Below is my current algorithm to align the rectangle (representing symbol) in the center of the canvas space (representing icon). It is only the algorithm I am interested in so ignore the rest of the code as it is merely for demonstration purposes as a visual aid.
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class IconSymbol extends JFrame {
public IconSymbol(double iWH, double s, double w, double h) {
getContentPane().add(new Canvas((int)iWH, s, w, h));
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize((int)iWH, (int)iWH);
setVisible(true);
}
public static void main(String arg[]) {
IconSymbol is = new IconSymbol(100, 0.9, 50, 50);
}
class Canvas extends JPanel {
// STIPULATED
double iconWH = 0;
double sScale = 0;
double sWidth = 0;
double sHeight = 0;
// CALCULATED
double padX = 0;
double padY = 0;
double xOffSet = 0;
double yOffSet = 0;
public Canvas(double iWH,double sS,double sW,double sH) {
this.iconWH = iWH;
this.sScale = sS;
this.sWidth = sW;
this.sHeight = sH;
}
public void paint(Graphics g) {
Graphics2D g2D = (Graphics2D) g;
g2D.setBackground(Color.WHITE);
g2D.setPaint(Color.BLUE);
Shape icon = new Rectangle.Double(0,0,(int)iconWH,(int)iconWH);
g2D.fill(icon);
g2D.setPaint(Color.BLACK);
int width = (int)iconWH / 10;
int height= (int)iconWH / 10;
for(int row=0;row<10;row++){
for(int col=0;col<10;col++){
g.drawRect(row*width,col*height,width,height);
}
}
Point off = algorithm();
g2D.setPaint(Color.RED);
Shape s = new Rectangle.Double(off.x,off.y,(int)sWidth,(int)sHeight);
AffineTransform tran = AffineTransform.getScaleInstance(sScale, sScale);
g2D.fill(tran.createTransformedShape(s));
}
public Point algorithm(){
// ALGORITHM WITH EXACT NEEDED PARAMETERS
padX = (sWidth - ((sWidth * sScale))) / 2;
padY = (sHeight - ((sHeight * sScale))) / 2;
xOffSet = padX + ((iconWH - (sWidth * sScale)) / 2);
yOffSet = padX + ((iconWH - (sHeight * sScale)) / 2);
Point point = new Point((int)xOffSet, (int)yOffSet);
return point;
}
}
}
The problem with your code is that the scale transform tran is scaling the calculated origin of the rectangle, off, as well as sWidth and sHeight. If you want to keep with your current scheme you need to apply the inverse of the scale transform to the calculated offset in your algorithm method:
public Point algorithm(){
// ALGORITHM WITH EXACT NEEDED PARAMETERS
xOffSet = ((iconWH - (sWidth * sScale)) / 2) / sScale;
yOffSet = ((iconWH - (sHeight * sScale)) / 2) / sScale;
Point point = new Point((int)xOffSet, (int)yOffSet);
return point;
}
Note that I removed padX and padY as they weren't required for calculating the offset.
My problem is that I cant get the diagonal to resize properly. If I run the code the diagonal is on the wrong side and when I expand it vertically it doesn't maintain a perfect diagonal from one corner to another.
Below I have my code for the program and the driver.
import javax.swing.JFrame;
public class Points
{
public static void main(String[] args)
{
JFrame frame = new JFrame("Points");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
PointsPanel panel = new PointsPanel();
frame.getContentPane().add(panel);
frame.pack();
frame.setVisible(true);
}
}
Here is the main program
import javax.swing.JPanel;
import java.awt.Dimension;
import java.awt.Graphics;
import java.util.Random;
import java.awt.Color;
import java.lang.Math.*;
public class PointsPanel extends JPanel
{
private final int MAX_POINTS = 20000;
private final int LENGTH = 1;
private int x,x1,y,y1;
private Random random;
double slope,b,c,g;
public PointsPanel(){
random = new Random();
setBackground(Color.black);
setPreferredSize(new Dimension(300,300));
}
public void paintComponent(Graphics page)
{
super.paintComponent(page);
for(int count = 0; count < MAX_POINTS; count++)
{
x = random.nextInt(getWidth()-1) + 1;
y = random.nextInt(getHeight()-1) + 1;
x1= x + LENGTH;
y1= y + LENGTH;
slope = x1/y1;
c = slope*x;
b = ((-1)*(y))-c;
g = (-1)*y1;
if (b <= g)
page.setColor(Color.red);
else
page.setColor(Color.green);
page.drawLine(x,y,x1,y1);
}
}
}
I solved your issue by making a little change to your PointsPanel class. Take a look at PointsPanel2 class. First of all the diagonal is a linear equation of the form y = aX + b and since it passes by the points of coordinate (0,0) we can reduce it to y = aX therefore a = Y/X for any (X,Y) point that is part of the diagonal.
Now event though the drawing methods use integer coordinate we still have to compute the a coefficient as a floating number (like a double), otherwise it won't work because of rounding issues.
Then once the other part of your code runs and we obtain (x,y) then x1 and y1, all I have to do is to compute the corresponding diagonal y for x1 and compare it to y1 and depending on the obtained value, change the color to red or green
Use this PointsPanel2 class instead of PointsPanel to test with your other Points class
import javax.swing.JPanel;
import java.awt.Dimension;
import java.awt.Graphics;
import java.util.Random;
import java.awt.Color;
import java.lang.Math.*;
public class PointsPanel2 extends JPanel
{
private final int MAX_POINTS = 20000;
private final int LENGTH = 1;
private int x,x1,y,y1;
private Random random;
double slope,b,c,g;
public PointsPanel2(){
random = new Random();
setBackground(Color.black);
setPreferredSize(new Dimension(300,300));
}
public void paintComponent(Graphics page)
{
super.paintComponent(page);
// Diagonal equation
// X0, Y0 = (0,0)
// Xl, Yl = width, height
// Equation y = aX + b
// 0 = 0 + b ==> b = 0
// Yl = aXl ==> a = Yl/Xl
// Computes the diagonal a coefficient
double aCoeff = (getHeight()*1.0)/(getWidth()*1.0);
System.out.println("Xl,Yl, a = " + getWidth() + " " + getHeight() + " " + aCoeff);
for(int count = 0; count < MAX_POINTS; count++)
{
x = random.nextInt(getWidth()-1) + 1;
y = random.nextInt(getHeight()-1) + 1;
x1= x + LENGTH;
y1= y + LENGTH;
// Computes the diagonal image of x in order to compare it with y1
double diagImage = aCoeff * x1;
slope = x1/y1;
c = slope*x;
b = ((-1)*(y))-c;
g = (-1)*y1;
//if (b <= g)
if (diagImage <= y1)
page.setColor(Color.red);
else
page.setColor(Color.green);
page.drawLine(x,y,x1,y1);
}
}
}
I am a beginner at Java, only been coding for a year. My task is to create distortions to any image given. I have been having a lot of trouble with the bulge effect lately. I have been researching all around google and I found these links very helpful:
https://math.stackexchange.com/questions/266250/explanation-of-this-image-warping-bulge-filter-algorithm
Image Warping - Bulge Effect Algorithm
I tried the algorithm that these two links gave me, but I ended up with nothing.
Let's say I have imported an image that is 100 pixels by 100 pixels, from the code below, am I using the algorithm correctly:
//modifiedImage is a global variable and contains the image that is 100x100
public BufferedImage buldge(){
double X = 0;
double Y = 0;
BufferedImage anImage = new BufferedImage (1000, 1000, BufferedImage.TYPE_INT_ARGB);
for(int x = 0; x < modifiedImage.getWidth(); x++){
for(int y = 0; y < modifiedImage.getHeight(); y++){
int rgb = modifiedImage.getRGB(x, y);
double newRadius = 0;
X = x - x/2;
Y = y - y/2;
double radius = Math.sqrt(X*X + Y*Y);
double angle = Math.atan2(X, Y);
newRadius = Math.pow(radius,1.5);
X = (int)(newRadius*Math.sin(angle));
Y = (int)(newRadius*Math.cos(angle));
anImage.setRGB((int)X, (int)Y,rgb);
}
}
return anImage;
}
The problem is that this code doesn't really bulge the image in the middle. I have made a new BufferedImage of dimensions 1000x1000 because the pixels from the original one gets extended really far and some are extended beyond 1000x1000. If anyone would help me show the problems in this code concerning the bulge effect, I would greatly appreciate it.
I think one (main) part of the problem is that you are computing the radius of the bulge effect in pixels. Although I have not read all anwers in the threads that you linked, it seems like they are referring to texture coordinates - that is, to values between 0 and 1.
Apart from that: With the current approach, you will have a sampling problem. Imagine that one pixel at the center of the input image will be "stretched" so that it covers an area of, say, 10x10 pixels in the output image. But still, you are only computing one new position for this pixel.
Imagine it like you are taking pixels from the input image, and move them to a new position in the output image - but you have to do it the other way around: You have to check each pixel in the output image, and compute which pixel of the input image was moved there.
I created a small example: It allows moving a "magnifying glass" over the image with the mouse. With the mouse wheel, you can change the strength of the distortion. With SHIFT+MouseWheel, you can change the size of the magnifying glass.
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.InputEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.image.BufferedImage;
import java.beans.Transient;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class ImageBulgeTest
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
createAndShowGUI();
}
});
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().setLayout(new GridLayout(1, 1));
frame.getContentPane().add(new ImageBulgePanel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
class ImageBulgePanel extends JPanel
{
private BufferedImage input;
private BufferedImage output;
private double bulgeStrength = 0.3;
private double bulgeRadius = 100;
ImageBulgePanel()
{
try
{
input = ImageIO.read(new File("lena512color.png"));
}
catch (IOException e1)
{
e1.printStackTrace();
}
addMouseMotionListener(new MouseAdapter()
{
#Override
public void mouseMoved(MouseEvent e)
{
updateImage(e.getX(), e.getY());
}
});
addMouseWheelListener(new MouseWheelListener()
{
#Override
public void mouseWheelMoved(MouseWheelEvent e)
{
if ((e.getModifiersEx() & InputEvent.SHIFT_DOWN_MASK) ==
InputEvent.SHIFT_DOWN_MASK)
{
bulgeRadius += 10 * e.getWheelRotation();
System.out.println("bulgeRadius "+bulgeRadius);
}
else
{
bulgeStrength += 0.1 * e.getWheelRotation();
bulgeStrength = Math.max(0, bulgeStrength);
System.out.println("bulgeStrength "+bulgeStrength);
}
updateImage(e.getX(), e.getY());
}
});
}
#Override
#Transient
public Dimension getPreferredSize()
{
if (isPreferredSizeSet())
{
return super.getPreferredSize();
}
return new Dimension(input.getWidth(), input.getHeight());
}
#Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
if (output != null)
{
g.drawImage(output, 0, 0, null);
}
}
private void updateImage(int x, int y)
{
if (output == null)
{
output = new BufferedImage(
input.getWidth(), input.getHeight(),
BufferedImage.TYPE_INT_ARGB);
}
computeBulgeImage(input, x, y,
bulgeStrength, bulgeRadius,
output);
repaint();
}
private static void computeBulgeImage(
BufferedImage input, int cx, int cy,
double bulgeStrength, double bulgeRadius,
BufferedImage output)
{
int w = input.getWidth();
int h = input.getHeight();
for(int x = 0; x < w; x++)
{
for(int y = 0; y < h; y++)
{
int dx = x-cx;
int dy = y-cy;
double distanceSquared = dx * dx + dy * dy;;
int sx = x;
int sy = y;
if (distanceSquared < bulgeRadius * bulgeRadius)
{
double distance = Math.sqrt(distanceSquared);
boolean otherMethod = false;
otherMethod = true;
if (otherMethod)
{
double r = distance / bulgeRadius;
double a = Math.atan2(dy, dx);
double rn = Math.pow(r, bulgeStrength)*distance;
double newX = rn*Math.cos(a) + cx;
double newY = rn*Math.sin(a) + cy;
sx += (newX - x);
sy += (newY - y);
}
else
{
double dirX = dx / distance;
double dirY = dy / distance;
double alpha = distance / bulgeRadius;
double distortionFactor =
distance * Math.pow(1-alpha, 1.0 / bulgeStrength);
sx -= distortionFactor * dirX;
sy -= distortionFactor * dirY;
}
}
if (sx >= 0 && sx < w && sy >= 0 && sy < h)
{
int rgb = input.getRGB(sx, sy);
output.setRGB(x, y, rgb);
}
}
}
}
}
I'm having trouble drawing the smallest arc described by 3 points: the arc center, an "anchored" end point, and a second point that gives the other end of the arc by determining a radius. I used the law of cosines to determine the length of the arc and tried using atan for the starting degree, but the starting position for the arc is off.
I managed to get the arc to lock onto the anchor point (x1,y1) when it's in Quadrant 2, but that will only work when it is in Quadrant 2.
Solutions I can see all have a bunch of if-statements to determine the location of the 2 points relative to each other, but I'm curious if I'm overlooking something simple. Any help would be greatly appreciated.
SSCCE:
import javax.swing.JComponent;
import javax.swing.JFrame;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.geom.*;
import java.awt.*;
import java.util.*;
class Canvas extends JComponent {
float circleX, circleY, x1, y1, x2, y2, dx, dy, dx2, dy2, radius, radius2;
Random random = new Random();
public Canvas() {
//Setup.
x1 = random.nextInt(250);
y1 = random.nextInt(250);
//Cant have x2 == circleX
while (x1 == 150 || y1 == 150)
{
x1 = random.nextInt(250);
y1 = random.nextInt(250);
}
circleX = 150; //circle center is always dead center.
circleY = 150;
//Radius between the 2 points must be equal.
dx = Math.abs(circleX-x1);
dy = Math.abs(circleY-y1);
//c^2 = a^2 + b^2 to solve for the radius
radius = (float) Math.sqrt((float)Math.pow(dx, 2) + (float)Math.pow(dy, 2));
//2nd random point
x2 = random.nextInt(250);
y2 = random.nextInt(250);
//I need to push it out to radius length, because the radius is equal for both points.
dx2 = Math.abs(circleX-x2);
dy2 = Math.abs(circleY-y2);
radius2 = (float) Math.sqrt((float)Math.pow(dx2, 2) + (float)Math.pow(dy2, 2));
dx2 *= radius/radius2;
dy2 *= radius/radius2;
y2 = circleY+dy2;
x2 = circleX+dx2;
//Radius now equal for both points.
}
public void paintComponent(Graphics g2) {
Graphics2D g = (Graphics2D) g2;
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g.setStroke(new BasicStroke(2.0f, BasicStroke.CAP_BUTT,
BasicStroke.JOIN_BEVEL));
Arc2D.Float centerPoint = new Arc2D.Float(150-2,150-2,4,4, 0, 360, Arc2D.OPEN);
Arc2D.Float point1 = new Arc2D.Float(x1-2, y1-2, 4, 4, 0, 360, Arc2D.OPEN);
Arc2D.Float point2 = new Arc2D.Float(x2-2, y2-2, 4, 4, 0, 360, Arc2D.OPEN);
//3 points drawn in black
g.setColor(Color.BLACK);
g.draw(centerPoint);
g.draw(point1);
g.draw(point2);
float start = 0;
float distance;
//Form a right triangle to find the length of the hypotenuse.
distance = (float) Math.sqrt(Math.pow(Math.abs(x2-x1),2) + Math.pow(Math.abs(y2-y1), 2));
//Law of cosines to determine the internal angle between the 2 points.
distance = (float) (Math.acos(((radius*radius) + (radius*radius) - (distance*distance)) / (2*radius*radius)) * 180/Math.PI);
float deltaY = circleY - y1;
float deltaX = circleX - x1;
float deltaY2 = circleY - y2;
float deltaX2 = circleX - x2;
float angleInDegrees = (float) ((float) Math.atan((float) (deltaY / deltaX)) * 180 / Math.PI);
float angleInDegrees2 = (float) ((float) Math.atan((float) (deltaY2 / deltaX2)) * 180 / Math.PI);
start = angleInDegrees;
//Q2 works.
if (x1 < circleX)
{
if (y1 < circleY)
{
start*=-1;
start+=180;
} else if (y2 > circleX) {
start+=180;
start+=distance;
}
}
//System.out.println("Start: " + start);
//Arc drawn in blue
g.setColor(Color.BLUE);
Arc2D.Float arc = new Arc2D.Float(circleX-radius, //Center x
circleY-radius, //Center y Rotates around this point.
radius*2,
radius*2,
start, //start degree
distance, //distance to travel
Arc2D.OPEN); //Type of arc.
g.draw(arc);
}
}
public class Angle implements MouseListener {
Canvas view;
JFrame window;
public Angle() {
window = new JFrame();
view = new Canvas();
view.addMouseListener(this);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setBounds(30, 30, 400, 400);
window.getContentPane().add(view);
window.setVisible(true);
}
public static void main(String[] a) {
new Angle();
}
#Override
public void mouseClicked(MouseEvent arg0) {
window.getContentPane().remove(view);
view = new Canvas();
window.getContentPane().add(view);
view.addMouseListener(this);
view.revalidate();
view.repaint();
}
#Override
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mousePressed(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseReleased(MouseEvent arg0) {
// TODO Auto-generated method stub
}
}
Perhaps this will help. It tests with click and drag to set the two points rather than random numbers. It's considerably simpler than what you were attempting and other solutions posted so far.
Notes:
Math.atan2() is a friend in problems like this.
Little helper functions make it easier to reason about your code.
It's best practice to use instance variables for independent values only and compute the dependent values in local variables.
My code fixes some Swing usage problems like calling Swing functions from the main thread.
Code follows:
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
class TestCanvas extends JComponent {
float x0 = 150f, y0 = 150f; // Arc center. Subscript 0 used for center throughout.
float xa = 200f, ya = 150f; // Arc anchor point. Subscript a for anchor.
float xd = 150f, yd = 50f; // Point determining arc angle. Subscript d for determiner.
// Return the distance from any point to the arc center.
float dist0(float x, float y) {
return (float)Math.sqrt(sqr(x - x0) + sqr(y - y0));
}
// Return polar angle of any point relative to arc center.
float angle0(float x, float y) {
return (float)Math.toDegrees(Math.atan2(y0 - y, x - x0));
}
#Override
protected void paintComponent(Graphics g0) {
Graphics2D g = (Graphics2D) g0;
// Can always draw the center point.
dot(g, x0, y0);
// Get radii of anchor and det point.
float ra = dist0(xa, ya);
float rd = dist0(xd, yd);
// If either is zero there's nothing else to draw.
if (ra == 0 || rd == 0) { return; }
// Get the angles from center to points.
float aa = angle0(xa, ya);
float ad = angle0(xd, yd); // (xb, yb) would work fine, too.
// Draw the arc and other dots.
g.draw(new Arc2D.Float(x0 - ra, y0 - ra, // box upper left
2 * ra, 2 * ra, // box width and height
aa, angleDiff(aa, ad), // angle start, extent
Arc2D.OPEN));
dot(g, xa, ya);
// Use similar triangles to get the second dot location.
float xb = x0 + (xd - x0) * ra / rd;
float yb = y0 + (yd - y0) * ra / rd;
dot(g, xb, yb);
}
// Some helper functions.
// Draw a small dot with the current color.
static void dot(Graphics2D g, float x, float y) {
final int rad = 2;
g.fill(new Ellipse2D.Float(x - rad, y - rad, 2 * rad, 2 * rad));
}
// Return the square of a float.
static float sqr(float x) { return x * x; }
// Find the angular difference between a and b, -180 <= diff < 180.
static float angleDiff(float a, float b) {
float d = b - a;
while (d >= 180f) { d -= 360f; }
while (d < -180f) { d += 360f; }
return d;
}
// Construct a test canvas with mouse handling.
TestCanvas() {
addMouseListener(mouseListener);
addMouseMotionListener(mouseListener);
}
// Listener changes arc parameters with click and drag.
MouseInputAdapter mouseListener = new MouseInputAdapter() {
boolean mouseDown = false; // Is left mouse button down?
#Override
public void mousePressed(MouseEvent e) {
if (e.getButton() == MouseEvent.BUTTON1) {
mouseDown = true;
xa = xd = e.getX();
ya = yd = e.getY();
repaint();
}
}
#Override
public void mouseReleased(MouseEvent e) {
if (e.getButton() == MouseEvent.BUTTON1) {
mouseDown = false;
}
}
#Override
public void mouseDragged(MouseEvent e) {
if (mouseDown) {
xd = e.getX();
yd = e.getY();
repaint();
}
}
};
}
public class Test extends JFrame {
public Test() {
setSize(400, 400);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
getContentPane().add(new TestCanvas());
}
public static void main(String[] args) {
// Swing code must run in the UI thread, so
// must invoke setVisible rather than just calling it.
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Test().setVisible(true);
}
});
}
}
package curve;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
public class Main
{
/**
* #param args the command line arguments
*/
public static void main(String[] args) throws IOException
{
PointF pFrom = new PointF(-10f, 30.0f);
PointF pTo = new PointF(-100f, 0.0f);
List<PointF> points = generateCurve(pFrom, pTo, 100f, 7f, true, true);
System.out.println(points);
// Calculate the bounds of the curve
Rectangle2D.Float bounds = new Rectangle2D.Float(points.get(0).x, points.get(0).y, 0, 0);
for (int i = 1; i < points.size(); ++i) {
bounds.add(points.get(i).x, points.get(i).y);
}
bounds.add(pFrom.x, pFrom.y);
bounds.add(pTo.x, pTo.y);
BufferedImage img = new BufferedImage((int) (bounds.width - bounds.x + 50), (int) (bounds.height - bounds.y + 50), BufferedImage.TYPE_4BYTE_ABGR_PRE);
Graphics2D g = img.createGraphics();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.translate(25.0f - bounds.getX(), 25.0f - bounds.getY());
g.setStroke(new BasicStroke(1.0f));
g.setColor(Color.DARK_GRAY);
g.drawLine(-1000, 0, 1000, 0);
g.drawLine(0, -1000, 0, 1000);
g.setColor(Color.RED);
for (int i = 0; i < points.size(); ++i) {
if (i > 0) {
Line2D.Float f = new Line2D.Float(points.get(i - 1).x, points.get(i - 1).y, points.get(i).x, points.get(i).y);
System.out.println("Dist : " + f.getP1().distance(f.getP2()));
// g.draw(f);
}
g.fill(new Ellipse2D.Float(points.get(i).x - 0.8f, points.get(i).y - 0.8f, 1.6f, 1.6f));
}
g.setColor(Color.BLUE);
g.fill(new Ellipse2D.Float(pFrom.x - 1, pFrom.y - 1, 3, 3));
g.fill(new Ellipse2D.Float(pTo.x - 1, pTo.y - 1, 3, 3));
g.dispose();
ImageIO.write(img, "PNG", new File("result.png"));
}
static class PointF
{
public float x, y;
public PointF(float x, float y)
{
this.x = x;
this.y = y;
}
#Override
public String toString()
{
return "(" + x + "," + y + ")";
}
}
private static List<PointF> generateCurve(PointF pFrom, PointF pTo, float pRadius, float pMinDistance, boolean shortest, boolean side)
{
List<PointF> pOutPut = new ArrayList<PointF>();
// Calculate the middle of the two given points.
PointF mPoint = new PointF(pFrom.x + pTo.x, pFrom.y + pTo.y);
mPoint.x /= 2.0f;
mPoint.y /= 2.0f;
System.out.println("Middle Between From and To = " + mPoint);
// Calculate the distance between the two points
float xDiff = pTo.x - pFrom.x;
float yDiff = pTo.y - pFrom.y;
float distance = (float) Math.sqrt(xDiff * xDiff + yDiff * yDiff);
System.out.println("Distance between From and To = " + distance);
if (pRadius * 2.0f < distance) {
throw new IllegalArgumentException("The radius is too small! The given points wont fall on the circle.");
}
// Calculate the middle of the expected curve.
float factor = (float) Math.sqrt((pRadius * pRadius) / ((pTo.x - pFrom.x) * (pTo.x - pFrom.x) + (pTo.y - pFrom.y) * (pTo.y - pFrom.y)) - 0.25f);
PointF circleMiddlePoint = new PointF(0, 0);
if (side) {
circleMiddlePoint.x = 0.5f * (pFrom.x + pTo.x) + factor * (pTo.y - pFrom.y);
circleMiddlePoint.y = 0.5f * (pFrom.y + pTo.y) + factor * (pFrom.x - pTo.x);
} else {
circleMiddlePoint.x = 0.5f * (pFrom.x + pTo.x) - factor * (pTo.y - pFrom.y);
circleMiddlePoint.y = 0.5f * (pFrom.y + pTo.y) - factor * (pFrom.x - pTo.x);
}
System.out.println("Middle = " + circleMiddlePoint);
// Calculate the two reference angles
float angle1 = (float) Math.atan2(pFrom.y - circleMiddlePoint.y, pFrom.x - circleMiddlePoint.x);
float angle2 = (float) Math.atan2(pTo.y - circleMiddlePoint.y, pTo.x - circleMiddlePoint.x);
// Calculate the step.
float step = pMinDistance / pRadius;
System.out.println("Step = " + step);
// Swap them if needed
if (angle1 > angle2) {
float temp = angle1;
angle1 = angle2;
angle2 = temp;
}
boolean flipped = false;
if (!shortest) {
if (angle2 - angle1 < Math.PI) {
float temp = angle1;
angle1 = angle2;
angle2 = temp;
angle2 += Math.PI * 2.0f;
flipped = true;
}
}
for (float f = angle1; f < angle2; f += step) {
PointF p = new PointF((float) Math.cos(f) * pRadius + circleMiddlePoint.x, (float) Math.sin(f) * pRadius + circleMiddlePoint.y);
pOutPut.add(p);
}
if (flipped ^ side) {
pOutPut.add(pFrom);
} else {
pOutPut.add(pTo);
}
return pOutPut;
}
}
and the use the generateCurve method like this to have a curve between the from and to points..
generateCurve(pFrom, pTo, 100f, 7f, true, false);
Okay, here it is, testing and working. The problems were based on the fact that I don't use graphics much, so I have to remind myself that the coordinate systems are backward, and on the fact that the Javadoc description of the Arc2D constructor is atrocious.
In addition to these, I found that your point creation (for the two points to be connected) was extremely inefficient given the requirements. I had assumed you actually had to receive two arbitrary points and then calculate their angles, etc., but based on what you put on Pastebin, we can define the two points however we please. This benefits us.
Anyway, here's a working version, with none of that gobbledegook from before. Simplified code is simplified:
import javax.swing.JComponent;
import java.awt.geom.*;
import java.awt.*;
import java.util.*;
public class Canvas extends JComponent {
double circleX, circleY, x1, y1, x2, y2, dx, dy, dx2, dy2, radius, radius2;
Random random = new Random();
double distance;
private static double theta1;
private static double theta2;
private static double theta;
// private static double radius;
private Point2D point1;
private Point2D point2;
private Point2D center;
private static int direction;
private static final int CW = -1;
private static final int CCW = 1;
public Canvas() {
/*
* You want two random points on a circle, so let's start correctly,
* by setting a random *radius*, and then two random *angles*.
*
* This has the added benefit of giving us the angles without having to calculate them
*/
radius = random.nextInt(175); //your maximum radius is higher, but we only have 200 pixels in each cardinal direction
theta1 = random.nextInt(360); //angle to first point (absolute measurement)
theta2 = random.nextInt(360); //angle to second point
//build the points
center = new Point2D.Double(200, 200); //your frame is actually 400 pixels on a side
point1 = new Point2D.Double(radius * Math.cos(toRadians(theta1)) + center.getX(), center.getY() - radius * Math.sin(toRadians(theta1)));
point2 = new Point2D.Double(radius * Math.cos(toRadians(theta2)) + center.getX(), center.getY() - radius * Math.sin(toRadians(theta2)));
theta = Math.abs(theta1 - theta2) <= 180 ? Math.abs(theta1 - theta2) : 360 - (Math.abs(theta1 - theta2));
if ((theta1 + theta) % 360 == theta2) {
direction = CCW;
} else {
direction = CW;
}
System.out.println("theta1: " + theta1 + "; theta2: " + theta2 + "; theta: " + theta + "; direction: " + (direction == CCW ? "CCW" : "CW"));
System.out.println("point1: (" + (point1.getX() - center.getX()) + ", " + (center.getY() - point1.getY()) + ")");
System.out.println("point2: (" + (point2.getX() - center.getX()) + ", " + (center.getY() - point2.getY()) + ")");
// Radius now equal for both points.
}
public double toRadians(double angle) {
return angle * Math.PI / 180;
}
public double toDegrees(double angle) {
return angle * 180 / Math.PI;
}
public void paintComponent(Graphics g2) {
Graphics2D g = (Graphics2D) g2;
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g.setStroke(new BasicStroke(2.0f, BasicStroke.CAP_BUTT,
BasicStroke.JOIN_BEVEL));
//centerpoint should be based on the actual center point
Arc2D.Double centerPoint = new Arc2D.Double(center.getX() - 2, center.getY() - 2, 4, 4, 0,
360, Arc2D.OPEN);
//likewise these points
Arc2D.Double point11 = new Arc2D.Double(point1.getX() - 2, point1.getY() - 2, 4, 4, 0, 360,
Arc2D.OPEN);
Arc2D.Double point22 = new Arc2D.Double(point2.getX() - 2, point2.getY() - 2, 4, 4, 0, 360,
Arc2D.OPEN);
// 3 points drawn in black
g.setColor(Color.BLACK);
g.draw(centerPoint);
g.draw(point11);
g.draw(point22);
// Arc drawn in blue
g.setColor(Color.BLUE);
g.draw(new Arc2D.Double(center.getX() - radius, center.getY() - radius, 2 * radius, 2 * radius, theta1, theta * direction, Arc2D.OPEN));
}
}
I want an circular movement of an image in JAVA, i thought I have the solution but it doesn't work and i'm a bit clueless now.
For calculating the points it needs to go im using pythagoras to calculate the height (point B).
if it does one round im satisfied but more rounds would be cool.
The image size is around 500 x 300 pixels.
Here's my code :
package vogel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.image.*;
import java.io.*;
import javax.imageio.*;
import javax.swing.*;
public class Vogel extends Component {
private int x;
private int r;
private int b;
BufferedImage img;
public vogel() {
try {
img = ImageIO.read(new File("F:/JAVA/workspace/School/src/vogel/vogel.png"));
} catch (IOException e) {
}
r = 60;
x = 10;
}
#Override
public void paint(Graphics g) {
for(int i = -x; i <= x; i++) {
b = (int)Math.sqrt(r^2 - i^2);
g.drawImage(img, x, b, this);
}
}
public static void main(String[] args) {
JFrame f = new JFrame("Vogel");
f.setSize(1000,1000);
f.add(new Vogel());
f.setVisible(true);
for (int number = 1; number <= 1500000; number++) {
f.repaint();
try {
Thread.sleep(50);
} catch (InterruptedException e) {}
}
}
}
Using your loop in the paint(Graphics) method, it draws 21 birds with one repaint.
You should do it with an angle stored in an object variable and use the Math.sin() and Math.cos() function calculate the x and y position. The angle should be increased with every repaint().
To add:
// To control the radius of moving
private final double MAX_X = 200;
private final double MAX_Y = 200;
private double angle = 0;
#Override
public void paint(Graphics g) {
// increase angle (should be a double value)
angle += 0.1;
// rotate around P(0/0), assuming that 0° is vector (1/0)
int x = (int) (Math.cos(angle) * MAX_X);
int y = (int) (Math.sin(angle) * MAX_Y);
// move P to center of JFrame (width and height = 1000)
x += 500;
y += 500;
// image is 500x300, calc upper left corner
x -= 250;
y -= 150;
// draw
g.drawImage(img, x, y, null);
}
To remove:
private double x, b, r;
So this is the code, try it.
Addition to Sibbo's code to convert angle to rads
private double angle = 0.1;
#Override
public void paint(Graphics g) {
// increase angle (should be a double value
double random = angle * 2.0 * Math.PI/360.0; //this will convert it to rads
// rotate around P(0/0)
int x = (int) (Math.cos(random) * MAX_X);
int y = (int) (Math.sin(random) * MAX_Y);
// move P to center of JFrame (width and height = 1000)
x += 500;
y += 500;
// image is 500x300, calc upper left corner
x -= 250;
y -= 150;
angle++
// draw
g.drawImage(img, x, y, null);
}