euglena/src/Rectangle.java

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


class Rectangle {

    float corner1x, corner1y, corner2x, corner2y;
    int color, brushSize;
    boolean visible;

    private boolean corner1complete;

    Rectangle(int color, int penWidth) {
        this.color = color;
        this.brushSize = penWidth;
        this.visible = false;

        this.corner1complete = false;
    }

    Rectangle(float corner1x, float corner1y, float corner2x, float corner2y, int color, int penWidth) {
        this.corner1x = corner1x;
        this.corner1y = corner1y;
        this.corner2x = corner2x;
        this.corner2y = corner2y;
        this.color = color;
        this.brushSize = penWidth;
        this.visible = true;

        this.corner1complete = true;
    }

    ProjectorCommand makeProjectorCommand() {
        return (ProjectorApplet p) -> {
            if (!visible) {
                //done drawing already
                return true;
            }

            float old_strokeWeight = p.g.strokeWeight;
            int old_strokeColor = p.g.strokeColor;

            p.rectMode(CORNERS);
            p.strokeWeight(brushSize);
            p.stroke(color);
            p.noFill();

            p.rect(p.convertXCoord(corner1x), p.convertYCoord(corner1y),
                   p.convertXCoord(corner2x), p.convertYCoord(corner2y));

            p.strokeWeight(old_strokeWeight);
            p.stroke(old_strokeColor);
            return true;
        };
    }

    ClickGetter makeClickGetter(ProjectorApplet p) {
        return (int x, int y) -> {
            if (!corner1complete){
                corner1x = x;
                corner1y = y;
                corner1complete = true;
                return false;

            } else {
                corner2x = x;
                corner2y = y;
                visible = true;

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