pencil.java

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import java.awt.*;

// a static pencil model

public class pencil implements model{
	private vector centre;
	private vector iDirection, jDirection, kDirection;
	private vector[][] vertix;
	private paste[] pastes;
	private vector[] polygonNormals;
	private paste[] boundary;
	private int NoOfPolygons;
	private vector[][] bound;
	private vector realCentre;

	public pencil(vector centre){
		this.centre = centre;
		realCentre = new vector(centre.x, centre.y, centre.z);
		NoOfPolygons = 25;
		iDirection = new vector(2,0,1);
		jDirection = new vector(0,1,0);
		kDirection = iDirection.cross(jDirection).unit();
		iDirection = iDirection.unit();
		jDirection = jDirection.unit();
		bound = new vector[6][4];
		boundary  = new paste[6];
		vertix = new vector[NoOfPolygons][];
		pastes = new paste[NoOfPolygons];
		createVertix();
		makePaste();
		createBoundary();
	}

	public void update(vector change, double xzRotate, double yzRotate){
		// update the vertix accroding to the camera position and direction
		vector[][] tempVertix = new vector[NoOfPolygons][];
		for(int i = 0; i < tempVertix.length; i++){
			tempVertix[i] = new vector[vertix[i].length];
			for(int j = 0; j < tempVertix[i].length; j++){
				tempVertix[i][j] = vertix[i][j].add(change).rotate_XZ(xzRotate).rotate_YZ(yzRotate);
			}
		}
		for(int i = 0; i < NoOfPolygons; i++)
			pastes[i].update(tempVertix[i]);
		//update boundary
		vector[][] tempBound = new vector[6][4];
		for(int i = 0; i < 6; i++){
			for(int j = 0; j < 4; j++){
				tempBound[i][j] = bound[i][j].add(change).rotate_XZ(xzRotate).rotate_YZ(yzRotate);
			}
		}
		for(int i = 0; i < 6; i ++)
			boundary[i].update(tempBound[i]);

		//update realcentre;
		realCentre = put(-0.07,-0.07,0).add(change).rotate_XZ(xzRotate).rotate_YZ(yzRotate);
	}

	private void createVertix(){
		// must add vertix in a clockwise manner
		int polygonIndex = 0;

		// pencil rubble
		double r = 0.075;
		double theta = Math.PI/3;
		for(int i = 0; i < 6; i++){
			vertix[polygonIndex] = new vector[]{put(r*Math.cos(i*theta), r*Math.sin(i*theta), 0),
											 put(r*Math.cos((i+1)*theta), r*Math.sin((i+1)*theta), 0),
											 put(r*Math.cos((i+1)*theta), r*Math.sin((i+1)*theta), 0.15),
											 put(r*Math.cos(i*theta), r*Math.sin(i*theta), 0.15)};
			polygonIndex++;
		}
		vertix[polygonIndex] = new vector[6];
		for(int i = 1; i < 7; i++)
			vertix[polygonIndex][6 - i] = put(r*Math.cos(i*theta), r*Math.sin(i*theta), 0);
		polygonIndex++;

		for(int i = 0; i < 6; i++){
			vertix[polygonIndex] = new vector[]{put(r*Math.cos(i*theta), r*Math.sin(i*theta), 0.15),
											 put(r*Math.cos((i+1)*theta), r*Math.sin((i+1)*theta), 0.15),
											 put(r*Math.cos((i+1)*theta), r*Math.sin((i+1)*theta), 3.5),
											 put(r*Math.cos(i*theta), r*Math.sin(i*theta), 3.5)};
			polygonIndex++;
		}
		for(int i = 0; i < 6; i++){
			vertix[polygonIndex] = new vector[]{put(r*Math.cos(i*theta), r*Math.sin(i*theta), 3.5),
											 put(r*Math.cos((i+1)*theta), r*Math.sin((i+1)*theta), 3.5),
											 put(0.2*r*Math.cos((i+1)*theta), 0.2*r*Math.sin((i+1)*theta), 3.8),
											 put(0.2*r*Math.cos(i*theta), 0.2*r*Math.sin(i*theta), 3.8)};
			polygonIndex++;
		}
		for(int i = 0; i < 6; i++){
			vertix[polygonIndex] = new vector[]{put(0.2*r*Math.cos(i*theta), 0.2*r*Math.sin(i*theta), 3.8),
											 put(0.2*r*Math.cos((i+1)*theta), 0.2*r*Math.sin((i+1)*theta), 3.8),
											 put(0.01*r*Math.cos((i+1)*theta), 0.01*r*Math.sin((i+1)*theta), 3.9),
											 put(0.01*r*Math.cos(i*theta), 0.01*r*Math.sin(i*theta), 3.9)};
			polygonIndex++;
		}

	}


	private vector put(double x, double y, double z){
		return centre.add(iDirection.scale(x)).add(jDirection.scale(y)).add(kDirection.scale(z));
	}


	public void createBoundary(){
		bound[0] = new vector[]{put(0,0,0), put(0,0,3.8), put(0,0.14,3.8), put(0,0.14,0)};
		boundary[0] = new paste(bound[0], Color.red, 1);
		bound[1] = new vector[]{put(0,0.14,3.8), put(0.14,0.14,3.8), put(0.14,0.14,0), put(0,0.14,0)};
		boundary[1] = new paste(bound[1], Color.blue, 1);
		bound[2] = new vector[]{put(0,0,0), put(0,0.14,0), put(0.14,0.14,0), put(0.14,0,0)};
		boundary[2] = new paste(bound[2], Color.green, 1);
		bound[3] = new vector[]{put(0.14,0.14,3.8), put(0,0.14,3.8), put(0,0,3.8), put(0.14,0,3.8)};
		boundary[3] = new paste(bound[3], Color.green, 1);
		bound[4] = new vector[]{put(0,0,0), put(0.14,0,0), put(0.14,0,3.8), put(0,0,3.8)};
		boundary[4] = new paste(bound[4], Color.green, 1);
		bound[5] = new vector[]{put(0.14,0.14,3.8), put(0.14,0,3.8), put(0.14,0,0), put(0.14,0.14,0)};
		boundary[5] = new paste(bound[5], Color.red, 1);
	}

	public paste[] getBoundary(){
		return  boundary;
	}


	public vector getCentre(){
		return realCentre;
	}

	private void makePaste(){
		for(int i = 0; i < 7; i++)
			pastes[i] = new paste(vertix[i], new Color(254,102,129), 1);
		for(int i = 7; i < 13; i++)
			pastes[i] = new paste(vertix[i], Color.orange, 1);
		for(int i = 13; i < 19; i++)
			pastes[i] = new paste(vertix[i], new Color(253, 204, 138), 1);
		for(int i = 19; i < 25; i++)
			pastes[i] = new paste(vertix[i], Color.darkGray, 1);
	}

	public paste[] getPolygon(){
		return pastes;
	}

}