[var] Implement DeltaSetIndexMap and advance delta fetching
Not hooked up to hb-ot-font yet.
diff --git a/src/hb-ot-layout-common-private.hh b/src/hb-ot-layout-common-private.hh
index 92b5c17..180e5f0 100644
--- a/src/hb-ot-layout-common-private.hh
+++ b/src/hb-ot-layout-common-private.hh
@@ -1323,6 +1323,14 @@
this+regions);
}
+ inline float get_delta (unsigned int index,
+ int *coords, unsigned int coord_count) const
+ {
+ unsigned int outer = index >> 16;
+ unsigned int inner = index & 0xFFFF;
+ return get_delta (outer, inner, coords, coord_count);
+ }
+
inline bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
diff --git a/src/hb-ot-var-hvar-table.hh b/src/hb-ot-var-hvar-table.hh
index 0cb24d2..cf22c9d 100644
--- a/src/hb-ot-var-hvar-table.hh
+++ b/src/hb-ot-var-hvar-table.hh
@@ -39,12 +39,52 @@
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
- c->check_array (this, 1, 12));
+ c->check_array (mapData, get_width (), mapCount));
}
- USHORT x;
+ unsigned int map (unsigned int v) const /* Returns 16.16 outer.inner. */
+ {
+ /* If count is zero, pass value unchanged. This takes
+ * care of direct mapping for advance map. */
+ if (!mapCount)
+ return v;
+
+ if (v >= mapCount)
+ v = mapCount - 1;
+
+ unsigned int u = 0;
+ { /* Fetch it. */
+ unsigned int w = get_width ();
+ const BYTE *p = mapData + w * v;
+ for (; w; w--)
+ u = (u << 8) + *p++;
+ }
+
+ { /* Repack it. */
+ unsigned int n = get_inner_bitcount ();
+ unsigned int outer = u >> n;
+ unsigned int inner = u & ((1 << n) - 1);
+ u = (outer<<16) | inner;
+ }
+
+ return u;
+ }
+
+ protected:
+ inline bool get_width (void) const
+ { return ((format >> 4) & 3) + 1; }
+
+ inline bool get_inner_bitcount (void) const
+ { return (format & 0xF) + 1; }
+
+ protected:
+ USHORT format; /* A packed field that describes the compressed
+ * representation of delta-set indices. */
+ USHORT mapCount; /* The number of mapping entries. */
+ BYTE mapData[VAR]; /* The delta-set index mapping data. */
+
public:
- DEFINE_SIZE_STATIC (2);
+ DEFINE_SIZE_ARRAY (4, mapData);
};
@@ -72,6 +112,16 @@
rsbMap.sanitize (c, this));
}
+ inline float get_advance_delta (hb_codepoint_t glyph,
+ int *coords, unsigned int coord_count) const
+ {
+ unsigned int varidx = (this+advMap).map (glyph);
+ return (this+varStore).get_delta (varidx, coords, coord_count);
+ }
+
+ inline bool has_sidebearing_deltas (void) const
+ { return lsbMap && rsbMap; }
+
protected:
FixedVersion<>version; /* Version of the metrics variation table
* initially set to 0x00010000u */
