euglena/src/ProjectorApplet.java

import processing.core.PApplet;
import java.util.ArrayList;

class ProjectorApplet extends PApplet {
    /*
        Secondary applet for controlling what gets displayed on
        the projector.

        This window runs as a separate thread, so in order to draw
        things, you should create a ProjectorCommand and queue it
        up with projectorApplet.commandQueue.add(myCommand).
     */

    // Which screen should we display on?
    final int projectorScreenNumber = 2;

    // Center coordinates of the screen
    final static int centerX = 860;
    final static int centerY = 540;

    // Background color
    int bgColor = color(0, 0, 0);

    // Pointer to the main applet
    EuglenaApplet parent;

    // Calibration component
    Calibrator calibrator;

    // Queue of commands to execute
    ArrayList<ProjectorCommand> commandQueue;

    ProjectorApplet(EuglenaApplet parent) {
        this.parent = parent;
        calibrator = new Calibrator(this);
        commandQueue = new ArrayList<>();
    }

    public void settings() {
        fullScreen(P2D, this.projectorScreenNumber);
    }

    @Override
    public void setup() {
        clear();
//        smooth();  // Smooth might create artifacts when animating?
    }

    @Override
    public void draw() {
        /*
            Main draw loop for the projector window
         */

        /*
            Exectue commands from the commandQueue.
            If a command finished, mark it for removal.
            If we get a ProjectorCommandException, don't execute
              any further commands.
         */
        ArrayList<Integer> entriesToRemove = new ArrayList<>();
        try {
            for (int i = 0; i < commandQueue.size(); i++) {

                boolean done = commandQueue.get(i).run(this);
                if (done) {
                    entriesToRemove.add(i);
                }

            }
        } catch (ProjectorCommandException e) {
            // Do nothing
        }

        // Remove finished commands (have to do it in reverse order to preserve indices)
        for (int i = entriesToRemove.size() - 1; i >= 0; i--) {
            commandQueue.remove(i);
        }

        // Let the calibration module draw anything it needs
        calibrator.draw(parent);
    }

    public void reset() {
        /*
            Clear the commandQueue and the screen
         */
        commandQueue.clear();
        this.clear();
    }

    public void clear() {
        /*
            Clear the screen
         */
        fill(bgColor);
        noStroke();
        rectMode(CORNER);
        rect(0, 0, width * 4, height * 4);
    }

    public void setBgColor(int c) {
        bgColor = c;
    }

    public void setBgColor(int r, int b, int g) {
        bgColor = color(r, g, b);
    }

    public int getBgColor() {
        return bgColor;
    }

    /*
        Functions for converting coordinates and distances from
         main-window to projector-window coordinates
     */

    public float convertXCoord(float x) {
        return (x / calibrator.magx + width * calibrator.offsetx);
    }

    public float convertYCoord(float y) {
        return (y / calibrator.magy + height * calibrator.offsety);
    }

    public float convertXDistance(float dx) {
        return (dx / calibrator.magx);
    }

    public float convertYDistance(float dy) {
        return (dy / calibrator.magy);
    }
}