DarkSlayer
Hi
I'm upgrading tank war to allegro 5 and See this code from old thread on the forum. I use the book, allegro wiki site and 2D Game Development Course site and forum to make it work.I am stuck on error: use of undeclared identifier 'screen' in line 31 and 26.I searched the forum and book and the old source code and I could not find the variable. can someone help me to upgrade it?
1
2void drawtank(int num)/*{{{*/
3{
4 int x = tanks[num].x;
5 int y = tanks[num].y;
6 int dir = tanks[num].dir;
7
8 //draw tank body and turret
9 al_draw_filled_rectangle(x-11, y-11, x+11, y+11, tanks[num].color);
10 al_draw_filled_rectangle(x-6, y-6, x+6, y+6, GREY);
11
12 //draw the treads based on orientation
13 if (dir == 0 || dir == 2)
14 {
15 al_draw_filled_rectangle(x-16, y-16, x-11, y+16, DARK_GREY);
16 al_draw_filled_rectangle(x+11, y-16, x+16, y+16, DARK_GREY);
17 }
18 else
19 if (dir == 1 || dir == 3)
20 {
21 al_draw_filled_rectangle(x-16, y-16, x+16, y-11, DARK_GREY);
22 al_draw_filled_rectangle(x-16, y+16, x+16, y+11, DARK_GREY);
23 }
24
25 //draw the turret based on direction
26 switch (dir)
27 {
28 case 0:
29 al_draw_filled_rectangle(x-1, y, x+1, y-16, DARK_GREY);
30 break;
31 case 1:
32 al_draw_filled_rectangle(x, y-1, x+16, y+1, DARK_GREY);
33 break;
34 case 2:
35 al_draw_filled_rectangle(x-1, y, x+1, y+16, DARK_GREY);
36 break;
37 case 3:
38 al_draw_filled_rectangle(x, y-1, x-16, y+1, DARK_GREY);
39 break;
40 }
41 al_flip_display();
42}/*}}}*/
43
44
45void erasetank(int num)/*{{{*/
46{
47 //calculate box to encompass the tank
48 int left = tanks[num].x - 17;
49 int top = tanks[num].y - 17;
50 int right = tanks[num].x + 17;
51 int bottom = tanks[num].y + 17;
52
53 //erase the tank
54 al_draw_filled_rectangle(left, top, right, bottom, BLACK);
55 al_flip_display();
56}/*}}}*/
57
58
59void movetank(int num)/*{{{*/
60{
61 int dir = tanks[num].dir;
62 int speed = tanks[num].speed;
63
64 //update tank position based on direction
65 switch(dir)
66 {
67 case 0:
68 tanks[num].y -= speed;
69 break;
70 case 1:
71 tanks[num].x += speed;
72 break;
73 case 2:
74 tanks[num].y += speed;
75 break;
76 case 3:
77 tanks[num].x -= speed;
78 }
79
80 //keep tank inside the screen
81 if (tanks[num].x > WIDTH-22)
82 {
83 tanks[num].x = WIDTH-22;
84 tanks[num].speed = 0;
85 }
86 if (tanks[num].x < 22)
87 {
88 tanks[num].x = 22;
89 tanks[num].speed = 0;
90 }
91 if (tanks[num].y > HEIGHT-22)
92 {
93 tanks[num].y = HEIGHT-22;
94 tanks[num].speed = 0;
95 }
96 if (tanks[num].y < 22)
97 {
98 tanks[num].y = 22;
99 tanks[num].speed = 0;
100 }
101}/*}}}*/
102
103
104void explode(int num, int x, int y)/*{{{*/
105{
106
107 int n;
108
109 //retrieve location of enemy tank
110 int tx = tanks[!num].x;
111 int ty = tanks[!num].y;
112
113 //is bullet inside the boundary of the enemy tank?
114 if (x > tx-16 && x < tx+16 && y > ty-16 && y < ty+16)
115 score(num);
116
117 //draw some random circles for the "explosion"
118 for (n = 0; n < 10; n++)
119 {
120 al_draw_filled_rectangle(x-16, y-16, x+16, y+16, RANDOM_COLOUR);
121 /* rest(1); */
122 }
123
124 //clear the area of debris
125 al_draw_filled_rectangle(x-16, y-16, x+16, y+16, BLACK);
126 al_flip_display();
127}/*}}}*/
128
129int cmp_colour(int x, int y, char r, char g, char b) {/*{{{*/
130 unsigned char pixelr, pixelg, pixelb;
131
132 al_unmap_rgb(al_get_pixel(screen, x, y), &pixelr, &pixelg, &pixelb);
133 if (r == pixelr && g == pixelg && b == pixelb)
134 return 1;
135 return 0;
136}/*}}}*/
137
138
139void updatebullet(int num)/*{{{*/
140{
141 int x = bullets[num].x;
142 int y = bullets[num].y;
143
144 if (bullets[num].alive)
145 {
146 //erase bullet
147 al_draw_rectangle(x-1, y-1, x+1, y+1, BLACK, 0);
148
149 //move bullet
150 bullets[num].x += bullets[num].xspd;
151 bullets[num].y += bullets[num].yspd;
152 x = bullets[num].x;
153 y = bullets[num].y;
154
155 //stay within the screen
156 if (x < 5 || x > WIDTH-5 || y < 20 || y > HEIGHT-5)
157 {
158 bullets[num].alive = 0;
159 return;
160 }
161
162 //draw bullet
163 x = bullets[num].x;
164 y = bullets[num].y;
165 al_draw_rectangle(x-1, y-1, x+1, y+1, YELLOW, 0);
166
167 //look for a hit
168 if (cmp_colour(bullets[num].x, bullets[num].y, 0xff, 0xff, 0xff)) // black
169 {
170 bullets[num].alive = 0;
171 explode(num, x, y);
172 }
173
174 //print the bullet's position
175 //al_draw_textf(font, al_map_rgb(255, 255, 255), WIDTH/2-50, 1, 2, "B1 %-3dx%-3d B2 %-3dx%-3d", bullets[0].x, bullets[0].y, bullets[1].x, bullets[1].y);
176 }
177 al_flip_display();
178}/*}}}*/
179
180
181int checkpath(int x1,int y1,int x2,int y2,int x3,int y3)/*{{{*/
182{
183 if (cmp_colour(x1, y1, 0xff, 0xff, 0xff) ||
184 cmp_colour(x2, y2, 0xff, 0xff, 0xff) ||
185 cmp_colour(x3, y3, 0xff, 0xff, 0xff))
186 return 1;
187 else
188 return 0;
189}/*}}}*/
190
191void clearpath(int num)/*{{{*/
192{
193 //shortcut vars
194 int dir = tanks[num].dir;
195 int speed = tanks[num].speed;
196 int x = tanks[num].x;
197 int y = tanks[num].y;
198
199 switch(dir)
200 {
201 //check pixels north
202 case 0:
203 if (speed > 0)
204 {
205 if (checkpath(x-16, y-20, x, y-20, x+16, y-20))
206 tanks[num].speed = 0;
207 }
208 else
209 //if reverse dir, check south
210 if (checkpath(x-16, y+20, x, y+20, x+16, y+20))
211 tanks[num].speed = 0;
212 break;
213
214 //check pixels east
215 case 1:
216 if (speed > 0)
217 {
218 if (checkpath(x+20, y-16, x+20, y, x+20, y+16))
219 tanks[num].speed = 0;
220 }
221 else
222 //if reverse dir, check west
223 if (checkpath(x-20, y-16, x-20, y, x-20, y+16))
224 tanks[num].speed = 0;
225 break;
226
227 //check pixels south
228 case 2:
229 if (speed > 0)
230 {
231 if (checkpath(x-16, y+20, x, y+20, x+16, y+20 ))
232 tanks[num].speed = 0;
233 }
234 else
235 //if reverse dir, check north
236 if (checkpath(x-16, y-20, x, y-20, x+16, y-20))
237 tanks[num].speed = 0;
238 break;
239
240 //check pixels west
241 case 3:
242 if (speed > 0)
243 {
244 if (checkpath(x-20, y-16, x-20, y, x-20, y+16))
245 tanks[num].speed = 0;
246 }
247 else
248 //if reverse dir, check east
249 if (checkpath(x+20, y-16, x+20, y, x+20, y+16))
250 tanks[num].speed = 0;
251 break;
252 }
253}/*}}}*/
254
255
256void fireweapon(int num)/*{{{*/
257{
258 int x = tanks[num].x;
259 int y = tanks[num].y;
260
261 //ready to fire again?
262 if (!bullets[num].alive)
263 {
264 bullets[num].alive = 1;
265
266 //fire bullet in direction tank is facing
267 switch (tanks[num].dir)
268 {
269 //north
270 case 0:
271 bullets[num].x = x;
272 bullets[num].y = y-22;
273 bullets[num].xspd = 0;
274 bullets[num].yspd = -BULLETSPEED;
275 break;
276 //east
277 case 1:
278 bullets[num].x = x+22;
279 bullets[num].y = y;
280 bullets[num].xspd = BULLETSPEED;
281 bullets[num].yspd = 0;
282 break;
283 //south
284 case 2:
285 bullets[num].x = x;
286 bullets[num].y = y+22;
287 bullets[num].xspd = 0;
288 bullets[num].yspd = BULLETSPEED;
289 break;
290 //west
291 case 3:
292 bullets[num].x = x-22;
293 bullets[num].y = y;
294 bullets[num].xspd = -BULLETSPEED;
295 bullets[num].yspd = 0;
296 }
297 }
298}
299void forward(int num)/*{{{*/
300{
301 tanks[num].speed++;
302 if (tanks[num].speed > MAXSPEED)
303 tanks[num].speed = MAXSPEED;
304}/*}}}*/
305
306
307void backward(int num)/*{{{*/
308{
309 tanks[num].speed--;
310 if (tanks[num].speed < -MAXSPEED)
311 tanks[num].speed = -MAXSPEED;
312}/*}}}*/
313
314
315void turnleft(int num)/*{{{*/
316{
317 tanks[num].dir--;
318 if (tanks[num].dir < 0)
319 tanks[num].dir = 3;
320}
321
322void turnright(int num)/*{{{*/
323{
324 tanks[num].dir++;
325 if (tanks[num].dir > 3)
326 tanks[num].dir = 0;
327}
328void getinput()/*{{{*/
329{
330 ALLEGRO_EVENT ev;
331 al_wait_for_event(event_queue, &ev);
332 if (ev.type != ALLEGRO_EVENT_KEY_DOWN)
333 ;
334 else if (ev.keyboard.keycode == ALLEGRO_KEY_ESCAPE)
335 gameOver = 1;
336 else if (ev.keyboard.keycode == ALLEGRO_KEY_UP)
337 forward(1);
338 else if (ev.keyboard.keycode == ALLEGRO_KEY_DOWN)
339 backward(1);
340 else if (ev.keyboard.keycode == ALLEGRO_KEY_RIGHT)
341 turnright(1);
342 else if (ev.keyboard.keycode == ALLEGRO_KEY_LEFT)
343 turnleft(1);
344 else if (ev.keyboard.keycode == ALLEGRO_KEY_ENTER)
345 fireweapon(1);
346
347 else if (ev.keyboard.keycode == ALLEGRO_KEY_W)
348 forward(0);
349 else if (ev.keyboard.keycode == ALLEGRO_KEY_D)
350 turnright(0);
351 else if (ev.keyboard.keycode == ALLEGRO_KEY_A)
352 turnleft(0);
353 else if (ev.keyboard.keycode == ALLEGRO_KEY_S)
354 backward(0);
355 else if (ev.keyboard.keycode == ALLEGRO_KEY_SPACE)
356 fireweapon(0);
357
358 //short delay after keypress
359 /* rest(10); */
360}
361void score(int player)/*{{{*/
362{
363 //update score
364 int points = ++tanks[player].score;
365
366 //display score
367 //al_draw_textf(font, BURST, WIDTH-70*(player+1), 1, 0, "P%d: %d", player+1, points);
368 al_flip_display();
369}
370
371void setuptanks()/*{{{*/
372{
373 //player 1
374 tanks[0].x = 30;
375 tanks[0].y = 40;
376 tanks[0].dir = 1;
377 tanks[0].speed = 0;
378 tanks[0].color = BLUE;
379 tanks[0].score = 0;
380
381 //player 2
382 tanks[1].x = WIDTH-30;
383 tanks[1].y = HEIGHT-30;
384 tanks[1].dir = 3;
385 tanks[1].speed = 0;
386 tanks[1].color = RED;
387 tanks[1].score = 0;
388}/*}}}*/
389
390
391void setupdebris()/*{{{*/
392{
393 int n,x,y,size,color;
394
395 //fill the battlefield with random debris
396 for (n = 0; n < BLOCKS; n++)
397 {
398 x = BLOCKSIZE + rand() % (WIDTH-BLOCKSIZE*2);
399 y = BLOCKSIZE + rand() % (HEIGHT-BLOCKSIZE*2);
400 size = (10 + rand() % BLOCKSIZE)/2;
401 al_draw_filled_rectangle(x-size, y-size, x+size, y+size, RANDOM_COLOUR);
402 }
403 al_flip_display();
404
405}/*}}}*/
406
407
408void setupscreen()/*{{{*/
409{
410#if 0
411 //set video mode
412 int ret = set_gfx_mode(MODE, WIDTH, HEIGHT, 0, 0);
413 if (ret != 0) {
414 allegro_message(allegro_error);
415 return;
416 }
417#endif
418
419 al_set_target_bitmap(screen);
420 //print title
421 //al_draw_textf(font, BURST, 1, 1, 0, "Tank War - %dx%d", WIDTH, HEIGHT);
422
423 //draw screen border
424 al_draw_rectangle(0, 12, WIDTH-1, HEIGHT-1, TAN, 0);
425 al_draw_rectangle(1, 13, WIDTH-2, HEIGHT-2, TAN, 0);
426 al_flip_display();
427}/*}}}*/
428
429
430int main(int argc, char **argv)/*{{{*/
431{
432
433 bool done = false;
434 bool render = false;
435
436 float gameTime = 0;
437 int frames = 0;
438 int gameFPS = 0;
439
440
441 ALLEGRO_DISPLAY *display = NULL;
442 ALLEGRO_EVENT_QUEUE *event_queue = NULL;
443 ALLEGRO_TIMER *timer;
444 ALLEGRO_FONT *font;
445
446
447 al_install_keyboard();
448 al_init_image_addon();
449 al_init_font_addon();
450 al_init_ttf_addon();
451 al_init_primitives_addon();
452
453
454
455 font = al_load_font("arial.ttf", 18, 0);
456
457
458 event_queue = al_create_event_queue();
459 timer = al_create_timer(1.0 / 60);
460
461 al_register_event_source(event_queue, al_get_timer_event_source(timer));
462 al_register_event_source(event_queue, al_get_keyboard_event_source());
463
464 al_start_timer(timer);
465 gameTime = al_current_time();
466
467 //initialize everything
468
469 if (!al_init()) {
470 printf("Failed to initialize Allegro library.\n");
471 return 1;
472 }
473
474 if (!al_install_keyboard()) {
475 printf("Failed to install keyboard.\n");
476 return 1;
477 }
478
479 /* install_timer(); */
480 srand(time(NULL));
481 al_init_font_addon();
482 if (!(display = al_create_display(640, 480))) {
483 printf("Failed to create display.\n");
484 return 1;
485 }
486
487 ALLEGRO_PATH *path = al_get_standard_path(ALLEGRO_RESOURCES_PATH);
488 al_append_path_component(path, "resources");
489 al_change_directory(al_path_cstr(path, '/')); // change the working directory
490 printf("Should be in %s\n", al_path_cstr(path, '/'));
491 font = al_load_ttf_font("Airacobra Alt.ttf", 72, 0);
492 if (!font) {
493 printf("Error loading Airacobra Alt.ttf.\n");
494 return 1;
495 }
496 al_destroy_path(path);
497
498 setupscreen();
499 setupdebris();
500 setuptanks();
501
502 //game loop
503 while(!gameOver)
504 {
505#if 0
506 //erase the tanks
507 erasetank(0);
508 erasetank(1);
509
510 //check for collisions
511 clearpath(0);
512 clearpath(1);
513
514 //move the tanks
515 movetank(0);
516 movetank(1);
517#endif
518
519 //draw the tanks
520 drawtank(0);
521 drawtank(1);
522
523#if 0
524 //update the bullets
525 updatebullet(0);
526 updatebullet(1);
527#endif
528
529 //check for keypresses
530 ALLEGRO_EVENT ev;
531 al_wait_for_event(event_queue, &ev);
532 if (ev.type == ALLEGRO_EVENT_KEY_DOWN)
533 getinput();
534
535 //slow the game down (adjust as necessary)
536 al_rest(30);
537 }
538
539 //end program
540 return 0;
541}/*}}}*/
Edgar Reynaldo
In Allegro 4, references to screen are used to draw directly to the screen. In Allegro 5, when you want to draw to the screen, you need to set the target bitmap to the back buffer of the display you are using.
/// Equivalent Allegro 5 Code al_set_target_bitmap(al_get_backbuffer(display)); al_draw_bitmap(bmp , 0 , 0 , 0);
DarkSlayer
just I want to ask. do you know whare I can I get source code of the game in allegro 5?
Edgar Reynaldo
I haven't the faintest clue. If you're lucky, somebody else has already done it for you. Google is (might be) your friend. 