scrsnap.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3 #include "config.h"
   4 #include "draw.h"
   5
   6 #define NSCRS           ((sizeof(saved) - 1) * 2)
   7 #define SNAPSZ          (1 << 23)
   8
   9 static char saved[] = TAGS_SAVED;
  10 static char scrs[NSCRS][SNAPSZ];
  11 static void *owners[NSCRS];
  12
  13 static int scr_find(void *owner)
  14 {
  15         int i;
  16         for (i = 0; i < NSCRS; i++)
  17                 if (owners[i] == owner)
  18                         return i;
  19         return -1;
  20 }
  21
  22 static int scr_slot(void)
  23 {
  24         int index = scr_find(NULL);
  25         return index > -1 ? index : 0;
  26 }
  27
  28 void scr_snap(void *owner)
  29 {
  30         int rowsz = sizeof(fbval_t) * fb_cols();
  31         int scr = scr_slot();
  32         int i;
  33         for (i = 0; i < fb_rows(); i++)
  34                 memcpy(scrs[scr] + i * rowsz, fb_mem(i), rowsz);
  35         owners[scr] = owner;
  36 }
  37
  38 void scr_free(void *owner)
  39 {
  40         int scr = scr_find(owner);
  41         if (scr != -1)
  42                 owners[scr] = NULL;
  43 }
  44
  45 int scr_load(void *owner)
  46 {
  47         int rowsz = sizeof(fbval_t) * fb_cols();
  48         int scr = scr_find(owner);
  49         int i;
  50         if (scr == -1)
  51                 return -1;
  52         for (i = 0; i < fb_rows(); i++)
  53                 memcpy(fb_mem(i), scrs[scr] + i * rowsz, rowsz);
  54         owners[scr] = NULL;
  55         return 0;
  56 }