Ive had trouble with this function since i first started using allegro 5 (a month ago 
).
It seems that al_load_bitmap refuses to load a bitmap for me, i had gotten it to work for a while but then after i changed a couple lines somewhere it stopped,
heres my code
1
2#include <stdio.h>
3#include <allegro5/allegro.h>
4#include <allegro5/allegro_image.h>
5#include <time.h>
6#include <cstdlib>
7
8const int SCREEN_W = 640;
9const int SCREEN_H = 480;
10const int FPS = 60;
11const int OBJECTD = 16;
12const float UPR=1;
13const float UPL=2;
14const float DNR=3;
15const float DNL=0;
16int num_of_enemy;
17
18class Game
19{
20 public:
21 ALLEGRO_DISPLAY *display;
22 ALLEGRO_EVENT_QUEUE *event_queue;
23 ALLEGRO_TIMER *timer;
24 bool Init();
25};
26
27bool Game::Init()
28{
29 if (!al_init()) {fprintf(stderr,"failed to initialize allegro!\n");return false;}
30 if (!al_install_keyboard()) {fprintf(stderr,"failed to install keyboard drivers!\n");return false;}
31 if (!al_init_image_addon()) {fprintf(stderr,"failed to initialize image addon\n");return false;}
32
33 display = al_create_display(SCREEN_W,SCREEN_H);
34 event_queue = al_create_event_queue();
35 timer = al_create_timer(1.0/FPS);
36
37 if (!display) {fprintf(stderr,"failed to create display!\n"); return false;}
38 if (!event_queue) {fprintf(stderr,"failed to create event queue!\n"); al_destroy_display(display); return false;}
39 if (!timer) {fprintf(stderr,"failed to create timer!\n"); al_destroy_display(display); al_destroy_event_queue(event_queue);return false;}
40
41 al_register_event_source(event_queue, al_get_display_event_source(display));
42 al_register_event_source(event_queue, al_get_timer_event_source(timer));
43 al_register_event_source(event_queue, al_get_keyboard_event_source());
44
45 return true;
46}
47
48class Object
49{
50 int x;
51 int y;
52 int d;
53 ALLEGRO_BITMAP *bitmap;
54 public:
55 Object(bool player);
56 Object();
57 void Move(ALLEGRO_KEYBOARD_STATE *state);
58 void Move();
59 void Draw();
60 bool Collide(Object victim);
61};
62
63Object::Object(bool player)
64{
65 if (player)
66 {
67 x = (SCREEN_W - OBJECTD)/2;
68 y = (SCREEN_H - OBJECTD)/2;
69 bitmap = al_load_bitmap("playerball.bmp");
70 if (bitmap == NULL) printf("erroer loding bitmap\n"); //displays this, meaning bitmap failed to load
71 al_convert_mask_to_alpha(bitmap,al_map_rgb(255,255,255)); // actually crashes on this line, most likely because the bitmap is null
72 }
73}
74
75Object::Object()
76{
77 d = rand() % 4;
78 x = rand() %SCREEN_H;
79 y = rand() %SCREEN_W;
80 bitmap = al_load_bitmap("cpuball.bmp");
81 al_convert_mask_to_alpha(bitmap,al_map_rgb(255,255,255));
82}
83
84void Object::Move(ALLEGRO_KEYBOARD_STATE *state)
85{
86 printf("1 ");
87 if ((al_key_down(state,ALLEGRO_KEY_UP) || al_key_down(state,ALLEGRO_KEY_W)) && y>0) y--;
88 printf("2 ");
89 if ((al_key_down(state,ALLEGRO_KEY_DOWN) || al_key_down(state,ALLEGRO_KEY_S)) && (y+OBJECTD)<SCREEN_H) y++;
90 printf("3 ");
91 if ((al_key_down(state,ALLEGRO_KEY_LEFT) || al_key_down(state,ALLEGRO_KEY_A)) && x>0) x--;
92 printf("4 ");
93 if ((al_key_down(state,ALLEGRO_KEY_RIGHT) || al_key_down(state,ALLEGRO_KEY_D)) && (x+OBJECTD)<SCREEN_W) x++;
94 printf("5 \n");
95}
96
97void Object::Move()
98{
99 if (x==0 && d==UPL) {d=UPR;}
100 if (x==0 && d==DNL) {d=DNR;}
101 if (x==(SCREEN_W-OBJECTD) && d==DNR) {d=DNL;}
102 if (x==(SCREEN_W-OBJECTD) && d==UPR) {d=UPL;}
103 if (y==0 && d==UPL) {d=DNL;}
104 if (y==0 && d==UPR) {d=DNR;}
105 if (y==(SCREEN_H-OBJECTD) && d==DNR) {d=UPR;}
106 if (y==(SCREEN_H-OBJECTD) && d==DNL) {d=UPL;}
107 if (d == UPR) {y--;x++;}
108 if (d == UPL) {y--;x--;}
109 if (d == DNR) {y++;x++;}
110 if (d == DNL) {y++;x--;}
111}
112
113void Object::Draw()
114{
115 printf("object.draw\n");
116 al_draw_bitmap(bitmap,x,y,0);
117}
118
119bool Object::Collide(Object victim)
120{
121
122}
123
124int main()
125{
126 srand(time(NULL));
127
128 Game Sally;
129 if (!Sally.Init()) {printf("Your Screwed\n"); return -1;}
130
131 Object Billy(true);
132 num_of_enemy = 5;
133 Object *Enemy;
134 Enemy = new Object[num_of_enemy];
135 bool redraw = true;
136
137 al_set_target_bitmap(al_get_backbuffer(Sally.display));
138 al_set_window_title(Sally.display,"TITLE");
139 al_clear_to_color(al_map_rgb(250,100,19));
140 al_flip_display();
141
142 al_start_timer(Sally.timer);
143
144 printf("starting loop\n");
145
146 ALLEGRO_KEYBOARD_STATE *ret_state;
147 ret_state = new ALLEGRO_KEYBOARD_STATE;
148
149 while (true)
150 {
151 ALLEGRO_EVENT ev;
152 al_wait_for_event(Sally.event_queue,&ev);
153
154 if (ev.type == ALLEGRO_EVENT_TIMER)
155 {
156 printf("timer\n");
157 Billy.Move(ret_state);
158 for (int a=0;a<num_of_enemy;a++)
159 {
160 Enemy[a].Move();
161 }
162 redraw = true;
163 }
164
165 else if (ev.type == ALLEGRO_EVENT_KEY_DOWN)
166 {
167 printf("keypressfghjiulkyjrtyuiiuytrtyuiuiy\n");
168 al_get_keyboard_state(ret_state);
169 }
170
171 else if (ev.type == ALLEGRO_EVENT_KEY_UP)
172 {
173 printf("keyrelaesesfghjiulkyjrtyuiiuytrtyuiuiy\n");
174 al_get_keyboard_state(ret_state);
175 }
176
177 else if (ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
178 {
179 printf("close\n");
180 al_destroy_timer(Sally.timer);
181 al_destroy_display(Sally.display);
182 al_destroy_event_queue(Sally.event_queue);
183 return 0;
184 }
185
186 if (redraw && al_is_event_queue_empty(Sally.event_queue))
187 {
188 printf("redraw\n");
189 al_clear_to_color(al_map_rgb(50,50,50));
190 Billy.Draw();
191 for (int a=0;a<num_of_enemy;a++)
192 {
193 Enemy[a].Draw();
194 }
195 al_flip_display();
196 redraw = false;
197 }
198 }
199
200 return 0;
201}
lines 69-71 are where it crashes
as a side note i double checked the spelling and the image file is in fact next to the .exe, Ive also attached the two image files.
]]>
