Decoded: Rogue (1980) by Toy, Arnold, Wichman DOS version (1983) by Mel Sibony and Jon Lane Source file: PACK.C Beginner friendly, line-by-line code walkthrough by MaiZure PACK.C provides inventory management functions Original code: https://britzl.github.io/roguearchive/ Original code with line numbers http://www.maizure.org/projects/decoded-rogue/PACK_linenum.txt 1 Include game header 2 Include the console management header 3 BLANK 4 COMMENT 5 COMMENT 6 COMMENT 7 COMMENT 8 COMMENT 9 BLANK GET INVENTORY ITEM BY LETTER 10 pack_obj returns a pointer to an object 11 Defines pack_obj with two arguments 12 Arguments 1 is an input object index and Argument 2 is the offset 13 BLOCK START - pack_obj, returns object and updates backpack pointer 14 Declares a pointer to an object 15 Declares a character to match 16 BLANK 17 Loop through each item in the inventory 18 If the input character matches an item's index character 19 Return the object 20 Set the input pointer to the character 21 Return NULL 22 BLOCK END - pack_obj 23 BLANK 24 COMMENT 25 COMMENT 26 COMMENT 27 COMMENT 28 COMMENT 29 COMMENT ADD ITEM TO INVENTORY 30 Defines add_pack with two arguments 31 Argument 1 is a pointer to an object 32 Argument 2 is a flag to report the pick up to the player 33 BLOCK START - add_pack, adds an item to inventory 34 Delcares two pointers to inventory objects to iterate over 35 Declares flags for picked up items and for exact matches 36 Declares a byte for the floor value/type 37 BLANK 38 If the input object isn't specified 39 BLOCK START - Check floor for object 40 Set from_floor flag 41 If there is no object on the floor 42 Return fail 43 BLOCK END - Check floor for object 44 Otherwise... 45 Object was input, not from floor 46 COMMENT 47 COMMENT 48 COMMENT 49 COMMENT 50 COMMENT 51 COMMENT 52 COMMENT 53 COMMENT 54 COMMENT 55 Get the floor type, either passage or floor based on room type 56 If the object is part of a group... 57 BLOCK START - Has inventory group 58 Loop through all items in a pack 59 BLOCK START - Check pack 60 If the object has a matching group.. 61 BLOCK START - Add object to inventory stack 62 COMMENT 63 COMMENT 64 COMMENT 65 Add to the inventory count 66 If the item came from the floor 67 BLOCK START - Item from floor 68 Remove item from the level 69 Add the proper floor character to the screen 70 Add the floor character to the map data 71 BLOCK END - Item from floor 72 Free the object from memory 73 Report object pointer to the backpack slot 74 Jump to line 178 to handle post-pickup effects (skip other pickup types) 75 BLOCK END - Add object to inventory pack 76 BLOCK END - Check pack 77 BLOCK END - Has inventory group 78 COMMENT 79 COMMENT 80 COMMENT 81 If the player's inventory is full 82 BLOCK START - Inventory full 83 Print inventory full message 84 Return failure 85 BLOCK END - Inventory full 86 COMMENT 87 COMMENT 88 COMMENT 89 If the object is a scare monster scroll... 90 And the player has found the object already... 91 BLOCK START - Moving scare monster scroll 92 Remove the scroll from the level 93 Add a floor character to the floor 94 Add a floor character to the map data 95 Send message that the scroll is destory 96 Return failure to pick up 97 BLOCK END - Moving scare monster scroll 98 Otherwise... 99 Set object to found 100 BLANK 101 Add to the inventory counter 102 If the object came from the floor 103 BLOCK START - Floor pickup 104 Remove the object from the level 105 Add the floor square to the position 106 Add the floor square to the map data 107 BLOCK END - Floor pickup 108 COMMENT 109 COMMENT 110 COMMENT 111 Assume object is new, doesn't match anything the character already has 112 Loop through the inventory 113 If we find a matching object 114 Break at this point to save the pointer position 115 If no matching object type was found... 116 BLOCK START - New object type in backpack 117 COMMENT 118 COMMENT 119 COMMENT 120 Loop through the backpack 121 BLOCK START - Find new position in backpack 122 If the object isn't of type food 123 Break at this position 124 Track the last pointer 125 BLOCK END - Find new position in backpack 126 BLOCK END - New object type in backpack 127 Otherwise we found a matching object 128 BLOCK START - Found a potential match in inventory 129 COMMENT 130 COMMENT 131 COMMENT 132 Loop to find matching object sub-types 133 BLOCK START - Matching object subtypes 134 If the subtypes match 135 BLOCK START - Found type/subtype match 136 Set exact flag to true 137 Break from loop with these pointers set 138 BLOCK END - Found type/subtype match 139 Set last pointer to this position 140 If this is the last item 141 Break from outer loop 142 BLOCK END - Matching object subtypes 143 BLOCK END - Found a potential match in inventory 144 If matching objects were found.. 145 BLOCK START - No match, insert object at the end 146 COMMENT 147 COMMENT 148 COMMENT 149 If the monster has no inventory at all... 150 This is the first object 151 Otherwise 152 BLOCK START - Add object to the end 153 Change the last valid object's next to the new object 154 Set the new object's last pointer to the previous 155 This is the last object, no next 156 BLOCK END - Add object to the end 157 BLOCK END - No match, insert object at the end 158 Otherwise, we've found an exactly match 159 BLOCK START - Verify inventory stack 160 COMMENT 161 COMMENT 162 COMMENT 163 COMMENT 164 If there is an exactly match and this is a stackable object... 165 BLOCK START - Add to stack 166 Add to inventory counter 167 Remove the object picked up 168 Point to the inventory position 169 Jump to picked up subroutine 170 BLOCK END - Add to stack 171 Set the previous object's pointer and check if it exists... 172 If so, set the previous object to the current object we're inserting 173 Otherwise this object is at the head of the inventory 174 The inventory points to this object 175 Set this object's next pointer 176 Set the next object to this object 177 BLOCK END - Verify inventory stack 178 Label for after pickup effects 179 COMMENT 180 COMMENT 181 COMMENT 182 COMMENT 183 Loop through all the monsters on the level 184 COMMENT 185 COMMENT 186 COMMENT 187 COMMENT 188 COMMENT 189 COMMENT 190 COMMENT 191 COMMENT 192 COMMENT 193 COMMENT 194 If the monster was trying to reach the object the player picked up... 195 The monster will now chase the player 196 BLANK 197 If the player just picked up the amulet of Yendor... 198 BLOCK START - Got amulet of Yendor 199 Set global flag that player has the amulet 200 Set global flag that player saw the amulet 201 BLOCK END - Got amulet of Yendor 202 COMMENT 203 COMMENT 204 COMMENT 205 If the silent flag isn't set 206 Send a message that he player picked up the object... 207 Include the inventory position 208 BLOCK END - add_pack 209 BLANK 210 COMMENT 211 COMMENT 212 COMMENT 213 COMMENT SHOW INVENTORY 214 Define inventory with three arguments 215 Argument 1 is a pointer to the first item in the list 216 Argument 2 is the type to filter for 217 Argument 3 is the substring to search for 218 BLOCK START - inventory, lists out the items in inventory 219 Declare the inventory index character 220 Declare a counter for number of objects 221 Declare a buffer 222 BLANK 223 Initialize the number of objects to zero 224 Loop throuh all of the items in inventory 225 BLOCK START - Inventory loop 226 COMMENT 227 COMMENT 228 COMMENT 229 COMMENT 230 COMMENT 231 COMMENT 232 If type is set and the object matches the type... 233 If it's not a callable scroll, or potion... 234 or ring or wand... 235 ...and it's not zappable... 236 ...or with a vorpal effect 237 Skip this item 238 Increment the number of object 239 Print the inventory item to the temporary buffer 240 Add the line from the temporary buffer to the output string 241 BLOCK END - Inventory loop 242 If no objects were added... 243 BLOCK START - No inventory 244 If no type was input...print empty handed or.. 245 Print no type available 246 Return no list 247 BLOCK END - No inventory 248 Return the inventory list after removing the final endline character 249 BLOCK END - inventory 250 BLANK 251 COMMENT 252 COMMENT 253 COMMENT 254 COMMENT PICK UP ITEM 255 Define pick_up with one argument 256 Argument 1 is the item to pick up 257 BLOCK START - pick_up, pick up an item 258 Declare a pointer to an object 259 BLANK 260 Switch on the type of object 261 BLOCK START - Switch on the type of object to pick up 262 CASE gold 263 If there is no object under the player.. 264 Return, nothing to do 265 Add the money in the stack 266 Remove the money from the map 267 Free the money object memory 268 Remove the gold value from the room 269 Break from picking up 270 CASE any type (fallthrough) 271 CASE armor (fallthrough) 272 CASE potion (fallthrough) 273 CASE food (fallthrough) 274 CASE weapon (fallthrough) 275 CASE scroll (fallthrough) 276 CASE amulet (fallthrough) 277 CASE ring (fallthrough) 278 CASE stick 279 Add the object to the pack 280 End check for object type 281 BLOCK END - Switch on the type of object to pick up 282 BLOCK END - pick_up 283 BLANK 284 COMMENT 285 COMMENT 286 COMMENT 287 COMMENT USE ITEM FROM PACK 288 get_item returns a pointer to an item 289 Defines get_item with two arguments 290 Argument one is a string describing the purpose of the item 291 Argument 2 is the type of item 292 BLOCK START - get_item, uses and item from inventory 293 Declare a pointer to an object 294 Declare a character used to hold user input 295 Declare a character used for inventory index 296 Declare yet another character 297 Declare a pointer to hold a previous object 298 Declare a character to match the repeat global state 299 Declare a flag for repeating 300 BLANK 301 If the purpose is to select or eat... 302 ...or drop, or wear 303 Only do this once 304 BLANK 305 Match the repeat state from the global 306 If there is nothing in inventory... 307 Print out empty inventory 308 Otherwise, search inventory 309 Match the last character (not init) 310 Loop until items are uses up 311 COMMENT 312 COMMENT 313 COMMENT 314 COMMENT 315 COMMENT 316 If we're getting multiple items but we still have one buffered... 317 Jump to line 329 to skip item selection 318 If we're only doing this one time... 319 Set character to the character that shows action list 320 Jump to line 329 to skip item selection 321 End of shortcut checks 322 We're not in terse mode... 323 Query the player to select an item... 324 And to choose a purpose 325 COMMENT 326 COMMENT 327 COMMENT 328 Get user input for purpose 329 Label for skipping input 330 Reset the message buffer 331 Clear the repeat input state 332 Clear the once flag 333 If we chose to look at the list of actions 334 If the user doesn't select an item... 335 Clear the repeat flag 336 Return nothing 337 End of check for nothing 338 If the player input a space 339 Skip this round 340 Otherwise, save the input for a possible repeat 341 End of check for listing options 342 COMMENT 343 COMMENT 344 COMMENT 345 Check if the player tried to escape out of the selection 346 Reset the repeat flag 347 Clear the message buffer 348 Return nothing 349 End of check for early escape 350 If the player chose an invalid option 351 Print the retry message 352 Skip this round 353 Otherwise... 354 COMMENT 355 COMMENT 356 COMMENT 357 COMMENT 358 COMMENT 359 COMMENT 360 If the input purpose is to identify 361 Save the input character 362 Save the repeated object 363 End check for identify 364 Return the object 365 End check for selected object 366 Repeat loop until object or nothing returns 367 End check inventory 368 Nothing was found, return nothing 369 BLOCK END - get_item 370 BLANK 371 COMMENT 372 COMMENT 373 COMMENT 374 COMMENT GET PACK INDEX 375 Defines pack_char with one argument 376 Argument one is a pointer to an object 377 BLOCK START - pack_char, gets the inventory index 378 Declare a pointer to an object 379 Declare the return character 380 BLANK 381 Set the character to the initial item 382 Loop through the pack 383 If the item matches input 384 Return the character 385 Otherwise... 386 Try the next character 387 Return unknown 388 BLOCK END - pack_char 389 BLANK 390 COMMENT 391 COMMENT 392 COMMENT 393 COMMENT GIVE MONEY TO INVENTORY 394 Define money with one argument 395 Argument 1 is a gold value 396 BLOCK START - money, add or take away gold 397 Declare a floor space byte 398 BLANK 399 Get the floor space, either passage or floor 400 Add the value to the purse (Could be negative) 401 Print the character to the screen 402 Add the character to the level data 403 If the input value is positive 404 BLOCK START - positive gold find 405 Print about gold find 406 BLOCK END - positive gold find 407 BLOCK END - money 408 EOFÿ