n为迭代精度，128比较合适，越高山越精细，但是程序会卡顿。
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.util.StringTokenizer;
public class moutain extends Applet
implements MouseListener, MouseMotionListener {
/**
* n:迭代次数
* n1：
* h:绘画区域高度
* w:绘画区域宽度
* h2:焦点坐标
* w2:焦点坐标
* mx0:
* my0:
* xpol:
* ypol:
* icol:
* */
int n =128, n1, h,w,h2,w2, mx0,my0, xPol[],yPol[], iCol[][][];
double rnd, fiX = .2, fiY = .3, dfi = .01, scale = .8, m20,m21,m22;
double vert[][][], vert1[][][], Norm[][][][], Norm1z[][][], M[];
Image buffImage; Graphics buffGraphics;
Color col[][];
boolean painted;
public void init(){
// w = getSize().width; h = getSize().height;
//设置绘画的区域高度和宽度
w=1024;h=768;
w2 = w/2; h2 = h/2;//视角聚焦点
String s=getParameter("N"); if (s != null) n = Integer.parseInt(s);
xPol = new int[3]; yPol = new int[3];
buffImage = createImage(w, h); buffGraphics = buffImage.getGraphics();
col = new Color[4][256];
for (int i = 0; i < 256; i++){
col[0][i] = new Color(0, 0, i);
col[1][i] = new Color(0, (i*220)/256, 0);
col[2][i] = new Color((i*150)/256, (i*150)/256, (i*50)/256);
col[3][i] = new Color(i, i, i);}
s = getParameter("bgColor"); if (s != null){
StringTokenizer st = new StringTokenizer(s);
int red = Integer.parseInt(st.nextToken());
int green = Integer.parseInt(st.nextToken());
int blue = Integer.parseInt(st.nextToken());
setBackground( new Color(red, green, blue));}
else setBackground(new Color(255,255,255));
addMouseListener(this);
addMouseMotionListener(this);
setup();
}
public double R(){ return rnd*(Math.random()-.5);}
public void setup(){
rnd = 1;
n1 = n+1;
iterate();
vert = new double[n1][n1][3]; vert1 = new double[n1][n1][2];
double dx = w/(double)n;
int t = 0;
for (int i = 0; i < n1; i++)
for (int j = 0; j < n1; j++){
vert[i][j][0] = dx*i - w2; vert[i][j][2] = dx*j - w2;
double mi = M[t++];
if (mi < 0) mi = .01*Math.random();
vert[i][j][1] = w*mi - w2/2;}
Norm = new double[n1][n1][2][3]; Norm1z = new double[n1][n1][2];
iCol = new int[n][n][2];
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++){
double s =
((vert[i][j][1] + vert[i+1][j][1] + vert[i+1][j+1][1])/3 + w2/2)/w;
if (s < .01) iCol[i][j][0] = 0;
else if (s+.1*Math.random() > .35) iCol[i][j][0] = 3;
else if (s+.1*Math.random() > .15) iCol[i][j][0] = 2;
else iCol[i][j][0] = 1;
s = ((vert[i][j][1] + vert[i][j+1][1] + vert[i+1][j+1][1])/3 + w2/2)/w;
if (s < .01) iCol[i][j][1] = 0;
else if (s+.1*Math.random() > .35) iCol[i][j][1] = 3;
else if (s+.1*Math.random() > .15) iCol[i][j][1] = 2;
else iCol[i][j][1] = 1;
Norm[i][j][0][0] = vert[i][j][1] - vert[i+1][j][1];
Norm[i][j][0][1] = dx;
Norm[i][j][0][2] = vert[i+1][j][1] - vert[i+1][j+1][1];
double mod = Math.sqrt(Norm[i][j][0][0]*Norm[i][j][0][0] + Norm[i][j][0][1]*
Norm[i][j][0][1] + Norm[i][j][0][2]*Norm[i][j][0][2]) / 255.5;
Norm[i][j][0][0] /= mod; Norm[i][j][0][1] /= mod; Norm[i][j][0][2] /= mod;
Norm[i][j][1][0] = vert[i][j+1][1] - vert[i+1][j+1][1];
Norm[i][j][1][1] = dx;
Norm[i][j][1][2] = vert[i][j][1] - vert[i][j+1][1];
mod = Math.sqrt(Norm[i][j][1][0]*Norm[i][j][1][0] + Norm[i][j][1][1]*
Norm[i][j][1][1] + Norm[i][j][1][2]*Norm[i][j][1][2]) / 255.5;
Norm[i][j][1][0] /= mod; Norm[i][j][1][1] /= mod; Norm[i][j][1][2] /= mod;}
rotate();
}
public void iterate(){
int nc=n, Max=n1*n1, ncn1;
double Min=-1;
M = new double[Max];
for (int i=n+2; i < n*n1-1; i++) M[i] = Min;
for (int i=2*n1; i < n*n1; i += n1) M[i] = M[i-1] = 0;
while ( (nc /= 2) >= 1){
ncn1 = nc*n1;
for (int j=ncn1; j < Max; j += ncn1+ncn1){
for (int i= nc; i < n; i += nc+nc){
if (M[i+j]==Min)
M[i+j] = (M[i+j+nc-ncn1] + M[i+j-nc+ncn1])/2.+R();
if (M[i+j+nc]==Min)
M[i+j+nc] = (M[i+j+nc+ncn1] + M[i+j+nc-ncn1])/2.+R();
if (M[i+j+ncn1]==Min)
M[i+j+ncn1] = (M[i+j-nc+ncn1] + M[i+j+nc+ncn1])/2.+R(); }}
rnd /= 2.;}
}
public void destroy() {
removeMouseListener(this);
removeMouseMotionListener(this);
}
public void mouseClicked(MouseEvent e){} // event handling
public void mousePressed(MouseEvent e) {
mx0 = e.getX(); my0 = e.getY();
if ( e.isControlDown() ){
setup();
repaint();}
if ( e.isAltDown() ){
if ( e.isShiftDown() ){ n /= 2; if (n < 1) n = 1;}
else n *= 2;
setup();
repaint();}
e.consume();
}
public void mouseReleased(MouseEvent e){}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mouseDragged(MouseEvent e) {
int x1 = e.getX(); int y1 = e.getY();
if ( e.isShiftDown() ) scale *= Math.exp(-(y1 - my0)/(double)w);
else fiX += dfi*(y1 - my0);
fiY += dfi*(x1 - mx0); mx0 = x1; my0 = y1;
rotate();
repaint();
e.consume();
}
public void rotate(){
double ct = Math.cos(fiX), cf = Math.cos(fiY),
st = Math.sin(fiX), sf = Math.sin(fiY),
m00 = scale*cf, m02 = scale*sf,
m10 = scale*st*sf, m11 = scale*ct, m12 = -scale*st*cf;
m20 = -ct*sf; m21 = st; m22 = ct*cf;
for (int i = 0; i < n1; i++)
for (int j = 0; j < n1; j++){
vert1[i][j][0] = m00*vert[i][j][0] + m02*vert[i][j][2];
vert1[i][j][1] = m10*vert[i][j][0] + m11*vert[i][j][1] + m12*vert[i][j][2];}
for (int i = 0; i < n; i++)
for (int j = 0; j < n; j++)
for (int k = 0; k < 2; k++)
Norm1z[i][j][k] = m20*Norm[i][j][k][0] + m21*Norm[i][j][k][1] +
m22*Norm[i][j][k][2];
painted = false;
}
public void mouseMoved(MouseEvent e) {}
public void paint(Graphics g) {
if ( !painted ){
buffGraphics.clearRect(0, 0, w, h);
int ib=0, ie=n, sti=1, jb=0, je=n, stj=1;
if (m20 < 0){ ib = n; ie = -1; sti = -1;}
if (m22 < 0){ jb = n; je = -1; stj = -1;}
for (int i = ib; i != ie; i += sti)
for (int j = jb; j != je; j += stj){
if (Norm1z[i][j][0] > 0){
xPol[0] = w2 + (int)vert1[i][j][0];
xPol[1] = w2 + (int)vert1[i+1][j][0];
xPol[2] = w2 + (int)vert1[i+1][j+1][0];
yPol[0] = h2 - (int)vert1[i][j][1];
yPol[1] = h2 - (int)vert1[i+1][j][1];
yPol[2] = h2 - (int)vert1[i+1][j+1][1];
buffGraphics.setColor(col[iCol[i][j][0]][(int)(Norm1z[i][j][0])]);
buffGraphics.fillPolygon(xPol,yPol, 3);}
if (Norm1z[i][j][1] > 0){
xPol[0] = w2 + (int)vert1[i][j][0];
xPol[1] = w2 + (int)vert1[i][j+1][0];
xPol[2] = w2 + (int)vert1[i+1][j+1][0];
yPol[0] = h2 - (int)vert1[i][j][1];
yPol[1] = h2 - (int)vert1[i][j+1][1];
yPol[2] = h2 - (int)vert1[i+1][j+1][1];
buffGraphics.setColor(col[iCol[i][j][1]][(int)(Norm1z[i][j][1])]);
buffGraphics.fillPolygon(xPol,yPol, 3);} }
painted = true;}
g.drawImage(buffImage, 0, 0, this);
showStatus( "n=" + n);
}
public void update(Graphics g){ paint(g); }
}
