Having a little problem with mouse eventing. I am drawing a bitmap with al_draw_rotated_bitmap() which rotates the player bitmap towards where the mouse cursor is pointing. It works nicely until I scroll the map, in which the coordinates seem to be stuck at the screen where the player "spawned". This causes the player bitmap to not respond towards mouse movement as soon as I scroll the map in X or Y direction.
1hero->setAngle(atan2(float(mouseAxesY - pos_y),float(mouseAxesX - pos_x))); // Radiens = arc tangent of mouseAxesX/Y - Player positionX/Y Set angle for player rotation on hero->update()
This is the code where I get the mouse cursor position:
1ALLEGRO_EVENT ev;
2
3if (ev.type == ALLEGRO_EVENT_MOUSE_AXES) {
4 mouseAxesX = ev.mouse.x;
5 mouseAxesY = ev.mouse.y;
6}
And the code which scrolls the map:
1// Update camera position
2
3map->setOffsetX(0);
4map->setOffsetY(0);
5
6map->setOffsetX(map->getOffsetX() - (screenW / 2) + (pos_x + hero->getPBitmapWidth() / 2));
7map->setOffsetY(map->getOffsetY() - (screenH / 2) + (pos_y + hero->getPBitmapHeight() / 2));
8
9if (map->getOffsetX() < 0)
10 map->setOffsetX(0);
11if (map->getOffsetY() < 0)
12 map->setOffsetY(0);
13
14al_identity_transform(&camera);
15al_translate_transform(&camera, -map->getOffsetX(), -map->getOffsetY());
16al_use_transform(&camera);
For reference, here is the entire function:
1void BasicGameEngine::start() {
2
3 al_start_timer(timer); // Start timer. This operates at the industry standard 60 FPS, see constructor
4 hero = new OurHero(50, 50);
5
6 // Initialize 5 projectiles for our hero
7
8 hero->initProjectile(Projectile, 5);
9
10 // Get X/Y position of player
11
12 float pos_y = hero->getPosY();
13 float pos_x = hero->getPosX();
14
15 // Maximum speed player can move (value = pixel pr. second)
16
17 hero->setSpeed(3);
18
19 // Generate our map
20
21 map = new OurMap(10,10);
22
23 // Initiate main game loop
24
25 while (!done) {
26 ALLEGRO_EVENT ev;
27 al_wait_for_event(eQueue, &ev);
28
29 if (ev.type == ALLEGRO_EVENT_MOUSE_AXES) {
30 mouseAxesX = ev.mouse.x;
31 mouseAxesY = ev.mouse.y;
32 }
33
34 if (ev.type == ALLEGRO_EVENT_KEY_DOWN) {
35 switch (ev.keyboard.keycode) {
36 case ALLEGRO_KEY_W:
37 key[UP] = true;
38 break;
39 case ALLEGRO_KEY_S:
40 key[DOWN] = true;
41 break;
42 case ALLEGRO_KEY_D:
43 key[RIGHT] = true;
44 break;
45 case ALLEGRO_KEY_A:
46 key[LEFT] = true;
47 break;
48 case ALLEGRO_KEY_SPACE:
49 hero->fireProjectile(Projectile, 5, mouseAxesX, mouseAxesY);
50 key[SPACE] = true;
51 break;
52 case ALLEGRO_KEY_RSHIFT:
53 key[SHIFT] = true;
54 break;
55 case ALLEGRO_KEY_LSHIFT:
56 key[SHIFT] = true;
57 break;
58 }
59 } else if (ev.type == ALLEGRO_EVENT_KEY_UP) {
60 switch(ev.keyboard.keycode) {
61 case ALLEGRO_KEY_W:
62 key[UP] = false;
63 break;
64 case ALLEGRO_KEY_S:
65 key[DOWN] = false;
66 break;
67 case ALLEGRO_KEY_D:
68 key[RIGHT] = false;
69 break;
70 case ALLEGRO_KEY_A:
71 key[LEFT] = false;
72 break;
73 case ALLEGRO_KEY_SPACE:
74 key[SPACE] = false;
75 break;
76 case ALLEGRO_KEY_RSHIFT:
77 key[SHIFT] = false;
78 break;
79 case ALLEGRO_KEY_LSHIFT:
80 key[SHIFT] = false;
81 break;
82 case ALLEGRO_KEY_ESCAPE:
83 done = true;
84 break;
85 }
86 } else if (ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE) {
87 done = true;
88 } else if (ev.type == ALLEGRO_EVENT_TIMER) {
89
90 // If player holds shift, increse speed by 4 pixels/s
91 // this simulates run, but will drain players stamina
92 // stamina will regenerate at 30% / s when the player
93 // is not running
94
95 if (key[SHIFT] && hero->getStamina() > 0) {
96 pos_y -= key[UP] * (hero->getSpeed() + 4);
97 pos_y += key[DOWN] * (hero->getSpeed() + 4);
98 pos_x -= key[LEFT] * (hero->getSpeed() + 4);
99 pos_x += key[RIGHT] * (hero->getSpeed() + 4);
100 hero->setStamina(hero->getStamina() - 1);
101
102 } else {
103 pos_y -= key[UP] * hero->getSpeed();
104 pos_y += key[DOWN] * hero->getSpeed();
105 pos_x -= key[LEFT] * hero->getSpeed();
106 pos_x += key[RIGHT] * hero->getSpeed();
107 }
108
109 if (!key[SHIFT] && hero->getStamina() < 1000)
110 hero->setStamina(hero->getStamina() + 0.3);
111
112 // Update projectile
113
114 hero->updateProjectile(Projectile, 5, 640, 480);
115
116
117 redraw = true;
118 }
119
120
121 if (redraw && al_event_queue_is_empty(eQueue)) {
122 redraw = false;
123
124 // redraw map sprites
125
126 map->draw();
127
128 // Update player position
129
130 hero->setPosX(pos_x);
131 hero->setPosY(pos_y);
132 hero->setAngle(atan2(float(mouseAxesY - pos_y),float(mouseAxesX - pos_x))); // Radiens = arc tangent of mouseAxesX/Y - Player positionX/Y
133 // Set angle for player rotation on hero->update()
134 hero->update();
135
136 // Update camera position
137
138 map->setOffsetX(0);
139 map->setOffsetY(0);
140
141 map->setOffsetX(map->getOffsetX() - (screenW / 2) + (pos_x + hero->getPBitmapWidth() / 2));
142 map->setOffsetY(map->getOffsetY() - (screenH / 2) + (pos_y + hero->getPBitmapHeight() / 2));
143
144 if (map->getOffsetX() < 0)
145 map->setOffsetX(0);
146 if (map->getOffsetY() < 0)
147 map->setOffsetY(0);
148
149 al_identity_transform(&camera);
150 al_translate_transform(&camera, -map->getOffsetX(), -map->getOffsetY());
151 al_use_transform(&camera);
152
153 // Draw projectiles if projectiles are fired
154 hero->drawProjectile(Projectile, 5);
155
156 al_flip_display();
157 al_clear_to_color(al_map_rgb(0, 0, 0));
158
159 }
160
161 }
162
163 delete map;
164}
Any help would be appreciated with this 