/* * Copyright (c) 2008, 2009, 2012 Google 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: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 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. * * Neither the name of Google Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT * OWNER OR 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 <windows.h> #include <vector> #include "Font.h" #include "GlyphPageTreeNode.h" #include "HWndDC.h" #include "PlatformSupport.h" #include "SimpleFontData.h" #include "SystemInfo.h" #include "UniscribeHelperTextRun.h" namespace WebCore { // Fills one page of font data pointers with 0 to indicate that there // are no glyphs for the characters. static void fillEmptyGlyphs(GlyphPage* page) { for (int i = 0; i < GlyphPage::size; ++i) page->setGlyphDataForIndex(i, 0, 0); } // Convert characters to glyph ids by GetGlyphIndices(), during which, we // ensure the font is loaded in memory to make it work in a sandboxed process. static bool getGlyphIndices(HFONT font, HDC dc, const UChar* characters, unsigned charactersLength, WORD* glyphBuffer, DWORD flag) { if (GetGlyphIndices(dc, characters, charactersLength, glyphBuffer, flag) != GDI_ERROR) return true; if (PlatformSupport::ensureFontLoaded(font)) { if (GetGlyphIndices(dc, characters, charactersLength, glyphBuffer, flag) != GDI_ERROR) return true; // FIXME: Handle gracefully the error if this call also fails. // See http://crbug.com/6401 LOG_ERROR("Unable to get the glyph indices after second attempt"); } return false; } // Initializes space glyph static bool initSpaceGlyph(HFONT font, HDC dc, Glyph* spaceGlyph) { static wchar_t space = ' '; return getGlyphIndices(font, dc, &space, 1, spaceGlyph, 0); } // Fills |length| glyphs starting at |offset| in a |page| in the Basic // Multilingual Plane (<= U+FFFF). The input buffer size should be the // same as |length|. We can use the standard Windows GDI functions here. // Returns true if any glyphs were found. static bool fillBMPGlyphs(unsigned offset, unsigned length, UChar* buffer, GlyphPage* page, const SimpleFontData* fontData) { HWndDC dc(0); HGDIOBJ oldFont = SelectObject(dc, fontData->platformData().hfont()); TEXTMETRIC tm = {0}; if (!GetTextMetrics(dc, &tm)) { if (PlatformSupport::ensureFontLoaded(fontData->platformData().hfont())) { if (!GetTextMetrics(dc, &tm)) { // FIXME: Handle gracefully the error if this call also fails. // See http://crbug.com/6401 LOG_ERROR("Unable to get the text metrics after second attempt"); SelectObject(dc, oldFont); fillEmptyGlyphs(page); return false; } } else { SelectObject(dc, oldFont); fillEmptyGlyphs(page); return false; } } // FIXME: GetGlyphIndices() sets each item of localGlyphBuffer[] // with the one of the values listed below. // * With the GGI_MARK_NONEXISTING_GLYPHS flag // + If the font has a glyph available for the character, // localGlyphBuffer[i] > 0x0. // + If the font does not have glyphs available for the character, // localGlyphBuffer[i] = 0x1F (TrueType Collection?) or // 0xFFFF (OpenType?). // * Without the GGI_MARK_NONEXISTING_GLYPHS flag // + If the font has a glyph available for the character, // localGlyphBuffer[i] > 0x0. // + If the font does not have glyphs available for the character, // localGlyphBuffer[i] = 0x80. // (Windows automatically assigns the glyph for a box character to // prevent ExtTextOut() from returning errors.) // To avoid from hurting the rendering performance, this code just // tells WebKit whether or not the all glyph indices for the given // characters are 0x80 (i.e. a possibly-invalid glyph) and let it // use alternative fonts for the characters. // Although this may cause a problem, it seems to work fine as far as I // have tested. (Obviously, I need more tests.) WORD localGlyphBuffer[GlyphPage::size]; // FIXME: I find some Chinese characters can not be correctly displayed // when call GetGlyphIndices without flag GGI_MARK_NONEXISTING_GLYPHS, // because the corresponding glyph index is set as 0x20 when current font // does not have glyphs available for the character. According a blog post // http://blogs.msdn.com/michkap/archive/2006/06/28/649791.aspx // I think we should switch to the way about calling GetGlyphIndices with // flag GGI_MARK_NONEXISTING_GLYPHS, it should be OK according the // description of MSDN. // Also according to Jungshik and Hironori's suggestion and modification // we treat turetype and raster Font as different way when windows version // is less than Vista. if (!getGlyphIndices(fontData->platformData().hfont(), dc, buffer, length, localGlyphBuffer, GGI_MARK_NONEXISTING_GLYPHS)) { SelectObject(dc, oldFont); fillEmptyGlyphs(page); return false; } // Copy the output to the GlyphPage bool haveGlyphs = false; int invalidGlyph = 0xFFFF; const DWORD cffTableTag = 0x20464643; // 4-byte identifier for OpenType CFF table ('CFF '). if ((windowsVersion() < WindowsVista) && !(tm.tmPitchAndFamily & TMPF_TRUETYPE) && (GetFontData(dc, cffTableTag, 0, 0, 0) == GDI_ERROR)) invalidGlyph = 0x1F; Glyph spaceGlyph = 0; // Glyph for a space. Lazily filled. bool spaceGlyphInitialized = false; for (unsigned i = 0; i < length; i++) { UChar c = buffer[i]; Glyph glyph = localGlyphBuffer[i]; const SimpleFontData* glyphFontData = fontData; // When this character should be a space, we ignore whatever the font // says and use a space. Otherwise, if fonts don't map one of these // space or zero width glyphs, we will get a box. if (Font::treatAsSpace(c)) { // Hard code the glyph indices for characters that should be // treated like spaces. if (!spaceGlyphInitialized) { // If initSpaceGlyph fails, spaceGlyph stays 0 (= glyph is not present). initSpaceGlyph(fontData->platformData().hfont(), dc, &spaceGlyph); spaceGlyphInitialized = true; } glyph = spaceGlyph; } else if (glyph == invalidGlyph) { // WebKit expects both the glyph index and FontData // pointer to be 0 if the glyph is not present glyph = 0; glyphFontData = 0; } else haveGlyphs = true; page->setGlyphDataForCharacter(offset + i, glyph, glyphFontData); } SelectObject(dc, oldFont); return haveGlyphs; } // For non-BMP characters, each is two words (UTF-16) and the input buffer // size is 2 * |length|. Since GDI doesn't know how to handle non-BMP // characters, we must use Uniscribe to tell us the glyph indices. // // We don't want to call this in the case of "regular" characters since some // fonts may not have the correct combining rules for accents. See the notes // at the bottom of ScriptGetCMap. We can't use ScriptGetCMap, though, since // it doesn't seem to support UTF-16, despite what this blog post says: // http://blogs.msdn.com/michkap/archive/2006/06/29/650680.aspx // // So we fire up the full Uniscribe doohicky, give it our string, and it will // correctly handle the UTF-16 for us. The hard part is taking this and getting // the glyph indices back out that correspond to the correct input characters, // since they may be missing. // // Returns true if any glyphs were found. static bool fillNonBMPGlyphs(unsigned offset, unsigned length, UChar* buffer, GlyphPage* page, const SimpleFontData* fontData) { bool haveGlyphs = false; UniscribeHelperTextRun state(buffer, length * 2, false, fontData->platformData().hfont(), fontData->platformData().scriptCache(), fontData->platformData().scriptFontProperties()); state.setInhibitLigate(true); state.setDisableFontFallback(true); state.init(); for (unsigned i = 0; i < length; i++) { // Each character in this input buffer is a surrogate pair, which // consists of two UChars. So, the offset for its i-th character is // (i * 2). WORD glyph = state.firstGlyphForCharacter(i * 2); if (glyph) { haveGlyphs = true; page->setGlyphDataForIndex(offset + i, glyph, fontData); } else // Clear both glyph and fontData fields. page->setGlyphDataForIndex(offset + i, 0, 0); } return haveGlyphs; } // We're supposed to return true if there are any glyphs in the range // specified by |offset| and |length| in our font, // false if there are none. bool GlyphPage::fill(unsigned offset, unsigned length, UChar* characterBuffer, unsigned bufferLength, const SimpleFontData* fontData) { // We have to handle BMP and non-BMP characters differently. // FIXME: Add assertions to make sure that buffer is entirely in BMP // or entirely in non-BMP. if (bufferLength == length) return fillBMPGlyphs(offset, length, characterBuffer, this, fontData); if (bufferLength == 2 * length) { // A non-BMP input buffer will be twice as long as output glyph buffer // because each character in the non-BMP input buffer will be // represented by a surrogate pair (two UChar's). return fillNonBMPGlyphs(offset, length, characterBuffer, this, fontData); } ASSERT_NOT_REACHED(); return false; } } // namespace WebCore