euglena/src/Rotate.java

import processing.core.*;
import static processing.core.PApplet.*;


public class Rotate {
    float centerx, centery, radius, speed;
    int timeElapsed, millisInit;
    PImage rotateRegion = null;

    private boolean centercomplete;

    Rotate(float speed) {
        this.speed = speed;
        this.centercomplete = false;
    }

    Rotate(float centerx, float centery, float radius, float speed) {
        this.centerx = centerx;
        this.centery = centery;
        this.radius = radius;
        this.speed = speed;

        this.centercomplete = true;
    }

    void saveRotateRegion(ProjectorApplet p) {
        this.rotateRegion = p.get(
                (int) p.convertXCoord(centerx - radius),
                (int) p.convertYCoord(centery - radius),
                (int) p.convertXDistance(2*radius),
                (int) p.convertYDistance(2*radius));
    }

    ProjectorCommand makeProjectorCommand() {
        return (ProjectorApplet p) -> {
            if (rotateRegion == null) {
                millisInit = p.millis();
                saveRotateRegion(p);
            }

            timeElapsed = p.millis() - millisInit;

            p.noFill();
            p.noStroke();
            p.rectMode(CENTER);
            p.rect(p.convertXCoord(centerx), p.convertYCoord(centery),
                   p.convertXDistance(radius), p.convertYDistance(radius));

            p.pushMatrix();
            p.translate(p.convertXCoord(centerx), p.convertYCoord(centery));

            p.rotate(radians(speed * timeElapsed/1000f));

            p.imageMode(CENTER);
            p.image(rotateRegion, 0, 0, p.convertXDistance(2*radius), p.convertYDistance(2*radius));

            p.popMatrix();

            return false;
        };
    }

    ClickGetter makeClickGetter(ProjectorApplet p){
        return (int x, int y) -> {
            if (!centercomplete){
                centerx = x;
                centery = y;
                centercomplete = true;
                return false;

            } else {
                radius = sqrt(pow(x - centerx, 2) + pow(y - centery, 2));

                p.commandQueue.add(makeProjectorCommand());
                return true;
            }
        };
    }
}