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 FT_INTERNAL_DEBUG_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 ) 53 cf2_stack_init( FT_Memory memory, 54 FT_Error* e, 55 FT_UInt stackSize ) 56 { 57 FT_Error error = FT_Err_Ok; /* for FT_NEW */ 58 59 CF2_Stack stack = NULL; 60 61 62 if ( !FT_NEW( stack ) ) 63 { 64 /* initialize the structure; FT_NEW zeroes it */ 65 stack->memory = memory; 66 stack->error = e; 67 } 68 69 /* allocate the stack buffer */ 70 if ( FT_NEW_ARRAY( stack->buffer, stackSize ) ) 71 { 72 FT_FREE( stack ); 73 return NULL; 74 } 75 76 stack->stackSize = stackSize; 77 stack->top = stack->buffer; /* empty stack */ 78 79 return stack; 80 } 81 82 83 FT_LOCAL_DEF( void ) 84 cf2_stack_free( CF2_Stack stack ) 85 { 86 if ( stack ) 87 { 88 FT_Memory memory = stack->memory; 89 90 /* free the buffer */ 91 FT_FREE( stack->buffer ); 92 93 /* free the main structure */ 94 FT_FREE( stack ); 95 } 96 } 97 98 99 FT_LOCAL_DEF( CF2_UInt ) 100 cf2_stack_count( CF2_Stack stack ) 101 { 102 return (CF2_UInt)( stack->top - stack->buffer ); 103 } 104 105 106 FT_LOCAL_DEF( void ) 107 cf2_stack_pushInt( CF2_Stack stack, 108 CF2_Int val ) 109 { 110 if ( stack->top == stack->buffer + stack->stackSize ) 111 { 112 CF2_SET_ERROR( stack->error, Stack_Overflow ); 113 return; /* stack overflow */ 114 } 115 116 stack->top->u.i = val; 117 stack->top->type = CF2_NumberInt; 118 stack->top++; 119 } 120 121 122 FT_LOCAL_DEF( void ) 123 cf2_stack_pushFixed( CF2_Stack stack, 124 CF2_Fixed val ) 125 { 126 if ( stack->top == stack->buffer + stack->stackSize ) 127 { 128 CF2_SET_ERROR( stack->error, Stack_Overflow ); 129 return; /* stack overflow */ 130 } 131 132 stack->top->u.r = val; 133 stack->top->type = CF2_NumberFixed; 134 stack->top++; 135 } 136 137 138 /* this function is only allowed to pop an integer type */ 139 FT_LOCAL_DEF( CF2_Int ) 140 cf2_stack_popInt( CF2_Stack stack ) 141 { 142 if ( stack->top == stack->buffer ) 143 { 144 CF2_SET_ERROR( stack->error, Stack_Underflow ); 145 return 0; /* underflow */ 146 } 147 if ( stack->top[-1].type != CF2_NumberInt ) 148 { 149 CF2_SET_ERROR( stack->error, Syntax_Error ); 150 return 0; /* type mismatch */ 151 } 152 153 stack->top--; 154 155 return stack->top->u.i; 156 } 157 158 159 /* Note: type mismatch is silently cast */ 160 /* TODO: check this */ 161 FT_LOCAL_DEF( CF2_Fixed ) 162 cf2_stack_popFixed( CF2_Stack stack ) 163 { 164 if ( stack->top == stack->buffer ) 165 { 166 CF2_SET_ERROR( stack->error, Stack_Underflow ); 167 return cf2_intToFixed( 0 ); /* underflow */ 168 } 169 170 stack->top--; 171 172 switch ( stack->top->type ) 173 { 174 case CF2_NumberInt: 175 return cf2_intToFixed( stack->top->u.i ); 176 case CF2_NumberFrac: 177 return cf2_fracToFixed( stack->top->u.f ); 178 default: 179 return stack->top->u.r; 180 } 181 } 182 183 184 /* Note: type mismatch is silently cast */ 185 /* TODO: check this */ 186 FT_LOCAL_DEF( CF2_Fixed ) 187 cf2_stack_getReal( CF2_Stack stack, 188 CF2_UInt idx ) 189 { 190 FT_ASSERT( cf2_stack_count( stack ) <= stack->stackSize ); 191 192 if ( idx >= cf2_stack_count( stack ) ) 193 { 194 CF2_SET_ERROR( stack->error, Stack_Overflow ); 195 return cf2_intToFixed( 0 ); /* bounds error */ 196 } 197 198 switch ( stack->buffer[idx].type ) 199 { 200 case CF2_NumberInt: 201 return cf2_intToFixed( stack->buffer[idx].u.i ); 202 case CF2_NumberFrac: 203 return cf2_fracToFixed( stack->buffer[idx].u.f ); 204 default: 205 return stack->buffer[idx].u.r; 206 } 207 } 208 209 210 /* provide random access to stack */ 211 FT_LOCAL_DEF( void ) 212 cf2_stack_setReal( CF2_Stack stack, 213 CF2_UInt idx, 214 CF2_Fixed val ) 215 { 216 if ( idx > cf2_stack_count( stack ) ) 217 { 218 CF2_SET_ERROR( stack->error, Stack_Overflow ); 219 return; 220 } 221 222 stack->buffer[idx].u.r = val; 223 stack->buffer[idx].type = CF2_NumberFixed; 224 } 225 226 227 /* discard (pop) num values from stack */ 228 FT_LOCAL_DEF( void ) 229 cf2_stack_pop( CF2_Stack stack, 230 CF2_UInt num ) 231 { 232 if ( num > cf2_stack_count( stack ) ) 233 { 234 CF2_SET_ERROR( stack->error, Stack_Underflow ); 235 return; 236 } 237 stack->top -= num; 238 } 239 240 241 FT_LOCAL_DEF( void ) 242 cf2_stack_roll( CF2_Stack stack, 243 CF2_Int count, 244 CF2_Int shift ) 245 { 246 /* we initialize this variable to avoid compiler warnings */ 247 CF2_StackNumber last = { { 0 }, CF2_NumberInt }; 248 249 CF2_Int start_idx, idx, i; 250 251 252 if ( count < 2 ) 253 return; /* nothing to do (values 0 and 1), or undefined value */ 254 255 if ( (CF2_UInt)count > cf2_stack_count( stack ) ) 256 { 257 CF2_SET_ERROR( stack->error, Stack_Overflow ); 258 return; 259 } 260 261 if ( shift < 0 ) 262 shift = -( ( -shift ) % count ); 263 else 264 shift %= count; 265 266 if ( shift == 0 ) 267 return; /* nothing to do */ 268 269 /* We use the following algorithm to do the rolling, */ 270 /* which needs two temporary variables only. */ 271 /* */ 272 /* Example: */ 273 /* */ 274 /* count = 8 */ 275 /* shift = 2 */ 276 /* */ 277 /* stack indices before roll: 7 6 5 4 3 2 1 0 */ 278 /* stack indices after roll: 1 0 7 6 5 4 3 2 */ 279 /* */ 280 /* The value of index 0 gets moved to index 2, while */ 281 /* the old value of index 2 gets moved to index 4, */ 282 /* and so on. We thus have the following copying */ 283 /* chains for shift value 2. */ 284 /* */ 285 /* 0 -> 2 -> 4 -> 6 -> 0 */ 286 /* 1 -> 3 -> 5 -> 7 -> 1 */ 287 /* */ 288 /* If `count' and `shift' are incommensurable, we */ 289 /* have a single chain only. Otherwise, increase */ 290 /* the start index by 1 after the first chain, then */ 291 /* do the next chain until all elements in all */ 292 /* chains are handled. */ 293 294 start_idx = -1; 295 idx = -1; 296 for ( i = 0; i < count; i++ ) 297 { 298 CF2_StackNumber tmp; 299 300 301 if ( start_idx == idx ) 302 { 303 start_idx++; 304 idx = start_idx; 305 last = stack->buffer[idx]; 306 } 307 308 idx += shift; 309 if ( idx >= count ) 310 idx -= count; 311 else if ( idx < 0 ) 312 idx += count; 313 314 tmp = stack->buffer[idx]; 315 stack->buffer[idx] = last; 316 last = tmp; 317 } 318 } 319 320 321 FT_LOCAL_DEF( void ) 322 cf2_stack_clear( CF2_Stack stack ) 323 { 324 stack->top = stack->buffer; 325 } 326 327 328 /* END */ 329
