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Diffstat (limited to 'WebCore/platform/graphics/chromium/VDMXParser.cpp')
| -rw-r--r-- | WebCore/platform/graphics/chromium/VDMXParser.cpp | 202 |
1 files changed, 0 insertions, 202 deletions
diff --git a/WebCore/platform/graphics/chromium/VDMXParser.cpp b/WebCore/platform/graphics/chromium/VDMXParser.cpp deleted file mode 100644 index bd30a97..0000000 --- a/WebCore/platform/graphics/chromium/VDMXParser.cpp +++ /dev/null @@ -1,202 +0,0 @@ -/* - * Copyright (c) 2008, 2009, 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 <stdint.h> -#include <stdlib.h> -#include <string.h> - -// For htons/ntohs -#include <arpa/inet.h> - -// Buffer helper class -// -// This class perform some trival buffer operations while checking for -// out-of-bounds errors. As a family they return false if anything is amiss, -// updating the current offset otherwise. -class Buffer { -public: - Buffer(const uint8_t* buffer, size_t length) - : m_buffer(buffer) - , m_length(length) - , m_offset(0) { } - - bool skip(size_t numBytes) - { - if (m_offset + numBytes > m_length) - return false; - m_offset += numBytes; - return true; - } - - bool readU8(uint8_t* value) - { - if (m_offset + sizeof(uint8_t) > m_length) - return false; - *value = m_buffer[m_offset]; - m_offset += sizeof(uint8_t); - return true; - } - - bool readU16(uint16_t* value) - { - if (m_offset + sizeof(uint16_t) > m_length) - return false; - memcpy(value, m_buffer + m_offset, sizeof(uint16_t)); - *value = ntohs(*value); - m_offset += sizeof(uint16_t); - return true; - } - - bool readS16(int16_t* value) - { - return readU16(reinterpret_cast<uint16_t*>(value)); - } - - size_t offset() const - { - return m_offset; - } - - void setOffset(size_t newoffset) - { - m_offset = newoffset; - } - -private: - const uint8_t *const m_buffer; - const size_t m_length; - size_t m_offset; -}; - -// VDMX parsing code. -// -// VDMX tables are found in some TrueType/OpenType fonts and contain -// ascender/descender overrides for certain (usually small) sizes. This is -// needed in order to match font metrics on Windows. -// -// Freetype does not parse these tables so we do so here. - -namespace WebCore { - -// Parse a TrueType VDMX table. -// yMax: (output) the ascender value from the table -// yMin: (output) the descender value from the table (negative!) -// vdmx: the table bytes -// vdmxLength: length of @vdmx, in bytes -// targetPixelSize: the pixel size of the font (e.g. 16) -// -// Returns true iff a suitable match are found. Otherwise, *yMax and *yMin are -// untouched. size_t must be 32-bits to avoid overflow. -// -// See http://www.microsoft.com/opentype/otspec/vdmx.htm -bool parseVDMX(int* yMax, int* yMin, - const uint8_t* vdmx, size_t vdmxLength, - unsigned targetPixelSize) -{ - Buffer buf(vdmx, vdmxLength); - - // We ignore the version. Future tables should be backwards compatible with - // this layout. - uint16_t numRatios; - if (!buf.skip(4) || !buf.readU16(&numRatios)) - return false; - - // Now we have two tables. Firstly we have @numRatios Ratio records, then a - // matching array of @numRatios offsets. We save the offset of the beginning - // of this second table. - // - // Range 6 <= x <= 262146 - unsigned long offsetTableOffset = - buf.offset() + 4 /* sizeof struct ratio */ * numRatios; - - unsigned desiredRatio = 0xffffffff; - // We read 4 bytes per record, so the offset range is - // 6 <= x <= 524286 - for (unsigned i = 0; i < numRatios; ++i) { - uint8_t xRatio, yRatio1, yRatio2; - - if (!buf.skip(1) - || !buf.readU8(&xRatio) - || !buf.readU8(&yRatio1) - || !buf.readU8(&yRatio2)) - return false; - - // This either covers 1:1, or this is the default entry (0, 0, 0) - if ((xRatio == 1 && yRatio1 <= 1 && yRatio2 >= 1) - || (xRatio == 0 && yRatio1 == 0 && yRatio2 == 0)) { - desiredRatio = i; - break; - } - } - - if (desiredRatio == 0xffffffff) // no ratio found - return false; - - // Range 10 <= x <= 393216 - buf.setOffset(offsetTableOffset + sizeof(uint16_t) * desiredRatio); - - // Now we read from the offset table to get the offset of another array - uint16_t groupOffset; - if (!buf.readU16(&groupOffset)) - return false; - // Range 0 <= x <= 65535 - buf.setOffset(groupOffset); - - uint16_t numRecords; - if (!buf.readU16(&numRecords) || !buf.skip(sizeof(uint16_t))) - return false; - - // We read 6 bytes per record, so the offset range is - // 4 <= x <= 458749 - for (unsigned i = 0; i < numRecords; ++i) { - uint16_t pixelSize; - if (!buf.readU16(&pixelSize)) - return false; - // the entries are sorted, so we can abort early if need be - if (pixelSize > targetPixelSize) - return false; - - if (pixelSize == targetPixelSize) { - int16_t tempYMax, tempYMin; - if (!buf.readS16(&tempYMax) - || !buf.readS16(&tempYMin)) - return false; - *yMin = tempYMin; - *yMax = tempYMax; - return true; - } - if (!buf.skip(2 * sizeof(int16_t))) - return false; - } - - return false; -} - -} // namespace WebCore |