src/common/wadres.c

   1 #include <stdint.h>
   2 #include <string.h>
   3 #include <stdlib.h>
   4 #include <assert.h>
   5
   6 #include "wadres.h"
   7 #include "streams.h"
   8 #include "cp866.h"
   9
  10 typedef struct Entry {
  11   long offset, size;
  12   char name[8];
  13   int f;
  14 } Entry;
  15
  16 typedef struct Block {
  17   int id;
  18   int ref;
  19   char data[];
  20 } Block;
  21
  22 static int n_wads;
  23 static int n_resources;
  24 static Stream *wads[MAX_WADS];
  25 static Entry resources[MAX_RESOURCES];
  26 static Block *blocks[MAX_RESOURCES];
  27
  28 static int s_start, s_end;
  29
  30 static int check_header (Stream *r) {
  31   assert(r != NULL);
  32   char ident[4];
  33   stream_setpos(r, 0); // !!!
  34   stream_read(ident, 4, 1, r);
  35   return (memcmp(ident, "IWAD", 4) == 0) || (memcmp(ident, "PWAD", 4) == 0);
  36 }
  37
  38 int WADRES_addwad (Stream *r) {
  39   assert(r != NULL);
  40   if (n_wads < MAX_WADS && check_header(r)) {
  41     wads[n_wads] = r;
  42     n_wads += 1;
  43     return 1;
  44   } else {
  45     return 0;
  46   }
  47 }
  48
  49 static int WADRES_addresource (const Entry *e) {
  50   assert(e != NULL);
  51   for (int i = 0; i < n_resources; ++i) {
  52     if (cp866_strncasecmp(resources[i].name, e->name, 8) == 0) {
  53       memcpy(&resources[i], e, sizeof(Entry));
  54       return i;
  55     }
  56   }
  57   if (n_resources < MAX_RESOURCES) {
  58     memcpy(&resources[n_resources], e, sizeof(Entry));
  59     n_resources += 1;
  60     return n_resources - 1;
  61   }
  62   return -1;
  63 }
  64
  65 static int WADRES_read (int f) {
  66   Stream *r = wads[f];
  67   stream_setpos(r, 4); // skip magic
  68   int32_t n = stream_read32(r);
  69   int32_t dir = stream_read32(r);
  70   stream_setpos(r, dir);
  71   int ok = 1;
  72   for (int32_t i = 0; ok && i < n; ++i) {
  73     Entry e;
  74     e.offset = stream_read32(r);
  75     e.size = stream_read32(r);
  76     e.f = f;
  77     stream_read(e.name, 8, 1, r);
  78     ok = WADRES_addresource(&e) != -1;
  79   }
  80   return ok;
  81 }
  82
  83 int WADRES_rehash (void) {
  84   int ok = 1;
  85   for (int i = 0; i < n_wads; ++i) {
  86     if (!WADRES_read(i)) {
  87       ok = 0;
  88     }
  89   }
  90   s_start = WADRES_find("S_START");
  91   s_end = WADRES_find("S_END");
  92   return ok;
  93 }
  94
  95 int WADRES_find (const char name[8]) {
  96   int i = n_resources - 1;
  97   while (i >= 0 && cp866_strncasecmp(name, resources[i].name, 8) != 0) {
  98     i -= 1;
  99   }
 100   return i;
 101 }
 102
 103 int WADRES_maxids (void) {
 104   return n_resources;
 105 }
 106
 107 int WADRES_findsprite (const char n[4], int s, int d, char *dir) {
 108   s += 'A';
 109   d += '0';
 110   for (int i = s_start + 1; i < s_end; i++) {
 111     char a, b;
 112     char *wn = resources[i].name;
 113     if (cp866_strncasecmp(wn, n, 4) == 0 && (wn[4] == s || wn[6] == s)) {
 114       a = wn[4] == s ? wn[5] : 0;
 115       b = wn[6] == s ? wn[7] : 0;
 116       if (a == '0' || b == '0' || a == d || b == d) {
 117         if (dir != NULL) {
 118           *dir = (a != '0' && b == '0') || (a != d && b == d);
 119         }
 120         return i;
 121       }
 122     }
 123   }
 124   return -1;
 125 }
 126
 127 Stream *WADRES_getbasereader (int id) {
 128   assert(id >= 0 && id < n_resources);
 129   return wads[resources[id].f];
 130 }
 131
 132 long WADRES_getoffset (int id) {
 133   assert(id >= 0 && id < n_resources);
 134   return resources[id].offset;
 135 }
 136
 137 long WADRES_getsize (int id) {
 138   assert(id >= 0 && id < n_resources);
 139   return resources[id].size;
 140 }
 141
 142 void WADRES_getname (int id, char *name) {
 143   assert(id >= 0 && id < n_resources);
 144   strncpy(name, resources[id].name, 8);
 145 }
 146
 147 void WADRES_getdata (int id, void *data) {
 148   assert(id >= 0 && id < n_resources);
 149   Stream *r = wads[resources[id].f];
 150   long pos = stream_getpos(r);
 151   stream_setpos(r, resources[id].offset);
 152   stream_read(data, resources[id].size, 1, r);
 153   stream_setpos(r, pos);
 154 }
 155
 156 void *WADRES_lock (int id) {
 157   assert(id >= -1 && id < MAX_RESOURCES);
 158   if (id >= 0) {
 159     Block *x = blocks[id];
 160     if (x) {
 161       x->ref += 1;
 162       return x->data;
 163     } else {
 164       x = malloc(sizeof(Block) + WADRES_getsize(id));
 165       if (x) {
 166         x->id = id;
 167         x->ref = 1;
 168         WADRES_getdata(id, x->data);
 169         blocks[id] = x;
 170         return x->data;
 171       }
 172     }
 173   }
 174   return NULL;
 175 }
 176
 177 void WADRES_unlock (void *data) {
 178   if (data) {
 179     Block *x = data - sizeof(Block);
 180     int id = x->id;
 181     assert(id >= 0 && id < MAX_RESOURCES);
 182     x->ref -= 1;
 183     assert(x->ref >= 0);
 184 #if 0
 185     if (x->ref == 0) {
 186       blocks[id] = NULL;
 187       free(x);
 188     }
 189 #endif
 190   }
 191 }
 192
 193 int WADRES_locked (int id) {
 194   assert(id >= -1 && id < MAX_RESOURCES);
 195   return (id >= 0) && (blocks[id] != NULL) && (blocks[id]->ref >= 1);
 196 }
 197
 198 int WADRES_was_locked (int id) {
 199   assert(id >= -1 && id < MAX_RESOURCES);
 200   return (id >= 0) && (blocks[id] != NULL) && (blocks[id]->ref >= 0);
 201 }