scrsnap.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3 #include "config.h"
   4 #include "draw.h"
   5 #include "scrsnap.h"
   6
   7 #define NSCRS           ((sizeof(saved) - 1) * 2)
   8 #define SNAPSZ          (1 << 23)
   9
  10 static char saved[] = TAGS_SAVED;
  11 static char scrs[NSCRS][SNAPSZ];
  12 static void *owners[NSCRS];
  13
  14 static int scr_find(void *owner)
  15 {
  16         int i;
  17         for (i = 0; i < NSCRS; i++)
  18                 if (owners[i] == owner)
  19                         return i;
  20         return -1;
  21 }
  22
  23 static int scr_slot(void)
  24 {
  25         int index = scr_find(NULL);
  26         return index > -1 ? index : 0;
  27 }
  28
  29 void scr_snap(void *owner)
  30 {
  31         int rowsz = sizeof(fbval_t) * fb_cols();
  32         int scr = scr_slot();
  33         int i;
  34         for (i = 0; i < fb_rows(); i++)
  35                 memcpy(scrs[scr] + i * rowsz, fb_mem(i), rowsz);
  36         owners[scr] = owner;
  37 }
  38
  39 void scr_free(void *owner)
  40 {
  41         int scr = scr_find(owner);
  42         if (scr != -1)
  43                 owners[scr] = NULL;
  44 }
  45
  46 int scr_load(void *owner)
  47 {
  48         int rowsz = sizeof(fbval_t) * fb_cols();
  49         int scr = scr_find(owner);
  50         int i;
  51         if (scr == -1)
  52                 return -1;
  53         for (i = 0; i < fb_rows(); i++)
  54                 memcpy(fb_mem(i), scrs[scr] + i * rowsz, rowsz);
  55         owners[scr] = NULL;
  56         return 0;
  57 }