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#ifndef OT_GLYF_SIMPLEGLYPH_HH
#define OT_GLYF_SIMPLEGLYPH_HH
#include "../../hb-open-type.hh"
namespace OT {
namespace glyf_impl {
struct SimpleGlyph
{
enum simple_glyph_flag_t
{
FLAG_ON_CURVE = 0x01,
FLAG_X_SHORT = 0x02,
FLAG_Y_SHORT = 0x04,
FLAG_REPEAT = 0x08,
FLAG_X_SAME = 0x10,
FLAG_Y_SAME = 0x20,
FLAG_OVERLAP_SIMPLE = 0x40,
FLAG_RESERVED2 = 0x80
};
const GlyphHeader &header;
hb_bytes_t bytes;
SimpleGlyph (const GlyphHeader &header_, hb_bytes_t bytes_) :
header (header_), bytes (bytes_) {}
unsigned int instruction_len_offset () const
{ return GlyphHeader::static_size + 2 * header.numberOfContours; }
unsigned int length (unsigned int instruction_len) const
{ return instruction_len_offset () + 2 + instruction_len; }
unsigned int instructions_length () const
{
unsigned int instruction_length_offset = instruction_len_offset ();
if (unlikely (instruction_length_offset + 2 > bytes.length)) return 0;
const HBUINT16 &instructionLength = StructAtOffset<HBUINT16> (&bytes, instruction_length_offset);
/* Out of bounds of the current glyph */
if (unlikely (length (instructionLength) > bytes.length)) return 0;
return instructionLength;
}
const hb_bytes_t trim_padding () const
{
/* based on FontTools _g_l_y_f.py::trim */
const uint8_t *glyph = (uint8_t*) bytes.arrayZ;
const uint8_t *glyph_end = glyph + bytes.length;
/* simple glyph w/contours, possibly trimmable */
glyph += instruction_len_offset ();
if (unlikely (glyph + 2 >= glyph_end)) return hb_bytes_t ();
unsigned int num_coordinates = StructAtOffset<HBUINT16> (glyph - 2, 0) + 1;
unsigned int num_instructions = StructAtOffset<HBUINT16> (glyph, 0);
glyph += 2 + num_instructions;
unsigned int coord_bytes = 0;
unsigned int coords_with_flags = 0;
while (glyph < glyph_end)
{
uint8_t flag = *glyph;
glyph++;
unsigned int repeat = 1;
if (flag & FLAG_REPEAT)
{
if (unlikely (glyph >= glyph_end)) return hb_bytes_t ();
repeat = *glyph + 1;
glyph++;
}
unsigned int xBytes, yBytes;
xBytes = yBytes = 0;
if (flag & FLAG_X_SHORT) xBytes = 1;
else if ((flag & FLAG_X_SAME) == 0) xBytes = 2;
if (flag & FLAG_Y_SHORT) yBytes = 1;
else if ((flag & FLAG_Y_SAME) == 0) yBytes = 2;
coord_bytes += (xBytes + yBytes) * repeat;
coords_with_flags += repeat;
if (coords_with_flags >= num_coordinates) break;
}
if (unlikely (coords_with_flags != num_coordinates)) return hb_bytes_t ();
return bytes.sub_array (0, bytes.length + coord_bytes - (glyph_end - glyph));
}
/* zero instruction length */
void drop_hints ()
{
GlyphHeader &glyph_header = const_cast<GlyphHeader &> (header);
(HBUINT16 &) StructAtOffset<HBUINT16> (&glyph_header, instruction_len_offset ()) = 0;
}
void drop_hints_bytes (hb_bytes_t &dest_start, hb_bytes_t &dest_end) const
{
unsigned int instructions_len = instructions_length ();
unsigned int glyph_length = length (instructions_len);
dest_start = bytes.sub_array (0, glyph_length - instructions_len);
dest_end = bytes.sub_array (glyph_length, bytes.length - glyph_length);
}
void set_overlaps_flag ()
{
if (unlikely (!header.numberOfContours)) return;
unsigned flags_offset = length (instructions_length ());
if (unlikely (flags_offset + 1 > bytes.length)) return;
HBUINT8 &first_flag = (HBUINT8 &) StructAtOffset<HBUINT16> (&bytes, flags_offset);
first_flag = (uint8_t) first_flag | FLAG_OVERLAP_SIMPLE;
}
static bool read_flags (const HBUINT8 *&p /* IN/OUT */,
contour_point_vector_t &points_ /* IN/OUT */,
const HBUINT8 *end)
{
unsigned count = points_.length;
for (unsigned int i = 0; i < count;)
{
if (unlikely (p + 1 > end)) return false;
uint8_t flag = *p++;
points_.arrayZ[i++].flag = flag;
if (flag & FLAG_REPEAT)
{
if (unlikely (p + 1 > end)) return false;
unsigned int repeat_count = *p++;
unsigned stop = hb_min (i + repeat_count, count);
for (; i < stop;)
points_.arrayZ[i++].flag = flag;
}
}
return true;
}
static bool read_points (const HBUINT8 *&p /* IN/OUT */,
contour_point_vector_t &points_ /* IN/OUT */,
const HBUINT8 *end,
float contour_point_t::*m,
const simple_glyph_flag_t short_flag,
const simple_glyph_flag_t same_flag)
{
int v = 0;
unsigned count = points_.length;
for (unsigned i = 0; i < count; i++)
{
unsigned flag = points_[i].flag;
if (flag & short_flag)
{
if (unlikely (p + 1 > end)) return false;
if (flag & same_flag)
v += *p++;
else
v -= *p++;
}
else
{
if (!(flag & same_flag))
{
if (unlikely (p + HBINT16::static_size > end)) return false;
v += *(const HBINT16 *) p;
p += HBINT16::static_size;
}
}
points_.arrayZ[i].*m = v;
}
return true;
}
bool get_contour_points (contour_point_vector_t &points_ /* OUT */,
bool phantom_only = false) const
{
const HBUINT16 *endPtsOfContours = &StructAfter<HBUINT16> (header);
int num_contours = header.numberOfContours;
assert (num_contours);
/* One extra item at the end, for the instruction-count below. */
if (unlikely (!bytes.check_range (&endPtsOfContours[num_contours]))) return false;
unsigned int num_points = endPtsOfContours[num_contours - 1] + 1;
points_.alloc (num_points + 4); // Allocate for phantom points, to avoid a possible copy
if (!points_.resize (num_points)) return false;
if (phantom_only) return true;
for (int i = 0; i < num_contours; i++)
points_[endPtsOfContours[i]].is_end_point = true;
/* Skip instructions */
const HBUINT8 *p = &StructAtOffset<HBUINT8> (&endPtsOfContours[num_contours + 1],
endPtsOfContours[num_contours]);
if (unlikely ((const char *) p < bytes.arrayZ)) return false; /* Unlikely overflow */
const HBUINT8 *end = (const HBUINT8 *) (bytes.arrayZ + bytes.length);
if (unlikely (p >= end)) return false;
/* Read x & y coordinates */
return read_flags (p, points_, end)
&& read_points (p, points_, end, &contour_point_t::x,
FLAG_X_SHORT, FLAG_X_SAME)
&& read_points (p, points_, end, &contour_point_t::y,
FLAG_Y_SHORT, FLAG_Y_SAME);
}
};
} /* namespace glyf_impl */
} /* namespace OT */
#endif /* OT_GLYF_SIMPLEGLYPH_HH */
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