3D模拟自然——山体

算法上使用分形插值算法。渲染上，效率和扩展性中最理想的是用shader，但为了方便也可以用封装好的pixmap或shapeRenderer。这里用pixmap来绘制3d山。值得一提，1.6.1API：Color.toIntBits（int r,int g,int b,int a）是错的，参数位置前后倒了，导致山体一片红，所以顺着对的修改完毕。可以重置，修改blend模式以及精细程度。

以下是代码和效果图。





（可以看到n值为2倍后内存消耗增加不止1倍，渲染算法上是需要改进的）

package indi.dawn.ff.work;

import java.util.StringTokenizer;

import com.badlogic.gdx.Application.ApplicationType;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Pixmap.Blending;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.Pixmap.Format;
import com.badlogic.gdx.graphics.g2d.Batch;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.scenes.scene2d.Actor;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.InputListener;
import com.badlogic.gdx.utils.Disposable;

class MountainC extends Actor implements Disposable{
ShapeRenderer jj;
int n = 32, 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[];
Color col[][];
boolean painted;
Texture buffImage;Pixmap buffGraphics;
InputListener ip;
public MountainC(){
ip=new InputListener(){

@Override
public boolean touchDown(InputEvent event, float x, float y,
int pointer, int button) {
// TODO Auto-generated method stub
mx0 = (int) x;  my0 = (int) y;
if ( Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT) ){
setup();
//				    repaint();
}
if ( Gdx.input.isKeyPressed(Input.Keys.ALT_LEFT) ){
if (Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT) ){ n /= 2;  if (n < 1) n = 1;}
else n *= 2;
setup();
//				    repaint();
}
if(Gdx.app.getType()==ApplicationType.Android){
if (pointer==1){
n *= 2;
setup();
//						    repaint();
}
if (pointer==2 )
{ n /= 2;  if (n < 1) n = 1;}
}

return true;
}

@Override
public void touchDragged(InputEvent event, float x, float y,
int pointer) {
// TODO Auto-generated method stub
int x1 = (int) x;  int y1 = (int) y;
if ( Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT) )  scale *= Math.exp(-(y1 - my0)/(double)w);
else   fiX += dfi*(y1 - my0);
fiY += dfi*(x1 - mx0);   mx0 = x1;  my0 = y1;
rotate();
//				  repaint();
}

};
init();
/*for(int i=0;i<4;i++){
for(Color c:col[i]){
System.out.println(c.toIntBits());
}
}*/

}
private Color calCol(int r,int g,int b){
return new Color(Color.toIntBits(255, b, g, r));
};
int getN(){
return 32;
}
Color getCol(){
return Color.WHITE;
}
Color bgColor;
int pmWidth=600,pmHeight=800;
public void init(){
//		w=(int) getWidth();h=(int) getHeight();
w = pmWidth;  h = pmHeight;
w2 = w/2;  h2 = h/2;
//		  n=getN();
xPol = new int[3];  yPol = new int[3];
buffGraphics=new Pixmap(w, h, Pixmap.Format.RGB888);
//		  buffGraphics.setBlending(Blending.SourceOver);

buffImage= new Texture(buffGraphics);
col = new Color[4][256];
for (int i = 0; i < 256; i++){
col[0][i] = calCol(0, 0, i);
col[1][i] = calCol(0, (i*220)/256, 0);
col[2][i] = calCol((i*150)/256, (i*150)/256, (i*50)/256);
col[3][i] = calCol(i, i, i);}
for(int i=0;i<4;i++){
for(Color c:col[i]){
System.out.println(c);
}
}
bgColor=getCol();
if(bgColor==null)
bgColor=Color.WHITE;
addListener(ip);
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

[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 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;
}
@Override
public void draw(Batch batch, float parentAlpha) {
// TODO Auto-generated method stub
if ( !painted ){
if(buffImage!=null){
buffImage.dispose();
buffImage=null;
/* buffGraphics.dispose();
buffGraphics=new Pixmap(w, h, Format.RGB888);*/
}
//			 buffGraphics.dispose();
//			 Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
buffGraphics.setColor(Color.WHITE);
buffGraphics.fill();
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];
System.out.println(iCol[i][j][0]+"?"+(int)(Norm1z[i][j][0]));
System.out.println(col[iCol[i][j][0]][(int)(Norm1z[i][j][0])].toString());
buffGraphics.setColor(col[iCol[i][j][0]][(int)(Norm1z[i][j][0])]);
buffGraphics.fillTriangle(xPol[0], yPol[0], xPol[1], yPol[1], xPol[2], yPol[2]);
//			     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.fillTriangle(xPol[0], yPol[0], xPol[1], yPol[1], xPol[2], yPol[2]);} }
painted = true;
buffImage=new Texture(buffGraphics, true);

}
//		 Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.draw(buffImage, getX(), getY());

/*if(!painted){
buffGraphics.setColor(col(255, 0, 0));
buffGraphics.fill();
buffImage=new Texture(buffGraphics);
painted = true;
}batch.draw(buffImage, getX(), getY());*/

//			 g.drawImage(buffImage, 0, 0, this);
}

@Override
public void dispose() {
// TODO Auto-generated method stub
buffGraphics.dispose();
buffImage.dispose();
}
/***************************************************/
/*public void init2(){
w = getSize().width;  h = getSize().height;   w2 = w/2;  h2 = h/2;
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();
for(int i=0;i<4;i++){
for(Color c:col[i]){
int a=c.getRed();
int b=c.getGreen();
int g=c.getBlue();
int r=			c.getAlpha();
int m=(a << 24) | (b << 16) | (g << 8) | r;
System.out.println(m);
}
}
}*/
public void rotate2(){
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 iterate2(){
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 setup2(){
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

[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();
}
}