+
+ g = g2 >> 1;
+ if (g)
+ {
+ // subdivide, diamond-square algorythm (really this has little to do with squares)
+ // diamond
+ for (y = 0;y < size;y += g2)
+ for (x = 0;x < size;x += g2)
+ n(x+g,y+g) = (n(x,y) + n(x+g2,y) + n(x,y+g2) + n(x+g2,y+g2)) >> 2;
+ // square
+ for (y = 0;y < size;y += g2)
+ for (x = 0;x < size;x += g2)
+ {
+ n(x+g,y) = (n(x,y) + n(x+g2,y) + n(x+g,y-g) + n(x+g,y+g)) >> 2;
+ n(x,y+g) = (n(x,y) + n(x,y+g2) + n(x-g,y+g) + n(x+g,y+g)) >> 2;
+ }
+ }