I am working on my Allegro 5 game, which is coming along nicely, I am really loving the library.
I do have one "problem" which I am not sure there is a solution to, but I thought I would throw this out there and see if anyone has any ideas.
I had the same "problem" with Allegro 4. It's not a library problem really though, at least I don't think so.
What happens in my Pacman style game is that a player can be moving along, say to the right in the maze. They wish to turn up. They get so wrapped up in the game and the ghosts chasing them that they forget to let go of the right cursor key and press UP key, so they have both keys pressed at the same time. This is fairly common. To their dismay, their character keeps going right and doesn't turn up at all and they end up dying and cursing the programmer.
I have tried to change how I code this, by clearing the key_pressed[] array when a new key is pressed and the player will then turn as expected, even with a new key pressed, but then the game won't respond to the right keypress until that key is released. Now obviously they should have released it and I have advised against holding keys down as you don't need to hold a key down at all in my game, just tap the direction you wish to go then let go of the key and your character will happily travel in that direction unless told otherwise. But is there a better solution to this do you think? I haven't tested if this happens in other games yet. Just thought I would throw this out there just in case there is something I am missing.
Thanks in advance.
Example code I use (edited to keep things brief)
#SelectExpand
1while(!done
&& !pacman.dead
) {
2 al_wait_for_event(event_queue,
&event
);
3
4 if(event.type
== ALLEGRO_EVENT_DISPLAY_CLOSE
) {
5 done
= true;
6 }
7
8 // check for key input and process it
9 else if(event.type
== ALLEGRO_EVENT_KEY_DOWN
) {
10 al_get_keyboard_state(&keys
);
11 switch(event.keyboard.keycode
) {
12 case ALLEGRO_KEY_ESCAPE:
13 // Do stuff for ESCAPE (removed for brevity)
14 break;
15 default:
16 pressed_key
[event.keyboard.keycode
] = true;
17 }
18 }
19 else if(event.type
== ALLEGRO_EVENT_KEY_UP
) {
20 al_get_keyboard_state(&keys
);
21 pressed_key
[event.keyboard.keycode
] = false;
22 }
23
24 else if(event.type
== ALLEGRO_EVENT_TIMER
) {
25 if(event.timer.source
== pacman.timer
) {
26 redraw
= true;
27 redraw_timer
= al_get_timer_count(setting.redraw_timer
);
28
29 if(pressed_key
[ALLEGRO_KEY_UP
]) {
30 // do stuff for up
31 }
32 else if(pressed_key
[ALLEGRO_KEY_DOWN
]) {
33 // do stuff for down
34 }
35 if(pressed_key
[ALLEGRO_KEY_LEFT
]) {
36 // do stuff for left
37 }
38 else if(pressed_key
[ALLEGRO_KEY_RIGHT
]) {
39 // do stuff for right
40 }
41 if(pressed_key
[ALLEGRO_KEY_LCTRL
] || pressed_key
[ALLEGRO_KEY_RCTRL
]) {
42 // do stuff for CTRL
43 }
44 else {
45 // do other stuff
46 }
47 /*** CHEAT KEYS ***
48 You don't want to know these :)
49 */
50 if(setting.cheat_mode
) {
51 }
52
53 // etc...
]]>
