michael@0: /*
michael@0:  * Copyright © 1998-2004  David Turner and Werner Lemberg
michael@0:  * Copyright © 2004,2007,2009,2010  Red Hat, Inc.
michael@0:  * Copyright © 2011,2012  Google, Inc.
michael@0:  *
michael@0:  *  This is part of HarfBuzz, a text shaping library.
michael@0:  *
michael@0:  * Permission is hereby granted, without written agreement and without
michael@0:  * license or royalty fees, to use, copy, modify, and distribute this
michael@0:  * software and its documentation for any purpose, provided that the
michael@0:  * above copyright notice and the following two paragraphs appear in
michael@0:  * all copies of this software.
michael@0:  *
michael@0:  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
michael@0:  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
michael@0:  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
michael@0:  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
michael@0:  * DAMAGE.
michael@0:  *
michael@0:  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
michael@0:  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
michael@0:  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
michael@0:  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
michael@0:  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
michael@0:  *
michael@0:  * Red Hat Author(s): Owen Taylor, Behdad Esfahbod
michael@0:  * Google Author(s): Behdad Esfahbod
michael@0:  */
michael@0: 
michael@0: #ifndef HB_BUFFER_PRIVATE_HH
michael@0: #define HB_BUFFER_PRIVATE_HH
michael@0: 
michael@0: #include "hb-private.hh"
michael@0: #include "hb-object-private.hh"
michael@0: #include "hb-unicode-private.hh"
michael@0: 
michael@0: 
michael@0: ASSERT_STATIC (sizeof (hb_glyph_info_t) == 20);
michael@0: ASSERT_STATIC (sizeof (hb_glyph_info_t) == sizeof (hb_glyph_position_t));
michael@0: 
michael@0: 
michael@0: /*
michael@0:  * hb_buffer_t
michael@0:  */
michael@0: 
michael@0: struct hb_buffer_t {
michael@0:   hb_object_header_t header;
michael@0:   ASSERT_POD ();
michael@0: 
michael@0:   /* Information about how the text in the buffer should be treated */
michael@0: 
michael@0:   hb_unicode_funcs_t *unicode; /* Unicode functions */
michael@0:   hb_segment_properties_t props; /* Script, language, direction */
michael@0:   hb_buffer_flags_t flags; /* BOT / EOT / etc. */
michael@0: 
michael@0:   /* Buffer contents */
michael@0: 
michael@0:   hb_buffer_content_type_t content_type;
michael@0: 
michael@0:   bool in_error; /* Allocation failed */
michael@0:   bool have_output; /* Whether we have an output buffer going on */
michael@0:   bool have_positions; /* Whether we have positions */
michael@0: 
michael@0:   unsigned int idx; /* Cursor into ->info and ->pos arrays */
michael@0:   unsigned int len; /* Length of ->info and ->pos arrays */
michael@0:   unsigned int out_len; /* Length of ->out array if have_output */
michael@0: 
michael@0:   unsigned int allocated; /* Length of allocated arrays */
michael@0:   hb_glyph_info_t     *info;
michael@0:   hb_glyph_info_t     *out_info;
michael@0:   hb_glyph_position_t *pos;
michael@0: 
michael@0:   inline hb_glyph_info_t &cur (unsigned int i = 0) { return info[idx + i]; }
michael@0:   inline hb_glyph_info_t cur (unsigned int i = 0) const { return info[idx + i]; }
michael@0: 
michael@0:   inline hb_glyph_position_t &cur_pos (unsigned int i = 0) { return pos[idx + i]; }
michael@0:   inline hb_glyph_position_t cur_pos (unsigned int i = 0) const { return pos[idx + i]; }
michael@0: 
michael@0:   inline hb_glyph_info_t &prev (void) { return out_info[out_len - 1]; }
michael@0:   inline hb_glyph_info_t prev (void) const { return info[out_len - 1]; }
michael@0: 
michael@0:   inline bool has_separate_output (void) const { return info != out_info; }
michael@0: 
michael@0:   unsigned int serial;
michael@0: 
michael@0:   /* These reflect current allocations of the bytes in glyph_info_t's var1 and var2. */
michael@0:   uint8_t allocated_var_bytes[8];
michael@0:   const char *allocated_var_owner[8];
michael@0: 
michael@0:   /* Text before / after the main buffer contents.
michael@0:    * Always in Unicode, and ordered outward.
michael@0:    * Index 0 is for "pre-context", 1 for "post-context". */
michael@0:   static const unsigned int CONTEXT_LENGTH = 5;
michael@0:   hb_codepoint_t context[2][CONTEXT_LENGTH];
michael@0:   unsigned int context_len[2];
michael@0: 
michael@0: 
michael@0:   /* Methods */
michael@0: 
michael@0:   HB_INTERNAL void reset (void);
michael@0:   HB_INTERNAL void clear (void);
michael@0: 
michael@0:   inline unsigned int backtrack_len (void) const
michael@0:   { return have_output? out_len : idx; }
michael@0:   inline unsigned int lookahead_len (void) const
michael@0:   { return len - idx; }
michael@0:   inline unsigned int next_serial (void) { return serial++; }
michael@0: 
michael@0:   HB_INTERNAL void allocate_var (unsigned int byte_i, unsigned int count, const char *owner);
michael@0:   HB_INTERNAL void deallocate_var (unsigned int byte_i, unsigned int count, const char *owner);
michael@0:   HB_INTERNAL void assert_var (unsigned int byte_i, unsigned int count, const char *owner);
michael@0:   HB_INTERNAL void deallocate_var_all (void);
michael@0: 
michael@0:   HB_INTERNAL void add (hb_codepoint_t  codepoint,
michael@0: 			unsigned int    cluster);
michael@0:   HB_INTERNAL void add_info (const hb_glyph_info_t &glyph_info);
michael@0: 
michael@0:   HB_INTERNAL void reverse_range (unsigned int start, unsigned int end);
michael@0:   HB_INTERNAL void reverse (void);
michael@0:   HB_INTERNAL void reverse_clusters (void);
michael@0:   HB_INTERNAL void guess_segment_properties (void);
michael@0: 
michael@0:   HB_INTERNAL void swap_buffers (void);
michael@0:   HB_INTERNAL void remove_output (void);
michael@0:   HB_INTERNAL void clear_output (void);
michael@0:   HB_INTERNAL void clear_positions (void);
michael@0: 
michael@0:   HB_INTERNAL void replace_glyphs (unsigned int num_in,
michael@0: 				   unsigned int num_out,
michael@0: 				   const hb_codepoint_t *glyph_data);
michael@0: 
michael@0:   HB_INTERNAL void replace_glyph (hb_codepoint_t glyph_index);
michael@0:   /* Makes a copy of the glyph at idx to output and replace glyph_index */
michael@0:   HB_INTERNAL void output_glyph (hb_codepoint_t glyph_index);
michael@0:   HB_INTERNAL void output_info (const hb_glyph_info_t &glyph_info);
michael@0:   /* Copies glyph at idx to output but doesn't advance idx */
michael@0:   HB_INTERNAL void copy_glyph (void);
michael@0:   HB_INTERNAL bool move_to (unsigned int i); /* i is output-buffer index. */
michael@0:   /* Copies glyph at idx to output and advance idx.
michael@0:    * If there's no output, just advance idx. */
michael@0:   inline void
michael@0:   next_glyph (void)
michael@0:   {
michael@0:     if (have_output)
michael@0:     {
michael@0:       if (unlikely (out_info != info || out_len != idx)) {
michael@0: 	if (unlikely (!make_room_for (1, 1))) return;
michael@0: 	out_info[out_len] = info[idx];
michael@0:       }
michael@0:       out_len++;
michael@0:     }
michael@0: 
michael@0:     idx++;
michael@0:   }
michael@0: 
michael@0:   /* Advance idx without copying to output. */
michael@0:   inline void skip_glyph (void) { idx++; }
michael@0: 
michael@0:   inline void reset_masks (hb_mask_t mask)
michael@0:   {
michael@0:     for (unsigned int j = 0; j < len; j++)
michael@0:       info[j].mask = mask;
michael@0:   }
michael@0:   inline void add_masks (hb_mask_t mask)
michael@0:   {
michael@0:     for (unsigned int j = 0; j < len; j++)
michael@0:       info[j].mask |= mask;
michael@0:   }
michael@0:   HB_INTERNAL void set_masks (hb_mask_t value,
michael@0: 			      hb_mask_t mask,
michael@0: 			      unsigned int cluster_start,
michael@0: 			      unsigned int cluster_end);
michael@0: 
michael@0:   HB_INTERNAL void merge_clusters (unsigned int start,
michael@0: 				   unsigned int end);
michael@0:   HB_INTERNAL void merge_out_clusters (unsigned int start,
michael@0: 				       unsigned int end);
michael@0: 
michael@0:   /* Internal methods */
michael@0:   HB_INTERNAL bool enlarge (unsigned int size);
michael@0: 
michael@0:   inline bool ensure (unsigned int size)
michael@0:   { return likely (!size || size < allocated) ? true : enlarge (size); }
michael@0: 
michael@0:   HB_INTERNAL bool make_room_for (unsigned int num_in, unsigned int num_out);
michael@0:   HB_INTERNAL bool shift_forward (unsigned int count);
michael@0: 
michael@0:   typedef long scratch_buffer_t;
michael@0:   HB_INTERNAL scratch_buffer_t *get_scratch_buffer (unsigned int *size);
michael@0: 
michael@0:   inline void clear_context (unsigned int side) { context_len[side] = 0; }
michael@0: };
michael@0: 
michael@0: 
michael@0: #define HB_BUFFER_XALLOCATE_VAR(b, func, var, owner) \
michael@0:   b->func (offsetof (hb_glyph_info_t, var) - offsetof(hb_glyph_info_t, var1), \
michael@0: 	   sizeof (b->info[0].var), owner)
michael@0: #define HB_BUFFER_ALLOCATE_VAR(b, var) \
michael@0: 	HB_BUFFER_XALLOCATE_VAR (b, allocate_var, var (), #var)
michael@0: #define HB_BUFFER_DEALLOCATE_VAR(b, var) \
michael@0: 	HB_BUFFER_XALLOCATE_VAR (b, deallocate_var, var (), #var)
michael@0: #define HB_BUFFER_ASSERT_VAR(b, var) \
michael@0: 	HB_BUFFER_XALLOCATE_VAR (b, assert_var, var (), #var)
michael@0: 
michael@0: 
michael@0: #endif /* HB_BUFFER_PRIVATE_HH */