| public putPixelWrap ( int x, int y, float value ) : void | ||
| x | int | |
| y | int | |
| value | float | |
| return | void | |
public static Channel erode5(Channel channel, Channel rain, float erosion_water, float erosion_flow, float evaporation, float water_threshold, float solulibility, int ipr, int iterations)
{
Channel w = new Channel(channel.width, channel.height); // water map
Channel dw = new Channel(channel.width, channel.height); // delta water map
Channel s = new Channel(channel.width, channel.height); // sediment map
Channel ds = new Channel(channel.width, channel.height); // delta sediment map
Console.Write("Hydraulic erosion 5: ");
for (int i = 0; i < iterations; i++) {
Console.Write(".");
// save frames
/*
if (channel.width > 128 && i%10 == 0) {
if (i < 10) {
channel.toLayer().saveAsPNG("erosion00" + i);
} else if (i < 100) {
channel.toLayer().saveAsPNG("erosion0" + i);
} else {
channel.toLayer().saveAsPNG("erosion" + i);
}
}
*/
// water is added according to rain map
if (i%ipr == 0) {
w.channelAdd(rain);
}
// the presence of water dissolves material
channel.channelSubtract(w.copy().multiply(erosion_water));
s.channelAdd(w.copy().multiply(erosion_water));
// water and sediment are transported
float h, h1, h2, h3, h4, d1, d2, d3, d4, total_height, total_height_diff, total_height_diff_inv, avr_height, water_amount;
int cells;
for (int y = 0; y < channel.height; y++) {
for (int x = 0; x < channel.width; x++) {
// water transport
// calculate total heights and height differences
h = channel.getPixel(x, y) + w.getPixel(x, y) + s.getPixel(x, y);
h1 = channel.getPixelWrap(x , y + 1) + w.getPixelWrap(x , y + 1) + s.getPixelWrap(x , y + 1);
h2 = channel.getPixelWrap(x - 1, y ) + w.getPixelWrap(x - 1, y ) + s.getPixelWrap(x - 1, y );
h3 = channel.getPixelWrap(x + 1, y ) + w.getPixelWrap(x + 1, y ) + s.getPixelWrap(x + 1, y );
h4 = channel.getPixelWrap(x , y - 1) + w.getPixelWrap(x , y - 1) + s.getPixelWrap(x , y - 1);
d1 = h - h1;
d2 = h - h2;
d3 = h - h3;
d4 = h - h4;
// calculate amount of water to transport
total_height = 0f;
total_height_diff = 0f;
cells = 1;
if (d1 > 0) {
total_height_diff+= d1;
total_height+= h1;
cells++;
}
if (d2 > 0) {
total_height_diff+= d2;
total_height+= h2;
cells++;
}
if (d3 > 0) {
total_height_diff+= d3;
total_height+= h3;
cells++;
}
if (d4 > 0) {
total_height_diff+= d4;
total_height+= h4;
cells++;
}
if (cells == 1) {
continue;
}
avr_height = total_height/cells;
water_amount = Math.Min(w.getPixel(x, y), h - avr_height);
dw.putPixel(x, y, dw.getPixel(x, y) - water_amount);
total_height_diff_inv = water_amount/total_height_diff;
// transport water
if (d1 > 0) {
dw.putPixelWrap(x, y + 1, dw.getPixelWrap(x, y + 1) + d1*total_height_diff_inv);
}
if (d2 > 0) {
dw.putPixelWrap(x - 1, y, dw.getPixelWrap(x - 1, y) + d2*total_height_diff_inv);
}
if (d3 > 0) {
dw.putPixelWrap(x + 1, y, dw.getPixelWrap(x + 1, y) + d3*total_height_diff_inv);
}
if (d4 > 0) {
dw.putPixelWrap(x, y - 1, dw.getPixelWrap(x, y - 1) + d4*total_height_diff_inv);
}
// sediment transport
/*
h = s.getPixel(x, y);
h1 = s.getPixelWrap(x , y + 1);
h2 = s.getPixelWrap(x - 1, y );
h3 = s.getPixelWrap(x + 1, y );
h4 = s.getPixelWrap(x , y - 1);
d1 = h - h1;
d2 = h - h2;
d3 = h - h3;
d4 = h - h4;
// calculate amount of sediment to transport
total_height = 0f;
total_height_diff = 0f;
cells = 1;
if (d1 > 0) {
total_height_diff+= d1;
total_height+= h1;
cells++;
}
if (d2 > 0) {
total_height_diff+= d2;
total_height+= h2;
cells++;
}
if (d3 > 0) {
total_height_diff+= d3;
total_height+= h3;
cells++;
}
if (d4 > 0) {
total_height_diff+= d4;
total_height+= h4;
cells++;
}
if (cells == 1) {
continue;
}
avr_height = total_height/cells;
sediment_amount = Math.Min(s.getPixel(x, y), h - avr_height);
ds.putPixel(x, y, ds.getPixel(x, y) - sediment_amount);
total_height_diff_inv = sediment_amount/total_height_diff;
// transport sediment
if (d1 > 0) {
ds.putPixelWrap(x, y + 1, ds.getPixelWrap(x, y + 1) + d1*total_height_diff_inv);
}
if (d2 > 0) {
ds.putPixelWrap(x - 1, y, ds.getPixelWrap(x - 1, y) + d2*total_height_diff_inv);
}
if (d3 > 0) {
ds.putPixelWrap(x + 1, y, ds.getPixelWrap(x + 1, y) + d3*total_height_diff_inv);
}
if (d4 > 0) {
ds.putPixelWrap(x, y - 1, ds.getPixelWrap(x, y - 1) + d4*total_height_diff_inv);
}
*/
}
}
// more sediment is dissolved according to amount of water flow
/*
channel.channelSubtract(dw.copy().fill(0f, Float.MIN_VALUE, 0f).multiply(erosion_flow));
s.channelAdd(dw.copy().fill(0f, Float.MIN_VALUE, 0f).multiply(erosion_flow));
*/
// apply water and sediment delta maps
w.channelAdd(dw);
//w.fill(0f, Float.MIN_VALUE, water_threshold); // remove water below threshold amount
s.channelAdd(ds);
dw.fill(0f);
ds.fill(0f);
// water evaporates
w.multiply(evaporation);
// sediment is deposited
for (int y = 0; y < channel.height; y++) {
for (int x = 0; x < channel.width; x++) {
float deposition = s.getPixel(x, y) - w.getPixel(x, y)*solulibility;
if (deposition > 0) {
s.putPixel(x, y, s.getPixel(x, y) - deposition);
channel.putPixel(x, y, channel.getPixel(x, y) + deposition);
}
}
}
}
Console.WriteLine("DONE");
return channel;
}
