-struct Map init_map () {
-// Initialize map with some experimental start values.
- struct Map map;
- map.size.x = 64;
- map.size.y = 64;
- map.offset.x = 0;
- map.offset.y = 0;
- uint32_t size = map.size.x * map.size.y;
- map.cells = malloc(size);
- uint16_t y, x;
- for (y = 0; y < map.size.y; y++)
- for (x = 0; x < map.size.x; x++)
- map.cells[(y * map.size.x) + x] = '~';
- map.cells[size / 2 + (map.size.x / 2)] = '.';
- uint32_t curpos;
- while (1) {
- y = rrand(0, 0) % map.size.y;
- x = rrand(0, 0) % map.size.x;
- curpos = y * map.size.x + x;
- if ('~' == map.cells[curpos] &&
- ( (curpos >= map.size.x && '.' == map.cells[curpos - map.size.x])
- || (curpos < map.size.x * (map.size.y-1) && '.' == map.cells[curpos + map.size.x])
- || (curpos > 0 && curpos % map.size.x != 0 && '.' == map.cells[curpos-1])
- || (curpos < (map.size.x * map.size.y) && (curpos+1) % map.size.x != 0 && '.' == map.cells[curpos+1]))) {
- if (y == 0 || y == map.size.y - 1 || x == 0 || x == map.size.x - 1)
- break;
- map.cells[y * map.size.x + x] = '.'; } }
- return map; }
-
-void map_scroll (struct Map * map, char dir) {
-// Scroll map into direction dir if possible by changing the offset.
- if (NORTH == dir && map->offset.y > 0) map->offset.y--;
- else if (SOUTH == dir) map->offset.y++;
- else if (WEST == dir && map->offset.x > 0) map->offset.x--;
- else if (EAST == dir) map->offset.x++; }
+uint16_t center_offset (uint16_t pos, uint16_t mapsize, uint16_t framesize) {
+// Return the offset for display of a map inside a frame centered on pos.
+ uint16_t offset = 0;
+ if (mapsize > framesize) {
+ if (pos > framesize / 2) {
+ if (pos < mapsize - (framesize / 2))
+ offset = pos - (framesize / 2);
+ else
+ offset = mapsize - framesize; } }
+ return offset; }