public static void GenerateRandomHeight(Array2D array, Func<float, float, int, float> noiseFunction)
{
float noiseMin = -1;
float noiseMax = 1;
array.Clear(0);
float corner = noiseFunction(noiseMin, noiseMax, 0);
array[0, 0] = array[0, array.Height - 1] = array[array.Width - 1, 0] = array[array.Width - 1, array.Height - 1] = corner;
int x_min = 0;
int y_min = 0;
int x_max = array.Width - 1;
int y_max = array.Height - 1;
int side = x_max;
int squares = 1;
int offset = 1;
int left, right, top, bottom, dx, dy, midX, midY, temp;
while (side > 1)
{
for (int i = 0; i < squares; i++)
{
for (int j = 0; j < squares; j++)
{
left = i * side;
right = (i + 1) * side;
top = j * side;
bottom = (j + 1) * side;
dx = dy = side / 2;
midX = left + dx;
midY = top + dy;
// Diamond step - create center average for each square
array[midX, midY] = MathUtil.Average(array[left, top],
array[left, bottom],
array[right, top],
array[right, bottom]);
array[midX, midY] += noiseFunction(noiseMin, noiseMax, offset);
// Square step - create squares for each diamond
// ==============
// Top Square
if (top - dy < y_min)
temp = y_max - dy;
else
temp = top - dy;
array[midX, top] = MathUtil.Average(array[left, top],
array[right, top],
array[midX, midY],
array[midX, temp]);
array[midX, top] += noiseFunction(noiseMin, noiseMax, offset);
// Top Wrapping
if (top == y_min)
array[midX, y_max] = array[midX, top];
// ==============
// Bottom Square
if (bottom + dy > y_max)
temp = top + dy;
else
temp = bottom - dy;
array[midX, bottom] = MathUtil.Average(array[left, bottom],
array[right, bottom],
array[midX, midY],
array[midX, temp]);
array[midX, bottom] += noiseFunction(noiseMin, noiseMax, offset);
// Bottom Wrapping
if (bottom == y_max)
array[midX, y_min] = array[midX, bottom];
// ==============
// Left Square
if (left - dx < x_min)
temp = x_max - dx;
else
temp = left - dx;
array[left, midY] = MathUtil.Average(array[left, top],
array[left, bottom],
array[midX, midY],
array[temp, midY]);
array[left, midY] += noiseFunction(noiseMin, noiseMax, offset);
// Left Wrapping
if (left == x_min)
array[x_max, midY] = array[left, midY];
// ==============
// Right Square
if (right + dx > x_max)
temp = x_min + dx;
else
temp = right + dx;
array[right, midY] = MathUtil.Average(array[right, top],
array[right, bottom],
array[midX, midY],
array[temp, midY]);
array[right, midY] += noiseFunction(noiseMin, noiseMax, offset);
// Right Wrapping
if (right == x_max)
array[x_min, midY] = array[right, midY];
}
} //End for loops
side /= 2;
squares *= 2;
offset += 1;
}
array.Normalize(0,1);
}
public static void ThreadedGenerateRandomHeight(Array2D array, Func<float, float, int, float> noiseFunction, Action onComplete=null)
{
if (generatorThread != null)
return;
if (onComplete == null)
onComplete = FunctionUtils.NoneAction;
generatorThread = new Thread(() => { GenerateRandomHeight(array, noiseFunction); onComplete(); generatorThread = null; });
generatorThread.Start();
}
