1 files changed, 71 insertions, 0 deletions
diff --git a/gfx/ots/src/ltsh.cc b/gfx/ots/src/ltsh.cc
new file mode 100644
index 0000000000..4c40c5eb77
--- /dev/null
+++ b/gfx/ots/src/ltsh.cc
@@ -0,0 +1,71 @@
+// Copyright (c) 2009-2017 The OTS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ltsh.h"
+
+#include "maxp.h"
+
+// LTSH - Linear Threshold
+// http://www.microsoft.com/typography/otspec/ltsh.htm
+
+namespace ots {
+
+bool OpenTypeLTSH::Parse(const uint8_t *data, size_t length) {
+  Buffer table(data, length);
+
+  OpenTypeMAXP *maxp = static_cast<OpenTypeMAXP*>(
+      GetFont()->GetTypedTable(OTS_TAG_MAXP));
+  if (!maxp) {
+    return Error("Required maxp table is missing");
+  }
+
+  uint16_t num_glyphs = 0;
+  if (!table.ReadU16(&this->version) ||
+      !table.ReadU16(&num_glyphs)) {
+    return Error("Failed to read table header");
+  }
+
+  if (this->version != 0) {
+    return Drop("Unsupported version: %u", this->version);
+  }
+
+  if (num_glyphs != maxp->num_glyphs) {
+    return Drop("Bad numGlyphs: %u", num_glyphs);
+  }
+
+  this->ypels.reserve(num_glyphs);
+  for (unsigned i = 0; i < num_glyphs; ++i) {
+    uint8_t pel = 0;
+    if (!table.ReadU8(&pel)) {
+      return Error("Failed to read pixels for glyph %d", i);
+    }
+    this->ypels.push_back(pel);
+  }
+
+  return true;
+}
+
+bool OpenTypeLTSH::Serialize(OTSStream *out) {
+  const uint16_t num_ypels = static_cast<uint16_t>(this->ypels.size());
+  if (num_ypels != this->ypels.size() ||
+      !out->WriteU16(this->version) ||
+      !out->WriteU16(num_ypels)) {
+    return Error("Failed to write table header");
+  }
+  for (uint16_t i = 0; i < num_ypels; ++i) {
+    if (!out->Write(&(this->ypels[i]), 1)) {
+      return Error("Failed to write pixel size for glyph %d", i);
+    }
+  }
+
+  return true;
+}
+
+bool OpenTypeLTSH::ShouldSerialize() {
+  return Table::ShouldSerialize() &&
+         // this table is not for CFF fonts.
+         GetFont()->GetTable(OTS_TAG_GLYF) != NULL;
+}
+
+}  // namespace ots