Develop Reference

Java draw 3d points to 2d system using 3d projection

I have tried to follow the Wikipedia page on 3d projection to draw my own 3d line using java and AWT with Swing.
The output file that is created as a result of the rendering doesn't contain anything.
What have I done wrong?
Why isn't this producing an image file that has points on it?
Are my formulas off?
I was following this Wikipedia page as my reference: https://en.wikipedia.org/wiki/3D_projection#Perspective_projection
I have a set of points which are generated using a loop.
I then calculate the position of the 3d coordinate to 2d without using matrices, like one of the suggested method in the link.
Have I miss-interpreted something or not implemented something?
Any help and feedback are welcome.
I known nothing is drawn to the window. That isn't a priority at the moment. The priority it's getting the algorithms to work.
public class Window {
JFrame f = new JFrame();
public Window() {
JPanel p = new JPanel();
render();
f.add(p);
f.setSize(500, 500);
f.setVisible(true);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
Window w = new Window();
}
void render() {
BufferedImage image = new BufferedImage(300, 300, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
g.setColor(Color.red);
for (int i = 0; i < 10; i++) {
Vector3 point = new Vector3(1 + i, 2, 1 + i);
int x = calculateBX(point, new Vector3(0, 0, 0));
int y = calculateBY(point, new Vector3(1, 1, 1));
g.drawLine(x, y, x, y);
}
try {
File outputfile = new File("saved.png");
ImageIO.write(image, "png", outputfile);
} catch (IOException e) {
e.printStackTrace();
}
}
double calculatDX(Vector3 v, Vector3 camera) {
double cx = Math.cos(0);
double cy = Math.cos(0);
double cz = Math.cos(0);
double sx = Math.sin(0);
double sy = Math.sin(0);
double sz = Math.sin(0);
int x = v.getX() - camera.getX();
int y = v.getY() - camera.getY();
int z = v.getZ() - camera.getZ();
double dx = cy * ((sz) * (y) + (cz) * (x)) - (sy) * (z);
return dx;
}
double calculatDY(Vector3 v, Vector3 camera) {
double cx = Math.cos(0);
double cy = Math.cos(0);
double cz = Math.cos(0);
double sx = Math.sin(0);
double sy = Math.sin(0);
double sz = Math.sin(0);
int x = v.getX() - camera.getX();
int y = v.getY() - camera.getY();
int z = v.getZ() - camera.getZ();
double dy = sx * ((cy) * (z) + (sy) * ((sz) * (y) + (cz) * (x))) + (cx) * (cz * (y) - sz * x);
return dy;
}
double calculatDZ(Vector3 v, Vector3 camera) {
double cx = Math.cos(0);
double cy = Math.cos(0);
double cz = Math.cos(0);
double sx = Math.sin(0);
double sy = Math.sin(0);
double sz = Math.sin(0);
int x = v.getX() - camera.getX();
int y = v.getY() - camera.getY();
int z = v.getZ() - camera.getZ();
double dz = cx * ((cy) * (z) + (sy) * ((sz) * (y) + (cz) * (x))) - (sx) * (cz * (y) - sz * x);
return dz;
}
int calculateBX(Vector3 v, Vector3 camera) {
int ez = camera.getZ();
int ex = camera.getX();
double dz = calculatDZ(v, camera);
double dx = calculatDX(v, camera);
return (int) ((ez / dz) * dx) - ex;
}
int calculateBY(Vector3 v, Vector3 camera) {
int ez = camera.getZ();
int ey = camera.getY();
double dz = calculatDZ(v, camera);
double dy = calculatDY(v, camera);
return (int) ((ez / dz) * dy) - ey;
}
}
Vector Class
public class Vector3 {
private int x, y, z;
public Vector3(int x, int y, int z) {
this.x = x;
this.y = y;
this.z = z;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public int getZ() {
return z;
}
}

How to draw a perfect triangle inside a circle orientated like a play button

I want to create a button which is a circle but has a triangle in the middle.
For a send button. I tried using xml and drawable but there are always problems when it comes to screensize and views are not centered always etc..
So how can I do that using just a canvas?
Like how do I get the points I need to draw, say, given the radius of circle, and a scale of sorts, give me points for the triangle and draw the circle.
Here is a image of what I want

I recently created something very similar to what you want..
Take a look at this: https://www.desmos.com/calculator/2wpnxwwnty
To see how the math/scaling works.
This is the class which resulted:
public class TriangleInscribedCircle {
private Triangle inscribedTriangle;
private double s = 1;
private double r = 100;
public TriangleInscribedCircle(float radius, float scale) {
setScale(scale);
this.r = radius;
calculateTriangle();
}
public Triangle getInscribedTriangle() {
return this.inscribedTriangle;
}
public double getScale() {
return this.s;
}
public void setScale(double scale) {
if (scale < 0 || scale > 12) {
throw new IllegalArgumentException("Scale must be between 0 and 12.");
}
this.s = scale;
calculateTriangle();
}
public double getCircleRadius() {
return this.r;
}
public void setCircleRadius(double radius) {
this.r = radius;
calculateTriangle();
}
private void calculateTriangle() {
double u = -((r) / (s + 1)) + r;
double x = (6 * u + 10 * r - Math.sqrt(36 * Math.pow(r, 2) + 24 * r * u - 12 * Math.pow(u, 2))) / (8);
double ax = x;
double ay = -Math.tan(Math.toRadians(30)) * (x - 2 * r + u) + r;
double bx = -u + 2 * r;
double by = r;
double cx = x;
double cy = Math.tan(Math.toRadians(30)) * (x - 2 * r + u) + r;
Point a = new Point(ax, ay);
Point b = new Point(bx, by);
Point c = new Point(cx, cy);
if (this.inscribedTriangle == null) {
this.inscribedTriangle = new Triangle(a, b, c);
} else {
this.inscribedTriangle.setA(a);
this.inscribedTriangle.setB(b);
this.inscribedTriangle.setC(c);
}
}
}
then inside your custom view
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
int width = getWidth();
int height = getHeight();
int radius = width / 2;
canvas.drawCircle(width / 2, height / 2, radius, mTextFieldEmpty ? mCircleDisabledPaint : mCirclePaint);
canvas.drawPath(mTrianglePath, mTextFieldEmpty ? mTriangleDisabledPaint : mTrianglePaint);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mTriangle = new TriangleInscribedCircle(w / 2, 1);
calculatePath();
}
private void calculatePath() {
mTrianglePath.reset();
mTrianglePath.moveTo((int) mTriangle.getInscribedTriangle().getA().x, (int) mTriangle.getInscribedTriangle().getA().y);
mTrianglePath.lineTo((int) mTriangle.getInscribedTriangle().getB().x, (int) mTriangle.getInscribedTriangle().getB().y);
mTrianglePath.lineTo((int) mTriangle.getInscribedTriangle().getC().x, (int) mTriangle.getInscribedTriangle().getC().y);
mTrianglePath.lineTo((int) mTriangle.getInscribedTriangle().getA().x, (int) mTriangle.getInscribedTriangle().getA().y);
}

Draw shapes where their methods are in another class

I need to create a GUI for a game and I will need to display on the screen the weapon and the shield. I need to modify the program so it displays the weapon and shield, however their properties are in another class. I know I will have to extend the JPanel class and overrite its paintComponent() method.
public class GraphicsUtil {
private static final int MUZZLE_FRACTION = 3;
private static final Color MUZZLE_COLOR = Color.MAGENTA;
public static void drawShield(IShield shield, Graphics g, GameSpace gameSpace, double origHealth) {
drawPiece(shield, g, gameSpace, origHealth);
}
public static void drawWeapon(IWeapon weapon, Graphics g,
GameSpace gameSpace, double origHealth) {
Color oldColor = g.getColor();
drawPiece(weapon, g, gameSpace, origHealth);
double orientation = weapon.getOrientation();
int x1 = gameSpace.convertToScreenX(weapon.getXPos());
int y1 = gameSpace.convertToScreenY(weapon.getYPos());
int radius = gameSpace.convertToScreenDistance(weapon.getRadius());
int x2 = gameSpace.convertToScreenX(weapon.getXPos()
+ weapon.getRadius() * Math.cos(weapon.getOrientation()));
int y2 = gameSpace.convertToScreenY(weapon.getYPos()
+ weapon.getRadius() * Math.sin(weapon.getOrientation()));
double frac = 1 - 1f / MUZZLE_FRACTION;
int muzzleCentreX
= x1 + (int) Math.round(frac * radius * Math.cos(orientation));
int muzzleCentreY
= y1 - (int) Math.round(frac * radius * Math.sin(orientation));
int muzzleRadius = radius / MUZZLE_FRACTION;
int topMuzzleX = muzzleCentreX - muzzleRadius;
int topMuzzleY = muzzleCentreY - muzzleRadius;
g.setColor(MUZZLE_COLOR);
g.fillOval(topMuzzleX, topMuzzleY, 2 * muzzleRadius, 2 * muzzleRadius);
g.setColor(Color.BLACK);
g.drawLine(x1, y1, x2, y2);
g.setColor(oldColor);
}
public static boolean isInMuzzle(IPiece piece, double x, double y) {
boolean result;
if (piece instanceof IWeapon) {
IWeapon weapon = (IWeapon) piece;
double radius = weapon.getRadius();
double orientation = weapon.getOrientation();
double frac = 1 - 1f / MUZZLE_FRACTION;
double cx = piece.getXPos() + frac * radius * Math.cos(orientation);
double cy = piece.getYPos() + frac * radius * Math.sin(orientation);
double dx = x - cx;
double dy = y - cy;
double dist = Math.sqrt(dx * dx + dy * dy);
result = dist <= radius / MUZZLE_FRACTION;
} else {
result = false;
}
return result;
}
public static double getAngle(double x1, double y1, double x2, double y2) {
double dx = x2 - x1;
double dy = y2 - y1;
double hypotenuse = Math.sqrt(dx * dx + dy * dy);
double angle;
if (dy > 0) {
angle = Math.acos(dx / hypotenuse);
} else {
angle = 2 * Math.PI - Math.acos(dx / hypotenuse);
}
return angle;
}
private static void drawPiece(IPiece piece, Graphics g, GameSpace gameSpace,
double maxHealth) {
Color oldColor = g.getColor();
int centreX = gameSpace.convertToScreenX(piece.getXPos());
int centreY = gameSpace.convertToScreenY(piece.getYPos());
int displayRadius = gameSpace.convertToScreenDistance(piece.getRadius());
int topX = centreX - displayRadius;
int topY = centreY - displayRadius;
if (piece.getOwner() == 0) {
g.setColor(Color.CYAN);
} else {
g.setColor(Color.PINK);
}
g.drawOval(topX, topY, 2 * displayRadius, 2 * displayRadius);
int healthRadius
= (int) Math.round(displayRadius * piece.getHealth() / maxHealth);
int topHealthX = centreX - healthRadius;
int topHealthY = centreY - healthRadius;
g.fillOval(topHealthX, topHealthY, 2 * healthRadius, 2 * healthRadius);
String name = piece.getName();
if (name != null) {
g.setColor(Color.BLACK);
g.drawString(name, centreX, centreY);
}
g.setColor(oldColor);
}
}
This is my main method:
public class Main extends JPanel {
public Main(){
setSize(new Dimension(400,400));
setPreferredSize(new Dimension(400,400));
GraphicsUtil object = new GraphicsUtil();
}
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
}
public static void main(String[] args) {
Main window = new Main();
JFrame frame = new JFrame("RICOCHET");
frame.add(window);
frame.pack();
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
How do I call those methods? What do I need to do in order to they appear in my frame? Thanks.

Presumably you have created one or more weapons or pieces. In your paintComponent() method, just call
GraphicsUtil.drawWeapon( myWeapon, g, ... );

How to smoothly zoom a canvas?

How could I smoothly create a zoom animation for a canvas?
GWT provides a onMouseWheel(MouseWheelEvent evt) method and a evt.getDeltaY() to get the amount of scroll wheel.
Problem here is, that every wheel movement executes this method, and if I call a canvas redraw in the method itself, things get very laggy.
So I thought of somehow making an animation for the zooming. But how?
I thought about creating a Timer, but have no real idea, as there is only the mousewheelevent as starting point, but no end point that the user finished zooming with the wheel...

Here is my scalable image class that I use to zoom into images, it is very quick and responsive. I found an example somewhere and made some minor modifications to make it more responsive. I don't remember the original source or I would give them credit here.
public class ScalableImage extends Composite implements MouseWheelHandler, MouseDownHandler, MouseMoveHandler, MouseUpHandler {
Canvas canvas = Canvas.createIfSupported();
Context2d context = canvas.getContext2d();
Canvas backCanvas = Canvas.createIfSupported();
Context2d backContext = backCanvas.getContext2d();
int width;
int height;
Image image;
ImageElement imageElement;
double zoom = 1;
double totalZoom = 1;
double offsetX = 0;
double offsetY = 0;
boolean mouseDown = false;
double mouseDownXPos = 0;
double mouseDownYPos = 0;
public ScalableImage(Image image) {
initWidget(canvas);
//width = Window.getClientWidth() - 50;
width = image.getWidth() + 200;
height = image.getHeight() + 200;
//canvas.setWidth(width + "px");
//canvas.setHeight(height + "px");
canvas.setCoordinateSpaceWidth(width);
canvas.setCoordinateSpaceHeight(height);
//backCanvas.setWidth(width + "px");
//backCanvas.setHeight(height + "px");
backCanvas.setCoordinateSpaceWidth(width);
backCanvas.setCoordinateSpaceHeight(height);
canvas.addMouseWheelHandler(this);
canvas.addMouseMoveHandler(this);
canvas.addMouseDownHandler(this);
canvas.addMouseUpHandler(this);
this.image = image;
this.imageElement = (ImageElement) image.getElement().cast();
mainDraw();
}
public void onMouseWheel(MouseWheelEvent event) {
int move = event.getDeltaY();
double xPos = (event.getRelativeX(canvas.getElement()));
double yPos = (event.getRelativeY(canvas.getElement()));
if (move < 0) {
zoom = 1.1;
} else {
zoom = 1 / 1.1;
}
double newX = (xPos - offsetX) / totalZoom;
double newY = (yPos - offsetY) / totalZoom;
double xPosition = (-newX * zoom) + newX;
double yPosition = (-newY * zoom) + newY;
backContext.clearRect(0, 0, width, height);
backContext.translate(xPosition, yPosition);
backContext.scale(zoom, zoom);
mainDraw();
offsetX += (xPosition * totalZoom);
offsetY += (yPosition * totalZoom);
totalZoom = totalZoom * zoom;
buffer(backContext, context);
}
public void onMouseDown(MouseDownEvent event) {
this.mouseDown = true;
mouseDownXPos = event.getRelativeX(image.getElement());
mouseDownYPos = event.getRelativeY(image.getElement());
}
public void onMouseMove(MouseMoveEvent event) {
if (mouseDown) {
backContext.setFillStyle("white");
backContext.fillRect(-5, -5, width + 5, height + 5);
backContext.setFillStyle("black");
double xPos = event.getRelativeX(image.getElement());
double yPos = event.getRelativeY(image.getElement());
backContext.translate((xPos - mouseDownXPos) / totalZoom, (yPos - mouseDownYPos) / totalZoom);
offsetX += (xPos - mouseDownXPos);
offsetY += (yPos - mouseDownYPos);
mainDraw();
mouseDownXPos = xPos;
mouseDownYPos = yPos;
}
}
public void onMouseUp(MouseUpEvent event) {
this.mouseDown = false;
}
public void mainDraw() {
backContext.drawImage(imageElement, 100, 100);
buffer(backContext, context);
}
public void buffer(Context2d back, Context2d front) {
front.beginPath();
front.clearRect(0, 0, width, height);
front.drawImage(back.getCanvas(), 0, 0);
}
}

Draw an Arc and gradient it

I would like to know if its possible to draw a Arc on a graphics Panel using a gradient and how I would go about it.
My end goal would be to rotate the arc in a full circle so it would be similar to a rotating loading circle. However it is not a loading bar. It would be a background of a custom JButton.
Any suggestions to alternatives that would create a similar effect would be appreciated.
This is similar to what oi want to draw. Keep in mind that it will be "rotating"

public class TestArc {
public static void main(String[] args) {
new TestArc();
}
public TestArc() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth() - radius) / 2;
int y = (getHeight() - radius) / 2;
RadialGradientPaint rgp = new RadialGradientPaint(
new Point(getWidth() / 2, getHeight() / 2),
radius,
new float[]{0f, 1f},
new Color[]{Color.RED, Color.YELLOW}
);
g2d.setPaint(rgp);
g2d.fill(new Arc2D.Float(x, y, radius, radius, 0, 45, Arc2D.PIE));
g2d.dispose();
}
}
}
You might like to have a look at 2D Graphics for more info
Updated after additional input
So you want a conical fill effect then...
The implementation I have comes from Harmonic Code, but I can't find a direct reference to it (I think it's part of his (excellent) series), but you can see the source code here
Now. I had issues with the angles as it appears that 0 starts at the top point (not the left) and it doesn't like negative angles...you might have better luck, but what I did was create a basic buffer at a position I could easily get working and then rotate the graphics context using an AffineTransformation...
public class TestArc {
public static void main(String[] args) {
new TestArc();
}
public TestArc() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private float angle = 0;
private float extent = 270;
private BufferedImage buffer;
public TestPane() {
Timer timer = new Timer(125, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
angle -= 5;
if (angle > 360) {
angle = 0;
}
repaint();
}
});
timer.setRepeats(true);
timer.setCoalesce(false);
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected BufferedImage getBuffer() {
if (buffer == null) {
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth() - radius) / 2;
int y = (getHeight() - radius) / 2;
buffer = new BufferedImage(radius, radius, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = buffer.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
float startAngle = 0;
Color start = new Color(0, 128, 0, 128);
Color end = new Color(0, 128, 0, 0);
ConicalGradientPaint rgp = new ConicalGradientPaint(
true,
new Point(getWidth() / 2, getHeight() / 2),
0.5f,
new float[]{startAngle, extent},
new Color[]{start, end});
g2d.setPaint(rgp);
g2d.fill(new Arc2D.Float(x, y, radius, radius, startAngle + 90, -extent, Arc2D.PIE));
// g2d.fill(new Ellipse2D.Float(0, 0, radius, radius));
g2d.dispose();
g2d.dispose();
}
return buffer;
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth()) / 2;
int y = (getHeight()) / 2;
BufferedImage buffer = getBuffer();
g2d.setTransform(AffineTransform.getRotateInstance(Math.toRadians(angle), x, y));
x = (getWidth() - buffer.getWidth()) / 2;
y = (getHeight() - buffer.getHeight()) / 2;
g2d.drawImage(buffer, x, y, this);
g2d.dispose();
}
}
public final class ConicalGradientPaint implements java.awt.Paint {
private final java.awt.geom.Point2D CENTER;
private final double[] FRACTION_ANGLES;
private final double[] RED_STEP_LOOKUP;
private final double[] GREEN_STEP_LOOKUP;
private final double[] BLUE_STEP_LOOKUP;
private final double[] ALPHA_STEP_LOOKUP;
private final java.awt.Color[] COLORS;
private static final float INT_TO_FLOAT_CONST = 1f / 255f;
/**
* Standard constructor which takes the FRACTIONS in values from 0.0f to
* 1.0f
*
* #param CENTER
* #param GIVEN_FRACTIONS
* #param GIVEN_COLORS
* #throws IllegalArgumentException
*/
public ConicalGradientPaint(final java.awt.geom.Point2D CENTER, final float[] GIVEN_FRACTIONS, final java.awt.Color[] GIVEN_COLORS) throws IllegalArgumentException {
this(false, CENTER, 0.0f, GIVEN_FRACTIONS, GIVEN_COLORS);
}
/**
* Enhanced constructor which takes the FRACTIONS in degress from 0.0f to
* 360.0f and also an GIVEN_OFFSET in degrees around the rotation CENTER
*
* #param USE_DEGREES
* #param CENTER
* #param GIVEN_OFFSET
* #param GIVEN_FRACTIONS
* #param GIVEN_COLORS
* #throws IllegalArgumentException
*/
public ConicalGradientPaint(final boolean USE_DEGREES, final java.awt.geom.Point2D CENTER, final float GIVEN_OFFSET, final float[] GIVEN_FRACTIONS, final java.awt.Color[] GIVEN_COLORS) throws IllegalArgumentException {
// Check that fractions and colors are of the same size
if (GIVEN_FRACTIONS.length != GIVEN_COLORS.length) {
throw new IllegalArgumentException("Fractions and colors must be equal in size");
}
final java.util.ArrayList<Float> FRACTION_LIST = new java.util.ArrayList<Float>(GIVEN_FRACTIONS.length);
final float OFFSET;
if (USE_DEGREES) {
final double DEG_FRACTION = 1f / 360f;
if (Double.compare((GIVEN_OFFSET * DEG_FRACTION), -0.5) == 0) {
OFFSET = -0.5f;
} else if (Double.compare((GIVEN_OFFSET * DEG_FRACTION), 0.5) == 0) {
OFFSET = 0.5f;
} else {
OFFSET = (float) (GIVEN_OFFSET * DEG_FRACTION);
}
for (float fraction : GIVEN_FRACTIONS) {
FRACTION_LIST.add((float) (fraction * DEG_FRACTION));
}
} else {
// Now it seems to work with rotation of 0.5f, below is the old code to correct the problem
// if (GIVEN_OFFSET == -0.5)
// {
// // This is needed because of problems in the creation of the Raster
// // with a angle offset of exactly -0.5
// OFFSET = -0.49999f;
// }
// else if (GIVEN_OFFSET == 0.5)
// {
// // This is needed because of problems in the creation of the Raster
// // with a angle offset of exactly +0.5
// OFFSET = 0.499999f;
// }
// else
{
OFFSET = GIVEN_OFFSET;
}
for (float fraction : GIVEN_FRACTIONS) {
FRACTION_LIST.add(fraction);
}
}
// Check for valid offset
if (OFFSET > 0.5f || OFFSET < -0.5f) {
throw new IllegalArgumentException("Offset has to be in the range of -0.5 to 0.5");
}
// Adjust fractions and colors array in the case where startvalue != 0.0f and/or endvalue != 1.0f
final java.util.List<java.awt.Color> COLOR_LIST = new java.util.ArrayList<java.awt.Color>(GIVEN_COLORS.length);
COLOR_LIST.addAll(java.util.Arrays.asList(GIVEN_COLORS));
// Assure that fractions start with 0.0f
if (FRACTION_LIST.get(0) != 0.0f) {
FRACTION_LIST.add(0, 0.0f);
final java.awt.Color TMP_COLOR = COLOR_LIST.get(0);
COLOR_LIST.add(0, TMP_COLOR);
}
// Assure that fractions end with 1.0f
if (FRACTION_LIST.get(FRACTION_LIST.size() - 1) != 1.0f) {
FRACTION_LIST.add(1.0f);
COLOR_LIST.add(GIVEN_COLORS[0]);
}
// Recalculate the fractions and colors with the given offset
final java.util.Map<Float, java.awt.Color> FRACTION_COLORS = recalculate(FRACTION_LIST, COLOR_LIST, OFFSET);
// Clear the original FRACTION_LIST and COLOR_LIST
FRACTION_LIST.clear();
COLOR_LIST.clear();
// Sort the hashmap by fraction and add the values to the FRACION_LIST and COLOR_LIST
final java.util.SortedSet<Float> SORTED_FRACTIONS = new java.util.TreeSet<Float>(FRACTION_COLORS.keySet());
final java.util.Iterator<Float> ITERATOR = SORTED_FRACTIONS.iterator();
while (ITERATOR.hasNext()) {
final float CURRENT_FRACTION = ITERATOR.next();
FRACTION_LIST.add(CURRENT_FRACTION);
COLOR_LIST.add(FRACTION_COLORS.get(CURRENT_FRACTION));
}
// Set the values
this.CENTER = CENTER;
COLORS = COLOR_LIST.toArray(new java.awt.Color[]{});
// Prepare lookup table for the angles of each fraction
final int MAX_FRACTIONS = FRACTION_LIST.size();
this.FRACTION_ANGLES = new double[MAX_FRACTIONS];
for (int i = 0; i < MAX_FRACTIONS; i++) {
FRACTION_ANGLES[i] = FRACTION_LIST.get(i) * 360;
}
// Prepare lookup tables for the color stepsize of each color
RED_STEP_LOOKUP = new double[COLORS.length];
GREEN_STEP_LOOKUP = new double[COLORS.length];
BLUE_STEP_LOOKUP = new double[COLORS.length];
ALPHA_STEP_LOOKUP = new double[COLORS.length];
for (int i = 0; i < (COLORS.length - 1); i++) {
RED_STEP_LOOKUP[i] = ((COLORS[i + 1].getRed() - COLORS[i].getRed()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
GREEN_STEP_LOOKUP[i] = ((COLORS[i + 1].getGreen() - COLORS[i].getGreen()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
BLUE_STEP_LOOKUP[i] = ((COLORS[i + 1].getBlue() - COLORS[i].getBlue()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
ALPHA_STEP_LOOKUP[i] = ((COLORS[i + 1].getAlpha() - COLORS[i].getAlpha()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
}
}
/**
* Recalculates the fractions in the FRACTION_LIST and their associated
* colors in the COLOR_LIST with a given OFFSET. Because the conical
* gradients always starts with 0 at the top and clockwise direction you
* could rotate the defined conical gradient from -180 to 180 degrees which
* equals values from -0.5 to +0.5
*
* #param FRACTION_LIST
* #param COLOR_LIST
* #param OFFSET
* #return Hashmap that contains the recalculated fractions and colors after
* a given rotation
*/
private java.util.HashMap<Float, java.awt.Color> recalculate(final java.util.List<Float> FRACTION_LIST, final java.util.List<java.awt.Color> COLOR_LIST, final float OFFSET) {
// Recalculate the fractions and colors with the given offset
final int MAX_FRACTIONS = FRACTION_LIST.size();
final java.util.HashMap<Float, java.awt.Color> FRACTION_COLORS = new java.util.HashMap<Float, java.awt.Color>(MAX_FRACTIONS);
for (int i = 0; i < MAX_FRACTIONS; i++) {
// Add offset to fraction
final float TMP_FRACTION = FRACTION_LIST.get(i) + OFFSET;
// Color related to current fraction
final java.awt.Color TMP_COLOR = COLOR_LIST.get(i);
// Check each fraction for limits (0...1)
if (TMP_FRACTION <= 0) {
FRACTION_COLORS.put(1.0f + TMP_FRACTION + 0.0001f, TMP_COLOR);
final float NEXT_FRACTION;
final java.awt.Color NEXT_COLOR;
if (i < MAX_FRACTIONS - 1) {
NEXT_FRACTION = FRACTION_LIST.get(i + 1) + OFFSET;
NEXT_COLOR = COLOR_LIST.get(i + 1);
} else {
NEXT_FRACTION = 1 - FRACTION_LIST.get(0) + OFFSET;
NEXT_COLOR = COLOR_LIST.get(0);
}
if (NEXT_FRACTION > 0) {
final java.awt.Color NEW_FRACTION_COLOR = getColorFromFraction(TMP_COLOR, NEXT_COLOR, (int) ((NEXT_FRACTION - TMP_FRACTION) * 10000), (int) ((-TMP_FRACTION) * 10000));
FRACTION_COLORS.put(0.0f, NEW_FRACTION_COLOR);
FRACTION_COLORS.put(1.0f, NEW_FRACTION_COLOR);
}
} else if (TMP_FRACTION >= 1) {
FRACTION_COLORS.put(TMP_FRACTION - 1.0f - 0.0001f, TMP_COLOR);
final float PREVIOUS_FRACTION;
final java.awt.Color PREVIOUS_COLOR;
if (i > 0) {
PREVIOUS_FRACTION = FRACTION_LIST.get(i - 1) + OFFSET;
PREVIOUS_COLOR = COLOR_LIST.get(i - 1);
} else {
PREVIOUS_FRACTION = FRACTION_LIST.get(MAX_FRACTIONS - 1) + OFFSET;
PREVIOUS_COLOR = COLOR_LIST.get(MAX_FRACTIONS - 1);
}
if (PREVIOUS_FRACTION < 1) {
final java.awt.Color NEW_FRACTION_COLOR = getColorFromFraction(TMP_COLOR, PREVIOUS_COLOR, (int) ((TMP_FRACTION - PREVIOUS_FRACTION) * 10000), (int) (TMP_FRACTION - 1.0f) * 10000);
FRACTION_COLORS.put(1.0f, NEW_FRACTION_COLOR);
FRACTION_COLORS.put(0.0f, NEW_FRACTION_COLOR);
}
} else {
FRACTION_COLORS.put(TMP_FRACTION, TMP_COLOR);
}
}
// Clear the original FRACTION_LIST and COLOR_LIST
FRACTION_LIST.clear();
COLOR_LIST.clear();
return FRACTION_COLORS;
}
/**
* With the START_COLOR at the beginning and the DESTINATION_COLOR at the
* end of the given RANGE the method will calculate and return the color
* that equals the given VALUE. e.g. a START_COLOR of BLACK (R:0, G:0, B:0,
* A:255) and a DESTINATION_COLOR of WHITE(R:255, G:255, B:255, A:255) with
* a given RANGE of 100 and a given VALUE of 50 will return the color that
* is exactly in the middle of the gradient between black and white which is
* gray(R:128, G:128, B:128, A:255) So this method is really useful to
* calculate colors in gradients between two given colors.
*
* #param START_COLOR
* #param DESTINATION_COLOR
* #param RANGE
* #param VALUE
* #return Color calculated from a range of values by given value
*/
public java.awt.Color getColorFromFraction(final java.awt.Color START_COLOR, final java.awt.Color DESTINATION_COLOR, final int RANGE, final int VALUE) {
final float SOURCE_RED = START_COLOR.getRed() * INT_TO_FLOAT_CONST;
final float SOURCE_GREEN = START_COLOR.getGreen() * INT_TO_FLOAT_CONST;
final float SOURCE_BLUE = START_COLOR.getBlue() * INT_TO_FLOAT_CONST;
final float SOURCE_ALPHA = START_COLOR.getAlpha() * INT_TO_FLOAT_CONST;
final float DESTINATION_RED = DESTINATION_COLOR.getRed() * INT_TO_FLOAT_CONST;
final float DESTINATION_GREEN = DESTINATION_COLOR.getGreen() * INT_TO_FLOAT_CONST;
final float DESTINATION_BLUE = DESTINATION_COLOR.getBlue() * INT_TO_FLOAT_CONST;
final float DESTINATION_ALPHA = DESTINATION_COLOR.getAlpha() * INT_TO_FLOAT_CONST;
final float RED_DELTA = DESTINATION_RED - SOURCE_RED;
final float GREEN_DELTA = DESTINATION_GREEN - SOURCE_GREEN;
final float BLUE_DELTA = DESTINATION_BLUE - SOURCE_BLUE;
final float ALPHA_DELTA = DESTINATION_ALPHA - SOURCE_ALPHA;
final float RED_FRACTION = RED_DELTA / RANGE;
final float GREEN_FRACTION = GREEN_DELTA / RANGE;
final float BLUE_FRACTION = BLUE_DELTA / RANGE;
final float ALPHA_FRACTION = ALPHA_DELTA / RANGE;
//System.out.println(DISTANCE + " " + CURRENT_FRACTION);
return new java.awt.Color(SOURCE_RED + RED_FRACTION * VALUE, SOURCE_GREEN + GREEN_FRACTION * VALUE, SOURCE_BLUE + BLUE_FRACTION * VALUE, SOURCE_ALPHA + ALPHA_FRACTION * VALUE);
}
#Override
public java.awt.PaintContext createContext(final java.awt.image.ColorModel COLOR_MODEL, final java.awt.Rectangle DEVICE_BOUNDS, final java.awt.geom.Rectangle2D USER_BOUNDS, final java.awt.geom.AffineTransform TRANSFORM, final java.awt.RenderingHints HINTS) {
final java.awt.geom.Point2D TRANSFORMED_CENTER = TRANSFORM.transform(CENTER, null);
return new ConicalGradientPaintContext(TRANSFORMED_CENTER);
}
#Override
public int getTransparency() {
return java.awt.Transparency.TRANSLUCENT;
}
private final class ConicalGradientPaintContext implements java.awt.PaintContext {
final private java.awt.geom.Point2D CENTER;
public ConicalGradientPaintContext(final java.awt.geom.Point2D CENTER) {
this.CENTER = new java.awt.geom.Point2D.Double(CENTER.getX(), CENTER.getY());
}
#Override
public void dispose() {
}
#Override
public java.awt.image.ColorModel getColorModel() {
return java.awt.image.ColorModel.getRGBdefault();
}
#Override
public java.awt.image.Raster getRaster(final int X, final int Y, final int TILE_WIDTH, final int TILE_HEIGHT) {
final double ROTATION_CENTER_X = -X + CENTER.getX();
final double ROTATION_CENTER_Y = -Y + CENTER.getY();
final int MAX = FRACTION_ANGLES.length;
// Create raster for given colormodel
final java.awt.image.WritableRaster RASTER = getColorModel().createCompatibleWritableRaster(TILE_WIDTH, TILE_HEIGHT);
// Create data array with place for red, green, blue and alpha values
int[] data = new int[(TILE_WIDTH * TILE_HEIGHT * 4)];
double dx;
double dy;
double distance;
double angle;
double currentRed = 0;
double currentGreen = 0;
double currentBlue = 0;
double currentAlpha = 0;
for (int py = 0; py < TILE_HEIGHT; py++) {
for (int px = 0; px < TILE_WIDTH; px++) {
// Calculate the distance between the current position and the rotation angle
dx = px - ROTATION_CENTER_X;
dy = py - ROTATION_CENTER_Y;
distance = Math.sqrt(dx * dx + dy * dy);
// Avoid division by zero
if (distance == 0) {
distance = 1;
}
// 0 degree on top
angle = Math.abs(Math.toDegrees(Math.acos(dx / distance)));
if (dx >= 0 && dy <= 0) {
angle = 90.0 - angle;
} else if (dx >= 0 && dy >= 0) {
angle += 90.0;
} else if (dx <= 0 && dy >= 0) {
angle += 90.0;
} else if (dx <= 0 && dy <= 0) {
angle = 450.0 - angle;
}
// Check for each angle in fractionAngles array
for (int i = 0; i < (MAX - 1); i++) {
if ((angle >= FRACTION_ANGLES[i])) {
currentRed = COLORS[i].getRed() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * RED_STEP_LOOKUP[i];
currentGreen = COLORS[i].getGreen() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * GREEN_STEP_LOOKUP[i];
currentBlue = COLORS[i].getBlue() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * BLUE_STEP_LOOKUP[i];
currentAlpha = COLORS[i].getAlpha() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * ALPHA_STEP_LOOKUP[i];
continue;
}
}
// Fill data array with calculated color values
final int BASE = (py * TILE_WIDTH + px) * 4;
data[BASE + 0] = (int) (currentRed * 255);
data[BASE + 1] = (int) (currentGreen * 255);
data[BASE + 2] = (int) (currentBlue * 255);
data[BASE + 3] = (int) (currentAlpha * 255);
}
}
// Fill the raster with the data
RASTER.setPixels(0, 0, TILE_WIDTH, TILE_HEIGHT, data);
return RASTER;
}
}
}
}