Map Randomisation

Posted September 30th, 2010 in Game Design by Callum Lawson
I was recently thinking about how I could generate a playable random map for my tile based strategy game. I can foresee many difficulties with this. Below is a sample map created in the map editor:
This map although not very well balanced looks sensible. The roads are connected and features such as trees and mountains are grouped in semi-realistic clumps. The river is also continuous and flows from one side of the map to another. If this sort of result is to be achieved my a random map generator it will need to follow these rules:
  • If the tile is blank there must be a chance that a feature is placed on it. This should be larger if adjacent tiles contain this feature.
  • Roads and rivers must form a closed loop. (counting the map edge as closed).
  • If there is a road or river section in an adjacent tile and it is “facing” into the tile it must be continued.

  • (Optional) The map be balanced in terms of resource and position or be symmetrical.

Ideally the chance of each feature (i.e. hills,woods,mountains) being placed in tile should be determined by an initial value and the tiles surrounding it. If this was a case the user could define the initial chances by selecting an option such as hilly or woodland before generating the map while the affect of nearby tiles could help produce the desired “clumping” of features.

I intend to try and write some pseudocode which achieves these effects soon.

Line of sight algorithm

Posted September 29th, 2010 in Game Design by Callum Lawson

I have been trying to find a algorithm which when given a integer which will determine “sight range” will produce a two dimensional array containing all the x,y values of tiles which fulfill x+y<=sight range in both positive and negative directions.

This is the method I used to accomplish this:

for (int y=0;y&lt;mapHeight;y++)
{
for (int x=0;x&lt;mapWidth;x++)
{
if(currentMap.getUnit(x, y)!=null)
{
int sightRange = currentMap.getUnit(x, y).getMovementRange()/2;
for(int sightStepY = -sightRange;sightStepY&lt;sightRange;sightStepY++)
{
for(int sightStepX = -sightRange;sightStepX&lt;sightRange;sightStepX++)
{
if(x+sightStepX>=0&&x+sightStepX&lt;mapWidth&&y+sightStepY>=0&&y+sightStepY&lt;mapHeight)
{

if(sightStepY>=0&&sightStepX>=0)
{
if(sightStepY+sightStepX&lt;=sightRange)
{
currentMap.fogArray[x+sightStepX][y+sightStepY]=0;
}
}

if(y+sightRange&lt;mapHeight){
currentMap.fogArray[x][y+sightRange]=0;}
if(x+sightRange&lt;mapHeight){
currentMap.fogArray[x+sightRange][y]=0;}


if(sightStepY&lt;=0&&sightStepX>=0)
{
if(sightStepX-sightStepY&lt;=sightRange)
{
currentMap.fogArray[x+sightStepX][y+sightStepY]=0;
}
}

if(sightStepY&lt;=0&&sightStepX&lt;=0)
{
if(-sightStepX-sightStepY&lt;=sightRange)
{
currentMap.fogArray[x+sightStepX][y+sightStepY]=0;
}
}

if(sightStepY>=0&&sightStepX&lt;=0)
{
if(sightStepY-sightStepX&lt;=sightRange)
{
currentMap.fogArray[x+sightStepX][y+sightStepY]=0;
}
}

}}}
}}}

Fog array is the two dimensional array which states if the tile should fog(1) or not (0).
Here is an example of the result when rendered in the game:

I think the above is rather messy and was achieved with a good deal of trial and error. I’m sure there is a more elegant way of achieving this. Any suggestions would be appreciated.

Pathfinding needed for multiplayer stratagy?

Posted September 29th, 2010 in Game Design by Callum Lawson

While developing my tile based strategy game I always assumed I would need path finding. I reasoned that when the user moves a unit from one tile to another the game would need to find the most efficient path. Yet this has a major drawback. A pathfinder would remove choice from the user. There will be cases where the user may want to move along a path that does not take the optimal route. Perhaps he wants to move around an enemy scout or keep out of range of artillery?

In this case he may want to dictate the movement of the unit it a more defined way. The player may wish to draw the path. This is what I am going to use in my tile based game. The real challenge seems to be making the drawing of the path intuitive.Perhaps if the unit is being moved into fog of war in this manner the player may route the path over an enemy unit. In this case I assume the best solution would be to let the player submit the move and then have the enemy unit “block” the moves progress. Many tile based games such as civilisation have adopted this approach.