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Java beginning if statement in for loop being skipped while others work

Back again with another problem that has stumped me completely and cannot for the life of me fix.
So I had previously posted a question about my Java game I am making for a class that with the help of #MadProgrammer was fixed...mostly. Now there is a new problem that needs a post all to it's own
Previous Post:
Rows and columns with multidimensional array java
Problem:
In the code below I have it set up to loop through the variables x and y to make rows and columns on a jPanel. Each time it loops through it should randomly mark the "x,y" location with one of the "terrains" so that later it can "paint" that location with the appropriate colored 20x20 square.
The code runs great except for one thing, it looks like it skips the very first "if statement" that marks the "terran[0]" which is "floor". When the code is ran it "paints" the other three "terrains" and not a single "floor" "terrain".
I have looked for a solution on these posts but no success:
Java if statement is skipped
If statement being skipped during execution
Java - for loops being skipped
Java if-statement being skipped
Here is a working piece of code that results in the problem at hand:
import java.awt.*;
import javax.swing.*;
import java.util.*;
public class gamePanel extends JPanel
{
public gamePanel()
{
setBounds(115,93,480,480);
}
private Random generator = new Random();
int floor = 0; //initializes the variable floor to zero for later use
int dirt = 1;
int stone = 2;
int water = 3;
int width = 24;
int height = 24;
int x, y; // my x & y variables for coordinates
int[][] coords = new int[width][height]; //my array that I want to store the coordinates for later use in painting
int[] terrain = {floor, dirt, stone, water}; //my terrain that will determine the color of the paint
public void mapGen() //what should mark/generate the JPanel
{
for(x = 0; x < width; x++)
{
for(y = 0; y < height; y++)
{
int z = generator.nextInt(20);// part of the randomization
if(z <= 10)
{
coords[x][y] = terrain[0]; //should mark the coordinates as floor
}
if(z == 11)
{
coords[x][y] = terrain[3];//should mark the coordinates as water
}
if(z >= 12 && z <= 16)
{
coords[x][y] = terrain[2];//should mark the coordinates as stone
}
if(z >= 17 && z <= 19)
{
coords[x][y] = terrain[1];//should mark the coordinates as dirt
}
coords[0][0] = terrain[0]; // sets coordinate 0,0 to floor //need to have these always be floor
coords[23][23] = terrain[0]; // sets coordinate 24,24 to floor //^^^^^^^^^^
}
}
}
#Override
public void paintComponent(Graphics g)//what will paint each 20x20 square on the grid what it is assigned
{
super.paintComponent(g);
for(int x = 0; x < width; x++)
{
for(int y = 0; y < height; y++)
{
mapGen();
if(coords[x][y] == terrain[floor])//should paint the floor color at marked coordinates
{
g.setColor(Color.white);
g.fillRect((x*20), (y*20), 20, 20);
}
if(coords[x][y] == terrain[dirt]);//should paint the dirt color at marked coordinates
{
g.setColor(new Color(135,102,31));
g.fillRect((x*20), (y*20), 20, 20);
}
if(coords[x][y] == terrain[stone])//should paint the stone color at marked coordinates
{
g.setColor(new Color(196,196,196));
g.fillRect((x*20),(y*20),20,20);
}
if(coords[x][y] == terrain[water])//should paint the water color at marked coordinates
{
g.setColor(new Color(85,199,237));
g.fillRect((x*20),(y*20),20,20);
}
}
}
}//end paintComponent
public static void main(String[] args)
{
gamePanel panel = new gamePanel();
JFrame frame = new JFrame();
frame.setSize(500,550);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(panel);
frame.setVisible(true);
}//end main
}// end gamePanel
Please keep in mind that I am a novice programmer and I am still learning. So anything that is not considered "basic" code please explain in detail.

When drawing multiple lines in applet, it shows only the last one

I am trying to draw multiple lines by using Java applet and canvas. I have defined class Canvas:
public class Canvas extends JPanel {
private static final int RIGHT=0, LEFT=1, UP=2, DOWN=3;
public static final int WIDTH=600, HEIGHT=500;
private int direction = 0 ;
private int pixels;
/**
* Canvas() constructor sets its size
*/
public Canvas() {
setSize(WIDTH, HEIGHT);
}
public void setPatt(int pat, int lev) {
direction = pat;
pixels = lev;
}
public void paintComponent(Graphics g) {
g.setColor(getForeground());
switch (direction) {
case LEFT:
drawLineLeft(g, pixels);
break;
case RIGHT:
drawLineRight(g, pixels);
break;
case UP:
drawLineUp(g, pixels);
break;
case DOWN:
drawLineDown(g, pixels);
break;
}
}
private void drawLineLeft(Graphics g, int pix){
if(pix > 0){
Dimension d = getSize();
int x = d.width/2;
int y = d.height/2;
g.drawLine(x, y, x-10*pix, y);//left
}
}
private void drawLineUp(Graphics g, int pix){
if(pix > 0){
Dimension d = getSize();
int x = d.width/2;
int y = d.height/2;
g.drawLine(x, y, x, y-10*pix);//up
}
}
private void drawLineRight(Graphics g, int pix){
//Graphics2D g2 = (Graphics2D) g;
if(pix > 0){
Dimension d = getSize();
int x = d.width/2;
int y = d.height/2;
g.drawLine(x, y, x+10*pix, y);//right
}
}
private void drawLineDown(Graphics g, int pix){
if(pix > 0){
Dimension d = getSize();
int x = d.width/2;
int y = d.height/2;
g.drawLine(x, y, x, y+10*pix);// down
}
}
}
I also have another class where I have defined drop down list, text field and button. I can choose direction from drop down list in which line should be painted (RIGHT, LEFT, UP, DOWN - direction) and I can define how long the line will be by typing a number in text field (pixels). When the button is pushed, method setPatt is called and line appears in canvas:
public class TurtleApplet extends JApplet implements ActionListener
{
.....
.....
.....
public void actionPerformed( ActionEvent e)
{
if(e.getSource() == drawButton){
int y = Integer.parseInt(pixels.getText());
canvas.setPatt(direction.getSelectedIndex(), Integer.parseInt(pixels.getText()));
}
//repaint();
}
.....
}
The problem is that when I push the button new line appears in canvas only then when I resize applet window. I tried to add repaint() method, this helped, but still there is another problem - how to make draw new line without losing the previous one?
Only the last line is visible on the screen, for example, when I draw a line to the left from center (line always starts from the center of canvas) and then I want to draw a new line to the right from the center, the line first line disappears and I can see only the second one and so on.

You should keep track of lines drawn already. The paintComponent method supposed to print (or reprint) the entire component. As far as I see you always print just 1 line, therefore you loose the previous state.
Try to create a Map<Integer, Integer> where you store the line data and iterate through in the paintComponent method to draw all lines.
The method setPatt may be called addPatt instead.
PS: If the order matters, try LinkedHashMap

Mapping rgbMap to depthMap

So I'm trying to map the pixel on the rgbMap to one on the depthMap so I can get the depth from a color tracked object.
I've noticed the depth map is smaller than the rgb map in addition to the different POV from being on a different spot on the kinect itself.
Is there an efficient way to do this that I'm unaware of? Currently I'm thinking of trying to line up the example pixels and then try to figure out an equation for the offset as you get farther away.
Code below, please not that the color tracking is far from done, and that I'm using mouse pressed for testing the pixel position.
/**
* ControlP5 Controlframe
* with controlP5 2.0 all java.awt dependencies have been removed
* as a consequence the option to display controllers in a separate
* window had to be removed as well.
* this example shows you how to create a java.awt.frame and use controlP5
*
* by Andreas Schlegel, 2012
* www.sojamo.de/libraries/controlp5
*
*/
import java.awt.Frame;
import java.awt.BorderLayout;
import controlP5.*;
import SimpleOpenNI.*;
private ControlP5 cp5;
ControlFrame cf;
SimpleOpenNI context;
Ktracker p,o,b;
float rx,ry,dx,dy;
int def;
void setup() {
size((2 * 640),480);
cp5 = new ControlP5(this);
o = new Ktracker(188,57,49);
// by calling function addControlFrame() a
// new frame is created and an instance of class
// ControlFrame is instanziated.
cf = addControlFrame("Output", 640,480);
// add Controllers to the 'extra' Frame inside
// the ControlFrame class setup() method below.
context = new SimpleOpenNI(this);
context.enableRGB();
context.enableDepth();
smooth();
rx=context.rgbWidth()/2;
ry=height/2;
}
void draw() {
context.update();
background(0,150,0);
image(context.depthImage(),context.rgbWidth(),0);
image(context.rgbImage(), 0,0);
int[] dm = context.depthMap();
o.run();
rectMode(CENTER);
noStroke();
fill(255,255,0);
rect(rx,ry,5,5);
dx=rx;
dy=ry;
fill(0,255,255);
rect(dx+context.rgbWidth(),dy,5,5);
rectMode(CORNER);
if(o.wr<10){
fill(0,0,255);
noStroke();
ellipse(o.currentPoints[0]+context.rgbWidth(),o.currentPoints[1],10,10);
cf.z = dm[int(o.currentPoints[0]*o.currentPoints[1])];
} else {
cf.z=0;
}
}
void mousePressed(){
rx=mouseX;
ry=mouseY;
}
ControlFrame addControlFrame(String theName, int theWidth, int theHeight) {
Frame f = new Frame(theName);
ControlFrame p = new ControlFrame(this, theWidth, theHeight);
f.add(p);
p.init();
f.setTitle(theName);
f.setSize(p.w, p.h);
f.setLocation(100, 100);
f.setResizable(false);
f.setVisible(true);
return p;
}
// the ControlFrame class extends PApplet, so we
// are creating a new processing applet inside a
// new frame with a controlP5 object loaded
public class ControlFrame extends PApplet {
int w, h;
float z;
int abc = 100;
public void setup() {
size(w, h, P3D);
frameRate(25);
z=0;
}
public void draw() {
background(abc);
translate(width/2,height/2,z/100);
sphere(250);
}
private ControlFrame() {
}
public ControlFrame(Object theParent, int theWidth, int theHeight) {
parent = theParent;
w = theWidth;
h = theHeight;
}
public ControlP5 control() {
return cp5;
}
ControlP5 cp5;
Object parent;
}
class Ktracker{
float mx,my,wr;
// A variable for the color we are searching for.
color trackColor;
float[] currentPoints, prevPoints;
Ktracker(int r,int g, int b){
trackColor = color(r,g,b);
currentPoints = new float[2];
prevPoints = new float[2];
prevPoints[0]=0;
prevPoints[1]=0;
}
void run(){
loadPixels();
// Before we begin searching, the "world record" for closest color is set to a high number that is easy for the first pixel to beat.
float worldRecord = 500;
// XY coordinate of closest color
int closestX = 0;
int closestY = 0;
// Begin loop to walk through every pixel
for (int x = 0; x < width/2; x ++ ) {
for (int y = 0; y < height; y ++ ) {
int loc = x + y*width;
// What is current color
color currentColor = pixels[loc];
float r1 = red(currentColor);
float g1 = green(currentColor);
float b1 = blue(currentColor);
float r2 = red(trackColor);
float g2 = green(trackColor);
float b2 = blue(trackColor);
// Using euclidean distance to compare colors
float d = dist(r1,g1,b1,r2,g2,b2); // We are using the dist( ) function to compare the current color with the color we are tracking.
// If current color is more similar to tracked color than
// closest color, save current location and current difference
if (d < worldRecord) {
worldRecord = d;
closestX = x;
closestY = y;
currentPoints[0] = closestX;
currentPoints[1] = closestY;
}
}
}
wr=worldRecord;
// We only consider the color found if its color distance is less than 10.
// This threshold of 10 is arbitrary and you can adjust this number depending on how accurate you require the tracking to be.
if (worldRecord < 10) {
// Draw a circle at the tracked pixel
fill(255,0,0);
//strokeWeight(4.0);
stroke(0,0);
ellipse(currentPoints[0],currentPoints[1],16,16);
}
println("wr: "+wr);
println("worldRecord: "+worldRecord);
}
}

If you want to align the depth map with the RGB map you need to simply tell OpenNI to do so fo you in setup:
context.alternativeViewPointDepthToImage();
Have a look at the AlternativeViewpoint3d sketch in Examples > SimpleOpenNI > OpenNI
OpenNI has the registration done already so all you need to do is enable it when you need it.

Draw series of concentric circles with random settings

I'm really stuck on how to go about programming this. Need to draw a series of 8 concentric circles using Java drawArc method with following conditions
using import java.util.Random library
Provide for starting the drawings at random location (i.e., the x-y
cooridinate must be calculated randomly).
Provide a random color for each circle
Provide a random diameter for each circle
My current code is able to get random random color for each circle but not clear how to meet other random conditions
// Exercise 12.6 Solution: CirclesJPanel.java
// This program draws concentric circles
import java.awt.Graphics;
import javax.swing.JPanel;
public class ConcentricCircles extends JPanel
{
// draw eight Circles separated by 10 pixels
public void paintComponent( Graphics g )
{
Random random = new Random();
super.paintComponent( g );
// create 8 concentric circles
for ( int topLeft = 0; topLeft < 80; topLeft += 10 )
{
int radius = 160 - ( topLeft * 2 );
int r = random.nextInt(255);
int gr = random.nextInt(255);
int b = random.nextInt(255);
Color c = new Color(r,gr,b);
g.setColor(c);
g.drawArc( topLeft + 10, topLeft + 25, radius, radius, 0, 360 );
} // end for
}
}
// This program draws concentric circles
import javax.swing.JFrame;
public class ConcentricCirclesTest extends JFrame {
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
JFrame frame=new JFrame("Concentric Circles");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ConcentricCircles cCirclesJPanel = new ConcentricCircles();
frame.add(cCirclesJPanel);
frame.setSize(200,250);
frame.setVisible(true);
}//end main
}

Several points are key to such an exercise:
Start with constants for the number of circles and step size; the random number generator in particular only needs to be created once.
private static final int N = 8;
private static final int S = 32;
private static Random random = new Random();
Choose a random point whose coordinates fall within the drawing area.
// a random point inset by S
int x = random.nextInt(getWidth() - S * 2) + S;
int y = random.nextInt(getHeight() - S * 2) + S;
For each circle, find the diameter as a function of S, adding a random fraction of a step, and render the arc at the chosen point offset by the radius.
for (int i = 0; i < N; i++) {
g2d.setColor(…);
int d = (i + 1) * S + random.nextInt(S / 2);
int r = d / 2;
g2d.drawArc(x - r, y - r, d, d, 0, 360);
}
Resize the enclosing frame, which forces a repaint(), to see the effect.
As random colors are not always appealing, consider Collections.shuffle() on a List<Color>.
private final List<Color> clut = new ArrayList<Color>();
…
for (int i = 0; i < N; i++) {
clut.add(Color.getHSBColor((float) i / N, 1, 1));
}
…
Collections.shuffle(clut);
…
g2d.setColor(clut.get(i));
Override getPreferredSize() to establsh the drawing panel's size.
private static final int W = S * 12;
private static final int H = W;
…
#Override
public Dimension getPreferredSize() {
return new Dimension(W, H);
See also Initial Threads.

Animated line graphs with primitive line graphic functions Java

In the effort to learn more about applets and Java, I am experimenting making wave applets by drawing lines (drawLine) and making animated line graphs.
I can make a static graph just fine. However I am struggling with the animated aspect of the graph: the axes of the graph should move from left to right, increasing and growing larger than 0.
My problem is translating my needs into a solution. Can anyone give me any pointers with my problem?
I have a multidimensional array indexed by points containing the x and y of a particular point. I have tried modifying my render function to decrease the Xs to make it appear as if it is moving left but this doesn't work right.
What approach am I looking to take? How different will my approach be if the values of Y could change due to user action or added data?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Random;
/**
* A graph that should in the future represent a wave according to my inputs
*
* #authorImprofane
* #version 1
*/
public class Graph extends JFrame
{
private InnerGraph inner;
private int width;
private Random RNG;
private int height;
private int[][] series;
private int xoffset;
int prevx = 0;
int prevy = 0;
/**
* Constructor for objects of class Graph
*/
public Graph(int width, int height) throws InterruptedException
{
RNG = new Random();
setTitle(" Graph");
series = new int[width][2];
this.width = width;
this.height = height;
inner = new InnerGraph(width, height);
add(inner, BorderLayout.CENTER);
setVisible(true);
inner.preparePaint();
pack();
updateGraph();
}
public static void main(String[] args) throws InterruptedException
{
new Graph(300, 300);
}
public void updateGraph() throws InterruptedException
{
// virtual x is how far along on the x axis we are, I ignore the 'real' X axis
int vx = 0;
int point = 0;
int xdecay = 0;
int inc = 5;
// how many times we need to plot a point
int points = (int) java.lang.Math.floor( width / inc );
System.out.println(points);
inner.preparePaint();
// draw all points to graph
// make some junk data, a saw like graph
for (vx = 0 ; vx < points ; vx++) {
series[vx] = new int[] { vx*inc, ( (vx*inc) % 120 ) };
}
Thread.sleep(150);
int n = 5;
while(n > 0) {
System.out.println(xdecay);
inner.preparePaint();
for (vx = 0 ; vx < points ; vx++) {
inner.updateSeries(vx, xdecay);
inner.repaint();
Thread.sleep(50);
}
xdecay += inc;
// shift the data points to the left
int[][] nseries = new int[points][2];
// System.arraycopy(series, 1, nseries, 0, points-1);
n--;
}
}
public class InnerGraph extends JPanel
{
private Graphics g;
private Image img;
private int gwidth;
private int gheight;
Dimension size;
public InnerGraph(int width, int height)
{
gwidth = width;
gheight = height;
size = new Dimension(1, 1);
}
/**
* Try make panel the requested size.
*/
public Dimension getPreferredSize()
{
return new Dimension(gwidth, gheight);
}
/**
* Create an image and graphics context
*
*/
public void preparePaint()
{
size = getSize();
img = inner.createImage( (size.width | gwidth), (size.height | gheight) );
g = img.getGraphics();
}
/**
* Draw a point to the chart given the point to use and the decay.
* Yes this is bad coding style until I work out the mathematics needed
* to do what I want.
*/
public void updateSeries(int point, int decay)
{
g.setColor(Color.blue);
int nx = series[point][0];
series[point][0] -= decay;
if ( point-1 >= 0 ) {
series[point-1][0] -= decay;
}
int ny = series[point][1];
prevx -= decay;
g.drawLine(prevx-decay, prevy, nx-decay, ny );
prevx = nx-decay;
prevy = ny;
}
public void paintComponent(Graphics g)
{
g.drawImage(img, 0, 0, null);
}
}
}

First, it looks like you are subtracting the decay too often in the updateSeries method.
Below is a new version of that method.
public void updateSeries(int point, int decay)
{
g.setColor(Color.blue);
int nx = series[point][0];
series[point][0] -= decay;
if ( point-1 >= 0 ) {
series[point-1][0] -= decay;
}
int ny = series[point][1];
// prevx -= decay;
// g.drawLine(prevx-decay, prevy, nx-decay, ny );
g.drawLine(prevx, prevy, nx-decay, ny );
prevx = nx-decay;
prevy = ny;
}
With those changes, the lines draw better, but they draw so slowly that the animation is hard to see. You probably need to build a new graphics and swap the whole thing so that you don't have to watch each individual line segment being drawn.

For a starter you could check out the following example (and the ones related to this)
Scroll Chart #java2s.com