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andiwand merged 2 commits into from
Oct 5, 2026
Merged

test: share SFNT fixtures and consolidate reencode checks #1062

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d4b5fc8
test: share SFNT fixtures and consolidate reencode checks
andiwand Oct 4, 2026
d07b544
test: include the SFNT fixtures by their path
andiwand Oct 5, 2026
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97 changes: 11 additions & 86 deletions test/src/internal/font/font_file.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -9,6 +9,8 @@
#include <odr/internal/magic.hpp>
#include <odr/internal/util/byte_string.hpp>

#include <internal/font/sfnt_test_util.hpp>

#include <gtest/gtest.h>

#include <cstdint>
Expand All @@ -25,95 +27,18 @@ using namespace odr::internal::font;

namespace {

namespace bs = odr::internal::util::byte_string;

std::string head_table() {
std::string t(54, '\0');
t[18] = 0x03; // unitsPerEm = 1000
t[19] = static_cast<char>(0xe8);
return t;
}

std::string maxp_table(std::uint16_t glyphs) {
std::string t;
bs::put_u32_be(t, 0x00010000);
bs::put_u16_be(t, glyphs);
t.resize(32, '\0');
return t;
}

std::string hhea_table(std::uint16_t metrics) {
std::string t(36, '\0');
t[34] = static_cast<char>(metrics >> 8);
t[35] = static_cast<char>(metrics & 0xff);
return t;
}

std::string hmtx_table(const std::vector<std::uint16_t> &advances) {
std::string t;
for (const std::uint16_t a : advances) {
bs::put_u16_be(t, a);
bs::put_u16_be(t, 0);
}
return t;
}
using namespace odr::test::font;

std::string cmap_table() {
std::string sub;
bs::put_u16_be(sub, 4);
bs::put_u16_be(sub, 32);
bs::put_u16_be(sub, 0);
bs::put_u16_be(sub, 4);
bs::put_u16_be(sub, 0);
bs::put_u16_be(sub, 0);
bs::put_u16_be(sub, 0);
bs::put_u16_be(sub, 'C'); // endCode[0]
bs::put_u16_be(sub, 0xffff); // endCode[1]
bs::put_u16_be(sub, 0);
bs::put_u16_be(sub, 'A'); // startCode[0]
bs::put_u16_be(sub, 0xffff); // startCode[1]
bs::put_u16_be(
sub, static_cast<std::uint16_t>(1 - 'A')); // idDelta[0]: A->1,B->2,C->3
bs::put_u16_be(sub, 1); // idDelta[1]
bs::put_u16_be(sub, 0);
bs::put_u16_be(sub, 0);

std::string t;
bs::put_u16_be(t, 0);
bs::put_u16_be(t, 1);
bs::put_u16_be(t, 3);
bs::put_u16_be(t, 1);
bs::put_u32_be(t, 12);
t += sub;
return t;
}

std::string name_table(const std::string &ascii) {
std::string strings;
for (const char c : ascii) {
bs::put_u16_be(strings, static_cast<std::uint8_t>(c));
}
std::string t;
bs::put_u16_be(t, 0);
bs::put_u16_be(t, 1);
bs::put_u16_be(t, 18);
bs::put_u16_be(t, 3);
bs::put_u16_be(t, 1);
bs::put_u16_be(t, 0x409);
bs::put_u16_be(t, 6);
bs::put_u16_be(t, static_cast<std::uint16_t>(strings.size()));
bs::put_u16_be(t, 0);
t += strings;
return t;
}
namespace bs = odr::internal::util::byte_string;

std::string sample_ttf() {
return build_sfnt(0x00010000, {{"cmap", cmap_table()},
{"head", head_table()},
{"hhea", hhea_table(4)},
{"hmtx", hmtx_table({500, 600, 700, 800})},
{"maxp", maxp_table(4)},
{"name", name_table("TestFont")}});
return build_sfnt(0x00010000,
{{"cmap", cmap_table(3, 1, cmap_format4('A', 3))},
{"head", head_table()},
{"hhea", hhea_table(4)},
{"hmtx", hmtx_table({500, 600, 700, 800})},
{"maxp", maxp_table(4)},
{"name", name_table("TestFont")}});
}

} // namespace
Expand Down
144 changes: 12 additions & 132 deletions test/src/internal/font/sfnt_font.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,8 @@
#include <odr/font.hpp>
#include <odr/internal/util/byte_string.hpp>

#include <internal/font/sfnt_test_util.hpp>

#include <gtest/gtest.h>

#include <array>
Expand All @@ -18,77 +20,15 @@ using namespace odr::internal::font::sfnt;

namespace {

using namespace odr::test::font;

namespace bs = odr::internal::util::byte_string;

/// Parse a font from its in-memory bytes.
SfntFont sfnt_font_from_string(std::string bytes) {
return SfntFont(std::move(bytes));
}

/// A `head` table: only unitsPerEm (offset 18) and the bbox (36..42) are read.
std::string head_table() {
std::string t(54, '\0');
const auto u16 = [&](std::size_t o, std::uint16_t v) {
t[o] = static_cast<char>(v >> 8);
t[o + 1] = static_cast<char>(v & 0xff);
};
u16(18, 1000); // unitsPerEm
u16(36, static_cast<std::uint16_t>(-100)); // xMin
u16(38, static_cast<std::uint16_t>(-200)); // yMin
u16(40, 900); // xMax
u16(42, 800); // yMax
return t;
}

std::string maxp_table(const std::uint16_t glyphs) {
std::string t;
bs::put_u32_be(t, 0x00010000); // version 1.0
bs::put_u16_be(t, glyphs);
t.resize(32, '\0');
return t;
}

std::string hhea_table(const std::uint16_t number_of_h_metrics) {
std::string t(36, '\0');
t[34] = static_cast<char>(number_of_h_metrics >> 8);
t[35] = static_cast<char>(number_of_h_metrics & 0xff);
return t;
}

std::string hmtx_table(const std::vector<std::uint16_t> &advances) {
std::string t;
for (const std::uint16_t a : advances) {
bs::put_u16_be(t, a); // advanceWidth
bs::put_u16_be(t, 0); // leftSideBearing
}
return t;
}

/// Format-4 subtable mapping the contiguous run [start, start+count) to glyph
/// ids [1, count] via a single idDelta segment, plus the required terminator.
std::string cmap_format4(const char16_t start, const std::uint16_t count) {
std::string t;
bs::put_u16_be(t, 4); // format
bs::put_u16_be(t, 32); // length
bs::put_u16_be(t, 0); // language
bs::put_u16_be(t, 4); // segCountX2 (2 segments)
bs::put_u16_be(t, 0); // searchRange
bs::put_u16_be(t, 0); // entrySelector
bs::put_u16_be(t, 0); // rangeShift
bs::put_u16_be(t,
static_cast<std::uint16_t>(start + count - 1)); // endCode[0]
bs::put_u16_be(t, 0xffff); // endCode[1]
bs::put_u16_be(t, 0); // reservedPad
bs::put_u16_be(t, start); // startCode[0]
bs::put_u16_be(t, 0xffff); // startCode[1]
bs::put_u16_be(
t, static_cast<std::uint16_t>(1 - start)); // idDelta[0] -> gid 1..count
bs::put_u16_be(t, 1); // idDelta[1]
bs::put_u16_be(t, 0); // idRangeOffset[0]
bs::put_u16_be(t, 0); // idRangeOffset[1]
return t;
}

/// Format-4 subtable mapping [start, start+count) to glyph ids [1, count] via a
/// non-zero idRangeOffset[0] that indexes the glyphIdArray, plus the
/// terminator. idRangeOffset[0] == 4 points at glyphIdArray[0] (past the one
Expand Down Expand Up @@ -134,70 +74,10 @@ std::string cmap_format12(const char32_t start, const std::uint32_t count) {
return t;
}

std::string cmap_table(const std::uint16_t platform,
const std::uint16_t encoding,
const std::string &subtable) {
std::string t;
bs::put_u16_be(t, 0); // version
bs::put_u16_be(t, 1); // numTables
bs::put_u16_be(t, platform);
bs::put_u16_be(t, encoding);
bs::put_u32_be(t, 12); // offset to the single subtable
t += subtable;
return t;
}

// A `name` table with a single PostScript-name (id 6) record, UTF-16BE.
std::string name_table(const std::string &ascii) {
std::string strings;
for (const char c : ascii) {
bs::put_u16_be(strings, static_cast<std::uint8_t>(c));
}
std::string t;
bs::put_u16_be(t, 0); // format
bs::put_u16_be(t, 1); // count
bs::put_u16_be(t, 18); // stringOffset (6 header + 12 record)
bs::put_u16_be(t, 3); // platformID (Windows)
bs::put_u16_be(t, 1); // encodingID
bs::put_u16_be(t, 0x409); // languageID
bs::put_u16_be(t, 6); // nameID (PostScript)
bs::put_u16_be(t, static_cast<std::uint16_t>(strings.size()));
bs::put_u16_be(t, 0); // offset within string storage
t += strings;
return t;
}

// Assemble a full SFNT from named tables, computing the table directory.
std::string
build_sfnt(const std::vector<std::pair<std::string, std::string>> &tables) {
const auto count = static_cast<std::uint16_t>(tables.size());
std::string out;
bs::put_u32_be(out, 0x00010000); // sfntVersion (TrueType)
bs::put_u16_be(out, count);
bs::put_u16_be(out, 0); // searchRange
bs::put_u16_be(out, 0); // entrySelector
bs::put_u16_be(out, 0); // rangeShift

std::uint32_t offset = 12 + count * 16U;
std::string body;
for (const auto &[tag, data] : tables) {
out += tag;
bs::put_u32_be(out, 0); // checksum (not validated by the reader)
bs::put_u32_be(out, offset);
bs::put_u32_be(out, static_cast<std::uint32_t>(data.size()));
body += data;
while (body.size() % 4 != 0) {
body += '\0';
}
offset = 12 + count * 16U + static_cast<std::uint32_t>(body.size());
}
return out + body;
}

std::string sample_font(const std::string &cmap) {
// Tables are stored in tag-sorted order, as required by the spec.
return build_sfnt({{"cmap", cmap},
{"head", head_table()},
return sfnt_bytes({{"cmap", cmap},
{"head", head_table({-100, -200, 900, 800})},
{"hhea", hhea_table(5)},
{"hmtx", hmtx_table({500, 600, 700, 222, 333})},
{"maxp", maxp_table(5)},
Expand Down Expand Up @@ -294,8 +174,8 @@ TEST(SfntFont, write_pads_a_short_hmtx) {
// Two longHorMetrics for five glyphs, and none of the three leftSideBearings
// that must follow them.
const SfntFont font = sfnt_font_from_string(
build_sfnt({{"cmap", cmap_table(3, 1, cmap_format4('A', 3))},
{"head", head_table()},
sfnt_bytes({{"cmap", cmap_table(3, 1, cmap_format4('A', 3))},
{"head", head_table({-100, -200, 900, 800})},
{"hhea", hhea_table(2)},
{"hmtx", hmtx_table({500, 600})},
{"maxp", maxp_table(5)}}));
Expand Down Expand Up @@ -328,15 +208,15 @@ TEST(SfntFont, rejects_invalid_headers_and_clips_quirky_ranges) {
bs::write_u32_be(bytes, 20, static_cast<std::uint32_t>(bytes.size() + 1));
EXPECT_THROW(SfntFont{bytes}, std::runtime_error);

std::string head = head_table();
std::string head = head_table({-100, -200, 900, 800});
bs::write_u16_be(head, 18, 0);
EXPECT_THROW(SfntFont(build_sfnt({{"head", head}})), std::runtime_error);
EXPECT_THROW(SfntFont(sfnt_bytes({{"head", head}})), std::runtime_error);

std::string name = name_table("A");
bs::write_u16_be(name, 14, 4);
EXPECT_EQ(SfntFont(build_sfnt({{"name", name}})).name(), "A");
EXPECT_EQ(SfntFont(sfnt_bytes({{"name", name}})).name(), "A");
bs::write_u16_be(name, 14, 1);
EXPECT_EQ(SfntFont(build_sfnt({{"name", name}})).name(), "");
EXPECT_EQ(SfntFont(sfnt_bytes({{"name", name}})).name(), "");
}

TEST(SfntFont, drops_an_invalid_cmap_and_keeps_the_font) {
Expand Down
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