Here's an idea for the landmasses. Pick N random points. Make them land.
For k iterations,
For each water point, count the number of times, l, it is adjacent to a land point. Make it land with probability P(a*l^2+l*b).
Tweak N, k, a, b as necessary.
Also, if you know Pascal, why do this in Excel? It seems that Pascal would be far more flexable and easier to use. Is it just the difficulty of rendering it as an image?
Edit:
I wrote a little C++ program to do the above. It's not very user friendly. You'll need to set a few constants at the start, compile, and run it, redirecting output to an appropriate file.
#include <time.h>
#include <stdlib.h>
#include <iostream>
#include <algorithm>
using namespace std;
const int N=10; //Number of random points to start as land
const int k=40; //Iterations
const int x=100; // X dimensions of map
const int y=100; // Y ...
const double a=-0.02; // Coefficient for probability function (see bool P(double l))
const double b=0.16; // Coefficient for probability function...
int* field;
pair<int,int> dims;
pair<int,int> rand_pair(){
return pair<int,int>(rand() % dims.first,
rand() % dims.second);
}
bool P(double l){
int limit = max(0.0,min(1.0,(l*l*a+l*b)))*RAND_MAX;
return (rand() < limit);
}
int field_deref(const pair<int,int>& trg){
return trg.first+dims.first*trg.second;
}
bool is_land(const pair<int,int>& trg){
if ( ((trg.first < dims.first) && (0 <= trg.first)) &&
((trg.second < dims.second) && (0 <= trg.second))){
return (1==field[field_deref(trg)]);
}
else{
return false;
}
}
int adjacent(const pair<int,int>& trg){
int count = 0;
for(int idx = -1; idx <= 1; ++idx){
for(int jdx = -1; jdx <= 1; ++jdx){
if((idx==0)&&(jdx==0)){
continue;
}
else{
if(is_land(pair<int,int>(trg.first+idx,trg.second+jdx))){
++count;
}
}
}
}
return count;
}
void survey(){
int* new_field = new int[dims.first*dims.second];
pair<int,int> trg(0,0);
for(; trg.first < dims.first; ++trg.first){
for(; trg.second < dims.second; ++trg.second){
{
int count = adjacent(trg);
if( (is_land(trg)) ||
( ( 0 < count) && P((double) count))){
new_field[field_deref(trg)]=1;
}
else{
new_field[field_deref(trg)]=0;
}
}
}
trg.second=0;
}
delete [] field;
field=new_field;
}
void setup(const pair<int,int>& new_dims){
dims=new_dims;
field=new int[dims.first*dims.second];
pair<int,int> trg(0,0);
for(; trg.first < dims.first; ++trg.first){
for(; trg.second < dims.second; ++trg.second){
field[field_deref(trg)]=0;
}
trg.second=0;
}
pair<int,int> extra;
for(int i=0; i < N; ++i){
// At most N starting land points--I don't want to do the extra checking to ensure it is exactly N.
extra = rand_pair();
field[field_deref(extra)]=1;
}
}
void print(){
pair<int,int> trg(0,dims.second-1);
for(; 0 <= trg.second ; --trg.second){
for(;trg.first < dims.first; ++trg.first){
cout << field[field_deref(trg)];
}
trg.first=0;
cout << '\n';
}
}
int main(){
srand (time(NULL));
setup(pair<int,int>(x,y));
for(int i=0; i < k; ++i){
survey();
}
print();
delete [] field;
}