I have a few rectangles that I assign rotation one by one ((javafx.scene.shape.Rectangle) shape).rotateProperty().bind(rotate);
For example, 45 degrees
My rectangle rotates around its center. Please tell me how to make the enemy a few right-angles around their common center.
To get something like this
this.rotate.addListener((obs, old, fresh) -> {
for (VObject vObject : children ) {
vObject.rotate.set(this.rotate.get());
}
});
This is how I add rotation. How can I specify the angle
Update: I used the advice below and now I set the rotation individually for each rectangle. (The selection is still a bit wrong)
this.rotate.addListener((obs, old, fresh) -> {
Rotate groupRotate = new Rotate(rotate.get(),
this.x.getValue().doubleValue() + this.width.getValue().doubleValue() / 2 ,
this.y.getValue().doubleValue() + this.height.getValue().doubleValue() / 2);
for (VObject vObject : children ) {
vObject.getShape().getTransforms().clear();
vObject.getShape().getTransforms().add(groupRotate);
}
});
But now the axis also rotates depending on the rotation.
Can I set the rotation to the rectangles without turning the coordinate axis?
If you put all rectangles into a common Group, you can rotate them at once:
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
public class RotateAllApplication extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
BorderPane root = new BorderPane();
// the common group
Group group = new Group();
group.getChildren().addAll(new Rectangle(10, 10, 80, 40), //
new Rectangle(110, 10, 80, 40), //
new Rectangle(10, 110, 80, 40), //
new Rectangle(110, 110, 80, 40));
// rotate the group instead of each rectangle
group.setRotate(45.0);
root.setCenter(group);
primaryStage.setScene(new Scene(root, 600, 400));
primaryStage.show();
}
public static void main(String[] args) {
Application.launch(args);
}
}
Update: If you don't want to create a parent Group object, you can apply the same rotation transformation to each child instead. While Node#setRotate(double) always rotates around the center of the node, adding a transformation to Node#getTransforms() is more general and not restricted to simple rotations.
The following statement will apply a rotation around the point (100.0/100.0) of the parent coordinate system to all children in the list:
childrenList.forEach(child -> child.getTransforms().add(Transform.rotate(45.0, 100.0, 100.0)));
Use a Rotate transform and specify the appropriate pivot point:
#Override
public void start(Stage primaryStage) throws IOException {
Pane pane = new Pane();
pane.setPrefSize(600, 600);
Rectangle[] rects = new Rectangle[4];
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 2; j++) {
Rectangle rect = new Rectangle(100 + i * 200, 100 + j * 100, 150, 50);
rects[i * 2 + j] = rect;
pane.getChildren().add(rect);
}
}
Slider slider = new Slider(0, 360, 0);
double minX = Double.POSITIVE_INFINITY;
double minY = Double.POSITIVE_INFINITY;
double maxX = Double.NEGATIVE_INFINITY;
double maxY = Double.NEGATIVE_INFINITY;
Rotate rotate = new Rotate();
// find pivot point
for (Rectangle rect : rects) {
double val = rect.getX();
if (minX > val) {
minX = val;
}
val += rect.getWidth();
if (maxX < val) {
maxX = val;
}
val = rect.getY();
if (minY > val) {
minY = val;
}
val += rect.getHeight();
if (maxY < val) {
maxY = val;
}
rect.getTransforms().add(rotate);
}
rotate.setPivotX(0.5 * (maxX + minX));
rotate.setPivotY(0.5 * (maxY + minY));
rotate.angleProperty().bind(slider.valueProperty());
Scene scene = new Scene(new VBox(10, pane, slider));
primaryStage.setScene(scene);
primaryStage.sizeToScene();
primaryStage.show();
}
If you're planing to apply multiple transformations, you may need to adjust the code for finding the pivot point to use transforms for calculating the bounds...
Related
I have this piece of code here that has a borderpane as a parent and 2 other panes, one is a minesweeper game and the other is an empty pane with a black background, the minesweeper game is set to be in the center of the borderpane and the empty pane is set to be in the bottom. Right now when I run the code, it will only show the minesweeper game and not the empty pane (can be seen in the image). How do I make it show the empty pane at the bottom of the borderpane?
(Layout as of right now)
package project;
import java.util.ArrayList;
import java.util.List;
import javafx.application.Application;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.Pane;
import javafx.scene.layout.StackPane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.scene.text.Font;
import javafx.scene.text.Text;
import javafx.stage.Stage;
public class MinesweeperApp extends Application {
private static final int TILE_SIZE = 40;
private static final int W = 800;
private static final int H = 800;
private static final int X_TILES = W / TILE_SIZE;
private static final int Y_TILES = H / TILE_SIZE;
private Tile[][] grid = new Tile[X_TILES][Y_TILES];
// private ArrayList[][] grid = new ArrayList[X_TILES][Y_TILES];
private Scene scene;
private Parent createContent() {
BorderPane root = new BorderPane();
Pane middlepane = new Pane();
Pane lowerPane = new Pane();
lowerPane.setStyle("-fx-background-color: black;");
root.setTop(lowerPane);
root.setBottom(middlepane);
middlepane.setPrefSize(W, H);
for (int y = 0; y < Y_TILES; y++) {
for (int x = 0; x < X_TILES; x++) {
Tile tile = new Tile(x, y, Math.random() < 0.2);
grid[x][y] = tile;
middlepane.getChildren().add(tile);
}
}
for (int y = 0; y < Y_TILES; y++) {
for (int x = 0; x < X_TILES; x++) {
Tile tile = grid[x][y];
if (tile.hasBomb)
continue;
long bombs = getNeighbors(tile).stream().filter(t -> t.hasBomb).count();
if (bombs > 0)
tile.text.setText(String.valueOf(bombs));
}
}
return root;
}
private List<Tile> getNeighbors(Tile tile) {
List<Tile> neighbors = new ArrayList<>();
// ttt
// tXt
// ttt
int[] points = new int[] {
-1, -1,
-1, 0,
-1, 1,
0, -1,
0, 1,
1, -1,
1, 0,
1, 1
};
for (int i = 0; i < points.length; i++) {
int dx = points[i];
int dy = points[++i];
int newX = tile.x + dx;
int newY = tile.y + dy;
if (newX >= 0 && newX < X_TILES
&& newY >= 0 && newY < Y_TILES) {
neighbors.add(grid[newX][newY]);
}
}
return neighbors;
}
private class Tile extends StackPane {
private int x, y;
private boolean hasBomb;
private boolean isOpen = false;
private Rectangle border = new Rectangle(TILE_SIZE - 2, TILE_SIZE - 2);
private Text text = new Text();
public Tile(int x, int y, boolean hasBomb) {
this.x = x;
this.y = y;
this.hasBomb = hasBomb;
border.setStroke(null);
border.setFill(Color.NAVY);
text.setFont(Font.font(18));
text.setText(hasBomb ? "X" : "");
text.setVisible(false);
getChildren().addAll(border, text);
setTranslateX(x * TILE_SIZE);
setTranslateY(y * TILE_SIZE);
setOnMouseClicked(e -> open());
}
public void open() {
System.out.println("clicked");
System.out.println("x: " + this.x + " " + "y: " + this.y);
if (isOpen){
return;
}
if (hasBomb) {
System.out.println("Game Over");
scene.setRoot(createContent());
return;
}
isOpen = true;
text.setVisible(true);
border.setFill(Color.RED);
if (text.getText().isEmpty()) {
getNeighbors(this).forEach(Tile::open);
}
}
}
#Override
public void start(Stage stage) throws Exception {
scene = new Scene(createContent());
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Absent children, an empty Pane has zero width and height. Try adding non-empty content to the top and bottom to see the effect:
root.setTop(new Label("top"));
root.setCenter(middlepane);
root.setBottom(new Label("bottom"));
As an aside, your original root.setBottom(middlepane) may be misleading.
Setting Constraints
Set size constraints on a pane to “see” a Pane which has no content.
This will make the pane take up space in the layout.
To make the app behave as you desire, configure the pane's:
min width or height, OR
pref width or height, OR
any combination of those.
For example, to set a min height for the top pane in a border pane:
BorderPane borderPane = new BorderPane();
Pane top = new Pane();
top.setMinHeight(15);
borderPane.setTop(top);
Hiding Content
Or you could put some content in the pane and make it invisible until it is needed, while still reserving the space required to display it.
For example:
Label header = new Label("header");
header.setVisible(false);
Pane top = new Pane(header);
borderPane.setTop(top);
This works because things in the scene graph which are not visible still take up layout space, even though they are not displayed, unless you also call setManaged(false).
For the specific case of a label, you wouldn’t need the visibility setting, you could just set the label to an empty string and it would still take up room, even though nothing would be shown.
For myself, I try to avoid sizing hints where I can, so I would use an empty label. Or, set the visibility, for a more complex pane. That way I let the layout engine calculate the appropriate amount of space to reserve.
Spacing Content
This doesn't apply in your case with border pane, but for other layouts like HBox and VBox you might want to push a node all the way right or to the bottom of the layout. You can do that by adding an empty pane before the last node and setting a layout constraint on the pane like this:
HBox.setHgrow(spacer, Priority.ALWAYS);
This technique is explained more in the answer to:
How to align a button right in JavaFX?
I need to implement sort of a pathfinding algorithm, the context is the following:
I have a starting Point2D, and and objective (a Circle).
I draw a line between the starting point and the circle center.
I try to calculate a path that does not cross any other circles.
(The blue square is my object I want to move (at starting point)) and the red circle is my objective).
What I wanted to do first was to do something like this:
But the code I have seems to be buggy as sometimes, I've got negatives intersection coordonates (black points).
Is there any other way to solve this problem ? Am I seeing the problem from a correct point of view ? There is also a problem as I'm iterating over the circles to determines which intersects or not, but if the line intersect 2 or more circles, the order of which it intersect planets is different from the order I see the points on screen.
My goal is to create a PathTransition between starting point and objective following the correct path (no intersection).
I've not mentioned it, but the container is a Pane.
EDIT:
public static Point2D getMidPoint(Point2D p1, Point2D p2) {
return new Point2D((p1.getX() + p2.getX()) / 2, (p1.getY() + p2.getY()) / 2);
}
public static Circle createCircleFromPoint2D(Point2D p) {
return new Circle(p.getX(), p.getY(), 5);
}
public static Point2D createPoint2D(double x, double y) {
return new Point2D(x, y);
}
public static Pair<Point2D, Point2D> translate(int distance, Point2D p1, Point2D p2, double reference, double startX) {
double pente = (p2.getY() - p1.getY()) / (p2.getX() - p1.getX());
double newX1 = p1.getX() + (startX < reference ? -1 : 1) * (Math.sqrt(((distance*distance) / (1 + (pente*pente)))));
double newX2 = p2.getX() + (startX > reference ? -1 : 1) * (Math.sqrt(((distance*distance) / (1 + (pente*pente)))));
double newY1 = pente * (newX1 - p1.getX()) + p1.getY();
double newY2 = pente * (newX2 - p2.getX()) + p2.getY();
return new Pair<>(new Point2D(newX1, newY1), new Point2D(newX2, newY2));
}
public void start(Stage primaryStage) throws Exception{
Pane pane = new Pane();
Circle objective = new Circle(800, 250, 25);
Circle circle2 = new Circle(500, 250, 125);
Circle circle3 = new Circle(240, 400, 75);
Circle circle4 = new Circle(700, 500, 150, Color.VIOLET);
Circle circle5 = new Circle(1150, 300, 115, Color.ORANGE);
Rectangle myObject = new Rectangle(175, 175, 15, 15);
objective.setFill(Color.RED);
circle2.setFill(Color.BLUE);
circle3.setFill(Color.GREEN);
myObject.setFill(Color.BLUE);
ArrayList<Circle> circles = new ArrayList<>();
circles.add(objective);
circles.add(circle2);
circles.add(circle3);
circles.add(circle4);
circles.add(circle5);
Line straightLine = new Line();
pane.setOnMouseClicked(new EventHandler<MouseEvent>() {
#Override
public void handle(MouseEvent event) {
myObject.setX(event.getX());
myObject.setY(event.getY());
// My starting coordinates (at mouse position)
double fromX = myObject.getX();
double fromY = myObject.getY();
// Where I want to go
double toX = objective.getCenterX();
double toY = objective.getCenterY();
// Line style
straightLine.setStartX(event.getX());
straightLine.setStartY(event.getY());
straightLine.setEndX(toX);
straightLine.setEndY(toY);
straightLine.setStrokeWidth(2);
straightLine.setStroke(Color.GRAY.deriveColor(0, 1, 1, 0.5));
straightLine.setStrokeLineCap(StrokeLineCap.BUTT);
straightLine.getStrokeDashArray().setAll(10.0, 5.0);
straightLine.setMouseTransparent(true);
// Coordinates to Point2D
Point2D from = new Point2D(fromX, fromY);
Point2D to = new Point2D(toX, toY);
Path path = new Path();
path.getElements().add(new MoveTo(fromX, fromY));
for (Circle c : circles) {
if (straightLine.intersects(c.getLayoutBounds())) {
// I don't want to do anything if I'm intersecting the objective (for now)
if (c == objective)
continue;
Shape s = Shape.intersect(straightLine, c);
double xmin = s.getBoundsInLocal().getMinX();
double ymin = s.getBoundsInLocal().getMinY();
double xmax = s.getBoundsInLocal().getMaxX();
double ymax = s.getBoundsInLocal().getMaxY();
Point2D intersectionPt1 = createPoint2D((fromX < objective.getCenterX()) ? xmin : xmax , (fromY < objective.getCenterY()) ? ymin : ymax);
Point2D intersectionPt2 = createPoint2D((fromX > objective.getCenterX()) ? xmin : xmax , (fromY < objective.getCenterY()) ? ymax : ymin);
Point2D middlePt = getMidPoint(intersectionPt1, intersectionPt2);
Circle circlePt1 = new Circle(intersectionPt1.getX(), intersectionPt1.getY(), 5);
Circle circlePt2 = new Circle(intersectionPt2.getX(), intersectionPt2.getY(), 5);
Circle circleMiddle = new Circle(middlePt.getX(), middlePt.getY(), 5, Color.RED);
if (c != objective) {
// To calculate the points just before/after the first/second points (green points)
Pair<Point2D, Point2D> pts = translate(50, intersectionPt1, intersectionPt2, objective.getCenterX(), fromX);
Point2D beforePt1 = pts.getKey();
Point2D beforePt2 = pts.getValue();
Circle circleBeforePt1 = createCircleFromPoint2D(beforePt1);
Circle circleBeforePt2 = createCircleFromPoint2D(beforePt2);
circleBeforePt1.setFill(Color.GREEN);
circleBeforePt2.setFill(Color.GREEN);
pane.getChildren().addAll(circleBeforePt1, circleBeforePt2);
}
pane.getChildren().addAll(s, circlePt1, circlePt2, circleMiddle);
}
}
PathTransition pathTransition = new PathTransition();
pathTransition.setDuration(Duration.seconds(2));
pathTransition.setNode(myObject);
pathTransition.setPath(path);
pathTransition.setOrientation(PathTransition.OrientationType.ORTHOGONAL_TO_TANGENT);
pathTransition.play();
}
});
pane.getChildren().addAll(circles);
pane.getChildren().addAll(myObject, straightLine);
Scene scene = new Scene(pane, 1600, 900);
primaryStage.setScene(scene);
primaryStage.show();
}
I want to calculate a path (not necessarily a shortest path) from Point A to Point B, but can't figure it out how. Now I have the points where I would like to pass, I don't know how to link them togethers.
Solution strategy and implementation
I built a solution with the following strategy: On a given line from(X,Y) to to(X,Y) I compute the closest intersection with one of the obstacle shapes. From that shape I take the length of the intersection as a measure of how large the obstacle is, and take a look at the points left and right by 1/2 of that length from some point shortly before the intersection. The first of the left and right points that is not inside an obstacle is then used to sub-divide the task of finding a path around the obstacles.
protected void computeIntersections(double fromX, double fromY, double toX, double toY) {
// recursively test for obstacles and try moving around them by
// calling this same procedure on the segments to and from
// a suitable new point away from the line
Line testLine = new Line(fromX, fromY, toX, toY);
//compute the unit direction of the line
double dX = toX-fromX, dY = toY-fromY;
double ds = Math.hypot(dX,dY);
dX /= ds; dY /= ds;
// get the length from the initial point of the minimal intersection point
// and the opposite point of the same obstacle, remember also the closest obstacle
double t1=-1, t2=-1;
Shape obst = null;
for (Shape c : lstObstacles) {
if (testLine.intersects(c.getLayoutBounds())) {
Shape s = Shape.intersect(testLine, c);
if( s.getLayoutBounds().isEmpty() ) continue;
// intersection bounds of the current shape
double s1, s2;
if(Math.abs(dX) < Math.abs(dY) ) {
s1 = ( s.getBoundsInLocal().getMinY()-fromY ) / dY;
s2 = ( s.getBoundsInLocal().getMaxY()-fromY ) / dY;
} else {
s1 = ( s.getBoundsInLocal().getMinX()-fromX ) / dX;
s2 = ( s.getBoundsInLocal().getMaxX()-fromX ) / dX;
}
// ensure s1 < s2
if ( s2 < s1 ) { double h=s2; s2=s1; s1=h; }
// remember the closest intersection
if ( ( t1 < 0 ) || ( s1 < t1 ) ) { t1 = s1; t2 = s2; obst = c; }
}
}
// at least one intersection found
if( ( obst != null ) && ( t1 > 0 ) ) {
intersectionDecorations.getChildren().add(Shape.intersect(testLine, obst));
// coordinates for the vertex point of the path
double midX, midY;
// go to slightly before the intersection set
double intersectX = fromX + 0.8*t1*dX, intersectY = fromY + 0.8*t1*dY;
// orthogonal segment of half the length of the intersection, go left and right
double perpX = 0.5*(t2-t1)*dY, perpY = 0.5*(t1-t2)*dX;
Rectangle testRect = new Rectangle( 10, 10);
// go away from the line to hopefully have less obstacle from the new point
while( true ) {
// go "left", test if free
midX = intersectX + perpX; midY = intersectY + perpY;
testRect.setX(midX-5); testRect.setY(midY-5);
if( Shape.intersect(testRect, obst).getLayoutBounds().isEmpty() ) break;
// go "right"
midX = intersectX - perpX; midY = intersectY - perpY;
testRect.setX(midX-5); testRect.setY(midY-5);
if( Shape.intersect(testRect, obst).getLayoutBounds().isEmpty() ) break;
// if obstacles left and right, try closer points next
perpX *= 0.5; perpY *= 0.5;
}
intersectionDecorations.getChildren().add(new Line(intersectX, intersectY, midX, midY));
// test the first segment for intersections with obstacles
computeIntersections(fromX, fromY, midX, midY);
// add the middle vertex to the solution path
connectingPath.getElements().add(new LineTo(midX, midY));
// test the second segment for intersections with obstacles
computeIntersections(midX, midY, toX, toY);
}
}
This first chosen point might not be the most optimal one, as one can see, but it does the job. To do better one would have to construct some kind of decision tree of the left-right decisions and then chose the shortest path among the variants. All the usual strategies then apply, like starting a second tree from the target location, depth-first search etc.
The auxillary lines are the intersections that were used and the perpendicular lines to the new midpoints.
PathfinderApp.java
I used this problem to familiarize myself with the use of FXML, thus the main application has the usual boilerplate code.
package pathfinder;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class PathfinderApp extends Application {
#Override
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("pathfinder.fxml"));
primaryStage.setTitle("Finding a path around obstacles");
primaryStage.setScene(new Scene(root, 1600, 900));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
pathfinder.fxml
The FXML file contains the "most" static (in the sense of always present for the given type of task) elements of the user interface. These are the cursor rectangle, the target circle and a line between them. Then groups for the obstacles and "decorations" from the path construction, and the path itself. This separation allows to clear and populate these groupings independent from each other with no other organizational effort.
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.layout.Pane?>
<?import javafx.scene.Group?>
<?import javafx.scene.text.Text?>
<?import javafx.scene.shape.Line?>
<?import javafx.scene.shape.Path?>
<?import javafx.scene.shape.Circle?>
<?import javafx.scene.shape.Rectangle?>
<?import javafx.scene.paint.Color?>
<Pane xmlns:fx="http://javafx.com/fxml"
fx:controller="pathfinder.PathfinderController" onMouseClicked="#setCursor">
<Circle fx:id="target" centerX="800" centerY="250" radius="25" fill="red"/>
<Rectangle fx:id="cursor" x="175" y="175" width="15" height="15" fill="lightblue"/>
<Line fx:id="straightLine" startX="${cursor.X}" startY="${cursor.Y}" endX="${target.centerX}" endY="${target.centerY}"
strokeWidth="2" stroke="gray" strokeLineCap="butt" strokeDashArray="10.0, 5.0" mouseTransparent="true" />
<Group fx:id="obstacles" />
<Group fx:id="intersectionDecorations" />
<Path fx:id="connectingPath" strokeWidth="2" stroke="blue" />
</Pane>
PathfinderController.java
The main work is done in the controller. Some minimal initialization binding the target and cursor to their connecting line and the mouse event handler (with code that prevents the cursor to be placed inside some obstacle) and then the path finding procedures. One framing procedure and the recursive workhorse from above.
package pathfinder;
import javafx.fxml.FXML;
import javafx.geometry.Bounds;
import javafx.scene.layout.Pane;
import javafx.scene.Group;
import javafx.scene.text.Text;
import javafx.scene.text.Font;
import javafx.scene.shape.Shape;
import javafx.scene.shape.Line;
import javafx.scene.shape.Path;
import javafx.scene.shape.LineTo;
import javafx.scene.shape.MoveTo;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Rectangle;
import javafx.scene.paint.Color;
import javafx.scene.input.MouseEvent;
import java.util.*;
public class PathfinderController {
#FXML
private Circle target;
#FXML
private Rectangle cursor;
#FXML
private Line straightLine;
#FXML
private Path connectingPath;
#FXML
private Group obstacles, intersectionDecorations;
private static List<Shape> lstObstacles = Arrays.asList(
new Circle( 500, 250, 125, Color.BLUE ),
new Circle( 240, 400, 75, Color.GREEN ),
new Circle( 700, 500, 150, Color.VIOLET),
new Circle(1150, 300, 115, Color.ORANGE)
);
#FXML
public void initialize() {
straightLine.startXProperty().bind(cursor.xProperty());
straightLine.startYProperty().bind(cursor.yProperty());
obstacles.getChildren().addAll(lstObstacles);
findPath();
}
#FXML
protected void setCursor(MouseEvent e) {
Shape test = new Rectangle(e.getX()-5, e.getY()-5, 10, 10);
for (Shape c : lstObstacles) {
if( !Shape.intersect(c, test).getLayoutBounds().isEmpty() ) return;
}
cursor.setX(e.getX());
cursor.setY(e.getY());
findPath();
}
protected void findPath() {
double fromX = cursor.getX();
double fromY = cursor.getY();
double toX = target.getCenterX();
double toY = target.getCenterY();
intersectionDecorations.getChildren().clear();
connectingPath.getElements().clear();
// first point of path
connectingPath.getElements().add(new MoveTo(fromX, fromY));
// check path for intersections, move around if necessary
computeIntersections(fromX, fromY, toX, toY);
// last point of the path
connectingPath.getElements().add(new LineTo(toX, toY));
}
protected void computeIntersections(double fromX, double fromY, double toX, double toY) {
...
}
// end class
}
It may not be the desired answer, but did you think about unit testing your math code? It is easy to do for math code and then you can be sure the low level functions work correct.
If you still have the bug afterwards, you can write a unit test for easier reproducing it and post it here.
On Topic:
Your algorithm with the lines can get quite complex or even find no solution with more and/or overlapping circles.
Why not use the standard A* algorithm, where all non-white pixels are obstacles. Is that overkill?
I am trying to set a panel that contains several points and then draw a triangle or any others forms. And all points that are inside that form will switch their colors to red.
Seems like i am doing something wrong, is this the correct way to draw point inside the for loop ?
Make sure the Polygon is created before creating the circles. This allows you to use check for intersection of the shapes as described in this answer: https://stackoverflow.com/a/15014709/2991525
Choose the circle fill accordingly:
#Override
public void start(Stage stage) {
Group root = new Group();
Polygon triangle = new Polygon(300d, 100d, 600d, 150d, 500d, 300d);
root.getChildren().add(triangle);
Scene scene = new Scene(root, 900, 500);
for (double x = 65; x < scene.getWidth(); x += 65) {
for (double y = 65; y < scene.getHeight(); y += 65) {
Circle circle = new Circle(x, y, 10);
root.getChildren().add(circle);
Shape intersection = Shape.intersect(circle, triangle);
//Setting the color of the circle
circle.setFill(intersection.getBoundsInLocal().getWidth() == -1 ? Color.BLACK : Color.RED);
}
}
triangle.setFill(Color.TRANSPARENT);
triangle.setStroke(Color.RED);
triangle.toFront();
stage.setTitle("Scale transition example");
stage.setScene(scene);
stage.show();
}
I made a 2D grid of ASCII characters before in which i was able to move an ascii character around. Now i want to take it to the next level by making a "visualised" version of it in a javafx window. I have tried making 2 image objects, one with a black square inside of it, and one with a white one and then putting those 2 objects multiple times inside a 2D grid like this:
Image[][] Grid = {
{B,W,B,B,B,B,B,B,B,B,B},
{B,B,B,B,W,W,W,B,B,B,B},
{B,B,B,B,B,B,B,B,B,B,B}
};
The problem is that the only way i know how to display them, is by making an imageview object for each index and if i were to say, want a 25X25 grid, that would mean i would have to make 625 imageview objects which would obviously be ridiculous.
I also tried simply putting the grid indexes one by one into the pane like this:
HBox gameLayout = new HBox(Grid[1][1], Grid[1][2], Grid[1][3]);
but that gives me a "invocationTargetException".
My goal is to be able to make snake by specifically targeting and manipulating grid elements. I want the square-color/imageView/rectangle/whatever to change when i change the value of a "B"array element to "W" (white) but the things i'v tried are either very inefficient or just don't work.
It's not at all clear what your objection is to creating multiple ImageViews. Since they can refer to the same Image instance, this should be fairly efficient (the image data doesn't need to be replicated).
This seems to work just fine:
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.image.WritableImage;
import javafx.scene.layout.GridPane;
import javafx.scene.paint.Color;
import javafx.stage.Stage;
public class TiledBoard extends Application {
private final int tileSize = 30 ;
#Override
public void start(Stage primaryStage) {
Image b = createImage(Color.BLACK);
Image w = createImage(Color.WHITE);
Image[][] grid = {
{b,w,b,b,b,b,b,b,b,b,b},
{b,b,b,b,w,w,w,b,b,b,b},
{b,b,b,b,b,b,b,b,b,b,b}
};
GridPane gridPane = new GridPane();
// for visualizing the different squares:
gridPane.setHgap(2);
gridPane.setVgap(2);
gridPane.setStyle("-fx-background-color: grey;");
for (int y = 0 ; y < grid.length ; y++) {
for (int x = 0 ; x < grid[y].length ; x++) {
ImageView imageView = new ImageView(grid[y][x]);
imageView.setFitWidth(tileSize);
imageView.setFitHeight(tileSize);
gridPane.add(imageView, x, y);
}
}
Scene scene = new Scene(gridPane);
primaryStage.setScene(scene);
primaryStage.show();
}
private Image createImage(Color color) {
WritableImage image = new WritableImage(1, 1);
image.getPixelWriter().setColor(0, 0, color);
return image ;
}
public static void main(String[] args) {
launch(args);
}
}
You could do this with some kind of Shape (e.g. Rectangle), if you prefer:
#Override
public void start(Stage primaryStage) {
Color b = Color.BLACK;
Color w = Color.WHITE;
Color[][] grid = {
{b,w,b,b,b,b,b,b,b,b,b},
{b,b,b,b,w,w,w,b,b,b,b},
{b,b,b,b,b,b,b,b,b,b,b}
};
GridPane gridPane = new GridPane();
// for visualizing the different squares:
gridPane.setHgap(2);
gridPane.setVgap(2);
gridPane.setStyle("-fx-background-color: grey;");
for (int y = 0 ; y < grid.length ; y++) {
for (int x = 0 ; x < grid[y].length ; x++) {
Rectangle rect = new Rectangle(tileSize, tileSize, grid[y][x]);
gridPane.add(rect, x, y);
}
}
Scene scene = new Scene(gridPane);
primaryStage.setScene(scene);
primaryStage.show();
}
or with a Region:
#Override
public void start(Stage primaryStage) {
Color b = Color.BLACK;
Color w = Color.WHITE;
Color[][] grid = {
{b,w,b,b,b,b,b,b,b,b,b},
{b,b,b,b,w,w,w,b,b,b,b},
{b,b,b,b,b,b,b,b,b,b,b}
};
GridPane gridPane = new GridPane();
// for visualizing the different squares:
gridPane.setHgap(2);
gridPane.setVgap(2);
gridPane.setStyle("-fx-background-color: grey;");
for (int y = 0 ; y < grid.length ; y++) {
for (int x = 0 ; x < grid[y].length ; x++) {
Region rect = new Region();
rect.setMinSize(tileSize, tileSize);
rect.setPrefSize(tileSize, tileSize);
rect.setMaxSize(tileSize, tileSize);
rect.setBackground(new Background(new BackgroundFill(grid[y][x], CornerRadii.EMPTY, Insets.EMPTY)));
gridPane.add(rect, x, y);
}
}
Scene scene = new Scene(gridPane);
primaryStage.setScene(scene);
primaryStage.show();
}
Which of these is better really just depends on what else you want to do with them.
I'm sorry, but I continue not understanding. My problem is I know nothing about physics but my teacher assigned to me this project.
private void shoot() {
Group group = new Group();
double angle = cannon.getRotate();
double speed = slider.getValue();
double x = cannon.getLayoutX();
double y = cannon.getLayoutY();
double v0X = Math.cos(angle)*speed;
double voY = Math.sin(angle)*speed;
Circle c = new Circle(x, y, 8, Color.BLACK);
/*t is the time, but I don't know its
value or has it the same value of the KeyFrame duration? */
double x2 = x + voX*t;
double y2 = y + v0Y * t - 0.5 * gravity * t * t;
Line l = new Line(x, y, x2, y2);
l.setStroke(Color.BLACK);
group.getChildren().addAll(c, l);
final Timeline timeline = new Timeline();
KeyValue xKV = new KeyValue(c.centerXProperty(), x2);
KeyValue yKV = new KeyValue(c.centerYProperty(), y2 , new Interpolator() {
#Override
//Maybe I need I splite, not a curve (?)
protected double curve(double t) {
//thisshould be trajectory's formula
return Math.tan(angle) * x*-(gravity/(2*speed*Math.cos(angle)))*x*x;
}
});
KeyFrame xKF = new KeyFrame(Duration.millis(2000), xKV);
KeyFrame yKF = new KeyFrame(Duration.millis(2000), yKV);
timeline.getKeyFrames().addAll(xKF, yKF);
timeline.play();
}
I'm at a standstill. Please, help meeee
In a KeyValue, the first parameter should be a WritableValue, e.g. circle.centerXProperty(), which represents the initial coordinate, say x. The second parameter should be a type compatible value, in this case the x coordinate toward which the projectile should move. As the timeline plays, the WritableValue will be updated accordingly. Add a second KeyValue to drive the y coordinate.
In the first example seen here, three instances of KeyValue move a figure from it's initial position to its destination position, which is size units away along each coordinate axis. In this related example, a figure moves form point p1 to p2.
In the example below, a Circle moves parallel to the x axis between 100 and 500. At the same time, that same Circle moves parallel to the y axis between 300 and 100 following the curve() defined by the parabola y = –4(x – ½)2 + 1, which has vertex (½, 1) and x intercepts at 0 and 1. This implementation of curve() models a parabolic path on a unit square, as required by the curve() API. You can change the angle of elevation by changing the ratio of height to width in the keys frames, e.g.
KeyValue xKV = new KeyValue(c.centerXProperty(), 200);
KeyValue yKV = new KeyValue(c.centerYProperty(), 0, new Interpolator() {…});
import javafx.animation.Interpolator;
import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.shape.Line;
import javafx.stage.Stage;
import javafx.util.Duration;
/**
* #see https://stackoverflow.com/a/38031826/230513
*/
public class Test extends Application {
#Override
public void start(Stage primaryStage) {
primaryStage.setTitle("Test");
Group group = new Group();
Scene scene = new Scene(group, 600, 350);
scene.setFill(Color.BLACK);
primaryStage.setScene(scene);
primaryStage.show();
Circle c = new Circle(100, 300, 16, Color.AQUA);
Line l = new Line(100, 300, 500, 300);
l.setStroke(Color.AQUA);
group.getChildren().addAll(c, l);
final Timeline timeline = new Timeline();
timeline.setCycleCount(Timeline.INDEFINITE);
timeline.setAutoReverse(false);
KeyValue xKV = new KeyValue(c.centerXProperty(), 500);
KeyValue yKV = new KeyValue(c.centerYProperty(), 100, new Interpolator() {
#Override
protected double curve(double t) {
return -4 * (t - .5) * (t - .5) + 1;
}
});
KeyFrame xKF = new KeyFrame(Duration.millis(2000), xKV);
KeyFrame yKF = new KeyFrame(Duration.millis(2000), yKV);
timeline.getKeyFrames().addAll(xKF, yKF);
timeline.play();
}
public static void main(String[] args) {
launch(args);
}
}