1/* 2 * Copyright (C) 2007, 2008, 2009, 2010 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include "config.h" 27#include "UniscribeController.h" 28#include "Font.h" 29#include "HWndDC.h" 30#include "SimpleFontData.h" 31#include "TextRun.h" 32#include <wtf/MathExtras.h> 33 34using namespace WTF; 35using namespace Unicode; 36using namespace std; 37 38namespace WebCore { 39 40// FIXME: Rearchitect this to be more like WidthIterator in Font.cpp. Have an advance() method 41// that does stuff in that method instead of doing everything in the constructor. Have advance() 42// take the GlyphBuffer as an arg so that we don't have to populate the glyph buffer when 43// measuring. 44UniscribeController::UniscribeController(const Font* font, const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts) 45 : m_font(*font) 46 , m_run(run) 47 , m_fallbackFonts(fallbackFonts) 48 , m_minGlyphBoundingBoxX(numeric_limits<float>::max()) 49 , m_maxGlyphBoundingBoxX(numeric_limits<float>::min()) 50 , m_minGlyphBoundingBoxY(numeric_limits<float>::max()) 51 , m_maxGlyphBoundingBoxY(numeric_limits<float>::min()) 52 , m_end(run.length()) 53 , m_currentCharacter(0) 54 , m_runWidthSoFar(0) 55 , m_padding(run.expansion()) 56 , m_computingOffsetPosition(false) 57 , m_includePartialGlyphs(false) 58 , m_offsetX(0) 59 , m_offsetPosition(0) 60{ 61 if (!m_padding) 62 m_padPerSpace = 0; 63 else { 64 float numSpaces = 0; 65 for (int s = 0; s < m_run.length(); s++) { 66 if (Font::treatAsSpace(m_run[s])) 67 numSpaces++; 68 } 69 70 if (numSpaces == 0) 71 m_padPerSpace = 0; 72 else 73 m_padPerSpace = m_padding / numSpaces; 74 } 75 76 // Null out our uniscribe structs 77 resetControlAndState(); 78} 79 80int UniscribeController::offsetForPosition(int x, bool includePartialGlyphs) 81{ 82 m_computingOffsetPosition = true; 83 m_includePartialGlyphs = includePartialGlyphs; 84 m_offsetX = x; 85 m_offsetPosition = 0; 86 advance(m_run.length()); 87 if (m_computingOffsetPosition) { 88 // The point is to the left or to the right of the entire run. 89 if (m_offsetX >= m_runWidthSoFar && m_run.ltr() || m_offsetX < 0 && m_run.rtl()) 90 m_offsetPosition = m_end; 91 } 92 m_computingOffsetPosition = false; 93 return m_offsetPosition; 94} 95 96void UniscribeController::advance(unsigned offset, GlyphBuffer* glyphBuffer) 97{ 98 // FIXME: We really want to be using a newer version of Uniscribe that supports the new OpenType 99 // functions. Those functions would allow us to turn off kerning and ligatures. Without being able 100 // to do that, we will have buggy line breaking and metrics when simple and complex text are close 101 // together (the complex code path will narrow the text because of kerning and ligatures and then 102 // when bidi processing splits into multiple runs, the simple portions will get wider and cause us to 103 // spill off the edge of a line). 104 if (static_cast<int>(offset) > m_end) 105 offset = m_end; 106 107 int length = offset - m_currentCharacter; 108 if (length <= 0) 109 return; 110 111 String bufferFor16BitData; 112 113 // Itemize the string. 114 const UChar* cp = nullptr; 115 if (m_run.is8Bit()) { 116 // Uniscribe only deals with 16-bit characters. Must generate them now. 117 bufferFor16BitData = String::make16BitFrom8BitSource(m_run.data8(m_currentCharacter), length); 118 cp = bufferFor16BitData.characters16(); 119 } else 120 cp = m_run.data16(m_currentCharacter); 121 122 unsigned baseCharacter = m_currentCharacter; 123 124 // We break up itemization of the string by fontData and (if needed) the use of small caps. 125 126 // FIXME: It's inconsistent that we use logical order when itemizing, since this 127 // does not match normal RTL. 128 129 // FIXME: This function should decode surrogate pairs. Currently it makes little difference that 130 // it does not because the font cache on Windows does not support non-BMP characters. 131 Vector<UChar, 256> smallCapsBuffer; 132 if (m_font.isSmallCaps()) 133 smallCapsBuffer.resize(length); 134 135 unsigned indexOfFontTransition = m_run.rtl() ? length - 1 : 0; 136 const UChar* curr = m_run.rtl() ? cp + length - 1 : cp; 137 const UChar* end = m_run.rtl() ? cp - 1 : cp + length; 138 139 const SimpleFontData* fontData; 140 const SimpleFontData* nextFontData = m_font.glyphDataForCharacter(*curr, false).fontData; 141 142 UChar newC = 0; 143 144 bool isSmallCaps; 145 bool nextIsSmallCaps = m_font.isSmallCaps() && !(U_GET_GC_MASK(*curr) & U_GC_M_MASK) && (newC = u_toupper(*curr)) != *curr; 146 147 if (nextIsSmallCaps) 148 smallCapsBuffer[curr - cp] = newC; 149 150 while (true) { 151 curr = m_run.rtl() ? curr - 1 : curr + 1; 152 if (curr == end) 153 break; 154 155 fontData = nextFontData; 156 isSmallCaps = nextIsSmallCaps; 157 int index = curr - cp; 158 UChar c = *curr; 159 160 bool forceSmallCaps = isSmallCaps && (U_GET_GC_MASK(c) & U_GC_M_MASK); 161 nextFontData = m_font.glyphDataForCharacter(*curr, false, forceSmallCaps ? SmallCapsVariant : AutoVariant).fontData; 162 if (m_font.isSmallCaps()) { 163 nextIsSmallCaps = forceSmallCaps || (newC = u_toupper(c)) != c; 164 if (nextIsSmallCaps) 165 smallCapsBuffer[index] = forceSmallCaps ? c : newC; 166 } 167 168 if (m_fallbackFonts && nextFontData != fontData && fontData != m_font.primaryFont()) 169 m_fallbackFonts->add(fontData); 170 171 if (nextFontData != fontData || nextIsSmallCaps != isSmallCaps) { 172 int itemStart = m_run.rtl() ? index + 1 : indexOfFontTransition; 173 int itemLength = m_run.rtl() ? indexOfFontTransition - index : index - indexOfFontTransition; 174 m_currentCharacter = baseCharacter + itemStart; 175 itemizeShapeAndPlace((isSmallCaps ? smallCapsBuffer.data() : cp) + itemStart, itemLength, fontData, glyphBuffer); 176 indexOfFontTransition = index; 177 } 178 } 179 180 int itemLength = m_run.rtl() ? indexOfFontTransition + 1 : length - indexOfFontTransition; 181 if (itemLength) { 182 if (m_fallbackFonts && nextFontData != m_font.primaryFont()) 183 m_fallbackFonts->add(nextFontData); 184 185 int itemStart = m_run.rtl() ? 0 : indexOfFontTransition; 186 m_currentCharacter = baseCharacter + itemStart; 187 itemizeShapeAndPlace((nextIsSmallCaps ? smallCapsBuffer.data() : cp) + itemStart, itemLength, nextFontData, glyphBuffer); 188 } 189 190 m_currentCharacter = baseCharacter + length; 191} 192 193void UniscribeController::itemizeShapeAndPlace(const UChar* cp, unsigned length, const SimpleFontData* fontData, GlyphBuffer* glyphBuffer) 194{ 195 // ScriptItemize (in Windows XP versions prior to SP2) can overflow by 1. This is why there is an extra empty item 196 // hanging out at the end of the array 197 m_items.resize(6); 198 int numItems = 0; 199 while (ScriptItemize(cp, length, m_items.size() - 1, &m_control, &m_state, m_items.data(), &numItems) == E_OUTOFMEMORY) { 200 m_items.resize(m_items.size() * 2); 201 resetControlAndState(); 202 } 203 m_items.resize(numItems + 1); 204 205 if (m_run.rtl()) { 206 for (int i = m_items.size() - 2; i >= 0; i--) { 207 if (!shapeAndPlaceItem(cp, i, fontData, glyphBuffer)) 208 return; 209 } 210 } else { 211 for (unsigned i = 0; i < m_items.size() - 1; i++) { 212 if (!shapeAndPlaceItem(cp, i, fontData, glyphBuffer)) 213 return; 214 } 215 } 216} 217 218void UniscribeController::resetControlAndState() 219{ 220 memset(&m_control, 0, sizeof(SCRIPT_CONTROL)); 221 memset(&m_state, 0, sizeof(SCRIPT_STATE)); 222 223 // Set up the correct direction for the run. 224 m_state.uBidiLevel = m_run.rtl(); 225 226 // Lock the correct directional override. 227 m_state.fOverrideDirection = m_run.directionalOverride(); 228} 229 230bool UniscribeController::shapeAndPlaceItem(const UChar* cp, unsigned i, const SimpleFontData* fontData, GlyphBuffer* glyphBuffer) 231{ 232 // Determine the string for this item. 233 const UChar* str = cp + m_items[i].iCharPos; 234 int len = m_items[i+1].iCharPos - m_items[i].iCharPos; 235 SCRIPT_ITEM item = m_items[i]; 236 237 // Set up buffers to hold the results of shaping the item. 238 Vector<WORD> glyphs; 239 Vector<WORD> clusters; 240 Vector<SCRIPT_VISATTR> visualAttributes; 241 clusters.resize(len); 242 243 // Shape the item. 244 // The recommended size for the glyph buffer is 1.5 * the character length + 16 in the uniscribe docs. 245 // Apparently this is a good size to avoid having to make repeated calls to ScriptShape. 246 glyphs.resize(1.5 * len + 16); 247 visualAttributes.resize(glyphs.size()); 248 249 if (!shape(str, len, item, fontData, glyphs, clusters, visualAttributes)) 250 return true; 251 252 // We now have a collection of glyphs. 253 Vector<GOFFSET> offsets; 254 Vector<int> advances; 255 offsets.resize(glyphs.size()); 256 advances.resize(glyphs.size()); 257 int glyphCount = 0; 258 HRESULT placeResult = ScriptPlace(0, fontData->scriptCache(), glyphs.data(), glyphs.size(), visualAttributes.data(), 259 &item.a, advances.data(), offsets.data(), 0); 260 if (placeResult == E_PENDING) { 261 // The script cache isn't primed with enough info yet. We need to select our HFONT into 262 // a DC and pass the DC in to ScriptPlace. 263 HWndDC hdc(0); 264 HFONT hfont = fontData->platformData().hfont(); 265 HFONT oldFont = (HFONT)SelectObject(hdc, hfont); 266 placeResult = ScriptPlace(hdc, fontData->scriptCache(), glyphs.data(), glyphs.size(), visualAttributes.data(), 267 &item.a, advances.data(), offsets.data(), 0); 268 SelectObject(hdc, oldFont); 269 } 270 271 if (FAILED(placeResult) || glyphs.isEmpty()) 272 return true; 273 274 // Convert all chars that should be treated as spaces to use the space glyph. 275 // We also create a map that allows us to quickly go from space glyphs back to their corresponding characters. 276 Vector<int> spaceCharacters(glyphs.size()); 277 spaceCharacters.fill(-1); 278 279 const float cLogicalScale = fontData->platformData().useGDI() ? 1.0f : 32.0f; 280 float spaceWidth = fontData->spaceWidth() - fontData->syntheticBoldOffset(); 281 unsigned logicalSpaceWidth = spaceWidth * cLogicalScale; 282 283 for (int k = 0; k < len; k++) { 284 UChar ch = *(str + k); 285 bool treatAsSpace = Font::treatAsSpace(ch); 286 bool treatAsZeroWidthSpace = Font::treatAsZeroWidthSpace(ch); 287 if (treatAsSpace || treatAsZeroWidthSpace) { 288 // Substitute in the space glyph at the appropriate place in the glyphs 289 // array. 290 glyphs[clusters[k]] = fontData->spaceGlyph(); 291 advances[clusters[k]] = treatAsSpace ? logicalSpaceWidth : 0; 292 if (treatAsSpace) 293 spaceCharacters[clusters[k]] = m_currentCharacter + k + item.iCharPos; 294 } 295 } 296 297 // Populate our glyph buffer with this information. 298 bool hasExtraSpacing = m_font.letterSpacing() || m_font.wordSpacing() || m_padding; 299 300 float leftEdge = m_runWidthSoFar; 301 302 for (unsigned k = 0; k < glyphs.size(); k++) { 303 Glyph glyph = glyphs[k]; 304 float advance = advances[k] / cLogicalScale; 305 float offsetX = offsets[k].du / cLogicalScale; 306 float offsetY = offsets[k].dv / cLogicalScale; 307 308 // Match AppKit's rules for the integer vs. non-integer rendering modes. 309 float roundedAdvance = roundf(advance); 310 if (!m_font.isPrinterFont() && !fontData->isSystemFont()) { 311 advance = roundedAdvance; 312 offsetX = roundf(offsetX); 313 offsetY = roundf(offsetY); 314 } 315 316 advance += fontData->syntheticBoldOffset(); 317 318 if (hasExtraSpacing) { 319 // If we're a glyph with an advance, go ahead and add in letter-spacing. 320 // That way we weed out zero width lurkers. This behavior matches the fast text code path. 321 if (advance && m_font.letterSpacing()) 322 advance += m_font.letterSpacing(); 323 324 // Handle justification and word-spacing. 325 int characterIndex = spaceCharacters[k]; 326 // characterIndex is left at the initial value of -1 for glyphs that do not map back to treated-as-space characters. 327 if (characterIndex != -1) { 328 // Account for padding. WebCore uses space padding to justify text. 329 // We distribute the specified padding over the available spaces in the run. 330 if (m_padding) { 331 // Use leftover padding if not evenly divisible by number of spaces. 332 if (m_padding < m_padPerSpace) { 333 advance += m_padding; 334 m_padding = 0; 335 } else { 336 m_padding -= m_padPerSpace; 337 advance += m_padPerSpace; 338 } 339 } 340 341 // Account for word-spacing. 342 if (characterIndex > 0 && m_font.wordSpacing()) { 343 UChar candidateSpace; 344 if (m_run.is8Bit()) 345 candidateSpace = *(m_run.data8(characterIndex - 1)); 346 else 347 candidateSpace = *(m_run.data16(characterIndex - 1)); 348 349 if (!Font::treatAsSpace(candidateSpace)) 350 advance += m_font.wordSpacing(); 351 } 352 } 353 } 354 355 m_runWidthSoFar += advance; 356 357 // FIXME: We need to take the GOFFSETS for combining glyphs and store them in the glyph buffer 358 // as well, so that when the time comes to draw those glyphs, we can apply the appropriate 359 // translation. 360 if (glyphBuffer) { 361 FloatSize size(offsetX, -offsetY); 362 glyphBuffer->add(glyph, fontData, advance, GlyphBuffer::kNoOffset, &size); 363 } 364 365 FloatRect glyphBounds = fontData->boundsForGlyph(glyph); 366 glyphBounds.move(m_glyphOrigin.x(), m_glyphOrigin.y()); 367 m_minGlyphBoundingBoxX = min(m_minGlyphBoundingBoxX, glyphBounds.x()); 368 m_maxGlyphBoundingBoxX = max(m_maxGlyphBoundingBoxX, glyphBounds.maxX()); 369 m_minGlyphBoundingBoxY = min(m_minGlyphBoundingBoxY, glyphBounds.y()); 370 m_maxGlyphBoundingBoxY = max(m_maxGlyphBoundingBoxY, glyphBounds.maxY()); 371 m_glyphOrigin.move(advance + offsetX, -offsetY); 372 373 // Mutate the glyph array to contain our altered advances. 374 if (m_computingOffsetPosition) 375 advances[k] = advance; 376 } 377 378 while (m_computingOffsetPosition && m_offsetX >= leftEdge && m_offsetX < m_runWidthSoFar) { 379 // The position is somewhere inside this run. 380 int trailing = 0; 381 ScriptXtoCP(m_offsetX - leftEdge, clusters.size(), glyphs.size(), clusters.data(), visualAttributes.data(), 382 advances.data(), &item.a, &m_offsetPosition, &trailing); 383 if (trailing && m_includePartialGlyphs && m_offsetPosition < len - 1) { 384 m_offsetPosition += m_currentCharacter + m_items[i].iCharPos; 385 m_offsetX += m_run.rtl() ? -trailing : trailing; 386 } else { 387 m_computingOffsetPosition = false; 388 m_offsetPosition += m_currentCharacter + m_items[i].iCharPos; 389 if (trailing && m_includePartialGlyphs) 390 m_offsetPosition++; 391 return false; 392 } 393 } 394 395 return true; 396} 397 398bool UniscribeController::shape(const UChar* str, int len, SCRIPT_ITEM item, const SimpleFontData* fontData, 399 Vector<WORD>& glyphs, Vector<WORD>& clusters, 400 Vector<SCRIPT_VISATTR>& visualAttributes) 401{ 402 HWndDC hdc; 403 HFONT oldFont = 0; 404 HRESULT shapeResult = E_PENDING; 405 int glyphCount = 0; 406 do { 407 shapeResult = ScriptShape(hdc, fontData->scriptCache(), str, len, glyphs.size(), &item.a, 408 glyphs.data(), clusters.data(), visualAttributes.data(), &glyphCount); 409 if (shapeResult == E_PENDING) { 410 // The script cache isn't primed with enough info yet. We need to select our HFONT into 411 // a DC and pass the DC in to ScriptShape. 412 ASSERT(!hdc); 413 hdc.setHWnd(0); 414 HFONT hfont = fontData->platformData().hfont(); 415 oldFont = (HFONT)SelectObject(hdc, hfont); 416 } else if (shapeResult == E_OUTOFMEMORY) { 417 // Need to resize our buffers. 418 glyphs.resize(glyphs.size() * 2); 419 visualAttributes.resize(glyphs.size()); 420 } 421 } while (shapeResult == E_PENDING || shapeResult == E_OUTOFMEMORY); 422 423 if (hdc) 424 SelectObject(hdc, oldFont); 425 426 if (FAILED(shapeResult)) 427 return false; 428 429 glyphs.shrink(glyphCount); 430 visualAttributes.shrink(glyphCount); 431 432 return true; 433} 434 435} 436