Camera.java

package de.skysoldier.graphics3D;

import de.skysoldier.graphics3D.Values3D;

public class Camera {

    private Matrix projection;
    private Values3D type;
    private double l, r, t, b, n, f;
    //only for debug...
    public boolean active = true;

    protected Camera(){
        this(Values3D.CAMERA_PERSPECTIVE);
    }

    protected Camera(Values3D type){
        this(type, -100, 100, 100, -100, 50, 500);
    }

    protected Camera(Values3D type, double l, double r, double t, double b, double n, double f){
        projection = new Matrix(4, 4, type);
        this.type = type;
        this.l = l;
        this.r = r;
        this.t = t;
        this.b = b;
        this.n = n;
        this.f = f;
        if(type == Values3D.CAMERA_PERSPECTIVE){
            projection.setCellData(0, 0, (2 * n) / (r - l));
            projection.setCellData(0, 1, 0);
            projection.setCellData(0, 2, (r + l) / (r - l));
            projection.setCellData(0, 3, 0);
            projection.setCellData(1, 0, 0);
            projection.setCellData(1, 1, (2 * n) / (t - b));
            projection.setCellData(1, 2, (t + b) / (t - b));
            projection.setCellData(1, 3, 0);
            projection.setCellData(2, 0, 0);
            projection.setCellData(2, 1, 0);
            projection.setCellData(2, 2, -(f + n) / (f - n));
            projection.setCellData(2, 3, -(2 * f * n) / (f - n));
            projection.setCellData(3, 0, 0);
            projection.setCellData(3, 1, 0);
            projection.setCellData(3, 2, -1);
            projection.setCellData(3, 3, 0);
        }
        else{
            throw new UnsupportedOperationException("Camera Type not supported.");
        }
    }

    public Matrix getProjectionMatrix(){
        return projection;
    }

    public void updateLeft(double l){
        this.l = l;
        if(type == Values3D.CAMERA_PERSPECTIVE){
            projection.setCellData(0, 0, (2 * n) / (r - l));
            projection.setCellData(0, 2, (r + l) / (r - l));
        }
    }

    public void updateRight(double r){
        this.r = r;
        if(type == Values3D.CAMERA_PERSPECTIVE){
            projection.setCellData(0, 0, (2 * n) / (r - l));
            projection.setCellData(0, 2, (r + l) / (r - l));
        }
    }

    public void updateTop(double t){
        this.t = t;
        if(type == Values3D.CAMERA_PERSPECTIVE){
            projection.setCellData(1, 1, (2 * n) / (t - b));
            projection.setCellData(1, 2, (t + b) / (t - b));
        }
    }

    public void updateBottom(double b){
        this.b = b;
        if(type == Values3D.CAMERA_PERSPECTIVE){
            projection.setCellData(1, 1, (2 * n) / (t - b));
            projection.setCellData(1, 2, (t + b) / (t - b));
        }
    }

    public void updateNear(double n){
        this.n = n;
        if(type == Values3D.CAMERA_PERSPECTIVE){
            projection.setCellData(0, 0, (2 * n) / (r - l));
            projection.setCellData(1, 1, (2 * n) / (t - b));
            projection.setCellData(2, 2, -(f + n) / (f - n));
            projection.setCellData(2, 3, -(2 * f * n) / (f - n));
        }
    }

    public void updateFar(double f){
        this.f = f;
        if(type == Values3D.CAMERA_PERSPECTIVE){
            projection.setCellData(2, 2, -(f + n) / (f - n));
            projection.setCellData(2, 3, -(2 * f * n) / (f - n));
        }
    }

    public void transform(Matrix... transformations){
        for(int i = 0; i < transformations.length; i++){
            projection = transformations[i].multiply(projection);
        }
    }

    public double getLeft(){
        return l;
    }

    public double getRight(){
        return r;
    }

    public double getTop(){
        return t;
    }

    public double getBottom(){
        return b;
    }

    public double getNear(){
        return n;
    }

    public double getFar(){
        return f;
    }
}