RiverRat  - An MIT iCampus project

http://web.mit.edu/riverrat/

Map.java

package riverrat;

public class Map {
        static final boolean DEBUG = false;
        
        private Fix nw;
        private Fix se;
        
        private boolean constrain_height = true;
        private boolean constrain_width = false;
        
        Map() {
                nw = new Fix();
                se = new Fix();
        }
        
        Map(Fix f1, Fix f2) {
                float northlat, southlat, eastlon, westlon;
                if(f1.getLon() > f2.getLon()) {
                        //f1's lon is farther east, so make it the east side
                        eastlon = f1.getLon();
                        westlon = f2.getLon();
                } else if(f1.getLon() < f2.getLon()) {
                        //f2's lon is farther east, so make it the east side
                        eastlon = f2.getLon();
                        westlon = f1.getLon();
                } else {
                        //both lon's are the same
                        eastlon = f1.getLon();
                        westlon = f1.getLon();
                }
                if(f1.getLat() > f2.getLat()) {
                        //f1's lat is farther noth, so make it the north side
                        northlat = f1.getLat();
                        southlat = f2.getLat();
                } else if(f1.getLat() < f2.getLat()) {
                        northlat = f2.getLat();
                        southlat = f1.getLat();
                } else {
                        northlat = f1.getLat();
                        southlat = f1.getLat();
                }
                nw = new Fix(northlat, westlon);
                se = new Fix(southlat, eastlon);
        }
        
        public float getAspect() {
                return (getWidth()/getHeight());
        }
        
        public boolean isFixedAspect() {
                return (constrain_height && constrain_width);
        }
        
        public void setAspect(float asp) {
                if(constrain_height && constrain_width) {
                        //this should throw an exception or something
                        return;
                } else if(constrain_height && !constrain_width) {
                        setWidth(asp*getHeight());
                } else if(!constrain_height && constrain_width) {
                        setHeight(getWidth()/asp);
                }
        }
        
        
        private void setWidth(float newwidth) {
                if(constrain_width) return;
                se.setLon(getWestLon() + newwidth);
        }
        
        private void setHeight(float newheight) {
                if(constrain_height) return;
                se.setLat(getNorthLat() - newheight);
        }
        
        public float getLonFromX(float x) {
                if(x > 1.0f) x = 1.0f;
                if(x < 0.0f) x = 0.0f;
                return ((getWidth()*x)+getEastLon());
        }
        
        public float getLatFromY(float y) {
                if(y > 1.0f) y = 1.0f;
                if(y < 0.0f) y = 0.0f;
                return ((getHeight()*(-y))+getSouthLat());
        }
        
        public float getXFromLon(float lon) {
                if(DEBUG) {
                        System.out.println("getXFromLon(): called with lon "+lon);
                }
                if((nw == null) || (se == null)) {
                        if(DEBUG) {
                                System.out.println("getXFromLon(): map has null corners, returning -1");
                        }
                        return -1;
                }
                if(DEBUG) {
                        System.out.println("getXFromLon(): returning "+((lon-getWestLon())/getWidth()));
                }
                return (float)(lon - getWestLon())/(getWidth());
        }
        
        public float getYFromLat(float lat) {
                if(DEBUG) {
                        System.out.println("getYFromLat(): called with lat "+lat);
                }
                if((nw == null) || (se == null)) {
                        if(DEBUG) {
                                System.out.println("getYFromLat(): map has null corners, returning -1");
                        }
                        return -1;
                }
                if(DEBUG) {
                        System.out.println("getYFromLat(): returning "+((lat-getSouthLat())/getHeight()));
                }
                return 1.0f - (float)((lat - getSouthLat())/(getHeight()));
        }
        
        public float getWidth() {
                return (float) Math.abs(nw.getLon() - se.getLon());
        }

        public float getHeight(){
                return (float) Math.abs(nw.getLat() - se.getLat());
        }
        
        public float getNorthLat() {
                return (float) nw.getLat();
        }
        
        public float getSouthLat() {
                return (float) se.getLat();
        }
        
        public float getWestLon() {
                return (float) nw.getLon();
        }
        
        public float getEastLon() {
                return (float) se.getLon();
        }

}

 

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