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/*
* Copyright (c) 2012 Google Inc. All rights reserved.
* Copyright (c) 2014 BlackBerry Limited. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "platform/fonts/harfbuzz/HarfBuzzFace.h"
#include "SkPaint.h"
#include "SkPath.h"
#include "SkPoint.h"
#include "SkRect.h"
#include "SkTypeface.h"
#include "SkUtils.h"
#include "platform/fonts/FontPlatformData.h"
#include "platform/fonts/SimpleFontData.h"
#include "platform/fonts/harfbuzz/HarfBuzzShaper.h"
#include "hb.h"
#include "wtf/HashMap.h"
namespace WebCore {
// Our implementation of the callbacks which HarfBuzz requires by using Skia
// calls. See the HarfBuzz source for references about what these callbacks do.
struct HarfBuzzFontData {
HarfBuzzFontData(WTF::HashMap<uint32_t, uint16_t>* glyphCacheForFaceCacheEntry)
: m_glyphCacheForFaceCacheEntry(glyphCacheForFaceCacheEntry)
{ }
SkPaint m_paint;
WTF::HashMap<uint32_t, uint16_t>* m_glyphCacheForFaceCacheEntry;
};
static hb_position_t SkiaScalarToHarfBuzzPosition(SkScalar value)
{
return SkScalarToFixed(value);
}
static void SkiaGetGlyphWidthAndExtents(SkPaint* paint, hb_codepoint_t codepoint, hb_position_t* width, hb_glyph_extents_t* extents)
{
ASSERT(codepoint <= 0xFFFF);
paint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
SkScalar skWidth;
SkRect skBounds;
uint16_t glyph = codepoint;
paint->getTextWidths(&glyph, sizeof(glyph), &skWidth, &skBounds);
if (width)
*width = SkiaScalarToHarfBuzzPosition(skWidth);
if (extents) {
// Invert y-axis because Skia is y-grows-down but we set up HarfBuzz to be y-grows-up.
extents->x_bearing = SkiaScalarToHarfBuzzPosition(skBounds.fLeft);
extents->y_bearing = SkiaScalarToHarfBuzzPosition(-skBounds.fTop);
extents->width = SkiaScalarToHarfBuzzPosition(skBounds.width());
extents->height = SkiaScalarToHarfBuzzPosition(-skBounds.height());
}
}
static hb_bool_t harfBuzzGetGlyph(hb_font_t* hbFont, void* fontData, hb_codepoint_t unicode, hb_codepoint_t variationSelector, hb_codepoint_t* glyph, void* userData)
{
HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
WTF::HashMap<uint32_t, uint16_t>::AddResult result = hbFontData->m_glyphCacheForFaceCacheEntry->add(unicode, 0);
if (result.isNewEntry) {
SkPaint* paint = &hbFontData->m_paint;
paint->setTextEncoding(SkPaint::kUTF32_TextEncoding);
uint16_t glyph16;
paint->textToGlyphs(&unicode, sizeof(hb_codepoint_t), &glyph16);
result.storedValue->value = glyph16;
*glyph = glyph16;
}
*glyph = result.storedValue->value;
return !!*glyph;
}
static hb_position_t harfBuzzGetGlyphHorizontalAdvance(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, void* userData)
{
HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
hb_position_t advance = 0;
SkiaGetGlyphWidthAndExtents(&hbFontData->m_paint, glyph, &advance, 0);
return advance;
}
static hb_bool_t harfBuzzGetGlyphHorizontalOrigin(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, hb_position_t* x, hb_position_t* y, void* userData)
{
// Just return true, following the way that HarfBuzz-FreeType
// implementation does.
return true;
}
static hb_position_t harfBuzzGetGlyphHorizontalKerning(hb_font_t*, void* fontData, hb_codepoint_t leftGlyph, hb_codepoint_t rightGlyph, void*)
{
HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
if (hbFontData->m_paint.isVerticalText()) {
// We don't support cross-stream kerning
return 0;
}
SkTypeface* typeface = hbFontData->m_paint.getTypeface();
const uint16_t glyphs[2] = { static_cast<uint16_t>(leftGlyph), static_cast<uint16_t>(rightGlyph) };
int32_t kerningAdjustments[1] = { 0 };
if (typeface->getKerningPairAdjustments(glyphs, 2, kerningAdjustments)) {
SkScalar upm = SkIntToScalar(typeface->getUnitsPerEm());
SkScalar size = hbFontData->m_paint.getTextSize();
return SkiaScalarToHarfBuzzPosition(SkScalarMulDiv(SkIntToScalar(kerningAdjustments[0]), size, upm));
}
return 0;
}
static hb_position_t harfBuzzGetGlyphVerticalKerning(hb_font_t*, void* fontData, hb_codepoint_t topGlyph, hb_codepoint_t bottomGlyph, void*)
{
HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
if (!hbFontData->m_paint.isVerticalText()) {
// We don't support cross-stream kerning
return 0;
}
SkTypeface* typeface = hbFontData->m_paint.getTypeface();
const uint16_t glyphs[2] = { static_cast<uint16_t>(topGlyph), static_cast<uint16_t>(bottomGlyph) };
int32_t kerningAdjustments[1] = { 0 };
if (typeface->getKerningPairAdjustments(glyphs, 2, kerningAdjustments)) {
SkScalar upm = SkIntToScalar(typeface->getUnitsPerEm());
SkScalar size = hbFontData->m_paint.getTextSize();
return SkiaScalarToHarfBuzzPosition(SkScalarMulDiv(SkIntToScalar(kerningAdjustments[0]), size, upm));
}
return 0;
}
static hb_bool_t harfBuzzGetGlyphExtents(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, hb_glyph_extents_t* extents, void* userData)
{
HarfBuzzFontData* hbFontData = reinterpret_cast<HarfBuzzFontData*>(fontData);
SkiaGetGlyphWidthAndExtents(&hbFontData->m_paint, glyph, 0, extents);
return true;
}
static hb_font_funcs_t* harfBuzzSkiaGetFontFuncs()
{
static hb_font_funcs_t* harfBuzzSkiaFontFuncs = 0;
// We don't set callback functions which we can't support.
// HarfBuzz will use the fallback implementation if they aren't set.
if (!harfBuzzSkiaFontFuncs) {
harfBuzzSkiaFontFuncs = hb_font_funcs_create();
hb_font_funcs_set_glyph_func(harfBuzzSkiaFontFuncs, harfBuzzGetGlyph, 0, 0);
hb_font_funcs_set_glyph_h_advance_func(harfBuzzSkiaFontFuncs, harfBuzzGetGlyphHorizontalAdvance, 0, 0);
hb_font_funcs_set_glyph_h_kerning_func(harfBuzzSkiaFontFuncs, harfBuzzGetGlyphHorizontalKerning, 0, 0);
hb_font_funcs_set_glyph_h_origin_func(harfBuzzSkiaFontFuncs, harfBuzzGetGlyphHorizontalOrigin, 0, 0);
hb_font_funcs_set_glyph_v_kerning_func(harfBuzzSkiaFontFuncs, harfBuzzGetGlyphVerticalKerning, 0, 0);
hb_font_funcs_set_glyph_extents_func(harfBuzzSkiaFontFuncs, harfBuzzGetGlyphExtents, 0, 0);
hb_font_funcs_make_immutable(harfBuzzSkiaFontFuncs);
}
return harfBuzzSkiaFontFuncs;
}
static hb_blob_t* harfBuzzSkiaGetTable(hb_face_t* face, hb_tag_t tag, void* userData)
{
SkTypeface* typeface = reinterpret_cast<SkTypeface*>(userData);
const size_t tableSize = typeface->getTableSize(tag);
if (!tableSize)
return 0;
char* buffer = reinterpret_cast<char*>(fastMalloc(tableSize));
if (!buffer)
return 0;
size_t actualSize = typeface->getTableData(tag, 0, tableSize, buffer);
if (tableSize != actualSize) {
fastFree(buffer);
return 0;
}
return hb_blob_create(const_cast<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(harfBuzzSkiaGetTable, m_platformData->typeface(), 0);
ASSERT(face);
return face;
}
hb_font_t* HarfBuzzFace::createFont()
{
HarfBuzzFontData* hbFontData = new HarfBuzzFontData(m_glyphCacheForFaceCacheEntry);
m_platformData->setupPaint(&hbFontData->m_paint);
hb_font_t* font = hb_font_create(m_face);
hb_font_set_funcs(font, harfBuzzSkiaGetFontFuncs(), hbFontData, destroyHarfBuzzFontData);
float size = m_platformData->size();
int scale = SkiaScalarToHarfBuzzPosition(size);
hb_font_set_scale(font, scale, scale);
hb_font_make_immutable(font);
return font;
}
} // namespace WebCore
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