public void GenerateContinents(HeightMap heightMap)
{
var mapSize = new IntPoint(heightMap.Size.X, heightMap.Size.Y);
var startPoints = new List<IntPoint> { new IntPoint(mapSize.X / 2, mapSize.Y / 2) };
foreach (var start in startPoints)
{
var size = Random.Next(MaximumContinentSize - MinimumContinentSize) + MinimumContinentSize;
var scaleStep = -(ScaleAmount - 1f) / size;
ScaleSquareAroundPoint(heightMap, start, size, ScaleAmount, scaleStep);
}
}
/// <summary>
/// From a start point, scales a box of given size on the HeightMap. The start point will be scaled by the given
/// scaleValue. scaleValue will then be incremented by scaleStep as we begin scaling points further from the start.
/// </summary>
private static void ScaleSquareAroundPoint(HeightMap heightMap, IntPoint start, int size, float scaleValue, float scaleStep)
{
MultiplyHeightAtPoint(heightMap, start.X, start.Y, scaleValue);
for (var d = 1; d < size + 1; d++, scaleValue += scaleStep)
{
//Corner values
MultiplyHeightAtPoint(heightMap, start.X - d, start.Y - d, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X + d, start.Y - d, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X - d, start.Y + d, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X + d, start.Y + d, scaleValue);
//Middle Edge values
MultiplyHeightAtPoint(heightMap, start.X - d, start.Y, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X, start.Y - d, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X, start.Y + d, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X + d, start.Y, scaleValue);
//Left & Right Sides
for (var y = 1; y < d; y++)
{
MultiplyHeightAtPoint(heightMap, start.X - d, start.Y - y, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X - d, start.Y + y, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X + d, start.Y - y, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X + d, start.Y + y, scaleValue);
}
//Top & Bottom Sides
for (var x = 1; x < d; x++)
{
MultiplyHeightAtPoint(heightMap, start.X - x, start.Y - d, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X + x, start.Y - d, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X - x, start.Y + d, scaleValue);
MultiplyHeightAtPoint(heightMap, start.X + x, start.Y + d, scaleValue);
}
}
}