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1 /*
2  * Copyright © 2016  Google, Inc.
3  * Copyright © 2018  Ebrahim Byagowi
4  *
5  *  This is part of HarfBuzz, a text shaping library.
6  *
7  * Permission is hereby granted, without written agreement and without
8  * license or royalty fees, to use, copy, modify, and distribute this
9  * software and its documentation for any purpose, provided that the
10  * above copyright notice and the following two paragraphs appear in
11  * all copies of this software.
12  *
13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
17  * DAMAGE.
18  *
19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24  *
25  * Google Author(s): Sascha Brawer
26  */
27 
28 #ifndef HB_OT_COLOR_CPAL_TABLE_HH
29 #define HB_OT_COLOR_CPAL_TABLE_HH
30 
31 #include "hb-open-type.hh"
32 #include "hb-ot-color.h"
33 #include "hb-ot-name.h"
34 
35 
36 /*
37  * CPAL -- Color Palette
38  * https://docs.microsoft.com/en-us/typography/opentype/spec/cpal
39  */
40 #define HB_OT_TAG_CPAL HB_TAG('C','P','A','L')
41 
42 
43 namespace OT {
44 
45 
46 struct CPALV1Tail
47 {
48   friend struct CPAL;
49 
50   private:
get_palette_flagsOT::CPALV1Tail51   hb_ot_color_palette_flags_t get_palette_flags (const void *base,
52 						 unsigned int palette_index,
53 						 unsigned int palette_count) const
54   {
55     if (!paletteFlagsZ) return HB_OT_COLOR_PALETTE_FLAG_DEFAULT;
56     return (hb_ot_color_palette_flags_t) (uint32_t)
57 	   (base+paletteFlagsZ).as_array (palette_count)[palette_index];
58   }
59 
get_palette_name_idOT::CPALV1Tail60   hb_ot_name_id_t get_palette_name_id (const void *base,
61 				       unsigned int palette_index,
62 				       unsigned int palette_count) const
63   {
64     if (!paletteLabelsZ) return HB_OT_NAME_ID_INVALID;
65     return (base+paletteLabelsZ).as_array (palette_count)[palette_index];
66   }
67 
get_color_name_idOT::CPALV1Tail68   hb_ot_name_id_t get_color_name_id (const void *base,
69 				     unsigned int color_index,
70 				     unsigned int color_count) const
71   {
72     if (!colorLabelsZ) return HB_OT_NAME_ID_INVALID;
73     return (base+colorLabelsZ).as_array (color_count)[color_index];
74   }
75 
76   public:
sanitizeOT::CPALV1Tail77   bool sanitize (hb_sanitize_context_t *c,
78 		 const void *base,
79 		 unsigned int palette_count,
80 		 unsigned int color_count) const
81   {
82     TRACE_SANITIZE (this);
83     return_trace (c->check_struct (this) &&
84 		  (!paletteFlagsZ  || (base+paletteFlagsZ).sanitize (c, palette_count)) &&
85 		  (!paletteLabelsZ || (base+paletteLabelsZ).sanitize (c, palette_count)) &&
86 		  (!colorLabelsZ   || (base+colorLabelsZ).sanitize (c, color_count)));
87   }
88 
89   protected:
90   LNNOffsetTo<UnsizedArrayOf<HBUINT32>>
91 		paletteFlagsZ;		/* Offset from the beginning of CPAL table to
92 					 * the Palette Type Array. Set to 0 if no array
93 					 * is provided. */
94   LNNOffsetTo<UnsizedArrayOf<NameID>>
95 		paletteLabelsZ;		/* Offset from the beginning of CPAL table to
96 					 * the palette labels array. Set to 0 if no
97 					 * array is provided. */
98   LNNOffsetTo<UnsizedArrayOf<NameID>>
99 		colorLabelsZ;		/* Offset from the beginning of CPAL table to
100 					 * the color labels array. Set to 0
101 					 * if no array is provided. */
102   public:
103   DEFINE_SIZE_STATIC (12);
104 };
105 
106 typedef HBUINT32 BGRAColor;
107 
108 struct CPAL
109 {
110   static constexpr hb_tag_t tableTag = HB_OT_TAG_CPAL;
111 
has_dataOT::CPAL112   bool has_data () const { return numPalettes; }
113 
get_sizeOT::CPAL114   unsigned int get_size () const
115   { return min_size + numPalettes * sizeof (colorRecordIndicesZ[0]); }
116 
get_palette_countOT::CPAL117   unsigned int get_palette_count () const { return numPalettes; }
get_color_countOT::CPAL118   unsigned int   get_color_count () const { return numColors; }
119 
get_palette_flagsOT::CPAL120   hb_ot_color_palette_flags_t get_palette_flags (unsigned int palette_index) const
121   { return v1 ().get_palette_flags (this, palette_index, numPalettes); }
122 
get_palette_name_idOT::CPAL123   hb_ot_name_id_t get_palette_name_id (unsigned int palette_index) const
124   { return v1 ().get_palette_name_id (this, palette_index, numPalettes); }
125 
get_color_name_idOT::CPAL126   hb_ot_name_id_t get_color_name_id (unsigned int color_index) const
127   { return v1 ().get_color_name_id (this, color_index, numColors); }
128 
get_palette_colorsOT::CPAL129   unsigned int get_palette_colors (unsigned int  palette_index,
130 				   unsigned int  start_offset,
131 				   unsigned int *color_count, /* IN/OUT.  May be NULL. */
132 				   hb_color_t   *colors       /* OUT.     May be NULL. */) const
133   {
134     if (unlikely (palette_index >= numPalettes))
135     {
136       if (color_count) *color_count = 0;
137       return 0;
138     }
139     unsigned int start_index = colorRecordIndicesZ[palette_index];
140     hb_array_t<const BGRAColor> all_colors ((this+colorRecordsZ).arrayZ, numColorRecords);
141     hb_array_t<const BGRAColor> palette_colors = all_colors.sub_array (start_index,
142 								       numColors);
143     if (color_count)
144     {
145       hb_array_t<const BGRAColor> segment_colors = palette_colors.sub_array (start_offset, *color_count);
146       /* Always return numColors colors per palette even if it has out-of-bounds start index. */
147       unsigned int count = hb_min ((unsigned) hb_max ((int) (numColors - start_offset), 0), *color_count);
148       *color_count = count;
149       for (unsigned int i = 0; i < count; i++)
150 	colors[i] = segment_colors[i]; /* Bound-checked read. */
151     }
152     return numColors;
153   }
154 
155   private:
v1OT::CPAL156   const CPALV1Tail& v1 () const
157   {
158     if (version == 0) return Null(CPALV1Tail);
159     return StructAfter<CPALV1Tail> (*this);
160   }
161 
162   public:
sanitizeOT::CPAL163   bool sanitize (hb_sanitize_context_t *c) const
164   {
165     TRACE_SANITIZE (this);
166     return_trace (c->check_struct (this) &&
167 		  (this+colorRecordsZ).sanitize (c, numColorRecords) &&
168 		  colorRecordIndicesZ.sanitize (c, numPalettes) &&
169 		  (version == 0 || v1 ().sanitize (c, this, numPalettes, numColors)));
170   }
171 
172   protected:
173   HBUINT16	version;		/* Table version number */
174   /* Version 0 */
175   HBUINT16	numColors;		/* Number of colors in each palette. */
176   HBUINT16	numPalettes;		/* Number of palettes in the table. */
177   HBUINT16	numColorRecords;	/* Total number of color records, combined for
178 					 * all palettes. */
179   LNNOffsetTo<UnsizedArrayOf<BGRAColor>>
180 		colorRecordsZ;		/* Offset from the beginning of CPAL table to
181 					 * the first ColorRecord. */
182   UnsizedArrayOf<HBUINT16>
183 		colorRecordIndicesZ;	/* Index of each palette’s first color record in
184 					 * the combined color record array. */
185 /*CPALV1Tail	v1;*/
186   public:
187   DEFINE_SIZE_ARRAY (12, colorRecordIndicesZ);
188 };
189 
190 } /* namespace OT */
191 
192 
193 #endif /* HB_OT_COLOR_CPAL_TABLE_HH */
194