algovi_sat_2

import java.awt.Color;
import java.awt.Font;
import java.util.ArrayList;
import java.util.List;

import algoanim.animalscript.AnimalCircleGenerator;
import algoanim.animalscript.AnimalPointGenerator;
import algoanim.animalscript.AnimalPolylineGenerator;
import algoanim.animalscript.AnimalRectGenerator;
import algoanim.animalscript.AnimalScript;
import algoanim.animalscript.AnimalTextGenerator;
import algoanim.animalscript.AnimalTriangleGenerator;
import algoanim.primitives.Circle;
import algoanim.primitives.Point;
import algoanim.primitives.Polyline;
import algoanim.primitives.Rect;
import algoanim.primitives.SourceCode;
import algoanim.primitives.Text;
import algoanim.primitives.Triangle;
import algoanim.primitives.generators.Language;
import algoanim.properties.AnimationPropertiesKeys;
import algoanim.properties.CircleProperties;
import algoanim.properties.PointProperties;
import algoanim.properties.PolylineProperties;
import algoanim.properties.RectProperties;
import algoanim.properties.SourceCodeProperties;
import algoanim.properties.TextProperties;
import algoanim.properties.TriangleProperties;
import algoanim.util.Coordinates;
import algoanim.util.Node;
import algoanim.util.TicksTiming;
import algoanim.util.Timing;
import auxiliary.Vector2f;

public class SAT {

    public static final Color LINE_DEFAULT_COLOR    = Color.BLACK;
    public static final Color VECTOR_DEFAULT_COLOR  = Color.RED;

    Language lang;

    Text text;
    Point point;
    Circle circle;
    Polyline line;
    Polyline edge;
    Polyline vector;
    Polyline separatingAxis;
    Triangle triangle;

    // temp
    Polyline[] vectors = new Polyline[3];

    SourceCode sc;
    Timing timing;

    // might need these properties
    TextProperties textProps;
    RectProperties rectProps;
    PointProperties pointProps;
    CircleProperties circleProps;
    PolylineProperties lineProps;
    PolylineProperties vectorProps;
    TriangleProperties triangleProps;


    int x = 40;
    int y = 140;
    int startY;
    int offsetY = 20;
    String vertexName;
    String neighbor1Name;
    String neighbor2Name;

    List<Text> textList = new ArrayList<>();

    public void init() {
        lang = new AnimalScript("Separating Axis Theorem (Circle-Triangle)", "Bekir Oezkara", 640, 480);
        lang.setStepMode(true);

        timing = new TicksTiming(200);

        textProps = new TextProperties();
        textProps.set(AnimationPropertiesKeys.COLOR_PROPERTY, Color.BLACK);
        textProps.set(AnimationPropertiesKeys.FONT_PROPERTY, new Font("Monospaced", Font.PLAIN, 12));

        rectProps = new RectProperties();
        rectProps.set(AnimationPropertiesKeys.COLOR_PROPERTY, Color.DARK_GRAY);
        rectProps.set(AnimationPropertiesKeys.FILLED_PROPERTY, true);
        rectProps.set(AnimationPropertiesKeys.FILL_PROPERTY, Color.LIGHT_GRAY);
        rectProps.set(AnimationPropertiesKeys.DEPTH_PROPERTY, 2);

        pointProps = new PointProperties();
        pointProps.set(AnimationPropertiesKeys.COLOR_PROPERTY, Color.CYAN);

        circleProps = new CircleProperties();
//      circleProps.set(AnimationPropertiesKeys.COLOR_PROPERTY, Color.RED);
        circleProps.set(AnimationPropertiesKeys.FILL_PROPERTY, Color.WHITE);

        lineProps = new PolylineProperties();
        lineProps.set(AnimationPropertiesKeys.COLOR_PROPERTY, LINE_DEFAULT_COLOR);

        vectorProps = new PolylineProperties();
        vectorProps.set(AnimationPropertiesKeys.COLOR_PROPERTY, VECTOR_DEFAULT_COLOR);
        vectorProps.set(AnimationPropertiesKeys.FWARROW_PROPERTY, true);

        triangleProps = new TriangleProperties();
//      triangleProps.set(AnimationPropertiesKeys.COLOR_PROPERTY, Color.GREEN);
        triangleProps.set(AnimationPropertiesKeys.FILL_PROPERTY, Color.WHITE);

        makeHeader();
        makeSideBox();
        drawCoordSystem();

    }


    public boolean hasSA(auxiliary.Circle circle, auxiliary.Triangle triangle) {

        makeCircle(circle.center.x, circle.center.y, circle.radius);
        makeTriangle(triangle.A, triangle.B, triangle.C);
        lang.nextStep();

        x = 910;
        startY = 160;
        y = startY;

        // vertices
        showSourceCodeVertexSA();
        Circle vertexHighlightCircle;
        boolean isFilled = true;

        vertexName = "A";
        neighbor1Name = "B";
        neighbor2Name = "C";
        vertexHighlightCircle = makeCircle(triangle.A.x, triangle.A.y, 0.1f, Color.PINK, isFilled);
        textAndStep("Vertex A");
        vertexHighlightCircle.hide();
        boolean separatedByVertexA = isVertexSA(circle, triangle, triangle.A);

        clearText();
        y = startY;

        vertexName = "B";
        neighbor1Name = "A";
        neighbor2Name = "C";
        vertexHighlightCircle = makeCircle(triangle.B.x, triangle.B.y, 0.1f, Color.PINK, isFilled);
        textAndStep("Vertex B");
        vertexHighlightCircle.hide();
        boolean separatedByVertexB = isVertexSA(circle, triangle, triangle.B);

        clearText();
        y = startY;

        vertexName = "C";
        neighbor1Name = "A";
        neighbor2Name = "B";
        vertexHighlightCircle = makeCircle(triangle.C.x, triangle.C.y, 0.1f, Color.PINK, isFilled);
        textAndStep("Vertex C");
        vertexHighlightCircle.hide();
        boolean separatedByVertexC = isVertexSA(circle, triangle, triangle.C);

        clearText();
        y = startY;

        // edges
        // sc.changeColor("", Color.WHITE, null, null);
        // showSourceCodeEdgeSA();

        edge = makeLine(triangle.A, triangle.B, false, true);
        edge.changeColor("", Color.PINK, null, null);
        textAndStep("Edge from A to B");
        boolean separatedByEdgeAB = isEdgeSA(circle, triangle, triangle.edgeAB, triangle.A, triangle.B, triangle.C);
        edge.hide();

        clearText();
        y = startY;

        edge = makeLine(triangle.A, triangle.C, false, true);
        edge.changeColor("", Color.PINK, null, null);
        textAndStep("Edge from A to C");
        boolean separatedByEdgeAC = isEdgeSA(circle, triangle, triangle.edgeAC, triangle.A, triangle.C, triangle.B);
        edge.changeColor("", Color.BLACK, null, null);

        clearText();
        y = startY;

        edge = makeLine(triangle.B, triangle.C, false, true);
        edge.changeColor("", Color.PINK, null, null);
        textAndStep("Edge from B to C");
        boolean separatedByEdgeBC = isEdgeSA(circle, triangle, triangle.edgeBC, triangle.B, triangle.C, triangle.A);
        edge.hide();

        clearText();
        y = startY;

        boolean result = separatedByVertexA || separatedByVertexB || separatedByVertexC || separatedByEdgeAB || separatedByEdgeAC || separatedByEdgeBC;
        if(result) {
            separatingAxis.changeColor("", Color.GREEN, null, null);
            separatingAxis.show();
        }
        textAndStep("we found separating axis = " + result);
        return result;
    }


    /**
     *
     * @param circle
     * @param triangle
     * @param vertex
     * @return
     */
    private boolean isVertexSA(auxiliary.Circle circle, auxiliary.Triangle triangle, Vector2f vertex) {
        line = makeLine(circle.center.x, circle.center.y, circle.center.x + circle.radius, circle.center.y, false, true);
        textAndStep("radius = " + circle.radius);
        line.hide();

        sc.highlight(1);
        float distToCenter = vertex.dist(circle.center);
        line = makeLine(vertex, circle.center, false, true);
        textAndStep("distance to center = " + distToCenter);
        line.hide();
        sc.unhighlight(1);


        sc.highlight(2);
        Vector2f vertexToCenter = circle.center.sub(vertex);
        vectors[0] = makeLine(vertex, circle.center, true, true);
        textAndStep("vector from vertex to center = " + vertexToCenter);
        sc.unhighlight(2);

        Vector2f vertexToNeighbor1;
        Vector2f vertexToNeighbor2;

        if(vertex == triangle.A) {
            sc.highlight(6);
            sc.highlight(7);
            sc.highlight(9);
            vertexToNeighbor1 = triangle.B.sub(vertex); // AB
            vertexToNeighbor2 = triangle.C.sub(vertex); // AC
            neighbor1Name = "B";
            neighbor2Name = "C";
            vectors[1] = makeLine(vertex, triangle.B, true, true);
            textAndStep("vector from " + vertexName + " to " + neighbor1Name + " = " + vertexToNeighbor1);
            sc.unhighlight(7);

            sc.highlight(8);
            vectors[2] = makeLine(vertex, triangle.C, true, true);
            textAndStep("vector from " + vertexName + " to " + neighbor2Name + " = " + vertexToNeighbor2);
            sc.unhighlight(6);
            sc.unhighlight(8);
            sc.unhighlight(9);
        }
        else if(vertex == triangle.B) {
            sc.highlight(10);
            sc.highlight(11);
            sc.highlight(13);
            vertexToNeighbor1 = triangle.A.sub(vertex); // BA
            vertexToNeighbor2 = triangle.C.sub(vertex); // BC
            neighbor1Name = "A";
            neighbor2Name = "C";
            vectors[1] = makeLine(vertex, triangle.A, true, true);
            textAndStep("vector from " + vertexName + " to " + neighbor1Name + " = " + vertexToNeighbor1);
            sc.unhighlight(11);

            sc.highlight(12);
            vectors[2] = makeLine(vertex, triangle.C, true, true);
            textAndStep("vector from " + vertexName + " to " + neighbor2Name + " = " + vertexToNeighbor2);
            sc.unhighlight(10);
            sc.unhighlight(12);
            sc.unhighlight(13);
        }
        else if(vertex == triangle.C) {
            sc.highlight(14);
            sc.highlight(15);
            sc.highlight(17);
            vertexToNeighbor1 = triangle.A.sub(vertex); // CA
            vertexToNeighbor2 = triangle.B.sub(vertex); // CB
            neighbor1Name = "A";
            neighbor2Name = "B";
            vectors[1] = makeLine(vertex, triangle.A, true, true);
            textAndStep("vector from " + vertexName + " to " + neighbor1Name + " = " + vertexToNeighbor1);
            sc.unhighlight(15);

            sc.highlight(16);
            vectors[2] = makeLine(vertex, triangle.B, true, true);
            textAndStep("vector from " + vertexName + " to " + neighbor2Name + " = " + vertexToNeighbor2);
            sc.unhighlight(14);
            sc.unhighlight(16);
            sc.unhighlight(17);
        }
        else {
            throw new IllegalArgumentException("The provided vertex: " + vertex + " does not match with any of the triangle's vertices.");
        }

//      textAndStep("vector from " + vertexName + " to " + neighbor1Name + " = " + vertexToNeighbor1);
//      textAndStep("vector from " + vertexName + " to " + neighbor2Name + " = " + vertexToNeighbor2);

        // they are on opposite sides if the dot product is less than zero
        vectors[0].changeColor("", Color.LIGHT_GRAY, null, null);

        sc.highlight(21);
        sc.highlight(22);
        boolean isOppositeNeighbor1 = vertexToCenter.dot(vertexToNeighbor1) < 0;
        vectors[1].changeColor("", Color.ORANGE, null, null);
        textAndStep(neighbor1Name + " is on opposite side = " + isOppositeNeighbor1);
        vectors[1].changeColor("", VECTOR_DEFAULT_COLOR, null, null);
        sc.unhighlight(21);
        sc.unhighlight(22);

        sc.highlight(23);
        sc.highlight(24);
        boolean isOppositeNeighbor2 = vertexToCenter.dot(vertexToNeighbor2) < 0;
        vectors[2].changeColor("", Color.ORANGE, null, null);
        textAndStep(neighbor2Name + " is on opposite side = " + isOppositeNeighbor2);
        sc.unhighlight(23);
        sc.unhighlight(24);

        vectors[0].hide();
        vectors[1].hide();
        vectors[2].hide();

        sc.highlight(26);
        boolean radius_less_than_dist = circle.radius < distToCenter;
        textAndStep("radius smaller than distance = " + radius_less_than_dist);

        boolean result = radius_less_than_dist && isOppositeNeighbor1 && isOppositeNeighbor2;
        line = makeLine(vertex, circle.center, false, true);
        line.changeColor("", result ? Color.GREEN : Color.RED, null, null);
        if(result) {
            separatingAxis =  makeLine(vertex, circle.center, false, true);
        }
        sc.highlight(27);
        textAndStep("vertex is separating axis = " + result);
        line.hide();
        sc.unhighlight(26);
        sc.unhighlight(27);
        if(separatingAxis != null) {
            separatingAxis.hide();
        }
        return result;
    }


    /**
     *
     * @param circle
     * @param triangle
     * @param edge
     * @param start
     * @param end
     * @param other
     * @return
     */
    private boolean isEdgeSA(auxiliary.Circle circle, auxiliary.Triangle triangle, Vector2f edge, Vector2f start, Vector2f end, Vector2f other) {
        line = makeLine(circle.center.x, circle.center.y, circle.center.x + circle.radius, circle.center.y, false, true);
        textAndStep("radius = " + circle.radius);
        line.hide();

        Vector2f normalizedEdge = edge.normalize();
        vector = makeLine(start.x, start.y, start.x + normalizedEdge.x, start.y + normalizedEdge.y, true, true);    // TODO: too small, does not show arrow in Animal !
        vector.changeColor("", VECTOR_DEFAULT_COLOR, null, null);
        textAndStep("normalized edge = " + normalizedEdge);
        vector.hide();

        Vector2f vecToCircle;
        if(edge == triangle.edgeAB) {
            vecToCircle = circle.center.sub(triangle.A);
            vector = makeLine(triangle.A, circle.center, true, true);
        }
        else if(edge == triangle.edgeAC) {
            // TODO: why not C, or: when A, when C ?
            vecToCircle = circle.center.sub(triangle.A);
            vector = makeLine(triangle.A, circle.center, true, true);
        }
        else if(edge == triangle.edgeBC) {
            vecToCircle = circle.center.sub(triangle.B);
            vector = makeLine(triangle.B, circle.center, true, true);
        }
        else {
            throw new IllegalArgumentException("The provided edge: " + edge + " does not match with any of the triangle's edges.");
        }

        textAndStep("vector to circle = " + vecToCircle);
        vector.hide();

        float dot = normalizedEdge.dot(vecToCircle);
        line = makeLine(start.x, start.y, start.x + dot, start.y + dot, false, true);
        textAndStep("dot product of normalizedEdge and vectorToCircle = " + dot);
        line.hide();

        Vector2f closestPointToCircle;
        if(dot <= 0) {
            closestPointToCircle = start;
        }
        else if(dot >= edge.length()) {
            closestPointToCircle = end;
        }
        else {
            closestPointToCircle = normalizedEdge.mul(dot).add(start);
        }

        Circle pointToHighlight;
        boolean isFilled = true;

        line = makeLine(start, closestPointToCircle, false, true);
        pointToHighlight = makeCircle(closestPointToCircle.x, closestPointToCircle.y, 0.1f, Color.PINK, isFilled);
        textAndStep("closest point to circle = " + closestPointToCircle);
        pointToHighlight.hide();
        line.hide();

        // check if the other vertex (the one that is not part of the current edge) and the circle-center lie on opposite sides of the edge
        Vector2f vecFromClosestPointToCircle        = circle.center.sub(closestPointToCircle);
        vectors[0] = makeLine(closestPointToCircle, circle.center, true, true);
        textAndStep("vector from closest point to circle = " + vecFromClosestPointToCircle);

        Vector2f vecFromClosestPointToOtherVertex   = other.sub(closestPointToCircle);
        vectors[1] = makeLine(closestPointToCircle, other, true, true);
        textAndStep("vector from closest point to other vertex = " + vecFromClosestPointToOtherVertex);

        boolean isOppositeOtherVertex               = vecFromClosestPointToCircle.dot(vecFromClosestPointToOtherVertex) < 0;
        vectors[0].changeColor("", Color.BLUE, null, null);
        vectors[1].changeColor("", Color.BLUE, null, null);
        textAndStep("other vertex on opposite side of circle = " + isOppositeOtherVertex);

        vectors[0].hide();
        vectors[1].hide();

        boolean radius_less_than_dist_to_closest_point = circle.radius < vecFromClosestPointToCircle.length();
        textAndStep("radius less than distance to closest point = " + radius_less_than_dist_to_closest_point);

        boolean result = radius_less_than_dist_to_closest_point && isOppositeOtherVertex;
        line = makeLine(closestPointToCircle, circle.center, false, true);
        line.changeColor("", result ? Color.GREEN : Color.RED, null, null);
        if(result) {
            separatingAxis = makeLine(closestPointToCircle, circle.center, false, true);
        }
        textAndStep("is separating axis = " + result);
        line.hide();
        if(separatingAxis != null) {
            separatingAxis.hide();
        }
        return result;
    }


    // ====================================================================================================================================
    // ====================================================================================================================================

    private Circle makeCircle(float x, float y, float radius) {
        return new Circle(new AnimalCircleGenerator(lang), transformCoords(x, y), transformRadius(radius), "circle", null, circleProps);
    }

    private Circle makeCircle(float x, float y, float radius, Color color, boolean isFilled) {
        CircleProperties props = new CircleProperties();
        props.set(AnimationPropertiesKeys.FILL_PROPERTY, color);
        props.set(AnimationPropertiesKeys.FILLED_PROPERTY, isFilled);
        return new Circle(new AnimalCircleGenerator(lang), transformCoords(x, y), transformRadius(radius), "circle", null, props);
    }

    private Triangle makeTriangle(Vector2f A, Vector2f B, Vector2f C) {
        return makeTriangle(A.x, A.y, B.x, B.y, C.x, C.y);
    }

    private Triangle makeTriangle(float Ax, float Ay, float Bx, float By, float Cx, float Cy) {
        return new Triangle(new AnimalTriangleGenerator(lang),
                transformCoords(Ax, Ay),
                transformCoords(Bx, By),
                transformCoords(Cx, Cy),
                "triangle",
                null,
                triangleProps);
    }

    private Coordinates transformCoords(float x, float y) {
        float newX = 600 + 40 * x;
        float newY = 300 - 40 * y;
        return new Coordinates((int)newX, (int)newY);
    }

    private int transformRadius(float radius) {
        float newRadius = 40 * radius;
        return (int)newRadius;
    }

    private Rect makeRect(int upperLeftX, int upperLeftY, int lowerRightX, int lowerRightY) {
        return new Rect(new AnimalRectGenerator(lang), new Coordinates(upperLeftX, upperLeftY), new Coordinates(lowerRightX, lowerRightY), "rect", null, rectProps);
    }

    private Text makeText(String text, int x, int y) {
        return new Text(new AnimalTextGenerator(lang), new Coordinates(x, y), text, "text", null, textProps);
    }

    private void textAndStep(String text) {
        textAndStep(text, this.x, this.y);
    }

    private void textAndStep(String text, int x, int y) {
        textList.add(makeText(text, x, y));
        this.y += offsetY;
        lang.nextStep();
    }

    private void clearText() {
        for(Text text : textList) {
            text.setText("", null, null);
        }

        textList = new ArrayList<>();
    }


    private Polyline makeLine(Vector2f from, Vector2f to, boolean isVector, boolean needsTransform) {
        return makeLine(from.x, from.y, to.x, to.y, isVector, needsTransform);
    }

    private Polyline makeLine(float startX, float startY, float endX, float endY, boolean isVector, boolean needsTransform) {
        Node[] nodeArray;
        if(needsTransform) {
            nodeArray = new Node[] {
                    transformCoords(startX, startY),
                    transformCoords(endX, endY)
            };
        }
        else {
            nodeArray = new Node[] {
                    new Coordinates((int)startX, (int)startY),
                    new Coordinates((int)endX, (int)endY)
            };
        }

        return new Polyline(new AnimalPolylineGenerator(lang), nodeArray, "line", null, isVector ? vectorProps : lineProps);
    }

    private void makeHeader() {
        makeRect(430, 25, 790, 50);

        TextProperties titleProps = new TextProperties();
        titleProps.set(AnimationPropertiesKeys.FONT_PROPERTY, new Font("Arial", Font.BOLD, 16));
        new Text(new AnimalTextGenerator(lang), new Coordinates(450, 27), "Separating Axis Theorem (Circle-Triangle)", "title", null, titleProps);
    }

    private void makeSideBox() {
        makeRect(900, 150, 1300, 380);
    }

    private void drawCoordSystem() {
        int xAxis       = 300;
        int xAxisStart  = 400;
        int xAxisEnd    = 800;

        int yAxis       = 600;
        int yAxisStart  = 500;
        int yAxisEnd    = 100;

        makeLine(xAxisStart, xAxis, xAxisEnd, xAxis, false, false); // x-axis (600px)
        makeLine(yAxis, yAxisStart, yAxis, yAxisEnd, false, false); // y-axis (400px)

        int offset = 40;    // 60px = 1cm

        // x-axis
        for(int i=xAxisStart; i <= xAxisEnd; i+=offset) {
            makeLine(i, xAxis-5, i, xAxis+5, false, false);
        }

        // y-axis
        for(int i=yAxisStart; i >= yAxisEnd; i-=offset) {
            makeLine(yAxis-5, i, yAxis+5, i, false, false);
        }
    }

    // ====================================================================================================================================
    // ====================================================================================================================================
    // ====================================================================================================================================
    // ====================================================================================================================================
    // ====================================================================================================================================
    // ====================================================================================================================================

    public static void main(String[] args) {
        // careful: animalscript y-coord goes downwards (i.e. 110 is below 100)
        SAT sat = new SAT();
        sat.init();

        auxiliary.Circle C = new auxiliary.Circle(new Vector2f(-2, 1), 2);
        auxiliary.Triangle T = new auxiliary.Triangle(new Vector2f(1, 1), new Vector2f(3, 1), new Vector2f(2, 4));
        sat.hasSA(C, T);

        System.out.println(sat.lang);
    }


    public void showSourceCodeVertexSA() {
        // first set the visual properties for the source code
        SourceCodeProperties scProps = new SourceCodeProperties();
        scProps.set(AnimationPropertiesKeys.CONTEXTCOLOR_PROPERTY, Color.BLUE);
        scProps.set(AnimationPropertiesKeys.FONT_PROPERTY, new Font("Monospaced", Font.PLAIN, 12));
        scProps.set(AnimationPropertiesKeys.HIGHLIGHTCOLOR_PROPERTY, Color.RED);
        scProps.set(AnimationPropertiesKeys.COLOR_PROPERTY, Color.BLACK);

        // now create the source code entity
        sc = lang.newSourceCode(new Coordinates(10, 50), "sourceCode", null, scProps);

        // add code lines (the actual sorting algo)
        // parameters: code itself, name (can be null), indention level, display options
        sc.addCodeLine("boolean isVertexSA(Circle circle, Triangle triangle, Vector2f vertex) {", null, 0, null);
        sc.addCodeLine("float distToCenter = vertex.dist(circle.center);", null, 1, null);
        sc.addCodeLine("Vector2f vertexToCenter = circle.center.sub(vertex);", null, 1, null);
        sc.addCodeLine("Vector2f vertexToNeighbor1;", null, 1, null);
        sc.addCodeLine("Vector2f vertexToNeighbor2;", null, 1, null);
        sc.addCodeLine("", null, 0, null);
        sc.addCodeLine("if(vertex == triangle.A) {", null, 1, null);
        sc.addCodeLine("vertexToNeighbor1 = triangle.B.sub(vertex); // AB", null, 2, null);
        sc.addCodeLine("vertexToNeighbor2 = triangle.C.sub(vertex); // AC", null, 2, null);
        sc.addCodeLine("}", null, 1, null);
        sc.addCodeLine("else if(vertex == triangle.B) {", null, 1, null);
        sc.addCodeLine("vertexToNeighbor1 = triangle.A.sub(vertex); // BA", null, 2, null);
        sc.addCodeLine("vertexToNeighbor2 = triangle.C.sub(vertex); // BC", null, 2, null);
        sc.addCodeLine("}", null, 1, null);
        sc.addCodeLine("else if(vertex == triangle.C) {", null, 1, null);
        sc.addCodeLine("vertexToNeighbor1 = triangle.A.sub(vertex); // CA", null, 2, null);
        sc.addCodeLine("vertexToNeighbor2 = triangle.B.sub(vertex); // CB", null, 2, null);
        sc.addCodeLine("}", null, 1, null);
        sc.addCodeLine("", null, 0, null);
        sc.addCodeLine("// they are on opposite sides", null, 1, null);
        sc.addCodeLine("// if the dot product is less than zero", null, 1, null);
        sc.addCodeLine("boolean isOppositeNeighbor1 = ", null, 1, null);
        sc.addCodeLine("vertexToCenter.dot(vertexToNeighbor1) < 0;", null, 2, null);
        sc.addCodeLine("boolean isOppositeNeighbor2 = ", null, 1, null);
        sc.addCodeLine("vertexToCenter.dot(vertexToNeighbor2) < 0;", null, 2, null);
        sc.addCodeLine("", null, 0, null);
        sc.addCodeLine("return circle.radius < distToCenter", null, 1, null);
        sc.addCodeLine("&& isOppositeNeighbor1 && isOppositeNeighbor2;", null, 2, null);
    } // showSourceCodeVertexSA()


    public void showSourceCodeEdgeSA() {
        // first set the visual properties for the source code
        SourceCodeProperties scProps = new SourceCodeProperties();
        scProps.set(AnimationPropertiesKeys.CONTEXTCOLOR_PROPERTY, Color.BLUE);
        scProps.set(AnimationPropertiesKeys.FONT_PROPERTY, new Font("Monospaced", Font.PLAIN, 12));
        scProps.set(AnimationPropertiesKeys.HIGHLIGHTCOLOR_PROPERTY, Color.RED);
        scProps.set(AnimationPropertiesKeys.COLOR_PROPERTY, Color.BLACK);

        // now create the source code entity
        sc = lang.newSourceCode(new Coordinates(10, 50), "sourceCode", null, scProps);

        // add code lines (the actual sorting algo)
        // parameters: code itself, name (can be null), indention level, display options
        sc.addCodeLine("boolean isEdgeSA(Circle circle, Triangle triangle, Vector2f edge, Vector2f start, Vector2f end, Vector2f other) {", null, 0, null);
        sc.addCodeLine("Vector2f normalizedEdge = edge.normalize();", null, 1, null);
        sc.addCodeLine("Vector2f vecToCircle;", null, 1, null);
        sc.addCodeLine("", null, 0, null);
        sc.addCodeLine("if(edge == triangle.edgeAB) {", null, 1, null);
        sc.addCodeLine("vecToCircle = circle.center.sub(triangle.A);", null, 2, null);
        sc.addCodeLine("}", null, 1, null);
        sc.addCodeLine("else if(edge == triangle.edgeAC) {", null, 1, null);
        sc.addCodeLine("vecToCircle = circle.center.sub(triangle.A);", null, 2, null);
        sc.addCodeLine("}", null, 1, null);
        sc.addCodeLine("else if(edge == triangle.edgeBC) {", null, 1, null);
        sc.addCodeLine("vecToCircle = circle.center.sub(triangle.B);", null, 2, null);
        sc.addCodeLine("}", null, 1, null);
        sc.addCodeLine("float dot = normalizedEdge.dot(vecToCircle);", null, 1, null);
        sc.addCodeLine("Vector2f closestPointToCircle;", null, 1, null);
        sc.addCodeLine("if(dot <= 0) {", null, 1, null);
        sc.addCodeLine("closestPointToCircle = start;", null, 2, null);
        sc.addCodeLine("}", null, 1, null);
        sc.addCodeLine("else if(dot >= edge.length()) {", null, 1, null);
        sc.addCodeLine("closestPointToCircle = end;", null, 2, null);
        sc.addCodeLine("}", null, 1, null);
        sc.addCodeLine("else {", null, 1, null);
        sc.addCodeLine("closestPointToCircle = ", null, 2, null);
        sc.addCodeLine("normalizedEdge.mul(dot).add(start);", null, 3, null);
        sc.addCodeLine("}", null, 1, null);
        sc.addCodeLine("", null, 0, null);
        sc.addCodeLine("// check if the other vertex", null, 1, null);
        sc.addCodeLine("// (the one that is not part of the current edge)", null, 1, null);
        sc.addCodeLine("// and the circle-center lie on opposite sides of the edge", null, 1, null);
        sc.addCodeLine("Vector2f vecFromClosestPointToCircle        = ", null, 1, null);
        sc.addCodeLine("circle.center.sub(closestPointToCircle);", null, 2, null);
        sc.addCodeLine("Vector2f vecFromClosestPointToOtherVertex   = ", null, 1, null);
        sc.addCodeLine("other.sub(closestPointToCircle); ", null, 2, null);
        sc.addCodeLine("boolean isOppositeOtherVertex               = vecFromClosestPointToCircle.dot(vecFromClosestPointToOtherVertex) < 0;", null, 1, null);
        sc.addCodeLine("", null, 0, null);
        sc.addCodeLine("return circle.radius < vecFromClosestPointToCircle.length() && isOppositeOtherVertex;", null, 1, null);
    } // showSourceCodeEdgeSA()
}