1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
| import java.awt.*;
import java.awt.image.*;
import java.applet.Applet;
import java.util.*;
public class PatternSimulator extends Applet {
SimCanvas canvas;
public Label time_label;
public Label number_label;
Button pause_button;
public void init() {
canvas = new SimCanvas();
canvas.init(this);
setLayout(new BorderLayout());
Panel p = new Panel();
p.setFont(new Font("TimesRoman", Font.BOLD, 12));
p.add(new Label("Simulation Time:", Label.RIGHT));
p.add(time_label = new Label("1000", Label.LEFT));
p.add(new Label("Airplanes in system:", Label.RIGHT));
p.add(number_label = new Label("0", Label.LEFT));
p.add(new Label(" "));
p.add(pause_button = new Button("Start Sim"));
pause_button.disable();
add("North", p);
add("Center", canvas);
}
public void start() {
if (canvas.sim_thread == null) {
canvas.sim_thread = new Thread(canvas);
canvas.sim_thread.start();
}
}
public void stop() {
canvas.sim_thread = null;
}
public boolean action(Event evt, Object arg) {
if ("Start Sim".equals(arg)) {
pause_button.setLabel("Pause");
canvas.startSim();
return true;
}
else if("Pause".equals(arg)) {
canvas.paused = true;
pause_button.setLabel("Resume");
return true;
}
else if("Resume".equals(arg)) {
canvas.paused = false;
pause_button.setLabel("Pause");
}
return false;
}
}
class SimCanvas extends Canvas implements Runnable {
Applet app;
public Thread sim_thread = null;
Image background;
Image hangar;
Image double_buffer;
Graphics double_buffer_graphics;
int mouse_down_at_x;
int mouse_down_at_y;
public Vector airplanes;
int simulation_units;
final static double new_plane_frequency = 0.10;
public boolean paused = true;
public void init(Applet app) {
resize(450, 450);
setBackground(new Color(10, 70, 30));
this.app = app;
background = app.getImage(app.getDocumentBase(), "backgrnd.gif");
hangar = app.getImage(app.getDocumentBase(), "hangar.gif");
CommercialAirplane.MakeImages(app.getImage(app.getDocumentBase(), "777.gif"), app);
PropellerAirplane.MakeImages(app.getImage(app.getDocumentBase(), "propeller.gif"), app);
double_buffer = app.createImage(450, 450);
double_buffer_graphics = double_buffer.getGraphics();
double_buffer_graphics.setColor(new Color(10, 70, 30));
double_buffer_graphics.fillRect(0,0,450,450);
double_buffer_graphics.setColor(Color.white);
double_buffer_graphics.drawString("Loading Pattern Simulator...", 10, 425);
airplanes = new Vector(20);
}
public void startSim() {
airplanes.removeAllElements();
airplanes.addElement(new CommercialAirplane());
repaint();
simulation_units = 1000;
paused = false;
}
public void paint(Graphics g) {
double_buffer_graphics.drawImage(background, 0, 0, app);
for (Enumeration e = airplanes.elements() ; e.hasMoreElements() ;) {
Airplane plane = (Airplane)e.nextElement();
plane.Draw(double_buffer_graphics, app);
}
double_buffer_graphics.drawImage(hangar, 170, 292, app);
g.drawImage(double_buffer, 0, 0, app);
}
public void update(Graphics g) {
paint(g);
}
public void run() {
//# Get the first image to the screen ASAP
while((app.checkImage(background, app) & ImageObserver.ALLBITS) == 0) {
repaint();
try {
Thread.sleep(250);
} catch (InterruptedException e) {}
}
((PatternSimulator)getParent()).pause_button.enable();
while (true) {
if(paused) {
try {
Thread.sleep(1500);
} catch (InterruptedException e) {}
}
else {
if(--simulation_units <= 0) {
((PatternSimulator)getParent()).pause_button.setLabel("Start Sim");
paused = true;
}
((PatternSimulator)getParent()).time_label.setText(Integer.toString(simulation_units));
((PatternSimulator)getParent()).number_label.setText(Integer.toString(airplanes.size()));
try {
Thread.sleep(100);
} catch (InterruptedException e) {}
DoUpdate();
try {
paint(getGraphics());
}
catch (Exception e){
sim_thread = null;
}
}
}
}
protected void DoUpdate() {
boolean CanAddAirplane = true;
boolean CanLandAirplane = true;
for (Enumeration e = airplanes.elements() ; e.hasMoreElements() ;) {
Airplane plane = (Airplane)e.nextElement();
if(plane.InTheWayOfNewAirplane()) {
CanAddAirplane = false;
}
if(plane.CurrentlyLanding()) {
CanLandAirplane = false;
}
}
for (Enumeration e = airplanes.elements() ; e.hasMoreElements() ;) {
Airplane plane = (Airplane)e.nextElement();
if(CanLandAirplane) {
if(plane.DoLandIfPossible()) {
CanLandAirplane = false;
}
}
if(mouse_down_at_x >= 0) {
plane.Release(mouse_down_at_x, mouse_down_at_y);
}
plane.Fly();
if(plane.RemoveMe()) {
airplanes.removeElement(plane);
}
}
if(CanAddAirplane) {
double random_number = Math.random();
if(random_number < new_plane_frequency / 2) {
airplanes.addElement(new PropellerAirplane());
}
else if(random_number < new_plane_frequency) {
airplanes.addElement(new CommercialAirplane());
}
}
}
public boolean mouseDown(java.awt.Event evt, int x, int y) {
mouse_down_at_x = x;
mouse_down_at_y = y;
return true;
}
public boolean mouseUp(java.awt.Event evt, int x, int y) {
mouse_down_at_x = -1;
mouse_down_at_y = -1;
return true;
}
public boolean mouseDrag(java.awt.Event evt, int x, int y) {
mouse_down_at_x = x;
mouse_down_at_y = y;
return true;
}
}
abstract class Airplane extends Object {
public static final int NORTH = 0;
public static final int NORTHEAST = 1;
public static final int EAST = 2;
public static final int SOUTHEAST = 3;
public static final int SOUTH = 4;
public static final int SOUTHWEST = 5;
public static final int WEST = 6;
public static final int NORTHWEST = 7;
public static final int SPEED = 18;
public static final int DIAGNAL_SPEED = 10;
public static final int GROUND_SPEED = 5;
public static final int DIAGNAL_GROUND_SPEED = 3;
public static final int NORMAL = 0;
public static final int LANDING = 1;
public static final int LEAVING = 2;
int x, y, w, h;
int direction;
int status;
int random_course;
Airplane() {
this.x = 410;
this.y = 0;
direction = SOUTH;
status = NORMAL;
random_course = (int) (Math.random() * 20.0f);
}
public abstract void Draw(Graphics g, ImageObserver ob);
public boolean InTheWayOfNewAirplane() {
if(status == LANDING)
return false;
switch(direction) {
case EAST :
return (x > 265);
case SOUTHEAST :
return status != LANDING;
case SOUTH :
return (status != LANDING && y < 135);
default :
return false;
}
}
public boolean CurrentlyLanding() {
return (status == LANDING && direction <= SOUTH);
}
public boolean RemoveMe() {
if(status == LANDING && direction == NORTH)
return true;
if(status == LEAVING &&(x < -40 || y < -40 || x > 450 || y > 450))
return true;
return false;
}
public boolean DoLandIfPossible() {
if(status == NORMAL && direction == EAST && x >= 250 && x <= 275) {
status = LANDING;
direction = SOUTHEAST;
return true;
}
return false;
}
public void Fly() {
if(status == LANDING) {
switch(direction) {
case SOUTHEAST :
y += DIAGNAL_SPEED;
x += DIAGNAL_SPEED;
if(x >= 280) {
x = 282;
direction = SOUTH;
}
break;
case SOUTH :
int gradual_slow = y / 20;
y += SPEED - gradual_slow;
if(y >= 269) {
direction = SOUTHWEST;
}
break;
case SOUTHWEST :
x -= DIAGNAL_GROUND_SPEED;
y += DIAGNAL_GROUND_SPEED;
if(y >= 292) {
direction = WEST;
}
break;
case WEST :
x -= GROUND_SPEED;
if(x <= 220) {
direction = NORTH;
}
break;
}
}
else {
switch(direction) {
case NORTH :
y -= SPEED;
if(y + random_course < 65 && status != LEAVING) {
direction = NORTHEAST;
random_course = (int) (Math.random() * 20.0f);
}
break;
case NORTHEAST :
y -= DIAGNAL_SPEED;
x += DIAGNAL_SPEED;
if(y + random_course < 35 && status != LEAVING) {
direction = EAST;
}
break;
case EAST :
x += SPEED;
if(x + random_course > 370 && status != LEAVING) {
direction = SOUTHEAST;
random_course = (int) (Math.random() * 20.0f);
}
break;
case SOUTHEAST :
x += DIAGNAL_SPEED;
y += DIAGNAL_SPEED;
if(x + random_course > 400 && status != LEAVING) {
direction = SOUTH;
}
break;
case SOUTH :
y += SPEED;
if(y + random_course > 358 && status != LEAVING) {
direction = SOUTHWEST;
random_course = (int) (Math.random() * 20.0f);
}
break;
case SOUTHWEST :
x -= DIAGNAL_SPEED;
y += DIAGNAL_SPEED;
if(y + random_course > 388 && status != LEAVING) {
direction = WEST;
}
break;
case WEST :
x -= SPEED;
if(x + random_course < 62 && status != LEAVING) {
direction = NORTHWEST;
random_course = (int) (Math.random() * 20.0f);
}
break;
case NORTHWEST :
x -= DIAGNAL_SPEED;
y -= DIAGNAL_SPEED;
if(x + random_course < 32 && status != LEAVING) {
direction = NORTH;
}
break;
}
}
}
public void Release(int x_press, int y_press) {
if( status == NORMAL &&
x_press >= x && x_press <= x + w &&
y_press >= y && y_press <= y + h) {
status = LEAVING;
}
}
}
class CommercialAirplane extends Airplane {
public static Image airplane_image[] = new Image[8];
public static void MakeImages(Image base_image, Component component) {
for(int y = 0 ; y < 8 ; ++y) {
ImageFilter crop = new CropImageFilter(0, 38 * y, 36, 38);
airplane_image[y] = component.createImage(
new FilteredImageSource(base_image.getSource(), crop));
component.prepareImage(airplane_image[y], component);
}
}
public CommercialAirplane() {
super();
w = 36;
h = 38;
}
public void Draw(Graphics g, ImageObserver ob) {
g.drawImage(airplane_image[direction], x, y, ob);
}
}
class PropellerAirplane extends Airplane {
public static Image airplane_image[] = new Image[8];
public static void MakeImages(Image base_image, Component component) {
for(int y = 0 ; y < 8 ; ++y) {
ImageFilter crop = new CropImageFilter(0, 31 * y, 31, 31);
airplane_image[y] = component.createImage(
new FilteredImageSource(base_image.getSource(), crop));
component.prepareImage(airplane_image[y], component);
}
}
public PropellerAirplane() {
super();
w = 31;
h = 31;
}
public void Draw(Graphics g, ImageObserver ob) {
g.drawImage(airplane_image[direction], x, y, ob);
}
} |
