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