {
struct HarfBuzzFontData {
HarfBuzzFontData(WTF::HashMap<uint32_t, uint16_t>* glyphCacheForFaceCacheEntry, cairo_scaled_font_t* cairoScaledFont)
: m_glyphCacheForFaceCacheEntry(glyphCacheForFaceCacheEntry)
, m_cairoScaledFont(cairoScaledFont)
{ }
WTF::HashMap<uint32_t, uint16_t>* m_glyphCacheForFaceCacheEntry;
cairo_scaled_font_t* m_cairoScaledFont;
};
static hb_position_t floatToHarfBuzzPosition(float value)
{
return static_cast<hb_position_t>(value * (1 << 16));
}
static hb_position_t doubleToHarfBuzzPosition(double value)
{
return static_cast<hb_position_t>(value * (1 << 16));
}
static void CairoGetGlyphWidthAndExtents(cairo_scaled_font_t* scaledFont, hb_codepoint_t codepoint, hb_position_t* advance, hb_glyph_extents_t* extents)
{
cairo_text_extents_t glyphExtents;
cairo_glyph_t glyph;
glyph.index = codepoint;
glyph.x = 0;
glyph.y = 0;
cairo_scaled_font_glyph_extents(scaledFont, &glyph, 1, &glyphExtents);
bool hasVerticalGlyphs = glyphExtents.y_advance;
if (advance)
*advance = doubleToHarfBuzzPosition(hasVerticalGlyphs ? -glyphExtents.y_advance : glyphExtents.x_advance);
if (extents) {
extents->x_bearing = doubleToHarfBuzzPosition(glyphExtents.x_bearing);
extents->y_bearing = doubleToHarfBuzzPosition(hasVerticalGlyphs ? -glyphExtents.y_bearing : glyphExtents.y_bearing);
extents->width = doubleToHarfBuzzPosition(hasVerticalGlyphs ? -glyphExtents.height : glyphExtents.width);
extents->height = doubleToHarfBuzzPosition(hasVerticalGlyphs ? glyphExtents.width : glyphExtents.height);
}
}
static hb_bool_t harfBuzzGetGlyph(hb_font_t*, void* fontData, hb_codepoint_t unicode, hb_codepoint_t, hb_codepoint_t* glyph, void*)
{
HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
cairo_scaled_font_t* scaledFont = hbFontData->m_cairoScaledFont;
ASSERT(scaledFont);
WTF::HashMap<uint32_t, uint16_t>::AddResult result = hbFontData->m_glyphCacheForFaceCacheEntry->add(unicode, 0);
if (result.isNewEntry) {
cairo_glyph_t* glyphs = 0;
int numGlyphs = 0;
UChar ch = unicode;
CString utf8Codepoint = UTF8Encoding().encode(StringView(&ch, 1), QuestionMarksForUnencodables);
if (cairo_scaled_font_text_to_glyphs(scaledFont, 0, 0, utf8Codepoint.data(), utf8Codepoint.length(), &glyphs, &numGlyphs, 0, 0, 0) != CAIRO_STATUS_SUCCESS)
return false;
if (!numGlyphs)
return false;
result.iterator->value = glyphs[0].index;
cairo_glyph_free(glyphs);
}
*glyph = result.iterator->value;
return !!*glyph;
}
static hb_position_t harfBuzzGetGlyphHorizontalAdvance(hb_font_t*, void* fontData, hb_codepoint_t glyph, void*)
{
HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
cairo_scaled_font_t* scaledFont = hbFontData->m_cairoScaledFont;
ASSERT(scaledFont);
hb_position_t advance = 0;
CairoGetGlyphWidthAndExtents(scaledFont, glyph, &advance, 0);
return advance;
}
static hb_bool_t harfBuzzGetGlyphHorizontalOrigin(hb_font_t*, void*, hb_codepoint_t, hb_position_t*, hb_position_t*, void*)
{
return true;
}
static hb_bool_t harfBuzzGetGlyphExtents(hb_font_t*, void* fontData, hb_codepoint_t glyph, hb_glyph_extents_t* extents, void*)
{
HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
cairo_scaled_font_t* scaledFont = hbFontData->m_cairoScaledFont;
ASSERT(scaledFont);
CairoGetGlyphWidthAndExtents(scaledFont, glyph, 0, extents);
return true;
}
static hb_font_funcs_t* harfBuzzCairoTextGetFontFuncs()
{
static hb_font_funcs_t* harfBuzzCairoFontFuncs = 0;
if (!harfBuzzCairoFontFuncs) {
harfBuzzCairoFontFuncs = hb_font_funcs_create();
hb_font_funcs_set_glyph_func(harfBuzzCairoFontFuncs, harfBuzzGetGlyph, 0, 0);
hb_font_funcs_set_glyph_h_advance_func(harfBuzzCairoFontFuncs, harfBuzzGetGlyphHorizontalAdvance, 0, 0);
hb_font_funcs_set_glyph_h_origin_func(harfBuzzCairoFontFuncs, harfBuzzGetGlyphHorizontalOrigin, 0, 0);
hb_font_funcs_set_glyph_extents_func(harfBuzzCairoFontFuncs, harfBuzzGetGlyphExtents, 0, 0);
hb_font_funcs_make_immutable(harfBuzzCairoFontFuncs);
}
return harfBuzzCairoFontFuncs;
}
static hb_blob_t* harfBuzzCairoGetTable(hb_face_t*, hb_tag_t tag, void* userData)
{
cairo_scaled_font_t* scaledFont = reinterpret_cast<cairo_scaled_font_t*>(userData);
if (!scaledFont)
return 0;
CairoFtFaceLocker cairoFtFaceLocker(scaledFont);
FT_Face ftFont = cairoFtFaceLocker.ftFace();
if (!ftFont)
return nullptr;
FT_ULong tableSize = 0;
FT_Error error = FT_Load_Sfnt_Table(ftFont, tag, 0, 0, &tableSize);
if (error)
return 0;
FT_Byte* buffer = reinterpret_cast<FT_Byte*>(fastMalloc(tableSize));
if (!buffer)
return 0;
FT_ULong expectedTableSize = tableSize;
error = FT_Load_Sfnt_Table(ftFont, tag, 0, buffer, &tableSize);
if (error || tableSize != expectedTableSize) {
fastFree(buffer);
return 0;
}
return hb_blob_create(reinterpret_cast<const char*>(buffer), tableSize, HB_MEMORY_MODE_WRITABLE, buffer, fastFree);
}
static void destroyHarfBuzzFontData(void* userData)
{
HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(userData);
delete hbFontData;
}
hb_face_t* HarfBuzzFace::createFace()
{
hb_face_t* face = hb_face_create_for_tables(harfBuzzCairoGetTable, m_platformData->scaledFont(), 0);
ASSERT(face);
return face;
}
hb_font_t* HarfBuzzFace::createFont()
{
hb_font_t* font = hb_font_create(m_face);
HarfBuzzFontData* hbFontData = new HarfBuzzFontData(m_glyphCacheForFaceCacheEntry, m_platformData->scaledFont());
hb_font_set_funcs(font, harfBuzzCairoTextGetFontFuncs(), hbFontData, destroyHarfBuzzFontData);
const float size = m_platformData->size();
if (floorf(size) == size)
hb_font_set_ppem(font, size, size);
int scale = floatToHarfBuzzPosition(size);
hb_font_set_scale(font, scale, scale);
hb_font_make_immutable(font);
return font;
}
GlyphBufferAdvance HarfBuzzShaper::createGlyphBufferAdvance(float width, float height)
{
return GlyphBufferAdvance(width, height);
}
}