xref: /aosp_15_r20/external/harfbuzz_ng/src/hb-cff2-interp-cs.hh (revision 2d1272b857b1f7575e6e246373e1cb218663db8a)
1 /*
2  * Copyright © 2018 Adobe Inc.
3  *
4  *  This is part of HarfBuzz, a text shaping library.
5  *
6  * Permission is hereby granted, without written agreement and without
7  * license or royalty fees, to use, copy, modify, and distribute this
8  * software and its documentation for any purpose, provided that the
9  * above copyright notice and the following two paragraphs appear in
10  * all copies of this software.
11  *
12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16  * DAMAGE.
17  *
18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23  *
24  * Adobe Author(s): Michiharu Ariza
25  */
26 #ifndef HB_CFF2_INTERP_CS_HH
27 #define HB_CFF2_INTERP_CS_HH
28 
29 #include "hb.hh"
30 #include "hb-cff-interp-cs-common.hh"
31 
32 namespace CFF {
33 
34 using namespace OT;
35 
36 struct blend_arg_t : number_t
37 {
set_intCFF::blend_arg_t38   void set_int (int v) { reset_blends (); number_t::set_int (v); }
set_fixedCFF::blend_arg_t39   void set_fixed (int32_t v) { reset_blends (); number_t::set_fixed (v); }
set_realCFF::blend_arg_t40   void set_real (double v) { reset_blends (); number_t::set_real (v); }
41 
set_blendsCFF::blend_arg_t42   void set_blends (unsigned int numValues_, unsigned int valueIndex_,
43 		   hb_array_t<const blend_arg_t> blends_)
44   {
45     numValues = numValues_;
46     valueIndex = valueIndex_;
47     unsigned numBlends = blends_.length;
48     if (unlikely (!deltas.resize_exact (numBlends)))
49       return;
50     for (unsigned int i = 0; i < numBlends; i++)
51       deltas.arrayZ[i] = blends_.arrayZ[i];
52   }
53 
blendingCFF::blend_arg_t54   bool blending () const { return deltas.length > 0; }
reset_blendsCFF::blend_arg_t55   void reset_blends ()
56   {
57     numValues = valueIndex = 0;
58     deltas.shrink (0);
59   }
60 
61   unsigned int numValues;
62   unsigned int valueIndex;
63   hb_vector_t<number_t> deltas;
64 };
65 
66 typedef biased_subrs_t<CFF2Subrs>   cff2_biased_subrs_t;
67 
68 template <typename ELEM>
69 struct cff2_cs_interp_env_t : cs_interp_env_t<ELEM, CFF2Subrs>
70 {
71   template <typename ACC>
cff2_cs_interp_env_tCFF::cff2_cs_interp_env_t72   cff2_cs_interp_env_t (const hb_ubytes_t &str, ACC &acc, unsigned int fd,
73 			const int *coords_=nullptr, unsigned int num_coords_=0)
74     : SUPER (str, acc.globalSubrs, acc.privateDicts[fd].localSubrs)
75   {
76     coords = coords_;
77     num_coords = num_coords_;
78     varStore = acc.varStore;
79     do_blend = num_coords && coords && varStore->size;
80     set_ivs (acc.privateDicts[fd].ivs);
81   }
82 
finiCFF::cff2_cs_interp_env_t83   void fini ()
84   {
85     SUPER::fini ();
86   }
87 
fetch_opCFF::cff2_cs_interp_env_t88   op_code_t fetch_op ()
89   {
90     if (this->str_ref.avail ())
91       return SUPER::fetch_op ();
92 
93     /* make up return or endchar op */
94     if (this->callStack.is_empty ())
95       return OpCode_endchar;
96     else
97       return OpCode_return;
98   }
99 
eval_argCFF::cff2_cs_interp_env_t100   const ELEM& eval_arg (unsigned int i)
101   {
102     return SUPER::argStack[i];
103   }
104 
pop_argCFF::cff2_cs_interp_env_t105   const ELEM& pop_arg ()
106   {
107     return SUPER::argStack.pop ();
108   }
109 
process_blendCFF::cff2_cs_interp_env_t110   void process_blend ()
111   {
112     if (!seen_blend)
113     {
114       region_count = varStore->varStore.get_region_index_count (get_ivs ());
115       if (do_blend)
116       {
117 	if (unlikely (!scalars.resize_exact (region_count)))
118 	  SUPER::set_error ();
119 	else
120 	  varStore->varStore.get_region_scalars (get_ivs (), coords, num_coords,
121 						 &scalars[0], region_count);
122       }
123       seen_blend = true;
124     }
125   }
126 
process_vsindexCFF::cff2_cs_interp_env_t127   void process_vsindex ()
128   {
129     unsigned int  index = SUPER::argStack.pop_uint ();
130     if (unlikely (seen_vsindex () || seen_blend))
131     {
132      SUPER::set_error ();
133     }
134     else
135     {
136       set_ivs (index);
137     }
138     seen_vsindex_ = true;
139   }
140 
get_region_countCFF::cff2_cs_interp_env_t141   unsigned int get_region_count () const { return region_count; }
set_region_countCFF::cff2_cs_interp_env_t142   void	 set_region_count (unsigned int region_count_) { region_count = region_count_; }
get_ivsCFF::cff2_cs_interp_env_t143   unsigned int get_ivs () const { return ivs; }
set_ivsCFF::cff2_cs_interp_env_t144   void	 set_ivs (unsigned int ivs_) { ivs = ivs_; }
seen_vsindexCFF::cff2_cs_interp_env_t145   bool	 seen_vsindex () const { return seen_vsindex_; }
146 
blend_deltasCFF::cff2_cs_interp_env_t147   double blend_deltas (hb_array_t<const ELEM> deltas) const
148   {
149     double v = 0;
150     if (do_blend)
151     {
152       if (likely (scalars.length == deltas.length))
153       {
154         unsigned count = scalars.length;
155 	for (unsigned i = 0; i < count; i++)
156 	  v += (double) scalars.arrayZ[i] * deltas.arrayZ[i].to_real ();
157       }
158     }
159     return v;
160   }
161 
have_coordsCFF::cff2_cs_interp_env_t162   bool have_coords () const { return num_coords; }
163 
164   protected:
165   const int     *coords;
166   unsigned int  num_coords;
167   const	 CFF2ItemVariationStore *varStore;
168   unsigned int  region_count;
169   unsigned int  ivs;
170   hb_vector_t<float>  scalars;
171   bool	  do_blend;
172   bool	  seen_vsindex_ = false;
173   bool	  seen_blend = false;
174 
175   typedef cs_interp_env_t<ELEM, CFF2Subrs> SUPER;
176 };
177 template <typename OPSET, typename PARAM, typename ELEM, typename PATH=path_procs_null_t<cff2_cs_interp_env_t<ELEM>, PARAM>>
178 struct cff2_cs_opset_t : cs_opset_t<ELEM, OPSET, cff2_cs_interp_env_t<ELEM>, PARAM, PATH>
179 {
process_opCFF::cff2_cs_opset_t180   static void process_op (op_code_t op, cff2_cs_interp_env_t<ELEM> &env, PARAM& param)
181   {
182     switch (op) {
183       case OpCode_callsubr:
184       case OpCode_callgsubr:
185 	/* a subroutine number shouldn't be a blended value */
186 #if 0
187 	if (unlikely (env.argStack.peek ().blending ()))
188 	{
189 	  env.set_error ();
190 	  break;
191 	}
192 #endif
193 	SUPER::process_op (op, env, param);
194 	break;
195 
196       case OpCode_blendcs:
197 	OPSET::process_blend (env, param);
198 	break;
199 
200       case OpCode_vsindexcs:
201 #if 0
202 	if (unlikely (env.argStack.peek ().blending ()))
203 	{
204 	  env.set_error ();
205 	  break;
206 	}
207 #endif
208 	OPSET::process_vsindex (env, param);
209 	break;
210 
211       default:
212 	SUPER::process_op (op, env, param);
213     }
214   }
215 
216   template <typename T = ELEM,
217 	    hb_enable_if (hb_is_same (T, blend_arg_t))>
process_arg_blendCFF::cff2_cs_opset_t218   static void process_arg_blend (cff2_cs_interp_env_t<ELEM> &env,
219 				 ELEM &arg,
220 				 const hb_array_t<const ELEM> blends,
221 				 unsigned n, unsigned i)
222   {
223     if (env.have_coords ())
224       arg.set_int (round (arg.to_real () + env.blend_deltas (blends)));
225     else
226       arg.set_blends (n, i, blends);
227   }
228   template <typename T = ELEM,
229 	    hb_enable_if (!hb_is_same (T, blend_arg_t))>
process_arg_blendCFF::cff2_cs_opset_t230   static void process_arg_blend (cff2_cs_interp_env_t<ELEM> &env,
231 				 ELEM &arg,
232 				 const hb_array_t<const ELEM> blends,
233 				 unsigned n, unsigned i)
234   {
235     arg.set_real (arg.to_real () + env.blend_deltas (blends));
236   }
237 
process_blendCFF::cff2_cs_opset_t238   static void process_blend (cff2_cs_interp_env_t<ELEM> &env, PARAM& param)
239   {
240     unsigned int n, k;
241 
242     env.process_blend ();
243     k = env.get_region_count ();
244     n = env.argStack.pop_uint ();
245     /* copy the blend values into blend array of the default values */
246     unsigned int start = env.argStack.get_count () - ((k+1) * n);
247     /* let an obvious error case fail, but note CFF2 spec doesn't forbid n==0 */
248     if (unlikely (start > env.argStack.get_count ()))
249     {
250       env.set_error ();
251       return;
252     }
253     for (unsigned int i = 0; i < n; i++)
254     {
255       const hb_array_t<const ELEM> blends = env.argStack.sub_array (start + n + (i * k), k);
256       process_arg_blend (env, env.argStack[start + i], blends, n, i);
257     }
258 
259     /* pop off blend values leaving default values now adorned with blend values */
260     env.argStack.pop (k * n);
261   }
262 
process_vsindexCFF::cff2_cs_opset_t263   static void process_vsindex (cff2_cs_interp_env_t<ELEM> &env, PARAM& param)
264   {
265     env.process_vsindex ();
266     env.clear_args ();
267   }
268 
269   private:
270   typedef cs_opset_t<ELEM, OPSET, cff2_cs_interp_env_t<ELEM>, PARAM, PATH>  SUPER;
271 };
272 
273 template <typename OPSET, typename PARAM, typename ELEM>
274 using cff2_cs_interpreter_t = cs_interpreter_t<cff2_cs_interp_env_t<ELEM>, OPSET, PARAM>;
275 
276 } /* namespace CFF */
277 
278 #endif /* HB_CFF2_INTERP_CS_HH */
279