1 /**************************************************************************** 2 * 3 * psstack.c 4 * 5 * Adobe's code for emulating a CFF stack (body). 6 * 7 * Copyright 2007-2013 Adobe Systems Incorporated. 8 * 9 * This software, and all works of authorship, whether in source or 10 * object code form as indicated by the copyright notice(s) included 11 * herein (collectively, the "Work") is made available, and may only be 12 * used, modified, and distributed under the FreeType Project License, 13 * LICENSE.TXT. Additionally, subject to the terms and conditions of the 14 * FreeType Project License, each contributor to the Work hereby grants 15 * to any individual or legal entity exercising permissions granted by 16 * the FreeType Project License and this section (hereafter, "You" or 17 * "Your") a perpetual, worldwide, non-exclusive, no-charge, 18 * royalty-free, irrevocable (except as stated in this section) patent 19 * license to make, have made, use, offer to sell, sell, import, and 20 * otherwise transfer the Work, where such license applies only to those 21 * patent claims licensable by such contributor that are necessarily 22 * infringed by their contribution(s) alone or by combination of their 23 * contribution(s) with the Work to which such contribution(s) was 24 * submitted. If You institute patent litigation against any entity 25 * (including a cross-claim or counterclaim in a lawsuit) alleging that 26 * the Work or a contribution incorporated within the Work constitutes 27 * direct or contributory patent infringement, then any patent licenses 28 * granted to You under this License for that Work shall terminate as of 29 * the date such litigation is filed. 30 * 31 * By using, modifying, or distributing the Work you indicate that you 32 * have read and understood the terms and conditions of the 33 * FreeType Project License as well as those provided in this section, 34 * and you accept them fully. 35 * 36 */ 37 38 39 #include "psft.h" 40 #include <freetype/internal/ftdebug.h> 41 42 #include "psglue.h" 43 #include "psfont.h" 44 #include "psstack.h" 45 46 #include "pserror.h" 47 48 49 /* Allocate and initialize an instance of CF2_Stack. */ 50 /* Note: This function returns NULL on error (does not set */ 51 /* `error'). */ 52 FT_LOCAL_DEF( CF2_Stack ) cf2_stack_init(FT_Memory memory,FT_Error * e,FT_UInt stackSize)53 cf2_stack_init( FT_Memory memory, 54 FT_Error* e, 55 FT_UInt stackSize ) 56 { 57 FT_Error error; /* for FT_QNEW */ 58 CF2_Stack stack = NULL; 59 60 61 if ( FT_QNEW( stack ) ) 62 return NULL; 63 64 stack->memory = memory; 65 stack->error = e; 66 67 /* allocate the stack buffer */ 68 if ( FT_QNEW_ARRAY( stack->buffer, stackSize ) ) 69 { 70 FT_FREE( stack ); 71 return NULL; 72 } 73 74 stack->stackSize = stackSize; 75 stack->top = stack->buffer; /* empty stack */ 76 77 return stack; 78 } 79 80 81 FT_LOCAL_DEF( void ) cf2_stack_free(CF2_Stack stack)82 cf2_stack_free( CF2_Stack stack ) 83 { 84 if ( stack ) 85 { 86 FT_Memory memory = stack->memory; 87 88 /* free the buffer */ 89 FT_FREE( stack->buffer ); 90 91 /* free the main structure */ 92 FT_FREE( stack ); 93 } 94 } 95 96 97 FT_LOCAL_DEF( CF2_UInt ) cf2_stack_count(CF2_Stack stack)98 cf2_stack_count( CF2_Stack stack ) 99 { 100 return (CF2_UInt)( stack->top - stack->buffer ); 101 } 102 103 104 FT_LOCAL_DEF( void ) cf2_stack_pushInt(CF2_Stack stack,CF2_Int val)105 cf2_stack_pushInt( CF2_Stack stack, 106 CF2_Int val ) 107 { 108 if ( stack->top == stack->buffer + stack->stackSize ) 109 { 110 CF2_SET_ERROR( stack->error, Stack_Overflow ); 111 return; /* stack overflow */ 112 } 113 114 stack->top->u.i = val; 115 stack->top->type = CF2_NumberInt; 116 stack->top++; 117 } 118 119 120 FT_LOCAL_DEF( void ) cf2_stack_pushFixed(CF2_Stack stack,CF2_Fixed val)121 cf2_stack_pushFixed( CF2_Stack stack, 122 CF2_Fixed val ) 123 { 124 if ( stack->top == stack->buffer + stack->stackSize ) 125 { 126 CF2_SET_ERROR( stack->error, Stack_Overflow ); 127 return; /* stack overflow */ 128 } 129 130 stack->top->u.r = val; 131 stack->top->type = CF2_NumberFixed; 132 stack->top++; 133 } 134 135 136 /* this function is only allowed to pop an integer type */ 137 FT_LOCAL_DEF( CF2_Int ) cf2_stack_popInt(CF2_Stack stack)138 cf2_stack_popInt( CF2_Stack stack ) 139 { 140 if ( stack->top == stack->buffer ) 141 { 142 CF2_SET_ERROR( stack->error, Stack_Underflow ); 143 return 0; /* underflow */ 144 } 145 if ( stack->top[-1].type != CF2_NumberInt ) 146 { 147 CF2_SET_ERROR( stack->error, Syntax_Error ); 148 return 0; /* type mismatch */ 149 } 150 151 stack->top--; 152 153 return stack->top->u.i; 154 } 155 156 157 /* Note: type mismatch is silently cast */ 158 /* TODO: check this */ 159 FT_LOCAL_DEF( CF2_Fixed ) cf2_stack_popFixed(CF2_Stack stack)160 cf2_stack_popFixed( CF2_Stack stack ) 161 { 162 if ( stack->top == stack->buffer ) 163 { 164 CF2_SET_ERROR( stack->error, Stack_Underflow ); 165 return cf2_intToFixed( 0 ); /* underflow */ 166 } 167 168 stack->top--; 169 170 switch ( stack->top->type ) 171 { 172 case CF2_NumberInt: 173 return cf2_intToFixed( stack->top->u.i ); 174 case CF2_NumberFrac: 175 return cf2_fracToFixed( stack->top->u.f ); 176 default: 177 return stack->top->u.r; 178 } 179 } 180 181 182 /* Note: type mismatch is silently cast */ 183 /* TODO: check this */ 184 FT_LOCAL_DEF( CF2_Fixed ) cf2_stack_getReal(CF2_Stack stack,CF2_UInt idx)185 cf2_stack_getReal( CF2_Stack stack, 186 CF2_UInt idx ) 187 { 188 FT_ASSERT( cf2_stack_count( stack ) <= stack->stackSize ); 189 190 if ( idx >= cf2_stack_count( stack ) ) 191 { 192 CF2_SET_ERROR( stack->error, Stack_Overflow ); 193 return cf2_intToFixed( 0 ); /* bounds error */ 194 } 195 196 switch ( stack->buffer[idx].type ) 197 { 198 case CF2_NumberInt: 199 return cf2_intToFixed( stack->buffer[idx].u.i ); 200 case CF2_NumberFrac: 201 return cf2_fracToFixed( stack->buffer[idx].u.f ); 202 default: 203 return stack->buffer[idx].u.r; 204 } 205 } 206 207 208 /* provide random access to stack */ 209 FT_LOCAL_DEF( void ) cf2_stack_setReal(CF2_Stack stack,CF2_UInt idx,CF2_Fixed val)210 cf2_stack_setReal( CF2_Stack stack, 211 CF2_UInt idx, 212 CF2_Fixed val ) 213 { 214 if ( idx > cf2_stack_count( stack ) ) 215 { 216 CF2_SET_ERROR( stack->error, Stack_Overflow ); 217 return; 218 } 219 220 stack->buffer[idx].u.r = val; 221 stack->buffer[idx].type = CF2_NumberFixed; 222 } 223 224 225 /* discard (pop) num values from stack */ 226 FT_LOCAL_DEF( void ) cf2_stack_pop(CF2_Stack stack,CF2_UInt num)227 cf2_stack_pop( CF2_Stack stack, 228 CF2_UInt num ) 229 { 230 if ( num > cf2_stack_count( stack ) ) 231 { 232 CF2_SET_ERROR( stack->error, Stack_Underflow ); 233 return; 234 } 235 stack->top -= num; 236 } 237 238 239 FT_LOCAL_DEF( void ) cf2_stack_roll(CF2_Stack stack,CF2_Int count,CF2_Int shift)240 cf2_stack_roll( CF2_Stack stack, 241 CF2_Int count, 242 CF2_Int shift ) 243 { 244 /* we initialize this variable to avoid compiler warnings */ 245 CF2_StackNumber last = { { 0 }, CF2_NumberInt }; 246 247 CF2_Int start_idx, idx, i; 248 249 250 if ( count < 2 ) 251 return; /* nothing to do (values 0 and 1), or undefined value */ 252 253 if ( (CF2_UInt)count > cf2_stack_count( stack ) ) 254 { 255 CF2_SET_ERROR( stack->error, Stack_Overflow ); 256 return; 257 } 258 259 /* before C99 it is implementation-defined whether */ 260 /* the result of `%' is negative if the first operand */ 261 /* is negative */ 262 if ( shift < 0 ) 263 shift = -( ( -shift ) % count ); 264 else 265 shift %= count; 266 267 if ( shift == 0 ) 268 return; /* nothing to do */ 269 270 /* We use the following algorithm to do the rolling, */ 271 /* which needs two temporary variables only. */ 272 /* */ 273 /* Example: */ 274 /* */ 275 /* count = 8 */ 276 /* shift = 2 */ 277 /* */ 278 /* stack indices before roll: 7 6 5 4 3 2 1 0 */ 279 /* stack indices after roll: 1 0 7 6 5 4 3 2 */ 280 /* */ 281 /* The value of index 0 gets moved to index 2, while */ 282 /* the old value of index 2 gets moved to index 4, */ 283 /* and so on. We thus have the following copying */ 284 /* chains for shift value 2. */ 285 /* */ 286 /* 0 -> 2 -> 4 -> 6 -> 0 */ 287 /* 1 -> 3 -> 5 -> 7 -> 1 */ 288 /* */ 289 /* If `count' and `shift' are incommensurable, we */ 290 /* have a single chain only. Otherwise, increase */ 291 /* the start index by 1 after the first chain, then */ 292 /* do the next chain until all elements in all */ 293 /* chains are handled. */ 294 295 start_idx = -1; 296 idx = -1; 297 for ( i = 0; i < count; i++ ) 298 { 299 CF2_StackNumber tmp; 300 301 302 if ( start_idx == idx ) 303 { 304 start_idx++; 305 idx = start_idx; 306 last = stack->buffer[idx]; 307 } 308 309 idx += shift; 310 if ( idx >= count ) 311 idx -= count; 312 else if ( idx < 0 ) 313 idx += count; 314 315 tmp = stack->buffer[idx]; 316 stack->buffer[idx] = last; 317 last = tmp; 318 } 319 } 320 321 322 FT_LOCAL_DEF( void ) cf2_stack_clear(CF2_Stack stack)323 cf2_stack_clear( CF2_Stack stack ) 324 { 325 stack->top = stack->buffer; 326 } 327 328 329 /* END */ 330