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Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-kern-table.hh')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-kern-table.hh | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-kern-table.hh b/gfx/harfbuzz/src/hb-ot-kern-table.hh new file mode 100644 index 0000000000..b65a6be392 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-kern-table.hh @@ -0,0 +1,359 @@ +/*
+ * Copyright © 2017 Google, Inc.
+ *
+ * This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_OT_KERN_TABLE_HH
+#define HB_OT_KERN_TABLE_HH
+
+#include "hb-aat-layout-kerx-table.hh"
+
+
+/*
+ * kern -- Kerning
+ * https://docs.microsoft.com/en-us/typography/opentype/spec/kern
+ * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6kern.html
+ */
+#define HB_OT_TAG_kern HB_TAG('k','e','r','n')
+
+
+namespace OT {
+
+
+template <typename KernSubTableHeader>
+struct KernSubTableFormat3
+{
+ int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const
+ {
+ hb_array_t<const FWORD> kernValue = kernValueZ.as_array (kernValueCount);
+ hb_array_t<const HBUINT8> leftClass = StructAfter<const UnsizedArrayOf<HBUINT8>> (kernValue).as_array (glyphCount);
+ hb_array_t<const HBUINT8> rightClass = StructAfter<const UnsizedArrayOf<HBUINT8>> (leftClass).as_array (glyphCount);
+ hb_array_t<const HBUINT8> kernIndex = StructAfter<const UnsizedArrayOf<HBUINT8>> (rightClass).as_array (leftClassCount * rightClassCount);
+
+ unsigned int leftC = leftClass[left];
+ unsigned int rightC = rightClass[right];
+ if (unlikely (leftC >= leftClassCount || rightC >= rightClassCount))
+ return 0;
+ unsigned int i = leftC * rightClassCount + rightC;
+ return kernValue[kernIndex[i]];
+ }
+
+ bool apply (AAT::hb_aat_apply_context_t *c) const
+ {
+ TRACE_APPLY (this);
+
+ if (!c->plan->requested_kerning)
+ return false;
+
+ if (header.coverage & header.Backwards)
+ return false;
+
+ hb_kern_machine_t<KernSubTableFormat3> machine (*this, header.coverage & header.CrossStream);
+ machine.kern (c->font, c->buffer, c->plan->kern_mask);
+
+ return_trace (true);
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this) &&
+ c->check_range (kernValueZ,
+ kernValueCount * sizeof (FWORD) +
+ glyphCount * 2 +
+ leftClassCount * rightClassCount));
+ }
+
+ protected:
+ KernSubTableHeader
+ header;
+ HBUINT16 glyphCount; /* The number of glyphs in this font. */
+ HBUINT8 kernValueCount; /* The number of kerning values. */
+ HBUINT8 leftClassCount; /* The number of left-hand classes. */
+ HBUINT8 rightClassCount;/* The number of right-hand classes. */
+ HBUINT8 flags; /* Set to zero (reserved for future use). */
+ UnsizedArrayOf<FWORD>
+ kernValueZ; /* The kerning values.
+ * Length kernValueCount. */
+#if 0
+ UnsizedArrayOf<HBUINT8>
+ leftClass; /* The left-hand classes.
+ * Length glyphCount. */
+ UnsizedArrayOf<HBUINT8>
+ rightClass; /* The right-hand classes.
+ * Length glyphCount. */
+ UnsizedArrayOf<HBUINT8>kernIndex;
+ /* The indices into the kernValue array.
+ * Length leftClassCount * rightClassCount */
+#endif
+ public:
+ DEFINE_SIZE_ARRAY (KernSubTableHeader::static_size + 6, kernValueZ);
+};
+
+template <typename KernSubTableHeader>
+struct KernSubTable
+{
+ unsigned int get_size () const { return u.header.length; }
+ unsigned int get_type () const { return u.header.format; }
+
+ int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const
+ {
+ switch (get_type ()) {
+ /* This method hooks up to hb_font_t's get_h_kerning. Only support Format0. */
+ case 0: return u.format0.get_kerning (left, right);
+ default:return 0;
+ }
+ }
+
+ template <typename context_t, typename ...Ts>
+ typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
+ {
+ unsigned int subtable_type = get_type ();
+ TRACE_DISPATCH (this, subtable_type);
+ switch (subtable_type) {
+ case 0: return_trace (c->dispatch (u.format0));
+#ifndef HB_NO_AAT_SHAPE
+ case 1: return_trace (u.header.apple ? c->dispatch (u.format1, std::forward<Ts> (ds)...) : c->default_return_value ());
+#endif
+ case 2: return_trace (c->dispatch (u.format2));
+#ifndef HB_NO_AAT_SHAPE
+ case 3: return_trace (u.header.apple ? c->dispatch (u.format3, std::forward<Ts> (ds)...) : c->default_return_value ());
+#endif
+ default: return_trace (c->default_return_value ());
+ }
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ if (unlikely (!u.header.sanitize (c) ||
+ u.header.length < u.header.min_size ||
+ !c->check_range (this, u.header.length))) return_trace (false);
+
+ return_trace (dispatch (c));
+ }
+
+ public:
+ union {
+ KernSubTableHeader header;
+ AAT::KerxSubTableFormat0<KernSubTableHeader> format0;
+ AAT::KerxSubTableFormat1<KernSubTableHeader> format1;
+ AAT::KerxSubTableFormat2<KernSubTableHeader> format2;
+ KernSubTableFormat3<KernSubTableHeader> format3;
+ } u;
+ public:
+ DEFINE_SIZE_MIN (KernSubTableHeader::static_size);
+};
+
+
+struct KernOTSubTableHeader
+{
+ static constexpr bool apple = false;
+ typedef AAT::ObsoleteTypes Types;
+
+ unsigned tuple_count () const { return 0; }
+ bool is_horizontal () const { return (coverage & Horizontal); }
+
+ enum Coverage
+ {
+ Horizontal = 0x01u,
+ Minimum = 0x02u,
+ CrossStream = 0x04u,
+ Override = 0x08u,
+
+ /* Not supported: */
+ Backwards = 0x00u,
+ Variation = 0x00u,
+ };
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this));
+ }
+
+ public:
+ HBUINT16 versionZ; /* Unused. */
+ HBUINT16 length; /* Length of the subtable (including this header). */
+ HBUINT8 format; /* Subtable format. */
+ HBUINT8 coverage; /* Coverage bits. */
+ public:
+ DEFINE_SIZE_STATIC (6);
+};
+
+struct KernOT : AAT::KerxTable<KernOT>
+{
+ friend struct AAT::KerxTable<KernOT>;
+
+ static constexpr hb_tag_t tableTag = HB_OT_TAG_kern;
+ static constexpr unsigned minVersion = 0u;
+
+ typedef KernOTSubTableHeader SubTableHeader;
+ typedef SubTableHeader::Types Types;
+ typedef KernSubTable<SubTableHeader> SubTable;
+
+ protected:
+ HBUINT16 version; /* Version--0x0000u */
+ HBUINT16 tableCount; /* Number of subtables in the kerning table. */
+ SubTable firstSubTable; /* Subtables. */
+ public:
+ DEFINE_SIZE_MIN (4);
+};
+
+
+struct KernAATSubTableHeader
+{
+ static constexpr bool apple = true;
+ typedef AAT::ObsoleteTypes Types;
+
+ unsigned tuple_count () const { return 0; }
+ bool is_horizontal () const { return !(coverage & Vertical); }
+
+ enum Coverage
+ {
+ Vertical = 0x80u,
+ CrossStream = 0x40u,
+ Variation = 0x20u,
+
+ /* Not supported: */
+ Backwards = 0x00u,
+ };
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ return_trace (c->check_struct (this));
+ }
+
+ public:
+ HBUINT32 length; /* Length of the subtable (including this header). */
+ HBUINT8 coverage; /* Coverage bits. */
+ HBUINT8 format; /* Subtable format. */
+ HBUINT16 tupleIndex; /* The tuple index (used for variations fonts).
+ * This value specifies which tuple this subtable covers.
+ * Note: We don't implement. */
+ public:
+ DEFINE_SIZE_STATIC (8);
+};
+
+struct KernAAT : AAT::KerxTable<KernAAT>
+{
+ friend struct AAT::KerxTable<KernAAT>;
+
+ static constexpr hb_tag_t tableTag = HB_OT_TAG_kern;
+ static constexpr unsigned minVersion = 0x00010000u;
+
+ typedef KernAATSubTableHeader SubTableHeader;
+ typedef SubTableHeader::Types Types;
+ typedef KernSubTable<SubTableHeader> SubTable;
+
+ protected:
+ HBUINT32 version; /* Version--0x00010000u */
+ HBUINT32 tableCount; /* Number of subtables in the kerning table. */
+ SubTable firstSubTable; /* Subtables. */
+ public:
+ DEFINE_SIZE_MIN (8);
+};
+
+struct kern
+{
+ static constexpr hb_tag_t tableTag = HB_OT_TAG_kern;
+
+ bool has_data () const { return u.version32; }
+ unsigned get_type () const { return u.major; }
+
+ bool has_state_machine () const
+ {
+ switch (get_type ()) {
+ case 0: return u.ot.has_state_machine ();
+#ifndef HB_NO_AAT_SHAPE
+ case 1: return u.aat.has_state_machine ();
+#endif
+ default:return false;
+ }
+ }
+
+ bool has_cross_stream () const
+ {
+ switch (get_type ()) {
+ case 0: return u.ot.has_cross_stream ();
+#ifndef HB_NO_AAT_SHAPE
+ case 1: return u.aat.has_cross_stream ();
+#endif
+ default:return false;
+ }
+ }
+
+ int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right) const
+ {
+ switch (get_type ()) {
+ case 0: return u.ot.get_h_kerning (left, right);
+#ifndef HB_NO_AAT_SHAPE
+ case 1: return u.aat.get_h_kerning (left, right);
+#endif
+ default:return 0;
+ }
+ }
+
+ bool apply (AAT::hb_aat_apply_context_t *c) const
+ { return dispatch (c); }
+
+ template <typename context_t, typename ...Ts>
+ typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
+ {
+ unsigned int subtable_type = get_type ();
+ TRACE_DISPATCH (this, subtable_type);
+ switch (subtable_type) {
+ case 0: return_trace (c->dispatch (u.ot, std::forward<Ts> (ds)...));
+#ifndef HB_NO_AAT_SHAPE
+ case 1: return_trace (c->dispatch (u.aat, std::forward<Ts> (ds)...));
+#endif
+ default: return_trace (c->default_return_value ());
+ }
+ }
+
+ bool sanitize (hb_sanitize_context_t *c) const
+ {
+ TRACE_SANITIZE (this);
+ if (!u.version32.sanitize (c)) return_trace (false);
+ return_trace (dispatch (c));
+ }
+
+ protected:
+ union {
+ HBUINT32 version32;
+ HBUINT16 major;
+ KernOT ot;
+#ifndef HB_NO_AAT_SHAPE
+ KernAAT aat;
+#endif
+ } u;
+ public:
+ DEFINE_SIZE_UNION (4, version32);
+};
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_KERN_TABLE_HH */
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