1 files changed, 84 insertions, 0 deletions
diff --git a/gfx/ots/src/gasp.cc b/gfx/ots/src/gasp.cc
new file mode 100644
index 0000000000..2a03c831ff
--- /dev/null
+++ b/gfx/ots/src/gasp.cc
@@ -0,0 +1,84 @@
+// 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 "gasp.h"
+
+// gasp - Grid-fitting And Scan-conversion Procedure
+// http://www.microsoft.com/typography/otspec/gasp.htm
+
+namespace ots {
+
+bool OpenTypeGASP::Parse(const uint8_t *data, size_t length) {
+  Buffer table(data, length);
+
+  uint16_t num_ranges = 0;
+  if (!table.ReadU16(&this->version) ||
+      !table.ReadU16(&num_ranges)) {
+    return Error("Failed to read table header");
+  }
+
+  if (this->version > 1) {
+    // Lots of Linux fonts have bad version numbers...
+    return Drop("Unsupported version: %u", this->version);
+  }
+
+  if (num_ranges == 0) {
+    return Drop("numRanges is zero");
+  }
+
+  this->gasp_ranges.reserve(num_ranges);
+  for (unsigned i = 0; i < num_ranges; ++i) {
+    uint16_t max_ppem = 0;
+    uint16_t behavior = 0;
+    if (!table.ReadU16(&max_ppem) ||
+        !table.ReadU16(&behavior)) {
+      return Error("Failed to read GASPRANGE %d", i);
+    }
+    if ((i > 0) && (this->gasp_ranges[i - 1].first >= max_ppem)) {
+      // The records in the gaspRange[] array must be sorted in order of
+      // increasing rangeMaxPPEM value.
+      return Drop("Ranges are not sorted");
+    }
+    if ((i == num_ranges - 1u) &&  // never underflow.
+        (max_ppem != 0xffffu)) {
+      return Drop("The last record should be 0xFFFF as a sentinel value "
+                  "for rangeMaxPPEM");
+    }
+
+    if (behavior >> 8) {
+      Warning("Undefined bits are used: %x", behavior);
+      // mask undefined bits.
+      behavior &= 0x000fu;
+    }
+
+    if (this->version == 0 && (behavior >> 2) != 0) {
+      Warning("Changed the version number to 1");
+      this->version = 1;
+    }
+
+    this->gasp_ranges.push_back(std::make_pair(max_ppem, behavior));
+  }
+
+  return true;
+}
+
+bool OpenTypeGASP::Serialize(OTSStream *out) {
+  const uint16_t num_ranges = static_cast<uint16_t>(this->gasp_ranges.size());
+  if (num_ranges != this->gasp_ranges.size() ||
+      !out->WriteU16(this->version) ||
+      !out->WriteU16(num_ranges)) {
+    return Error("Failed to write table header");
+  }
+
+  for (uint16_t i = 0; i < num_ranges; ++i) {
+    if (!out->WriteU16(this->gasp_ranges[i].first) ||
+        !out->WriteU16(this->gasp_ranges[i].second)) {
+      return Error("Failed to write GASPRANGE %d", i);
+    }
+  }
+
+  return true;
+}
+
+}  // namespace ots