gfx/ots/ots-1850314.patch

   1 commit 362a59be47f9e187eec43df0938def661be6c972
   2 Author: Jonathan Kew <jkew@mozilla.com>
   3 Date:   Wed Aug 30 12:55:02 2023 +0000
   4
   5     Bug 1850314 - Don't do glyph bounding-box fixup for "tricky" fonts, because it may disrupt glyph rendering on macOS. r=gfx-reviewers,lsalzman
   6
   7     Differential Revision: https://phabricator.services.mozilla.com/D187096
   8
   9 diff --git a/src/glyf.cc b/src/glyf.cc
  10 index 0ed9515ef16d6..31487957bf99b 100644
  11 --- a/src/glyf.cc
  12 +++ b/src/glyf.cc
  13 @@ -10,6 +10,7 @@
  14  #include "head.h"
  15  #include "loca.h"
  16  #include "maxp.h"
  17 +#include "name.h"
  18
  19  // glyf - Glyph Data
  20  // http://www.microsoft.com/typography/otspec/glyf.htm
  21 @@ -97,7 +98,8 @@ bool OpenTypeGLYF::ParseSimpleGlyph(Buffer &glyph,
  22                                      int16_t& xmin,
  23                                      int16_t& ymin,
  24                                      int16_t& xmax,
  25 -                                    int16_t& ymax) {
  26 +                                    int16_t& ymax,
  27 +                                    bool is_tricky_font) {
  28    // read the end-points array
  29    uint16_t num_flags = 0;
  30    for (int i = 0; i < num_contours; ++i) {
  31 @@ -219,27 +221,32 @@ bool OpenTypeGLYF::ParseSimpleGlyph(Buffer &glyph,
  32    }
  33
  34    if (adjusted_bbox) {
  35 -    Warning("Glyph bbox was incorrect; adjusting (glyph %u)", gid);
  36 -    // copy the numberOfContours field
  37 -    this->iov.push_back(std::make_pair(glyph.buffer(), 2));
  38 -    // output a fixed-up version of the bounding box
  39 -    uint8_t* fixed_bbox = new uint8_t[8];
  40 -    fixed_bboxes.push_back(fixed_bbox);
  41 -    xmin = ots_htons(xmin);
  42 -    std::memcpy(fixed_bbox, &xmin, 2);
  43 -    ymin = ots_htons(ymin);
  44 -    std::memcpy(fixed_bbox + 2, &ymin, 2);
  45 -    xmax = ots_htons(xmax);
  46 -    std::memcpy(fixed_bbox + 4, &xmax, 2);
  47 -    ymax = ots_htons(ymax);
  48 -    std::memcpy(fixed_bbox + 6, &ymax, 2);
  49 -    this->iov.push_back(std::make_pair(fixed_bbox, 8));
  50 -    // copy the remainder of the glyph data
  51 -    this->iov.push_back(std::make_pair(glyph.buffer() + 10, glyph.offset() - 10));
  52 -  } else {
  53 -    this->iov.push_back(std::make_pair(glyph.buffer(), glyph.offset()));
  54 +    if (is_tricky_font) {
  55 +      Warning("Glyph bbox was incorrect; NOT adjusting tricky font (glyph %u)", gid);
  56 +    } else {
  57 +      Warning("Glyph bbox was incorrect; adjusting (glyph %u)", gid);
  58 +      // copy the numberOfContours field
  59 +      this->iov.push_back(std::make_pair(glyph.buffer(), 2));
  60 +      // output a fixed-up version of the bounding box
  61 +      uint8_t* fixed_bbox = new uint8_t[8];
  62 +      fixed_bboxes.push_back(fixed_bbox);
  63 +      xmin = ots_htons(xmin);
  64 +      std::memcpy(fixed_bbox, &xmin, 2);
  65 +      ymin = ots_htons(ymin);
  66 +      std::memcpy(fixed_bbox + 2, &ymin, 2);
  67 +      xmax = ots_htons(xmax);
  68 +      std::memcpy(fixed_bbox + 4, &xmax, 2);
  69 +      ymax = ots_htons(ymax);
  70 +      std::memcpy(fixed_bbox + 6, &ymax, 2);
  71 +      this->iov.push_back(std::make_pair(fixed_bbox, 8));
  72 +      // copy the remainder of the glyph data
  73 +      this->iov.push_back(std::make_pair(glyph.buffer() + 10, glyph.offset() - 10));
  74 +      return true;
  75 +    }
  76    }
  77
  78 +  this->iov.push_back(std::make_pair(glyph.buffer(), glyph.offset()));
  79 +
  80    return true;
  81  }
  82
  83 @@ -342,6 +349,10 @@ bool OpenTypeGLYF::Parse(const uint8_t *data, size_t length) {
  84      return Error("Missing maxp or loca or head table needed by glyf table");
  85    }
  86
  87 +  OpenTypeNAME *name = static_cast<OpenTypeNAME*>(
  88 +      GetFont()->GetTypedTable(OTS_TAG_NAME));
  89 +  bool is_tricky = name->IsTrickyFont();
  90 +
  91    this->maxp = maxp;
  92
  93    const unsigned num_glyphs = maxp->num_glyphs;
  94 @@ -397,7 +408,7 @@ bool OpenTypeGLYF::Parse(const uint8_t *data, size_t length) {
  95        // does we will simply ignore it.
  96        glyph.set_offset(0);
  97      } else if (num_contours > 0) {
  98 -      if (!ParseSimpleGlyph(glyph, i, num_contours, xmin, ymin, xmax, ymax)) {
  99 +      if (!ParseSimpleGlyph(glyph, i, num_contours, xmin, ymin, xmax, ymax, is_tricky)) {
 100          return Error("Failed to parse glyph %d", i);
 101        }
 102      } else {
 103 diff --git a/src/glyf.h b/src/glyf.h
 104 index 05e846f1cb6e8..f85fdc4652fcf 100644
 105 --- a/src/glyf.h
 106 +++ b/src/glyf.h
 107 @@ -51,7 +51,8 @@ class OpenTypeGLYF : public Table {
 108                          int16_t& xmin,
 109                          int16_t& ymin,
 110                          int16_t& xmax,
 111 -                        int16_t& ymax);
 112 +                        int16_t& ymax,
 113 +                        bool is_tricky_font);
 114    bool ParseCompositeGlyph(
 115        Buffer &glyph,
 116        ComponentPointCount* component_point_count);
 117 diff --git a/src/name.cc b/src/name.cc
 118 index fc5074b0587a3..7526e1f72b9ea 100644
 119 --- a/src/name.cc
 120 +++ b/src/name.cc
 121 @@ -366,4 +366,44 @@ bool OpenTypeNAME::IsValidNameId(uint16_t nameID, bool addIfMissing) {
 122    return this->name_ids.count(nameID);
 123  }
 124
 125 +// List of font names considered "tricky" (dependent on applying original TrueType instructions) by FreeType, see
 126 +// https://gitlab.freedesktop.org/freetype/freetype/-/blob/2d9fce53d4ce89f36075168282fcdd7289e082f9/src/truetype/ttobjs.c#L170-241
 127 +static const char* tricky_font_names[] = {
 128 +  "cpop",
 129 +  "DFGirl-W6-WIN-BF",
 130 +  "DFGothic-EB",
 131 +  "DFGyoSho-Lt",
 132 +  "DFHei",
 133 +  "DFHSGothic-W5",
 134 +  "DFHSMincho-W3",
 135 +  "DFHSMincho-W7",
 136 +  "DFKaiSho-SB",
 137 +  "DFKaiShu",
 138 +  "DFKai-SB",
 139 +  "DFMing",
 140 +  "DLC",
 141 +  "HuaTianKaiTi?",
 142 +  "HuaTianSongTi?",
 143 +  "Ming(for ISO10646)",
 144 +  "MingLiU",
 145 +  "MingMedium",
 146 +  "PMingLiU",
 147 +  "MingLi43"
 148 +};
 149 +
 150 +bool OpenTypeNAME::IsTrickyFont() const {
 151 +  for (const auto& name : this->names) {
 152 +    const uint16_t id = name.name_id;
 153 +    if (id != 1) {
 154 +      continue;
 155 +    }
 156 +    for (const auto* p : tricky_font_names) {
 157 +      if (name.text.find(p) != std::string::npos) {
 158 +        return true;
 159 +      }
 160 +    }
 161 +  }
 162 +  return false;
 163 +}
 164 +
 165  }  // namespace
 166 diff --git a/src/name.h b/src/name.h
 167 index 68c7ac096d3f8..a241e77ee26bb 100644
 168 --- a/src/name.h
 169 +++ b/src/name.h
 170 @@ -52,6 +52,7 @@ class OpenTypeNAME : public Table {
 171    bool Parse(const uint8_t *data, size_t length);
 172    bool Serialize(OTSStream *out);
 173    bool IsValidNameId(uint16_t nameID, bool addIfMissing = false);
 174 +  bool IsTrickyFont() const;
 175
 176   private:
 177    std::vector<NameRecord> names;