1 files changed, 149 insertions, 0 deletions
diff --git a/chromium/third_party/skia/third_party/harfbuzz/contrib/harfbuzz-freetype.c b/chromium/third_party/skia/third_party/harfbuzz/contrib/harfbuzz-freetype.c
new file mode 100644
index 00000000000..a2962df48f6
--- /dev/null
+++ b/chromium/third_party/skia/third_party/harfbuzz/contrib/harfbuzz-freetype.c
@@ -0,0 +1,149 @@
+#include <stdint.h>
+
+#include <ft2build.h>
+#include FT_FREETYPE_H
+#include FT_TRUETYPE_TABLES_H
+
+#if 0
+#include <freetype/freetype.h>
+#include <freetype/tttables.h>
+#endif
+
+#include <harfbuzz-shaper.h>
+#include "harfbuzz-unicode.h"
+
+static HB_Bool
+hb_freetype_string_to_glyphs(HB_Font font,
+                             const HB_UChar16 *chars, hb_uint32 len,
+                             HB_Glyph *glyphs, hb_uint32 *numGlyphs,
+                             HB_Bool is_rtl) {
+  FT_Face face = (FT_Face) font->userData;
+  if (len > *numGlyphs)
+    return 0;
+
+  size_t i = 0, j = 0;
+  while (i < len) {
+    const uint32_t cp = utf16_to_code_point(chars, len, &i);
+    glyphs[j++] = FT_Get_Char_Index(face, cp);
+  }
+
+  *numGlyphs = j;
+
+  return 1;
+}
+
+static void
+hb_freetype_advances_get(HB_Font font, const HB_Glyph *glyphs, hb_uint32 len,
+                         HB_Fixed *advances, int flags) {
+  FT_Face face = (FT_Face) font->userData;
+
+  hb_uint32 i;
+  for (i = 0; i < len; ++i) {
+    const FT_Error error = FT_Load_Glyph(face, glyphs[i], FT_LOAD_DEFAULT);
+    if (error) {
+      advances[i] = 0;
+      continue;
+    }
+
+    advances[i] = face->glyph->advance.x;
+  }
+}
+
+static HB_Bool
+hb_freetype_can_render(HB_Font font, const HB_UChar16 *chars, hb_uint32 len) {
+  FT_Face face = (FT_Face)font->userData;
+
+  size_t i = 0;
+  while (i < len) {
+    const uint32_t cp = utf16_to_code_point(chars, len, &i);
+    if (FT_Get_Char_Index(face, cp) == 0)
+      return 0;
+  }
+
+  return 1;
+}
+
+static HB_Error
+hb_freetype_outline_point_get(HB_Font font, HB_Glyph glyph, int flags,
+                              hb_uint32 point, HB_Fixed *xpos, HB_Fixed *ypos,
+                              hb_uint32 *n_points) {
+  HB_Error error = HB_Err_Ok;
+  FT_Face face = (FT_Face) font->userData;
+
+  int load_flags = (flags & HB_ShaperFlag_UseDesignMetrics) ? FT_LOAD_NO_HINTING : FT_LOAD_DEFAULT;
+
+  if ((error = (HB_Error) FT_Load_Glyph(face, glyph, load_flags)))
+    return error;
+
+  if (face->glyph->format != ft_glyph_format_outline)
+    return (HB_Error)HB_Err_Invalid_SubTable;
+
+  *n_points = face->glyph->outline.n_points;
+  if (!(*n_points))
+    return HB_Err_Ok;
+
+  if (point > *n_points)
+    return (HB_Error)HB_Err_Invalid_SubTable;
+
+  *xpos = face->glyph->outline.points[point].x;
+  *ypos = face->glyph->outline.points[point].y;
+
+  return HB_Err_Ok;
+}
+
+static void
+hb_freetype_glyph_metrics_get(HB_Font font, HB_Glyph glyph,
+                              HB_GlyphMetrics *metrics) {
+  FT_Face face = (FT_Face) font->userData;
+
+  const FT_Error error = FT_Load_Glyph(face, glyph, FT_LOAD_DEFAULT);
+  if (error) {
+    metrics->x = metrics->y = metrics->width = metrics->height = 0;
+    metrics->xOffset = metrics->yOffset = 0;
+    return;
+  }
+
+  const FT_Glyph_Metrics *ftmetrics = &face->glyph->metrics;
+  metrics->width = ftmetrics->width;
+  metrics->height = ftmetrics->height;
+  metrics->x = ftmetrics->horiAdvance;
+  metrics->y = 0;  // unclear what this is
+  metrics->xOffset = ftmetrics->horiBearingX;
+  metrics->yOffset = ftmetrics->horiBearingY;
+}
+
+static HB_Fixed
+hb_freetype_font_metric_get(HB_Font font, HB_FontMetric metric) {
+  FT_Face face = (FT_Face) font->userData;
+
+  switch (metric) {
+  case HB_FontAscent:
+    // Note that we aren't scanning the VDMX table which we probably would in
+    // an ideal world.
+    return face->ascender;
+  default:
+    return 0;
+  }
+}
+
+const HB_FontClass hb_freetype_class = {
+  hb_freetype_string_to_glyphs,
+  hb_freetype_advances_get,
+  hb_freetype_can_render,
+  hb_freetype_outline_point_get,
+  hb_freetype_glyph_metrics_get,
+  hb_freetype_font_metric_get,
+};
+
+HB_Error
+hb_freetype_table_sfnt_get(void *voidface, const HB_Tag tag, HB_Byte *buffer, HB_UInt *len) {
+  FT_Face face = (FT_Face) voidface;
+  FT_ULong ftlen = *len;
+
+  if (!FT_IS_SFNT(face))
+    return HB_Err_Invalid_Argument;
+
+  const FT_Error error = FT_Load_Sfnt_Table(face, tag, 0, buffer, &ftlen);
+  *len = ftlen;
+  return (HB_Error) error;
+}