need an explanation, or a report where I can simply understand how this code works. I am learning Java and have some programming knowledge. My professors told us to evaluate this code and discover how every line interacts in between. So I would be glad if someone could explain me in detail how this code works using JavaFX Graphics 

 

App.java

/* Imports */ import javafx.application.Application; import javafx.scene.Scene; import javafx.scene.canvas.Canvas; import javafx.scene.canvas.GraphicsContext; import javafx.scene.layout.StackPane; import javafx.stage.Stage; /* Driver class */ public class App extends Application { // Sets boundaries of stage final int WIDTH = 1000; final int HEIGHT = 600; @Override public void start(Stage primaryStage) { try { // Sets up primary stage, canvas, and graphics context primaryStage.setTitle("Assignment 1"); Canvas canvas = new Canvas(WIDTH, HEIGHT); GraphicsContext gc = canvas.getGraphicsContext2D(); // Draws alternate ovals and rectangles of random colors double width = 500, height = 300, centerX = WIDTH / 2, centerY = HEIGHT / 2; MyOval oval; MyRectangle rect; rect = new MyRectangle(centerX - width / 2, centerY - height / 2, width, height, MyColor.getRandom()); rect.draw(gc); System.out.println(rect + " "); for (int i = 1; i < 6; ++i) { if (i % 2 != 0) { oval = new MyOval(centerX - width / 2, centerY - height / 2, width, height, MyColor.getRandom()); oval.draw(gc); System.out.println(oval + " "); } else { width /= Math.sqrt(2); height /= Math.sqrt(2); rect = new MyRectangle(centerX - width / 2, centerY - height / 2, width, height, MyColor.getRandom()); rect.draw(gc); System.out.println(rect + " "); } } // Finishing off with desired horizontal line and slightly thick window border MyLine line1 = new MyLine(0, 0, WIDTH, HEIGHT, MyColor.BLACK.getCol()); line1.draw(gc); System.out.println(line1 + " "); gc.setLineWidth(5); gc.strokeRect(0, 0, WIDTH, HEIGHT); // Sets stack pane and scene for image to appear on StackPane root = new StackPane(canvas); Scene scene = new Scene(root, WIDTH, HEIGHT); primaryStage.setScene(scene); primaryStage.show(); } catch (Exception e) { e.printStackTrace(); } } public static void main(String[] args) { launch(args); } }

My Point.java

import javafx.scene.canvas.GraphicsContext; public class MyPoint { private double x; private double y; public MyPoint(double x, double y) { this.x = x; this.y = y; } public double getX() { return x; } public double getY() { return y; } public void setX(double x) { this.x = x; } public void setY(double y) { this.y = y; } @Override public String toString() { return String.format("----- Point Properties ----- %15s (%.2f,%.2f)", "Point:", x, y); } public void draw(GraphicsContext gc) { gc.setFill(MyColor.BLACK.getCol()); gc.fillOval(x, y, 1, 1); } }

MyColor.java

 import javafx.scene.paint.Color; public enum MyColor { RED(255, 0, 0, 255), BLUE(0, 0, 255, 255), LIME(0, 255, 0, 255), CYAN(0, 255, 255, 255), GREEN(0, 128, 0, 255), GREY(128, 128, 128, 255), MAGENTA(255, 0, 255, 255), PURPLE(128, 0, 128, 255), VIOLET(148, 0, 211, 255), YELLOW(255, 255, 0, 255), WHITE(255, 255, 255, 255), BLACK(0, 0, 0, 255), HOTPINK(255, 105, 180, 255), ORANGE(255, 165, 0, 255); private int r, g, b, a; // Value for red, green, blue, and opacity /* Random color picker from color library */ public static Color getRandom() { int r, g, b; r = (int) ((Math.random() * (255))); g = (int) ((Math.random() * (255))); b = (int) ((Math.random() * (255))); return Color.rgb(r, g, b, 1); } MyColor(int r, int g, int b, int a) { this.r = r; this.g = g; this.b = b; this.a = a; } public Color getCol() { return Color.rgb(r, g, b, (double) (a / 255)); } }

MyShape.java

import javafx.scene.canvas.GraphicsContext; import javafx.scene.paint.Color; import java.util.ArrayList; import java.util.HashSet; // implements MyShapeInterface public abstract class MyShape implements MyShapeInterface { private MyPoint point; // Point of shape in pixels private Color color; MyShape(double x, double y, Color color) { this.point = new MyPoint(x, y); this.color = color; } public double getX() { return point.getX(); } public double getY() { return point.getY(); } public Color getColor() { return color; } public void setX(int x) { this.point.setX(x); } public void setY(int y) { this.point.setY(y); } public void setColor(Color color) { this.color = color; } @Override public ArrayList overlapMyShapes(MyShape shape) { ArrayList overlap = new ArrayList<>(); HashSet pointStr = new HashSet<>(); for (MyPoint point : shape.getMyArea()) { pointStr.add(point.toString()); } for (MyPoint point : this.getMyArea()) { if (pointStr.contains(point.toString())) { overlap.add(point); } } return overlap; } public abstract String toString(); public abstract void draw(GraphicsContext gc); }

MyLine.java

 import javafx.scene.canvas.GraphicsContext; import javafx.scene.paint.Color; import java.util.ArrayList; public class MyLine extends MyShape { private final double x1, y1, x2, y2; // Coordinates of two points of line MyLine(double x1, double y1, double x2, double y2, Color color) { super(0, 0, color); this.x1 = x1; this.y1 = y1; this.x2 = x2; this.y2 = y2; } public double getLength() { return Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2)); } public static double getLength(double x1, double y1, double x2, double y2) { return Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2)); } public double get_xAngle() { double angle = Math.toDegrees(Math.atan2(y2 - y1, x2 - x1)); if (angle < 0) { angle += 360; } return angle; } @Override public String toString() { return String.format( "----- Line Properties ----- %15s (%.2f,%.2f) %15s (%.2f,%.2f) %15s %.2f %15s %.2f %15s " + super.getColor(), "Point 1:", x1, y1, "Point 2:", x2, y2, "Line Length:", getLength(), "Angle:", get_xAngle(), "Color:"); } @Override public MyRectangle getMyBoundingRectangle() { double cornerX, cornerY; cornerX = Math.min(x1, x2); cornerY = Math.min(y1, y2); return new MyRectangle(cornerX, cornerY, Math.abs(x2 - x1), Math.abs(y2 - y1), super.getColor()); } @Override public ArrayList getMyArea() { ArrayList set = new ArrayList<>(); double m = (y2 - y1) / (x2 - x1), intersect = y1 - (m * x1); MyRectangle bound = getMyBoundingRectangle(); double len = getLength(), bX = bound.getX(), bY = bound.getY(); for (double x = bX; x <= bX + bound.getWidth(); ++x) for (double y = bY; y <= bY + bound.getHeight(); ++y) if (Math.abs(y - (m * x + intersect)) < 1) set.add(new MyPoint(x, y)); if (Math.abs(get_xAngle() - 90) < 1) { for (int i = 0; i < len; ++i) set.add(new MyPoint(x1, y1 + i)); } else if (Math.abs(get_xAngle() - 270) < 1) { for (int i = 0; i < len; ++i) set.add(new MyPoint(x1, y1 - i)); } return set; } @Override public void draw(GraphicsContext gc) { gc.setStroke(super.getColor()); gc.strokeLine(x1, y1, x2, y2); } }

MyRectangle.java

import javafx.scene.canvas.GraphicsContext; import javafx.scene.paint.Color; import java.util.ArrayList; public class MyRectangle extends MyShape { private double width; private double height; // (x,y) Top Left Corner MyRectangle(double x, double y, double width, double height, Color color) { super(x, y, color); this.width = width; this.height = height; } public double getWidth() { return width; } public double getHeight() { return height; } public double getPerimeter() { return 2 * (width + height); } private double getArea() { return width * height; } public void setWidth(int width) { this.width = width; } public void setHeight(int height) { this.height = height; } @Override public void draw(GraphicsContext gc) { gc.setFill(super.getColor()); gc.setStroke(super.getColor()); gc.strokeRect(super.getX(), super.getY(), width, height); gc.fillRect(super.getX(), super.getY(), width, height); } @Override public MyRectangle getMyBoundingRectangle() { return this; } @Override public ArrayList getMyArea() { ArrayList set = new ArrayList<>(); // Picks up points from every column and row within rectangle, starting from top // left to bottom right for (double x = super.getX(); x <= super.getX() + width; ++x) { for (double y = super.getY(); y <= super.getY() + height; ++y) { set.add(new MyPoint(x, y)); } } return set; } @Override public String toString() { return String.format( "----- Rectangle Properties ----- %15s (%.2f,%.2f) %15s %.2f %15s %.2f %15s %.2f %15s %.2f %15s " + super.getColor(), "Corner Point:", super.getX(), super.getY(), "Area:", getArea(), "Perimeter:", getPerimeter(), "Width:", width, "Height:", height, "Color:"); } }

MyOval.java

import javafx.scene.canvas.GraphicsContext; import javafx.scene.paint.Color; import java.util.ArrayList; public class MyOval extends MyShape { private final MyPoint center; private double width; private double height; MyOval(double x, double y, double width, double height, Color color) { // (x,y) is top left corner super(x, y, color); this.width = width; this.height = height; this.center = new MyPoint(x + width / 2, y + height / 2); } public double getArea() { return Math.PI * width * height * 0.5; } public double getPerimeter() { return 2 * Math.PI * Math.sqrt((width + height) / 2); } public MyPoint getCenter() { return center; } public double getRadius(double angle) { double semiW = width / 2; double semiH = height / 2; double temp = Math.pow(semiW, 2) * Math.pow(Math.sin(Math.toRadians(angle)), 2); temp += Math.pow(semiH, 2) * Math.pow(Math.cos(Math.toRadians(angle)), 2); return (semiH * semiW) / (Math.sqrt(temp)); } public void setAxes(double width, double height) { this.width = width; this.height = height; } public void setCenter(double x, double y) { this.center.setX(x); this.center.setY(y); } @Override public String toString() { return String.format( "----- Oval Properties ----- %15s (%.2f,%.2f) %15s %.2f %15s %.2f %15s %.2f %15s %.2f %15s " + super.getColor(), "Center:", center.getX(), center.getY(), "Area:", getArea(), "Perimeter:", getPerimeter(), "Width:", width, "Height:", height, "Color:"); } @Override public MyRectangle getMyBoundingRectangle() { return new MyRectangle(super.getX(), super.getY(), width, height, super.getColor()); } @Override public ArrayList getMyArea() { ArrayList set = new ArrayList<>(); double horizonLen = width / 2; double verticalLen = height / 2; double dx, dy; for (double x = getX(); x <= getX() + width; ++x) { for (double y = getY(); y <= getY() + height; ++y) { dx = Math.abs(x - center.getX()); dy = Math.abs(y - center.getY()); if (Math.pow((dx) / horizonLen, 2) + Math.pow((dy) / verticalLen, 2) <= 1) { // Accounts for 4 quadrants of oval set.add(new MyPoint(x, y)); set.add(new MyPoint(x - 2 * dx, y - 2 * dy)); set.add(new MyPoint(x - 2 * dx, y)); set.add(new MyPoint(x, y - 2 * dy)); } } } return set; } @Override public void draw(GraphicsContext gc) { gc.setFill(super.getColor()); gc.setStroke(super.getColor()); gc.strokeOval(super.getX(), super.getY(), width, height); gc.fillOval(super.getX(), super.getY(), width, height); } }