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/*
* Copyright (C) 2007 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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 "UniscribeController.h"
#include "Font.h"
#include "SimpleFontData.h"
#include <wtf/MathExtras.h>
using namespace std;
namespace WebCore {
// FIXME: Rearchitect this to be more like WidthIterator in Font.cpp. Have an advance() method
// that does stuff in that method instead of doing everything in the constructor. Have advance()
// take the GlyphBuffer as an arg so that we don't have to populate the glyph buffer when
// measuring.
UniscribeController::UniscribeController(const Font* font, const TextRun& run, HashSet<const SimpleFontData*>* 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_computingOffsetPosition(false)
, m_includePartialGlyphs(false)
, m_offsetX(0)
, m_offsetPosition(0)
{
m_padding = m_run.padding();
if (!m_padding)
m_padPerSpace = 0;
else {
float numSpaces = 0;
for (int s = 0; s < m_run.length(); s++)
if (Font::treatAsSpace(m_run[s]))
numSpaces++;
if (numSpaces == 0)
m_padPerSpace = 0;
else
m_padPerSpace = ceilf(m_run.padding() / numSpaces);
}
// Null out our uniscribe structs
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) {
// The point is to the left or to the right of the entire run.
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)
{
// FIXME: We really want to be using a newer version of Uniscribe that supports the new OpenType
// functions. Those functions would allow us to turn off kerning and ligatures. Without being able
// to do that, we will have buggy line breaking and metrics when simple and complex text are close
// together (the complex code path will narrow the text because of kerning and ligatures and then
// when bidi processing splits into multiple runs, the simple portions will get wider and cause us to
// spill off the edge of a line).
if (static_cast<int>(offset) > m_end)
offset = m_end;
// Itemize the string.
const UChar* cp = m_run.data(m_currentCharacter);
int length = offset - m_currentCharacter;
if (length <= 0)
return;
unsigned baseCharacter = m_currentCharacter;
// We break up itemization of the string by fontData and (if needed) the use of small caps.
// FIXME: It's inconsistent that we use logical order when itemizing, since this
// does not match normal RTL.
// FIXME: This function should decode surrogate pairs. Currently it makes little difference that
// it does not because the font cache on Windows does not support non-BMP characters.
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 SimpleFontData* fontData;
const SimpleFontData* nextFontData = m_font.glyphDataForCharacter(*curr, false).fontData;
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).fontData;
if (m_font.isSmallCaps()) {
nextIsSmallCaps = forceSmallCaps || (newC = u_toupper(c)) != c;
if (nextIsSmallCaps)
smallCapsBuffer[index] = forceSmallCaps ? c : newC;
}
if (m_fallbackFonts && 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 != 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 SimpleFontData* fontData, GlyphBuffer* glyphBuffer)
{
// ScriptItemize (in Windows XP versions prior to SP2) can overflow by 1. This is why there is an extra empty item
// hanging out at the end of the array
m_items.resize(6);
int numItems = 0;
while (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();
}
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));
// Set up the correct direction for the run.
m_state.uBidiLevel = m_run.rtl();
// Lock the correct directional override.
m_state.fOverrideDirection = m_run.directionalOverride();
}
bool UniscribeController::shapeAndPlaceItem(const UChar* cp, unsigned i, const SimpleFontData* fontData, GlyphBuffer* glyphBuffer)
{
// Determine the string for this item.
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];
// Set up buffers to hold the results of shaping the item.
Vector<WORD> glyphs;
Vector<WORD> clusters;
Vector<SCRIPT_VISATTR> visualAttributes;
clusters.resize(len);
// Shape the item.
// The recommended size for the glyph buffer is 1.5 * the character length + 16 in the uniscribe docs.
// Apparently this is a good size to avoid having to make repeated calls to ScriptShape.
glyphs.resize(1.5 * len + 16);
visualAttributes.resize(glyphs.size());
if (!shape(str, len, item, fontData, glyphs, clusters, visualAttributes))
return true;
// We now have a collection of glyphs.
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) {
// The script cache isn't primed with enough info yet. We need to select our HFONT into
// a DC and pass the DC in to ScriptPlace.
HDC hdc = GetDC(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);
ReleaseDC(0, hdc);
}
if (FAILED(placeResult) || glyphs.isEmpty())
return true;
// Convert all chars that should be treated as spaces to use the space glyph.
// We also create a map that allows us to quickly go from space glyphs or rounding
// hack glyphs back to their corresponding characters.
Vector<int> spaceCharacters(glyphs.size());
spaceCharacters.fill(-1);
Vector<int> roundingHackCharacters(glyphs.size());
roundingHackCharacters.fill(-1);
Vector<int> roundingHackWordBoundaries(glyphs.size());
roundingHackWordBoundaries.fill(-1);
const float cLogicalScale = fontData->platformData().useGDI() ? 1.0f : 32.0f;
unsigned logicalSpaceWidth = fontData->spaceWidth() * cLogicalScale;
float roundedSpaceWidth = roundf(fontData->spaceWidth());
for (int k = 0; k < len; k++) {
UChar ch = *(str + k);
if (Font::treatAsSpace(ch)) {
// Substitute in the space glyph at the appropriate place in the glyphs
// array.
glyphs[clusters[k]] = fontData->spaceGlyph();
advances[clusters[k]] = logicalSpaceWidth;
spaceCharacters[clusters[k]] = m_currentCharacter + k + item.iCharPos;
}
if (Font::isRoundingHackCharacter(ch))
roundingHackCharacters[clusters[k]] = m_currentCharacter + k + item.iCharPos;
int boundary = k + m_currentCharacter + item.iCharPos;
if (boundary < m_run.length() &&
Font::isRoundingHackCharacter(*(str + k + 1)))
roundingHackWordBoundaries[clusters[k]] = boundary;
}
// Populate our glyph buffer with this information.
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;
// Match AppKit's rules for the integer vs. non-integer rendering modes.
float roundedAdvance = roundf(advance);
if (!m_font.isPrinterFont() && !fontData->isSystemFont()) {
advance = roundedAdvance;
offsetX = roundf(offsetX);
offsetY = roundf(offsetY);
}
advance += fontData->syntheticBoldOffset();
// We special case spaces in two ways when applying word rounding.
// First, we round spaces to an adjusted width in all fonts.
// Second, in fixed-pitch fonts we ensure that all glyphs that
// match the width of the space glyph have the same width as the space glyph.
if (roundedAdvance == roundedSpaceWidth && (fontData->pitch() == FixedPitch || glyph == fontData->spaceGlyph()) &&
m_run.applyWordRounding())
advance = fontData->adjustedSpaceWidth();
if (hasExtraSpacing) {
// If we're a glyph with an advance, go ahead and add in letter-spacing.
// That way we weed out zero width lurkers. This behavior matches the fast text code path.
if (advance && m_font.letterSpacing())
advance += m_font.letterSpacing();
// Handle justification and word-spacing.
if (glyph == fontData->spaceGlyph()) {
// Account for padding. WebCore uses space padding to justify text.
// We distribute the specified padding over the available spaces in the run.
if (m_padding) {
// Use leftover padding if not evenly divisible by number of spaces.
if (m_padding < m_padPerSpace) {
advance += m_padding;
m_padding = 0;
} else {
advance += m_padPerSpace;
m_padding -= m_padPerSpace;
}
}
// Account for word-spacing.
int characterIndex = spaceCharacters[k];
if (characterIndex > 0 && !Font::treatAsSpace(*m_run.data(characterIndex - 1)) && m_font.wordSpacing())
advance += m_font.wordSpacing();
}
}
// Deal with the float/integer impedance mismatch between CG and WebCore. "Words" (characters
// followed by a character defined by isRoundingHackCharacter()) are always an integer width.
// We adjust the width of the last character of a "word" to ensure an integer width.
// Force characters that are used to determine word boundaries for the rounding hack
// to be integer width, so the following words will start on an integer boundary.
int roundingHackIndex = roundingHackCharacters[k];
if (m_run.applyWordRounding() && roundingHackIndex != -1)
advance = ceilf(advance);
// Check to see if the next character is a "rounding hack character", if so, adjust the
// width so that the total run width will be on an integer boundary.
int position = m_currentCharacter + len;
bool lastGlyph = (k == glyphs.size() - 1) && (m_run.rtl() ? i == 0 : i == m_items.size() - 2) && (position >= m_end);
if ((m_run.applyWordRounding() && roundingHackWordBoundaries[k] != -1) ||
(m_run.applyRunRounding() && lastGlyph)) {
float totalWidth = m_runWidthSoFar + advance;
advance += ceilf(totalWidth) - totalWidth;
}
m_runWidthSoFar += advance;
// FIXME: We need to take the GOFFSETS for combining glyphs and store them in the glyph buffer
// as well, so that when the time comes to draw those glyphs, we can apply the appropriate
// translation.
if (glyphBuffer) {
FloatSize size(offsetX, -offsetY);
glyphBuffer->add(glyph, fontData, advance, &size);
}
GlyphMetrics glyphMetrics = fontData->metricsForGlyph(glyph);
glyphMetrics.boundingBox.move(m_glyphOrigin.x(), m_glyphOrigin.y());
m_minGlyphBoundingBoxX = min(m_minGlyphBoundingBoxX, glyphMetrics.boundingBox.x());
m_maxGlyphBoundingBoxX = max(m_maxGlyphBoundingBoxX, glyphMetrics.boundingBox.right());
m_minGlyphBoundingBoxY = min(m_minGlyphBoundingBoxY, glyphMetrics.boundingBox.y());
m_maxGlyphBoundingBoxY = max(m_maxGlyphBoundingBoxY, glyphMetrics.boundingBox.bottom());
m_glyphOrigin.move(advance + offsetX, -offsetY);
// Mutate the glyph array to contain our altered advances.
if (m_computingOffsetPosition)
advances[k] = advance;
}
while (m_computingOffsetPosition && m_offsetX >= leftEdge && m_offsetX < m_runWidthSoFar) {
// The position is somewhere inside this run.
int trailing = 0;
ScriptXtoCP(m_offsetX - leftEdge, clusters.size(), glyphs.size(), clusters.data(), visualAttributes.data(),
advances.data(), &item.a, &m_offsetPosition, &trailing);
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 SimpleFontData* fontData,
Vector<WORD>& glyphs, Vector<WORD>& clusters,
Vector<SCRIPT_VISATTR>& visualAttributes)
{
HDC hdc = 0;
HFONT oldFont = 0;
HRESULT shapeResult = E_PENDING;
int glyphCount = 0;
do {
shapeResult = ScriptShape(hdc, fontData->scriptCache(), str, len, glyphs.size(), &item.a,
glyphs.data(), clusters.data(), visualAttributes.data(), &glyphCount);
if (shapeResult == E_PENDING) {
// The script cache isn't primed with enough info yet. We need to select our HFONT into
// a DC and pass the DC in to ScriptShape.
ASSERT(!hdc);
hdc = GetDC(0);
HFONT hfont = fontData->platformData().hfont();
oldFont = (HFONT)SelectObject(hdc, hfont);
} else if (shapeResult == E_OUTOFMEMORY) {
// Need to resize our buffers.
glyphs.resize(glyphs.size() * 2);
visualAttributes.resize(glyphs.size());
}
} while (shapeResult == E_PENDING || shapeResult == E_OUTOFMEMORY);
if (hdc) {
SelectObject(hdc, oldFont);
ReleaseDC(0, hdc);
}
if (FAILED(shapeResult))
return false;
glyphs.shrink(glyphCount);
visualAttributes.shrink(glyphCount);
return true;
}
}