1 files changed, 119 insertions, 0 deletions
diff --git a/gfx/ots/src/gasp.cc b/gfx/ots/src/gasp.cc
new file mode 100644
index 0000000000..5ebf5d84b4
--- /dev/null
+++ b/gfx/ots/src/gasp.cc
@@ -0,0 +1,119 @@
+// Copyright (c) 2009 The Chromium 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
+
+#define TABLE_NAME "gasp"
+
+#define DROP_THIS_TABLE(...) \
+  do { \
+    OTS_FAILURE_MSG_(font->file, TABLE_NAME ": " __VA_ARGS__); \
+    OTS_FAILURE_MSG("Table discarded"); \
+    delete font->gasp; \
+    font->gasp = 0; \
+  } while (0)
+
+namespace ots {
+
+bool ots_gasp_parse(Font *font, const uint8_t *data, size_t length) {
+  Buffer table(data, length);
+
+  OpenTypeGASP *gasp = new OpenTypeGASP;
+  font->gasp = gasp;
+
+  uint16_t num_ranges = 0;
+  if (!table.ReadU16(&gasp->version) ||
+      !table.ReadU16(&num_ranges)) {
+    return OTS_FAILURE_MSG("Failed to read table header");
+  }
+
+  if (gasp->version > 1) {
+    // Lots of Linux fonts have bad version numbers...
+    DROP_THIS_TABLE("bad version: %u", gasp->version);
+    return true;
+  }
+
+  if (num_ranges == 0) {
+    DROP_THIS_TABLE("num_ranges is zero");
+    return true;
+  }
+
+  gasp->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 OTS_FAILURE_MSG("Failed to read subrange %d", i);
+    }
+    if ((i > 0) && (gasp->gasp_ranges[i - 1].first >= max_ppem)) {
+      // The records in the gaspRange[] array must be sorted in order of
+      // increasing rangeMaxPPEM value.
+      DROP_THIS_TABLE("ranges are not sorted");
+      return true;
+    }
+    if ((i == num_ranges - 1u) &&  // never underflow.
+        (max_ppem != 0xffffu)) {
+      DROP_THIS_TABLE("The last record should be 0xFFFF as a sentinel value "
+                  "for rangeMaxPPEM");
+      return true;
+    }
+
+    if (behavior >> 8) {
+      OTS_WARNING("undefined bits are used: %x", behavior);
+      // mask undefined bits.
+      behavior &= 0x000fu;
+    }
+
+    if (gasp->version == 0 && (behavior >> 2) != 0) {
+      OTS_WARNING("changed the version number to 1");
+      gasp->version = 1;
+    }
+
+    gasp->gasp_ranges.push_back(std::make_pair(max_ppem, behavior));
+  }
+
+  return true;
+}
+
+bool ots_gasp_should_serialise(Font *font) {
+  return font->gasp != NULL;
+}
+
+bool ots_gasp_serialise(OTSStream *out, Font *font) {
+  const OpenTypeGASP *gasp = font->gasp;
+
+  const uint16_t num_ranges = static_cast<uint16_t>(gasp->gasp_ranges.size());
+  if (num_ranges != gasp->gasp_ranges.size() ||
+      !out->WriteU16(gasp->version) ||
+      !out->WriteU16(num_ranges)) {
+    return OTS_FAILURE_MSG("failed to write gasp header");
+  }
+
+  for (uint16_t i = 0; i < num_ranges; ++i) {
+    if (!out->WriteU16(gasp->gasp_ranges[i].first) ||
+        !out->WriteU16(gasp->gasp_ranges[i].second)) {
+      return OTS_FAILURE_MSG("Failed to write gasp subtable %d", i);
+    }
+  }
+
+  return true;
+}
+
+void ots_gasp_reuse(Font *font, Font *other) {
+  font->gasp = other->gasp;
+  font->gasp_reused = true;
+}
+
+void ots_gasp_free(Font *font) {
+  delete font->gasp;
+}
+
+}  // namespace ots
+
+#undef TABLE_NAME
+#undef DROP_THIS_TABLE