I got a below java code which plots a 2D graph where x axis has values 1,2,3,......20
and y axis has values 21,14,18..........18
The code works perfectly but the only problem is that the graph does not shows the corresponding x and y values on x axis and y axis respectively. I know it could be a small addition to the code. but i am new to java graphics and i am not able to figure out where to add the relevant code considering the time constraint.
/*Sample code */
public class GraphingData extends JPanel {
int[] data = {
21, 14, 18, 03, 86, 88, 74, 87, 54, 77,
61, 55, 48, 60, 49, 36, 38, 27, 20, 18
};
final int PAD = 20;
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
int w = getWidth();
int h = getHeight();
// Draw ordinate.
g2.draw(new Line2D.Double(PAD, PAD, PAD, h-PAD));
// Draw abcissa.
g2.draw(new Line2D.Double(PAD, h-PAD, w-PAD, h-PAD));
// Draw labels.
Font font = g2.getFont();
FontRenderContext frc = g2.getFontRenderContext();
LineMetrics lm = font.getLineMetrics("0", frc);
float sh = lm.getAscent() + lm.getDescent();
// Ordinate label.
String s = "Average Byte Value";
float sy = PAD + ((h - 2*PAD) - s.length()*sh)/2 + lm.getAscent();
for(int i = 0; i < s.length(); i++) {
String letter = String.valueOf(s.charAt(i));
float sw = (float)font.getStringBounds(letter, frc).getWidth();
float sx = (PAD - sw)/2;
g2.drawString(letter, sx, sy);
sy += sh;
}
// Abcissa label.
s = "file blocks";
sy = h - PAD + (PAD - sh)/2 + lm.getAscent();
float sw = (float)font.getStringBounds(s, frc).getWidth();
float sx = (w - sw)/2;
g2.drawString(s, sx, sy);
// Draw lines.
double xInc = (double)(w - 2*PAD)/(data.length-1);
double scale = (double)(h - 2*PAD)/getMax();
g2.setPaint(Color.green.darker());
for(int i = 0; i < data.length-1; i++) {
double x1 = PAD + i*xInc;
double y1 = h - PAD - scale*data[i];
double x2 = PAD + (i+1)*xInc;
double y2 = h - PAD - scale*data[i+1];
g2.draw(new Line2D.Double(x1, y1, x2, y2));
}
// Mark data points.
g2.setPaint(Color.red);
for(int i = 0; i < data.length; i++) {
double x = PAD + i*xInc;
double y = h - PAD - scale*data[i];
g2.fill(new Ellipse2D.Double(x-2, y-2, 4, 4));
}
}
private int getMax() {
int max = -Integer.MAX_VALUE;
for(int i = 0; i < data.length; i++) {
if(data[i] > max)
max = data[i];
}
return max;
}
public static void main(String[] args) {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new GraphingData());
f.setSize(400,400);
f.setLocation(200,200);
f.setVisible(true);
}
}
public void drawGrid(Graphics g)
{
g.setColor(Color.black);
int rows = model.maxy-model.miny+1;
int cols = model.maxx-model.minx+1;
int colWidth = (getWidth()-paddingFromRight - ylabelWidth)/cols;
int rowHeight = (getHeight()-xlabelHeight-headingHeight)/rows;
int endX = ylabelWidth + cols * colWidth;
int endY = headingHeight + rows*rowHeight;
for (int k = 0; k <= cols; k++)
{
g.drawLine(ylabelWidth+colWidth*k, headingHeight, ylabelWidth+colWidth*k, endY); //getHeight()-xlabelHeight
}
for (int k = 0; k <= rows;k++)
{
g.drawLine(ylabelWidth, headingHeight+rowHeight*k,endX, headingHeight+rowHeight*k);
}
}
public void drawLines(Graphics g)
{
ArrayList<Line> lines = model.getLines();
Random random = new Random(50);
for (int k = 0; k < lines.size(); k++)
{
g.setColor(new Color(255-50*k, 50*k, 2*50*k));
//g.setColor(Color.red);
drawLine(g, lines.get(k));
}
}
public void drawLine(Graphics g, Line line)
{
ArrayList<Point> points = line.points;
for (int k = 0; k<points.size()-1;k++)
{
//scale up points
Point p1 = points.get(k);
Point p2 = points.get(k+1);
g.drawLine(scaleUpX(p1.x), scaleUpY(p1.y), scaleUpX(p2.x), scaleUpY(p2.y));
g.fillOval(scaleUpX(p1.x)-5, scaleUpY(p1.y)-5, 10, 10);
}
Point p1 = points.get(points.size()-1);
g.fillOval(scaleUpX(p1.x)-5, scaleUpY(p1.y)-5, 10, 10);
}
public int scaleUpX(int x)
{
int cols = model.maxx-model.minx+1;
int colWidth = (getWidth()-paddingFromRight - ylabelWidth)/cols;
return ylabelWidth+colWidth*x;
}
public int scaleUpY(int y)
{
int rows = model.maxy-model.miny+1;
int rowHeight = (getHeight()-xlabelHeight-headingHeight)/(rows);
//int endY = getHeight()-xlabelHeight;
int endY = headingHeight+rows*rowHeight;
return endY - rowHeight*y;
}
public void drawLabels(Graphics g)
{
Dimension d = getSize();
//xlabel
g.drawString(model.xlabel, d.width/2, d.height-xlabelHeight/4);
//ylabel
g.drawString(model.ylabel, 0+5, d.height/2);
//xaxis
int rows = model.maxy-model.miny+1;
int cols = model.maxx-model.minx+1;
int colWidth = (getWidth()-paddingFromRight - ylabelWidth)/cols;
int rowHeight = (getHeight()-xlabelHeight-headingHeight)/rows;
for (int k = 0;k<=cols;k++)
{
g.drawString(String.valueOf(model.minx+k), ylabelWidth+k*colWidth-5, rowHeight*rows+headingHeight+15);
}
//yaxis
for (int k = 0;k<=rows;k++)
{
g.drawString(String.valueOf(model.maxy-k+1),ylabelWidth-15,headingHeight+k*rowHeight);
}
//heading
FontMetrics fm = g.getFontMetrics();
g.setFont(g.getFont().deriveFont((float)25.0));
g.drawString(model.title, d.width/2-fm.stringWidth(model.title), headingHeight/2+headingHeight/4);
}
Related
I have a Voronoi diagram being displayed thanks to the Graphics2D class. I would like to know how to display a String in one of black dots located within the patterns. I've tried things such as labels, etc., and can't manage to output a String anywhere in the diagram.
Here's how the code looks:
public Voronoi() {
super("Voronoi Diagram");
setBounds(0, 0, size, size);
setDefaultCloseOperation(EXIT_ON_CLOSE);
int n = 0;
Random rand = new Random();
I = new BufferedImage(size, size, BufferedImage.TYPE_INT_RGB);
px = new int[cells];
py = new int[cells];
color = new int[cells];
for (int i = 0; i < cells; i++) {
px[i] = rand.nextInt(size);
py[i] = rand.nextInt(size);
color[i] = rand.nextInt(16777215);
}
for (int x = 0; x < size; x++) {
for (int y = 0; y < size; y++) {
n = 0;
for (byte i = 0; i < cells; i++) {
if (distance(px[i], x, py[i], y) < distance(px[n], x, py[n], y)) {
n = i;
}
}
I.setRGB(x, y, color[n]);
}
}
Graphics2D g = I.createGraphics();
g.setColor(Color.BLACK);
for (int i = 0; i < cells; i++) {
g.fill(new Ellipse2D .Double(px[i] - 2.5, py[i] - 2.5, 5, 5));
}
try {
ImageIO.write(I, "png", new File("voronoi.png"));
} catch (IOException e) {
}
}
public void paint(Graphics g) {
g.drawImage(I, 0, 0, this);
}
static double distance(int x1, int x2, int y1, int y2) {
double d;
// d = Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)); // Euclidian
d = Math.abs(x1 - x2) + Math.abs(y1 - y2); // Manhattan
// d = Math.pow(Math.pow(Math.abs(x1 - x2), p) + Math.pow(Math.abs(y1 - y2), p), (1 / p)); // Minkovski
return d;
}
public static void main(String[] args) {
new Voronoi().setVisible(true);
}
}
I am trying to add a square to the canvas when a mouse key is pressed and i want it to remain on the canvas when the mouse key is released, but it disappears when is released the key. Can anybody help me, what am i doing wrong?
int squareSize = 6;
final float DIFF_SIZE = 1;
final int MIN_COLOUR = 1;
final int MAX_COLOUR = 10;
final float INIT_RED = 100, INIT_GREEN = 50, INIT_BLUE = 80;
final float FINAL_RED = 255, FINAL_GREEN = 200, FINAL_BLUE = 250;
final float MAX_SIZE = 40;
final float X_SPACING = 10;
final float Y_SPACING = 10;
float squareX, squareY;
void setup() {
size(600, 600);
}
void draw() {
squareX = mouseX - squareSize / 2;
squareY = mouseY - squareSize / 2;
background(255);
drawRowsOfBlocks();
}
void drawOneBlock() {
rect(squareX, squareY, squareSize, squareSize);
for (int i = MIN_COLOUR; mousePressed && i <= MAX_COLOUR / 10; i++)
{
float redValue = INIT_RED + (i - MIN_COLOUR) / (MAX_COLOUR - MIN_COLOUR)(FINAL_RED - INIT_RED);
float greenValue = INIT_GREEN + (i - MIN_COLOUR) / (MAX_COLOUR - MIN_COLOUR)(FINAL_GREEN - INIT_GREEN);
float blueValue = INIT_BLUE + (i - MIN_COLOUR) / (MAX_COLOUR - MIN_COLOUR) * (FINAL_BLUE - INIT_BLUE);
fill(redValue, greenValue, blueValue);
rect(squareX, squareY, squareSize, squareSize);
squareSize += DIFF_SIZE;
}
if (squareSize > MAX_SIZE) {
squareSize = 6;
}
}
void drawRowsOfBlocks() {
drawOneBlock();
for (int i = 1; keyPressed && i <= 2; i++) {
drawOneBlock();
float squareY2;
squareY2 = squareY + squareSize + Y_SPACING;
squareY = squareY2;
}
}
Create a class which can handle a rectangle. The calls needs a method to draw the rectangle (Draw()) and a method to update the position and size of the rectangle (Update()):
final int DIFF_SIZE = 1;
final int MIN_SIZE = 6;
final int MAX_SIZE = 40;
final float INIT_RED = 100, INIT_GREEN = 50, INIT_BLUE = 80;
final float FINAL_RED = 255, FINAL_GREEN = 200, FINAL_BLUE = 250;
class Rectangle {
int pos_x, pos_y, size;
color col;
Rectangle(int px, int py, int s, color c) {
col = c;
pos_x = px; pos_y = py;
size = s;
}
void Update(int px, int py, int inc_size) {
pos_x = px; pos_y = py;
size += inc_size;
if (size > MAX_SIZE)
size = MIN_SIZE;
float w = float(size - MIN_SIZE) / float(MAX_SIZE - MIN_SIZE);
float redValue = INIT_RED + w * (FINAL_RED - INIT_RED);
float greenValue = INIT_GREEN + w * (FINAL_GREEN - INIT_GREEN);
float blueValue = INIT_BLUE + w * (FINAL_BLUE - INIT_BLUE);
col = color(int(redValue), int(greenValue), int(blueValue));
}
void Draw() {
fill(col);
rect(pos_x-size/2, pos_y-size/2, size, size);
}
}
Use ArrayList to store all the drawn rectangles:
ArrayList<Rectangle> rectangles = new ArrayList<Rectangle>();
Add a global, boolean state (drawingRect) which indicates if the mouse button is currently pressed. Set the state and add new rectangle at the end of the list when the mousePressed() event occurs. rest the state when the mouseReleased() event occurs
boolean drawingRect = false;
void mousePressed() {
drawingRect = true;
color col = color(int(INIT_RED), int(INIT_GREEN), int(INIT_BLUE));
rectangles.add(new Rectangle(mouseX, mouseY, MIN_SIZE, col));
}
void mouseReleased() {
drawingRect = false;
}
Use the method .Update(), to change the location and size of the last rectangle in the list as long as the state drawingRect indicates that a mouse button is pressed.
Continuously draw all te rectangles in a loop:
void setup() {
size(600, 600);
}
void draw() {
if (drawingRect && rectangles.size() > 0) {
Rectangle lastRect = rectangles.get(rectangles.size()-1);
lastRect.Update(mouseX, mouseY, DIFF_SIZE);
}
background(255);
for (int i = 0; i < rectangles.size(); i++) {
Rectangle rect = rectangles.get(i);
rect.Draw();
}
}
The image rotates with code below, but wrong, some black dots appears on original image. I believe it's something with rotation code. Any solution? Thanks. The image dimensions is 32x32 pixels loaded on center of screen (320x240).
public class RendPanel extends JPanel {
private static final long serialVersionUID = 1L;
int widthe = 320;
int heighte = 240;
double angle = Math.toRadians(220);
double sin = Math.sin(angle);
double cos = Math.cos(angle);
double x0 = 0.5 * (widthe - 1); // point to rotate about
double y0 = 0.5 * (heighte - 1); // center of image
public static BufferedImage fbuffer;
public RendPanel(int width, int height) {
fbuffer = new BufferedImage(320, 240, BufferedImage.TYPE_INT_RGB);
BufferedImage in = null;
try { in = ImageIO.read(new File("square.png")); } //32x32 square .png
catch (IOException e) { e.printStackTrace(); }
for (int i = 0; i < in.getWidth(); i++) {
for (int j = 0; j < in.getHeight(); j++) {
fbuffer.setRGB(i + (320 / 2) - 16, j + (240 / 2) - 16, in.getRGB(i, j));
}
}
BufferedImage neww = new BufferedImage(320, 240, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < widthe; x++) {
for (int y = 0; y < heighte; y++) {
if(x >= x0 - 32 && x <= x0 + 32 && y >= y0 - 32 && y <= y0 + 32){
double a = x - x0;
double b = y - y0;
int xx = (int) (+a * cos - b * sin + x0);
int yy = (int) (+a * sin + b * cos + y0);
// plot pixel (x, y) the same color as (xx, yy) if it's in bounds
if (xx >= 0 && xx < width && yy >= 0 && yy < height) {
neww.setRGB(xx, yy, fbuffer.getRGB(x, y));
}
}
}
}
fbuffer = neww;
repaint();
setPreferredSize(new Dimension(width, height));
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(fbuffer, 0, 0, null);
}
}
A beginner's mistake (sorry).
Taking every source pixel in turn, transforming the coordinates to the destination and copying the pixel value is not the right way.because the regular input grid will not map to a regular grid, and there will be voids (and overlaps).
The correct way is to scan the destination image (so that every destination pixel is reached) and counter-transform the coordinates to fetch the pixel value from the source.
As a refinement, you can use the four neighboring pixel from where you land in the source and perform bilinear interpolation, to reduce aliasing.
Man, it's strange, because in this code it works properly!
Heres a working code:
public class RendPanel extends JPanel {
private static final long serialVersionUID = 1L;
int widthe = 320;
int heighte = 240;
int ang = 0;
double x0 = 0.5 * (widthe - 1); // point to rotate about
double y0 = 0.5 * (heighte - 1); // center of image
public static BufferedImage fbuffer;
public RendPanel(int width, int height) {
fbuffer = new BufferedImage(320, 240, BufferedImage.TYPE_INT_RGB);
BufferedImage in = null;
try { in = ImageIO.read(new File("square.png")); } //32x32 square .png
catch (IOException e) { e.printStackTrace(); }
for (int i = 0; i < in.getWidth(); i++) {
for (int j = 0; j < in.getHeight(); j++) {
fbuffer.setRGB(i + (320 / 2) - 16, j + (240 / 2) - 16, in.getRGB(i, j));
}
}
setPreferredSize(new Dimension(width, height));
}
BufferedImage neww;
public void r(){
neww = new BufferedImage(320, 240, BufferedImage.TYPE_INT_RGB);
double angle = Math.toRadians(ang);
double sin = Math.sin(angle);
double cos = Math.cos(angle);
for (int x = 0; x < widthe; x++) {
for (int y = 0; y < heighte; y++) {
if(x >= x0 - 32 && x <= x0 + 32 && y >= y0 - 32 && y <= y0 + 32){
double a = x - x0;
double b = y - y0;
int xx = (int) (+a * cos - b * sin + x0);
int yy = (int) (+a * sin + b * cos + y0);
// plot pixel (x, y) the same color as (xx, yy) if it's in bounds
if (xx >= 0 && xx < widthe && yy >= 0 && yy < heighte) {
neww.setRGB(x, y, fbuffer.getRGB(xx, yy));
}
}
}
}
ang++;
repaint();
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(neww, 0, 0, null);
}
}
Thanks for:
https://introcs.cs.princeton.edu/java/31datatype/Rotation.java.html
EDIT:
You have to invert the vars on bf2.setRGB(x, y, fbuffer.getRGB(xx, yy)); to the rotated coordinate.
i have been trying to make a custom BarChart in Java for a school project but for some reason it has some weird Scaling issues. Here is the Code.
static class BarChart extends JPanel
{
private int[] chartValues;
private String[] chartLabels;
private String chartTitle;
public BarChart(String title,int[] values,String[]labels)
{
this.chartTitle = title;
this.chartValues = values;
this.chartLabels = labels;
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Random r = new Random();
if(this.chartValues == null || this.chartValues.length==0)
{
return;
}
Dimension chartDimension = this.getSize();
int panelWidth = chartDimension.width;
int panelHeight = chartDimension.height;
int barWidth = panelWidth / this.chartValues.length;
int maxValue = this.chartValues[0];
int minValue = this.chartValues[0];
for(int tempValue:this.chartValues)
{
maxValue = Math.max(maxValue, tempValue);
minValue = Math.min(minValue, tempValue);
}
Font titleFont = new Font("Book Antiqua", Font.BOLD, 15);
FontMetrics titleFontMetrics = g.getFontMetrics(titleFont);
Font labelFont = new Font("Book Antiqua", Font.PLAIN, 14);
FontMetrics labelFontMetrics = g.getFontMetrics(labelFont);
int titleWidth = titleFontMetrics.stringWidth(this.chartTitle);
int stringHeight = titleFontMetrics.getAscent();
int stringWidth = (panelWidth - titleWidth) / 2;
g.setFont(titleFont);
g.drawString(this.chartTitle, stringWidth, stringHeight);
int top = titleFontMetrics.getHeight();
int bottom = labelFontMetrics.getHeight();
if(maxValue==minValue)
{
return;
}
double barScale = (panelHeight - top - bottom)/(maxValue - minValue);
stringHeight = panelHeight - labelFontMetrics.getDescent();
int xPos = 5;
g.setFont(labelFont);
for(int i=0; i<this.chartValues.length;i++)
{
int tempValue = this.chartValues[i];
int barHeight = (int) ( (double)tempValue * barScale);
int yPos = top;
if(tempValue>=0)
{
yPos += (int) ((maxValue - tempValue)* barScale);
}
else
{
yPos += (int) (maxValue * barScale);
barHeight = - barHeight;
}
g.setColor(new Color(r.nextInt(255),r.nextInt(255),r.nextInt(255)));
g.fillRect(xPos, yPos, barWidth, barHeight);
g.setColor(Color.BLUE);
g.drawRect(xPos, yPos, barWidth, barHeight);
xPos += barWidth;
}
g.setColor(Color.BLACK);
g.drawString("Xronos", stringWidth, stringHeight);
}
}
But when i run this with my main with values {1,5,4,7,120} i get this depending on the screen resolution.
Wrong image (the height between bars and label is too much).
Correct height between bars and label. I really apreciate any help. And sorry if this stupid is a question.
you are doing integer division here:
double barScale = (panelHeight - top - bottom)/(maxValue - minValue);
try
double barScale = (panelHeight - top - bottom)/(double)(maxValue - minValue);
instead
I can not seem to figure out why my concentric circles are not lining up. My loops seem correct to me and the measurements are correct but for some reason the last few circles are off-centered. That's the first issue I'm having. The second issue is, i can't seem to get the concentric circles to print in each square. Once again, i can't seem to find any issue in my logic, but obviously there is an issue. Any help on this at all would be great.
This should be the end product
*Now this is my source code- ExampleGUI.java *
import javax.swing.*;
public class ExampleGUI {
public static void main(String args []) {
JFrame frame = new JFrame("Example Graphics");
ExamplePanel panel = new ExamplePanel();
frame.getContentPane().add(panel);
frame.setDefaultCloseOperation(3);
frame.pack();
frame.setVisible(true);
}
}
* ExamplePanel.java *
import java.awt.*;
import javax.swing.*;
public class ExamplePanel extends JPanel{
public ExamplePanel() {
setPreferredSize(new Dimension (600, 600));
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
int x = 0;
int x2 = 5;
int y = 500;
int y2 = 505;
int w = 100;
int w2 = 90;
int h = 100;
int h2 = 90;
int i, j, k;
for(j = 1; j < 7; j++) {
x = 0;
x2 = x + 5;
for(i = 1; i < 7; i++) {
if ((i + j) % 2 == 0) {
g.setColor(Color.white);
} else {
g.setColor(Color.yellow);
}
g.fillRect(x, y, w, h);
g.setColor(Color.black);
g.drawRect(x, y, w, h);
g.setColor(Color.green);
g.fillOval(x2, y2, w2, h2);
for(k = 1; k < 7; k++) {
g.setColor(Color.black);
g.drawOval(x2, y2, w2, h2);
x2 = x2 + 5;
y2 = y2 + 5;
w2 = w2 - 10;
h2 = h2 - 10;
}
x = x + w;
x2 = x2 + w2 + 10;
}
x = x + w;
y = y - h;
y2 = (y2 - h2) - 10;
}
}
}
* This is what my program looks like when i run it. It doesn't look like the other picture for some reason *
Basically, you "spiral" loop is modifying the state of variables that are required elsewhere
What I would do, is create a new series of variables, initialized to the current state and modify those instead...
int ix = x2;
int iy = y2;
int ih = h2;
int iw = w2;
for (k = 1; k < 7; k++) {
g.setColor(Color.black);
g.drawOval(ix, iy, iw, ih);
ix = ix + 5;
iy = iy + 5;
iw = iw - 10;
ih = ih - 10;
}