+/* First alternative maze creator: Pick a random, empty corner in the maze.
+ * Pick a random direction. Draw a wall in that direction, from that corner
+ * until we hit a wall. Option: Only draw the wall if it's going to be
+ * shorter than a certain length. Otherwise we get lots of long walls.
+ */
+static void
+alt_create_maze(struct state *st)
+{
+ char *corners;
+ int *c_idx;
+ int i, j, height, width, open_corners, k, dir, xx, yy;
+
+ height = st->maze_size_y+1;
+ width = st->maze_size_x+1;
+
+ /* Allocate and clear some mem. */
+ corners = (char *)calloc(height*width, 1);
+ if(!corners)
+ return;
+
+ /* Set up the indexing array. */
+ c_idx = (int *)malloc(sizeof(int)*height*width);
+ if(!c_idx)
+ {
+ free(corners);
+ return;
+ }
+ for(i = 0; i < height*width; i++)
+ c_idx[i] = i;
+ for(i = 0; i < height*width; i++)
+ {
+ j = c_idx[i];
+ k = random()%(height*width);
+ c_idx[i] = c_idx[k];
+ c_idx[k] = j;
+ }
+
+ /* Set up some initial walls. */
+ /* Outside walls. */
+ for(i = 0; i < width; i++)
+ {
+ corners[i] = 1;
+ corners[i+width*(height-1)] = 1;
+ }
+ for(i = 0; i < height; i++)
+ {
+ corners[i*width] = 1;
+ corners[i*width+width-1] = 1;
+ }
+ /* Walls around logo. In fact, inside the logo, too. */
+ /* Also draw the walls. */
+ if(st->logo_x!=-1)
+ {
+ int logow = 1 + st->logo_width / st->grid_width;
+ int logoh = 1 + st->logo_height / st->grid_height;
+ int bridge_dir, bridge_c;
+
+ if(st->bridge_p && logoh>=3 && logow>=3)
+ {
+ bridge_dir = 1+random()%2;
+ if(bridge_dir==1)
+ {
+ bridge_c = st->logo_y+random()%(logoh-2)+1;
+ }
+ else
+ {
+ bridge_c = st->logo_x+random()%(logow-2)+1;
+ }
+ }
+ else
+ {
+ bridge_dir = 0;
+ bridge_c = -1;
+ }
+ for(i = st->logo_x; i <= st->logo_x + logow; i++)
+ {
+ for(j = st->logo_y; j <= st->logo_y + logoh; j++)
+ {
+ corners[i+width*j] = 1;
+ }
+ }
+ for(xx = st->logo_x; xx < st->logo_x+logow; xx++)
+ {
+ if(!(bridge_dir==2 && xx==bridge_c))
+ {
+ build_wall(st, xx, st->logo_y, 0);
+ build_wall(st, xx, st->logo_y+logoh, 0);
+ }
+ if(bridge_dir==1)
+ {
+ build_wall(st, xx, bridge_c, 0);
+ build_wall(st, xx, bridge_c, 2);
+ }
+ }
+ for(yy = st->logo_y; yy < st->logo_y+logoh; yy++)
+ {
+ if(!(bridge_dir==1 && yy==bridge_c))
+ {
+ build_wall(st, st->logo_x, yy, 3);
+ build_wall(st, st->logo_x+logow, yy, 3);
+ }
+ if(bridge_dir==2)
+ {
+ build_wall(st, bridge_c, yy, 1);
+ build_wall(st, bridge_c, yy, 3);
+ }
+ }
+ /* Connect one wall of the logo with an outside wall. */
+ if(st->bridge_p)
+ dir = (bridge_dir+1)%4;
+ else
+ dir = random()%4;
+ switch(dir)
+ {
+ case 0:
+ xx = st->logo_x+(random()%(logow+1));
+ yy = st->logo_y;
+ break;
+ case 1:
+ xx = st->logo_x+logow;
+ yy = st->logo_y+(random()%(logoh+1));
+ break;
+ case 2:
+ xx = st->logo_x+(random()%(logow+1));
+ yy = st->logo_y+logoh;
+ break;
+ case 3:
+ xx = st->logo_x;
+ yy = st->logo_y+(random()%(logoh+1));
+ break;
+ }
+ do
+ {
+ corners[xx+width*yy] = 1;
+ switch(dir)
+ {
+ case 0:
+ build_wall(st, xx-1, yy-1, 1);
+ yy--;
+ break;
+ case 1:
+ build_wall(st, xx, yy, 0);
+ xx++;
+ break;
+ case 2:
+ build_wall(st, xx, yy, 3);
+ yy++;
+ break;
+ case 3:
+ build_wall(st, xx-1, yy-1, 2);
+ xx--;
+ break;
+ }
+ }
+ while(!corners[xx+width*yy]);
+ if(st->bridge_p)
+ {
+ dir = (dir+2)%4;
+ switch(dir)
+ {
+ case 0:
+ xx = st->logo_x+(random()%(logow+1));
+ yy = st->logo_y;
+ break;
+ case 1:
+ xx = st->logo_x+logow;
+ yy = st->logo_y+(random()%(logoh+1));
+ break;
+ case 2:
+ xx = st->logo_x+(random()%(logow+1));
+ yy = st->logo_y+logoh;
+ break;
+ case 3:
+ xx = st->logo_x;
+ yy = st->logo_y+(random()%(logoh+1));
+ break;
+ }
+ do
+ {
+ corners[xx+width*yy] = 1;
+ switch(dir)
+ {
+ case 0:
+ build_wall(st, xx-1, yy-1, 1);
+ yy--;
+ break;
+ case 1:
+ build_wall(st, xx, yy, 0);
+ xx++;
+ break;
+ case 2:
+ build_wall(st, xx, yy, 3);
+ yy++;
+ break;
+ case 3:
+ build_wall(st, xx-1, yy-1, 2);
+ xx--;
+ break;
+ }
+ }
+ while(!corners[xx+width*yy]);
+ }
+ }
+
+ /* Count open gridpoints. */
+ open_corners = 0;
+ for(i = 0; i < width; i++)
+ for(j = 0; j < height; j++)
+ if(!corners[i+width*j])
+ open_corners++;