UniscribeController.cpp [plain text]
#include "config.h"
#include "UniscribeController.h"
#include "Font.h"
#include "FontCascade.h"
#include "HWndDC.h"
#include "TextRun.h"
#include <wtf/MathExtras.h>
namespace WebCore {
using namespace WTF;
using namespace Unicode;
using namespace std;
UniscribeController::UniscribeController(const FontCascade* font, const TextRun& run, HashSet<const Font*>* fallbackFonts)
: m_font(*font)
, m_run(run)
, m_fallbackFonts(fallbackFonts)
, m_minGlyphBoundingBoxX(numeric_limits<float>::max())
, m_maxGlyphBoundingBoxX(numeric_limits<float>::min())
, m_minGlyphBoundingBoxY(numeric_limits<float>::max())
, m_maxGlyphBoundingBoxY(numeric_limits<float>::min())
, m_end(run.length())
, m_currentCharacter(0)
, m_runWidthSoFar(0)
, m_padding(run.expansion())
, m_computingOffsetPosition(false)
, m_includePartialGlyphs(false)
, m_offsetX(0)
, m_offsetPosition(0)
{
if (!m_padding)
m_padPerSpace = 0;
else {
float numSpaces = 0;
for (int s = 0; s < m_run.length(); s++) {
if (FontCascade::treatAsSpace(m_run[s]))
numSpaces++;
}
if (numSpaces == 0)
m_padPerSpace = 0;
else
m_padPerSpace = m_padding / numSpaces;
}
resetControlAndState();
}
int UniscribeController::offsetForPosition(int x, bool includePartialGlyphs)
{
m_computingOffsetPosition = true;
m_includePartialGlyphs = includePartialGlyphs;
m_offsetX = x;
m_offsetPosition = 0;
advance(m_run.length());
if (m_computingOffsetPosition) {
if (m_offsetX >= m_runWidthSoFar && m_run.ltr() || m_offsetX < 0 && m_run.rtl())
m_offsetPosition = m_end;
}
m_computingOffsetPosition = false;
return m_offsetPosition;
}
void UniscribeController::advance(unsigned offset, GlyphBuffer* glyphBuffer)
{
if (static_cast<int>(offset) > m_end)
offset = m_end;
int length = offset - m_currentCharacter;
if (length <= 0)
return;
String bufferFor16BitData;
const UChar* cp = nullptr;
if (m_run.is8Bit()) {
bufferFor16BitData = String::make16BitFrom8BitSource(m_run.data8(m_currentCharacter), length);
cp = bufferFor16BitData.characters16();
} else
cp = m_run.data16(m_currentCharacter);
unsigned baseCharacter = m_currentCharacter;
Vector<UChar, 256> smallCapsBuffer;
if (m_font.isSmallCaps())
smallCapsBuffer.resize(length);
unsigned indexOfFontTransition = m_run.rtl() ? length - 1 : 0;
const UChar* curr = m_run.rtl() ? cp + length - 1 : cp;
const UChar* end = m_run.rtl() ? cp - 1 : cp + length;
const Font* fontData;
const Font* nextFontData = m_font.glyphDataForCharacter(*curr, false).font;
UChar newC = 0;
bool isSmallCaps;
bool nextIsSmallCaps = m_font.isSmallCaps() && !(U_GET_GC_MASK(*curr) & U_GC_M_MASK) && (newC = u_toupper(*curr)) != *curr;
if (nextIsSmallCaps)
smallCapsBuffer[curr - cp] = newC;
while (true) {
curr = m_run.rtl() ? curr - 1 : curr + 1;
if (curr == end)
break;
fontData = nextFontData;
isSmallCaps = nextIsSmallCaps;
int index = curr - cp;
UChar c = *curr;
bool forceSmallCaps = isSmallCaps && (U_GET_GC_MASK(c) & U_GC_M_MASK);
nextFontData = m_font.glyphDataForCharacter(*curr, false, forceSmallCaps ? SmallCapsVariant : AutoVariant).font;
if (m_font.isSmallCaps()) {
nextIsSmallCaps = forceSmallCaps || (newC = u_toupper(c)) != c;
if (nextIsSmallCaps)
smallCapsBuffer[index] = forceSmallCaps ? c : newC;
}
if (m_fallbackFonts && fontData && nextFontData != fontData && fontData != &m_font.primaryFont())
m_fallbackFonts->add(fontData);
if (nextFontData != fontData || nextIsSmallCaps != isSmallCaps) {
int itemStart = m_run.rtl() ? index + 1 : indexOfFontTransition;
int itemLength = m_run.rtl() ? indexOfFontTransition - index : index - indexOfFontTransition;
m_currentCharacter = baseCharacter + itemStart;
itemizeShapeAndPlace((isSmallCaps ? smallCapsBuffer.data() : cp) + itemStart, itemLength, fontData, glyphBuffer);
indexOfFontTransition = index;
}
}
int itemLength = m_run.rtl() ? indexOfFontTransition + 1 : length - indexOfFontTransition;
if (itemLength) {
if (m_fallbackFonts && nextFontData && nextFontData != &m_font.primaryFont())
m_fallbackFonts->add(nextFontData);
int itemStart = m_run.rtl() ? 0 : indexOfFontTransition;
m_currentCharacter = baseCharacter + itemStart;
itemizeShapeAndPlace((nextIsSmallCaps ? smallCapsBuffer.data() : cp) + itemStart, itemLength, nextFontData, glyphBuffer);
}
m_currentCharacter = baseCharacter + length;
}
void UniscribeController::itemizeShapeAndPlace(const UChar* cp, unsigned length, const Font* fontData, GlyphBuffer* glyphBuffer)
{
m_items.resize(6);
int numItems = 0;
HRESULT rc = S_OK;
while (rc = ::ScriptItemize(cp, length, m_items.size() - 1, &m_control, &m_state, m_items.data(), &numItems) == E_OUTOFMEMORY) {
m_items.resize(m_items.size() * 2);
resetControlAndState();
}
if (FAILED(rc)) {
WTFLogAlways("UniscribeController::itemizeShapeAndPlace: ScriptItemize failed, rc=%lx", rc);
return;
}
m_items.resize(numItems + 1);
if (m_run.rtl()) {
for (int i = m_items.size() - 2; i >= 0; i--) {
if (!shapeAndPlaceItem(cp, i, fontData, glyphBuffer))
return;
}
} else {
for (unsigned i = 0; i < m_items.size() - 1; i++) {
if (!shapeAndPlaceItem(cp, i, fontData, glyphBuffer))
return;
}
}
}
void UniscribeController::resetControlAndState()
{
memset(&m_control, 0, sizeof(SCRIPT_CONTROL));
memset(&m_state, 0, sizeof(SCRIPT_STATE));
m_state.uBidiLevel = m_run.rtl();
m_state.fOverrideDirection = m_run.directionalOverride();
}
bool UniscribeController::shapeAndPlaceItem(const UChar* cp, unsigned i, const Font* fontData, GlyphBuffer* glyphBuffer)
{
const UChar* str = cp + m_items[i].iCharPos;
int len = m_items[i+1].iCharPos - m_items[i].iCharPos;
SCRIPT_ITEM item = m_items[i];
Vector<WORD> glyphs;
Vector<WORD> clusters;
Vector<SCRIPT_VISATTR> visualAttributes;
clusters.resize(len);
glyphs.resize(1.5 * len + 16);
visualAttributes.resize(glyphs.size());
if (!shape(str, len, item, fontData, glyphs, clusters, visualAttributes))
return true;
Vector<GOFFSET> offsets;
Vector<int> advances;
offsets.resize(glyphs.size());
advances.resize(glyphs.size());
int glyphCount = 0;
HRESULT placeResult = ScriptPlace(0, fontData->scriptCache(), glyphs.data(), glyphs.size(), visualAttributes.data(),
&item.a, advances.data(), offsets.data(), 0);
if (placeResult == E_PENDING) {
HWndDC hdc(0);
HFONT hfont = fontData->platformData().hfont();
HFONT oldFont = (HFONT)SelectObject(hdc, hfont);
placeResult = ScriptPlace(hdc, fontData->scriptCache(), glyphs.data(), glyphs.size(), visualAttributes.data(),
&item.a, advances.data(), offsets.data(), 0);
SelectObject(hdc, oldFont);
}
if (FAILED(placeResult) || glyphs.isEmpty())
return true;
Vector<int> spaceCharacters(glyphs.size());
spaceCharacters.fill(-1);
const float cLogicalScale = fontData->platformData().useGDI() ? 1.0f : 32.0f;
float spaceWidth = fontData->spaceWidth() - fontData->syntheticBoldOffset();
unsigned logicalSpaceWidth = spaceWidth * cLogicalScale;
for (int k = 0; k < len; k++) {
UChar ch = *(str + k);
bool treatAsSpace = FontCascade::treatAsSpace(ch);
bool treatAsZeroWidthSpace = FontCascade::treatAsZeroWidthSpace(ch);
if (treatAsSpace || treatAsZeroWidthSpace) {
glyphs[clusters[k]] = fontData->spaceGlyph();
advances[clusters[k]] = treatAsSpace ? logicalSpaceWidth : 0;
if (treatAsSpace)
spaceCharacters[clusters[k]] = m_currentCharacter + k + item.iCharPos;
}
}
bool hasExtraSpacing = m_font.letterSpacing() || m_font.wordSpacing() || m_padding;
float leftEdge = m_runWidthSoFar;
for (unsigned k = 0; k < glyphs.size(); k++) {
Glyph glyph = glyphs[k];
float advance = advances[k] / cLogicalScale;
float offsetX = offsets[k].du / cLogicalScale;
float offsetY = offsets[k].dv / cLogicalScale;
float roundedAdvance = roundf(advance);
if (!fontData->platformData().isSystemFont()) {
advance = roundedAdvance;
offsetX = roundf(offsetX);
offsetY = roundf(offsetY);
}
advance += fontData->syntheticBoldOffset();
if (hasExtraSpacing) {
if (advance && m_font.letterSpacing())
advance += m_font.letterSpacing();
int characterIndex = spaceCharacters[k];
if (characterIndex != -1) {
if (m_padding) {
if (m_padding < m_padPerSpace) {
advance += m_padding;
m_padding = 0;
} else {
m_padding -= m_padPerSpace;
advance += m_padPerSpace;
}
}
if (characterIndex > 0 && m_font.wordSpacing()) {
UChar candidateSpace;
if (m_run.is8Bit())
candidateSpace = *(m_run.data8(characterIndex - 1));
else
candidateSpace = *(m_run.data16(characterIndex - 1));
if (!FontCascade::treatAsSpace(candidateSpace))
advance += m_font.wordSpacing();
}
}
}
m_runWidthSoFar += advance;
if (glyphBuffer) {
GlyphBufferAdvance origin(offsetX, -offsetY);
if (!glyphBuffer->advancesCount())
glyphBuffer->setInitialAdvance(origin);
else
glyphBuffer->expandLastAdvance(origin);
GlyphBufferAdvance advance(-origin.width() + advance, -origin.height());
glyphBuffer->add(glyph, fontData, advance);
}
FloatRect glyphBounds = fontData->boundsForGlyph(glyph);
glyphBounds.move(m_glyphOrigin.x(), m_glyphOrigin.y());
m_minGlyphBoundingBoxX = min(m_minGlyphBoundingBoxX, glyphBounds.x());
m_maxGlyphBoundingBoxX = max(m_maxGlyphBoundingBoxX, glyphBounds.maxX());
m_minGlyphBoundingBoxY = min(m_minGlyphBoundingBoxY, glyphBounds.y());
m_maxGlyphBoundingBoxY = max(m_maxGlyphBoundingBoxY, glyphBounds.maxY());
m_glyphOrigin.move(advance + offsetX, -offsetY);
if (m_computingOffsetPosition)
advances[k] = advance;
}
while (m_computingOffsetPosition && m_offsetX >= leftEdge && m_offsetX < m_runWidthSoFar) {
int trailing = 0;
HRESULT rc = ::ScriptXtoCP(m_offsetX - leftEdge, clusters.size(), glyphs.size(), clusters.data(), visualAttributes.data(),
advances.data(), &item.a, &m_offsetPosition, &trailing);
if (FAILED(rc)) {
WTFLogAlways("UniscribeController::shapeAndPlaceItem: ScriptXtoCP failed rc=%lx", rc);
return true;
}
if (trailing && m_includePartialGlyphs && m_offsetPosition < len - 1) {
m_offsetPosition += m_currentCharacter + m_items[i].iCharPos;
m_offsetX += m_run.rtl() ? -trailing : trailing;
} else {
m_computingOffsetPosition = false;
m_offsetPosition += m_currentCharacter + m_items[i].iCharPos;
if (trailing && m_includePartialGlyphs)
m_offsetPosition++;
return false;
}
}
return true;
}
bool UniscribeController::shape(const UChar* str, int len, SCRIPT_ITEM item, const Font* fontData,
Vector<WORD>& glyphs, Vector<WORD>& clusters,
Vector<SCRIPT_VISATTR>& visualAttributes)
{
HWndDC hdc;
HFONT oldFont = 0;
HRESULT shapeResult = E_PENDING;
int glyphCount = 0;
if (!fontData)
return false;
do {
shapeResult = ScriptShape(hdc, fontData->scriptCache(), str, len, glyphs.size(), &item.a,
glyphs.data(), clusters.data(), visualAttributes.data(), &glyphCount);
if (shapeResult == E_PENDING) {
ASSERT(!hdc);
hdc.setHWnd(0);
HFONT hfont = fontData->platformData().hfont();
oldFont = (HFONT)SelectObject(hdc, hfont);
} else if (shapeResult == E_OUTOFMEMORY) {
glyphs.resize(glyphs.size() * 2);
visualAttributes.resize(glyphs.size());
}
} while (shapeResult == E_PENDING || shapeResult == E_OUTOFMEMORY);
if (hdc)
SelectObject(hdc, oldFont);
if (FAILED(shapeResult))
return false;
glyphs.shrink(glyphCount);
visualAttributes.shrink(glyphCount);
return true;
}
}