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 // Itemize the string. 112 const UChar* cp = m_run.data16(m_currentCharacter); 113 unsigned baseCharacter = m_currentCharacter; 114 115 // We break up itemization of the string by fontData and (if needed) the use of small caps. 116 117 // FIXME: It's inconsistent that we use logical order when itemizing, since this 118 // does not match normal RTL. 119 120 // FIXME: This function should decode surrogate pairs. Currently it makes little difference that 121 // it does not because the font cache on Windows does not support non-BMP characters. 122 Vector<UChar, 256> smallCapsBuffer; 123 if (m_font.isSmallCaps()) 124 smallCapsBuffer.resize(length); 125 126 unsigned indexOfFontTransition = m_run.rtl() ? length - 1 : 0; 127 const UChar* curr = m_run.rtl() ? cp + length - 1 : cp; 128 const UChar* end = m_run.rtl() ? cp - 1 : cp + length; 129 130 const SimpleFontData* fontData; 131 const SimpleFontData* nextFontData = m_font.glyphDataForCharacter(*curr, false).fontData; 132 133 UChar newC = 0; 134 135 bool isSmallCaps; 136 bool nextIsSmallCaps = m_font.isSmallCaps() && !(category(*curr) & (Mark_NonSpacing | Mark_Enclosing | Mark_SpacingCombining)) && (newC = toUpper(*curr)) != *curr; 137 138 if (nextIsSmallCaps) 139 smallCapsBuffer[curr - cp] = newC; 140 141 while (true) { 142 curr = m_run.rtl() ? curr - 1 : curr + 1; 143 if (curr == end) 144 break; 145 146 fontData = nextFontData; 147 isSmallCaps = nextIsSmallCaps; 148 int index = curr - cp; 149 UChar c = *curr; 150 151 bool forceSmallCaps = isSmallCaps && (category(c) & (Mark_NonSpacing | Mark_Enclosing | Mark_SpacingCombining)); 152 nextFontData = m_font.glyphDataForCharacter(*curr, false, forceSmallCaps ? SmallCapsVariant : AutoVariant).fontData; 153 if (m_font.isSmallCaps()) { 154 nextIsSmallCaps = forceSmallCaps || (newC = toUpper(c)) != c; 155 if (nextIsSmallCaps) 156 smallCapsBuffer[index] = forceSmallCaps ? c : newC; 157 } 158 159 if (m_fallbackFonts && nextFontData != fontData && fontData != m_font.primaryFont()) 160 m_fallbackFonts->add(fontData); 161 162 if (nextFontData != fontData || nextIsSmallCaps != isSmallCaps) { 163 int itemStart = m_run.rtl() ? index + 1 : indexOfFontTransition; 164 int itemLength = m_run.rtl() ? indexOfFontTransition - index : index - indexOfFontTransition; 165 m_currentCharacter = baseCharacter + itemStart; 166 itemizeShapeAndPlace((isSmallCaps ? smallCapsBuffer.data() : cp) + itemStart, itemLength, fontData, glyphBuffer); 167 indexOfFontTransition = index; 168 } 169 } 170 171 int itemLength = m_run.rtl() ? indexOfFontTransition + 1 : length - indexOfFontTransition; 172 if (itemLength) { 173 if (m_fallbackFonts && nextFontData != m_font.primaryFont()) 174 m_fallbackFonts->add(nextFontData); 175 176 int itemStart = m_run.rtl() ? 0 : indexOfFontTransition; 177 m_currentCharacter = baseCharacter + itemStart; 178 itemizeShapeAndPlace((nextIsSmallCaps ? smallCapsBuffer.data() : cp) + itemStart, itemLength, nextFontData, glyphBuffer); 179 } 180 181 m_currentCharacter = baseCharacter + length; 182} 183 184void UniscribeController::itemizeShapeAndPlace(const UChar* cp, unsigned length, const SimpleFontData* fontData, GlyphBuffer* glyphBuffer) 185{ 186 // ScriptItemize (in Windows XP versions prior to SP2) can overflow by 1. This is why there is an extra empty item 187 // hanging out at the end of the array 188 m_items.resize(6); 189 int numItems = 0; 190 while (ScriptItemize(cp, length, m_items.size() - 1, &m_control, &m_state, m_items.data(), &numItems) == E_OUTOFMEMORY) { 191 m_items.resize(m_items.size() * 2); 192 resetControlAndState(); 193 } 194 m_items.resize(numItems + 1); 195 196 if (m_run.rtl()) { 197 for (int i = m_items.size() - 2; i >= 0; i--) { 198 if (!shapeAndPlaceItem(cp, i, fontData, glyphBuffer)) 199 return; 200 } 201 } else { 202 for (unsigned i = 0; i < m_items.size() - 1; i++) { 203 if (!shapeAndPlaceItem(cp, i, fontData, glyphBuffer)) 204 return; 205 } 206 } 207} 208 209void UniscribeController::resetControlAndState() 210{ 211 memset(&m_control, 0, sizeof(SCRIPT_CONTROL)); 212 memset(&m_state, 0, sizeof(SCRIPT_STATE)); 213 214 // Set up the correct direction for the run. 215 m_state.uBidiLevel = m_run.rtl(); 216 217 // Lock the correct directional override. 218 m_state.fOverrideDirection = m_run.directionalOverride(); 219} 220 221bool UniscribeController::shapeAndPlaceItem(const UChar* cp, unsigned i, const SimpleFontData* fontData, GlyphBuffer* glyphBuffer) 222{ 223 // Determine the string for this item. 224 const UChar* str = cp + m_items[i].iCharPos; 225 int len = m_items[i+1].iCharPos - m_items[i].iCharPos; 226 SCRIPT_ITEM item = m_items[i]; 227 228 // Set up buffers to hold the results of shaping the item. 229 Vector<WORD> glyphs; 230 Vector<WORD> clusters; 231 Vector<SCRIPT_VISATTR> visualAttributes; 232 clusters.resize(len); 233 234 // Shape the item. 235 // The recommended size for the glyph buffer is 1.5 * the character length + 16 in the uniscribe docs. 236 // Apparently this is a good size to avoid having to make repeated calls to ScriptShape. 237 glyphs.resize(1.5 * len + 16); 238 visualAttributes.resize(glyphs.size()); 239 240 if (!shape(str, len, item, fontData, glyphs, clusters, visualAttributes)) 241 return true; 242 243 // We now have a collection of glyphs. 244 Vector<GOFFSET> offsets; 245 Vector<int> advances; 246 offsets.resize(glyphs.size()); 247 advances.resize(glyphs.size()); 248 int glyphCount = 0; 249 HRESULT placeResult = ScriptPlace(0, fontData->scriptCache(), glyphs.data(), glyphs.size(), visualAttributes.data(), 250 &item.a, advances.data(), offsets.data(), 0); 251 if (placeResult == E_PENDING) { 252 // The script cache isn't primed with enough info yet. We need to select our HFONT into 253 // a DC and pass the DC in to ScriptPlace. 254 HWndDC hdc(0); 255 HFONT hfont = fontData->platformData().hfont(); 256 HFONT oldFont = (HFONT)SelectObject(hdc, hfont); 257 placeResult = ScriptPlace(hdc, fontData->scriptCache(), glyphs.data(), glyphs.size(), visualAttributes.data(), 258 &item.a, advances.data(), offsets.data(), 0); 259 SelectObject(hdc, oldFont); 260 } 261 262 if (FAILED(placeResult) || glyphs.isEmpty()) 263 return true; 264 265 // Convert all chars that should be treated as spaces to use the space glyph. 266 // We also create a map that allows us to quickly go from space glyphs back to their corresponding characters. 267 Vector<int> spaceCharacters(glyphs.size()); 268 spaceCharacters.fill(-1); 269 270 const float cLogicalScale = fontData->platformData().useGDI() ? 1.0f : 32.0f; 271 float spaceWidth = fontData->spaceWidth() - fontData->syntheticBoldOffset(); 272 unsigned logicalSpaceWidth = spaceWidth * cLogicalScale; 273 274 for (int k = 0; k < len; k++) { 275 UChar ch = *(str + k); 276 bool treatAsSpace = Font::treatAsSpace(ch); 277 bool treatAsZeroWidthSpace = Font::treatAsZeroWidthSpace(ch); 278 if (treatAsSpace || treatAsZeroWidthSpace) { 279 // Substitute in the space glyph at the appropriate place in the glyphs 280 // array. 281 glyphs[clusters[k]] = fontData->spaceGlyph(); 282 advances[clusters[k]] = treatAsSpace ? logicalSpaceWidth : 0; 283 if (treatAsSpace) 284 spaceCharacters[clusters[k]] = m_currentCharacter + k + item.iCharPos; 285 } 286 } 287 288 // Populate our glyph buffer with this information. 289 bool hasExtraSpacing = m_font.letterSpacing() || m_font.wordSpacing() || m_padding; 290 291 float leftEdge = m_runWidthSoFar; 292 293 for (unsigned k = 0; k < glyphs.size(); k++) { 294 Glyph glyph = glyphs[k]; 295 float advance = advances[k] / cLogicalScale; 296 float offsetX = offsets[k].du / cLogicalScale; 297 float offsetY = offsets[k].dv / cLogicalScale; 298 299 // Match AppKit's rules for the integer vs. non-integer rendering modes. 300 float roundedAdvance = roundf(advance); 301 if (!m_font.isPrinterFont() && !fontData->isSystemFont()) { 302 advance = roundedAdvance; 303 offsetX = roundf(offsetX); 304 offsetY = roundf(offsetY); 305 } 306 307 advance += fontData->syntheticBoldOffset(); 308 309 if (hasExtraSpacing) { 310 // If we're a glyph with an advance, go ahead and add in letter-spacing. 311 // That way we weed out zero width lurkers. This behavior matches the fast text code path. 312 if (advance && m_font.letterSpacing()) 313 advance += m_font.letterSpacing(); 314 315 // Handle justification and word-spacing. 316 int characterIndex = spaceCharacters[k]; 317 // characterIndex is left at the initial value of -1 for glyphs that do not map back to treated-as-space characters. 318 if (characterIndex != -1) { 319 // Account for padding. WebCore uses space padding to justify text. 320 // We distribute the specified padding over the available spaces in the run. 321 if (m_padding) { 322 // Use leftover padding if not evenly divisible by number of spaces. 323 if (m_padding < m_padPerSpace) { 324 advance += m_padding; 325 m_padding = 0; 326 } else { 327 m_padding -= m_padPerSpace; 328 advance += m_padPerSpace; 329 } 330 } 331 332 // Account for word-spacing. 333 if (characterIndex > 0 && !Font::treatAsSpace(*m_run.data16(characterIndex - 1)) && m_font.wordSpacing()) 334 advance += m_font.wordSpacing(); 335 } 336 } 337 338 m_runWidthSoFar += advance; 339 340 // FIXME: We need to take the GOFFSETS for combining glyphs and store them in the glyph buffer 341 // as well, so that when the time comes to draw those glyphs, we can apply the appropriate 342 // translation. 343 if (glyphBuffer) { 344 FloatSize size(offsetX, -offsetY); 345 glyphBuffer->add(glyph, fontData, advance, &size); 346 } 347 348 FloatRect glyphBounds = fontData->boundsForGlyph(glyph); 349 glyphBounds.move(m_glyphOrigin.x(), m_glyphOrigin.y()); 350 m_minGlyphBoundingBoxX = min(m_minGlyphBoundingBoxX, glyphBounds.x()); 351 m_maxGlyphBoundingBoxX = max(m_maxGlyphBoundingBoxX, glyphBounds.maxX()); 352 m_minGlyphBoundingBoxY = min(m_minGlyphBoundingBoxY, glyphBounds.y()); 353 m_maxGlyphBoundingBoxY = max(m_maxGlyphBoundingBoxY, glyphBounds.maxY()); 354 m_glyphOrigin.move(advance + offsetX, -offsetY); 355 356 // Mutate the glyph array to contain our altered advances. 357 if (m_computingOffsetPosition) 358 advances[k] = advance; 359 } 360 361 while (m_computingOffsetPosition && m_offsetX >= leftEdge && m_offsetX < m_runWidthSoFar) { 362 // The position is somewhere inside this run. 363 int trailing = 0; 364 ScriptXtoCP(m_offsetX - leftEdge, clusters.size(), glyphs.size(), clusters.data(), visualAttributes.data(), 365 advances.data(), &item.a, &m_offsetPosition, &trailing); 366 if (trailing && m_includePartialGlyphs && m_offsetPosition < len - 1) { 367 m_offsetPosition += m_currentCharacter + m_items[i].iCharPos; 368 m_offsetX += m_run.rtl() ? -trailing : trailing; 369 } else { 370 m_computingOffsetPosition = false; 371 m_offsetPosition += m_currentCharacter + m_items[i].iCharPos; 372 if (trailing && m_includePartialGlyphs) 373 m_offsetPosition++; 374 return false; 375 } 376 } 377 378 return true; 379} 380 381bool UniscribeController::shape(const UChar* str, int len, SCRIPT_ITEM item, const SimpleFontData* fontData, 382 Vector<WORD>& glyphs, Vector<WORD>& clusters, 383 Vector<SCRIPT_VISATTR>& visualAttributes) 384{ 385 HWndDC hdc; 386 HFONT oldFont = 0; 387 HRESULT shapeResult = E_PENDING; 388 int glyphCount = 0; 389 do { 390 shapeResult = ScriptShape(hdc, fontData->scriptCache(), str, len, glyphs.size(), &item.a, 391 glyphs.data(), clusters.data(), visualAttributes.data(), &glyphCount); 392 if (shapeResult == E_PENDING) { 393 // The script cache isn't primed with enough info yet. We need to select our HFONT into 394 // a DC and pass the DC in to ScriptShape. 395 ASSERT(!hdc); 396 hdc.setHWnd(0); 397 HFONT hfont = fontData->platformData().hfont(); 398 oldFont = (HFONT)SelectObject(hdc, hfont); 399 } else if (shapeResult == E_OUTOFMEMORY) { 400 // Need to resize our buffers. 401 glyphs.resize(glyphs.size() * 2); 402 visualAttributes.resize(glyphs.size()); 403 } 404 } while (shapeResult == E_PENDING || shapeResult == E_OUTOFMEMORY); 405 406 if (hdc) 407 SelectObject(hdc, oldFont); 408 409 if (FAILED(shapeResult)) 410 return false; 411 412 glyphs.shrink(glyphCount); 413 visualAttributes.shrink(glyphCount); 414 415 return true; 416} 417 418} 419