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Blank Screen
agonvs
Member #15,917
March 2015

Hi all,

I'm getting nothing but a white screen here (although the music plays fine). It won't even clear to black. What am I doing wrong?

#SelectExpand
1#include<allegro5/allegro.h> 2#include<allegro5/allegro_primitives.h> 3#include<allegro5/allegro_image.h> 4#include<allegro5/allegro_audio.h> 5#include<allegro5/allegro_acodec.h> 6#include<iostream> 7#include"globals.h" 8#include"paddle.h" 9using namespace std; 10 11int main() 12{ 13 float gameTime = 0; 14 int frames = 0; 15 int gameFPS = 0; 16 if(!(al_init())) 17 cout << "Couldn't initialize Allegro." << cout; 18 if(!(al_install_joystick())) 19 cout << "Couldn't install joystick." << endl; 20 al_init_image_addon(); 21 al_init_primitives_addon(); 22 ALLEGRO_DISPLAY *display = NULL; 23 display = al_create_display(1280,720); 24 al_install_audio(); 25 al_init_acodec_addon(); 26 al_reserve_samples(1); 27 ALLEGRO_SAMPLE* sample = NULL; 28 ALLEGRO_SAMPLE_INSTANCE* instance = NULL; 29 sample=al_load_sample("The Heat Is On.ogg"); 30 instance = al_create_sample_instance(sample); 31 al_attach_sample_instance_to_mixer(instance, al_get_default_mixer()); 32 ALLEGRO_EVENT_QUEUE *event_queue = NULL; 33 event_queue = al_create_event_queue(); 34 if(!event_queue) 35 cout << "al_create_event_queue failed." << endl; 36 ALLEGRO_TIMER *timer; 37 timer = al_create_timer(1.0/60); 38 al_register_event_source(event_queue, al_get_timer_event_source(timer)); 39 40 gameTime = al_current_time(); 41 al_register_event_source(event_queue, al_get_joystick_event_source()); 42 ALLEGRO_JOYSTICK* joy = al_get_joystick(0); 43 ALLEGRO_JOYSTICK_STATE jst; 44 buttons button; 45 direction dir = NONE; 46 bool render = false; 47 ALLEGRO_BITMAP *image = NULL; 48 image = al_load_bitmap("batonspritesheet.png"); 49 const int arraySize = 3; 50 bool alive = true; 51 Paddle paddle; 52 paddle.initialize(576, 687, 0, 0, 128, 32, image); 53 al_start_timer(timer); 54 al_play_sample_instance(instance); 55 while(alive) 56 { 57 ALLEGRO_EVENT ev; 58 al_wait_for_event(event_queue, &ev); 59 al_get_joystick_state(joy, &jst); 60 if (ev.type == ALLEGRO_EVENT_JOYSTICK_AXIS) 61 { 62 if ((jst.stick[2].axis[0] == 0) && (jst.stick[2].axis[1] == 0)) 63 dir = NONE; 64 if ((jst.stick[2].axis[0] == 1) && (jst.stick[2].axis[1] == 0)) 65 dir = RIGHT; 66 if ((jst.stick[2].axis[0] == -1) && (jst.stick[2].axis[1] == 0)) 67 dir = LEFT; 68 } 69 if (ev.type == ALLEGRO_EVENT_JOYSTICK_BUTTON_DOWN) 70 if (jst.button[9]) 71 button = NINE; 72//update 73 else if (ev.type == ALLEGRO_EVENT_TIMER) 74 { 75 render = true; 76 paddle.update(dir); 77 frames++; 78 if (al_current_time() - gameTime >= 1) 79 { 80 gameTime = al_current_time(); 81 gameFPS = frames; 82 frames = 0; 83 } 84 } 85//render 86 if (render && al_is_event_queue_empty(event_queue)) 87 { 88 //al_set_target_bitmap(al_get_backbuffer(display)); 89 al_clear_to_color(al_map_rgb(0,0,0)); 90 paddle.Render(); 91 al_flip_display(); 92 } 93 if (jst.button[9]) 94 alive = false; 95 } 96 al_destroy_bitmap(image); 97 al_destroy_timer(timer); 98 al_destroy_event_queue(event_queue); 99 return 0; 100}

Please help! :)

SiegeLord
Member #7,827
October 2006
avatar

Does this reduced code work for you (it does for me, should clear everything to red):

#SelectExpand
1#include<allegro5/allegro.h> 2#include<allegro5/allegro_primitives.h> 3#include<allegro5/allegro_image.h> 4#include<allegro5/allegro_audio.h> 5#include<allegro5/allegro_acodec.h> 6#include<iostream> 7//~ #include"globals.h" 8//~ #include"paddle.h" 9using namespace std; 10 11int main() 12{ 13 float gameTime = 0; 14 int frames = 0; 15 int gameFPS = 0; 16 if(!(al_init())) 17 cout << "Couldn't initialize Allegro." << cout; 18 if(!(al_install_joystick())) 19 cout << "Couldn't install joystick." << endl; 20 al_init_image_addon(); 21 al_init_primitives_addon(); 22 ALLEGRO_DISPLAY *display = NULL; 23 display = al_create_display(1280,720); 24 al_install_audio(); 25 al_init_acodec_addon(); 26 al_reserve_samples(1); 27 ALLEGRO_SAMPLE* sample = NULL; 28 ALLEGRO_SAMPLE_INSTANCE* instance = NULL; 29 sample=al_load_sample("The Heat Is On.ogg"); 30 instance = al_create_sample_instance(sample); 31 al_attach_sample_instance_to_mixer(instance, al_get_default_mixer()); 32 ALLEGRO_EVENT_QUEUE *event_queue = NULL; 33 event_queue = al_create_event_queue(); 34 if(!event_queue) 35 cout << "al_create_event_queue failed." << endl; 36 ALLEGRO_TIMER *timer; 37 timer = al_create_timer(1.0/60); 38 al_register_event_source(event_queue, al_get_timer_event_source(timer)); 39 40 gameTime = al_current_time(); 41 al_register_event_source(event_queue, al_get_joystick_event_source()); 42 ALLEGRO_JOYSTICK* joy = al_get_joystick(0); 43 ALLEGRO_JOYSTICK_STATE jst; 44 //~ buttons button; 45 //~ direction dir = NONE; 46 bool render = false; 47 //~ ALLEGRO_BITMAP *image = NULL; 48 //~ image = al_load_bitmap("batonspritesheet.png"); 49 const int arraySize = 3; 50 bool alive = true; 51 //~ Paddle paddle; 52 //~ paddle.initialize(576, 687, 0, 0, 128, 32, image); 53 al_start_timer(timer); 54 //~ al_play_sample_instance(instance); 55 while(alive) 56 { 57 ALLEGRO_EVENT ev; 58 al_wait_for_event(event_queue, &ev); 59 al_get_joystick_state(joy, &jst); 60 if (ev.type == ALLEGRO_EVENT_JOYSTICK_AXIS) 61 { 62 //~ if ((jst.stick[2].axis[0] == 0) && (jst.stick[2].axis[1] == 0)) 63 //~ dir = NONE; 64 //~ if ((jst.stick[2].axis[0] == 1) && (jst.stick[2].axis[1] == 0)) 65 //~ dir = RIGHT; 66 //~ if ((jst.stick[2].axis[0] == -1) && (jst.stick[2].axis[1] == 0)) 67 //~ dir = LEFT; 68 } 69 //~ if (ev.type == ALLEGRO_EVENT_JOYSTICK_BUTTON_DOWN) 70 //~ if (jst.button[9]) 71 //~ button = NINE; 72//update 73 else if (ev.type == ALLEGRO_EVENT_TIMER) 74 { 75 render = true; 76 //~ paddle.update(dir); 77 frames++; 78 if (al_current_time() - gameTime >= 1) 79 { 80 gameTime = al_current_time(); 81 gameFPS = frames; 82 frames = 0; 83 } 84 } 85//render 86 if (render && al_is_event_queue_empty(event_queue)) 87 { 88 //~ al_set_target_bitmap(al_get_backbuffer(display)); 89 al_clear_to_color(al_map_rgb_f(1,0,0)); 90 //~ paddle.Render(); 91 al_flip_display(); 92 } 93 if (jst.button[9]) 94 alive = false; 95 } 96 //~ al_destroy_bitmap(image); 97 al_destroy_timer(timer); 98 al_destroy_event_queue(event_queue); 99 return 0; 100}

If it does, then something is wrong with your paddle functions.

"For in much wisdom is much grief: and he that increases knowledge increases sorrow."-Ecclesiastes 1:18
[SiegeLord's Abode][Codes]:[DAllegro5]:[RustAllegro]

agonvs
Member #15,917
March 2015

Yes that worked. I don't know what's wrong with the paddle code but here it is:

#SelectExpand
1#include"allegro5/allegro.h" 2 3void Paddle::initialize(int x, int y, int velX, int velY, int width, int height) 4{ 5 mX = x; 6 mY = y; 7 mVelX = velX; 8 mVelY = velY; 9 mWidth = width; 10 mHeight = height; 11 mImage = al_load_bitmap("batonspritesheet.png"); 12 mDir = NONE; 13 mFrame = 0; 14 mCount = 0; 15 16} 17 18void Paddle::update(direction dir) 19{ 20 if (dir == LEFT) 21 { 22 tempX = mX - 8; 23 if (tempX < 0) 24 mX = 0; 25 else 26 mX = tempX; 27 } 28 else if (dir == NONE){} 29 else 30 { 31 tempX = mX + 8; 32 if ((mX + mWidth) >= 1279) 33 mX = (1279 - mWidth); 34 else 35 mX = tempX; 36 } 37} 38 39void Paddle::render() 40{ 41 if (mCount == 5) 42 { 43 mFrame++; 44 mCount = 0; 45 } 46 if (mFrame == 3) 47 mFrame = 0; 48 al_draw_bitmap_region(mImage, (mFrame * 128), 0, 128, 32, mX, mY, 0); 49 mCount++; 50}

That was paddle.cpp. Here's the updated main.cpp code:

#SelectExpand
1#include<allegro5/allegro.h> 2#include<allegro5/allegro_primitives.h> 3#include<allegro5/allegro_image.h> 4#include<allegro5/allegro_audio.h> 5#include<allegro5/allegro_acodec.h> 6#include<iostream> 7#include"globals.h" 8#include"paddle.h" 9using namespace std; 10 11int main() 12{ 13 float gameTime = 0; 14 int frames = 0; 15 int gameFPS = 0; 16 if(!(al_init())) 17 cout << "Couldn't initialize Allegro." << cout; 18 if(!(al_install_joystick())) 19 cout << "Couldn't install joystick." << endl; 20 al_init_image_addon(); 21 al_init_primitives_addon(); 22 ALLEGRO_DISPLAY *display = NULL; 23 display = al_create_display(1280,720); 24 //al_install_audio(); 25 //al_init_acodec_addon(); 26 //al_reserve_samples(1); 27 //ALLEGRO_SAMPLE* sample = NULL; 28 //ALLEGRO_SAMPLE_INSTANCE* instance = NULL; 29 //sample=al_load_sample("The Heat Is On.ogg"); 30 //instance = al_create_sample_instance(sample); 31 //al_attach_sample_instance_to_mixer(instance, al_get_default_mixer()); 32 ALLEGRO_EVENT_QUEUE *event_queue = NULL; 33 event_queue = al_create_event_queue(); 34 if(!event_queue) 35 cout << "al_create_event_queue failed." << endl; 36 ALLEGRO_TIMER *timer; 37 timer = al_create_timer(1.0/60); 38 al_register_event_source(event_queue, al_get_timer_event_source(timer)); 39 gameTime = al_current_time(); 40 al_register_event_source(event_queue, al_get_joystick_event_source()); 41 ALLEGRO_JOYSTICK* joy = al_get_joystick(0); 42 ALLEGRO_JOYSTICK_STATE jst; 43 buttons button; 44 direction dir = NONE; 45 bool render = false; 46 ALLEGRO_BITMAP *image = NULL; 47 48 const int arraySize = 3; 49 bool alive = true; 50 //Paddle paddle; 51 //paddle.initialize(576, 687, 0, 0, 128, 32); 52 al_start_timer(timer); 53 //al_play_sample_instance(instance); 54 while(alive) 55 { 56 ALLEGRO_EVENT ev; 57 al_wait_for_event(event_queue, &ev); 58 al_get_joystick_state(joy, &jst); 59 if (ev.type == ALLEGRO_EVENT_JOYSTICK_AXIS) 60 { 61 if ((jst.stick[2].axis[0] == 0) && (jst.stick[2].axis[1] == 0)) 62 dir = NONE; 63 if ((jst.stick[2].axis[0] == 1) && (jst.stick[2].axis[1] == 0)) 64 dir = RIGHT; 65 if ((jst.stick[2].axis[0] == -1) && (jst.stick[2].axis[1] == 0)) 66 dir = LEFT; 67 } 68 if (ev.type == ALLEGRO_EVENT_JOYSTICK_BUTTON_DOWN) 69 if (jst.button[9]) 70 button = NINE; 71//update 72 else if (ev.type == ALLEGRO_EVENT_TIMER) 73 { 74 render = true; 75 //paddle.update(dir); 76 frames++; 77 if (al_current_time() - gameTime >= 1) 78 { 79 gameTime = al_current_time(); 80 gameFPS = frames; 81 frames = 0; 82 } 83 } 84//render 85 if (render && al_is_event_queue_empty(event_queue)) 86 { 87 //al_set_target_bitmap(al_get_backbuffer(display)); 88 al_clear_to_color(al_map_rgb(0,0,0)); 89 //paddle.Render(); 90 al_flip_display(); 91 } 92 if (jst.button[9]) 93 alive = false; 94 } 95 al_destroy_bitmap(image); 96 al_destroy_timer(timer); 97 al_destroy_event_queue(event_queue); 98 return 0; 99}

Thoughts?::)

SiegeLord
Member #7,827
October 2006
avatar

Hmm... I don't see anything wrong either :/. Have you also tried commenting out just the audio routines?

"For in much wisdom is much grief: and he that increases knowledge increases sorrow."-Ecclesiastes 1:18
[SiegeLord's Abode][Codes]:[DAllegro5]:[RustAllegro]

agonvs
Member #15,917
March 2015

I figured it out. It was an incredibly stupid error. I capitalized Render when it should have been lower case. In the base class I inherited from, Render was uppercase. I changed it. It works now.

SiegeLord
Member #7,827
October 2006
avatar

Phew, you had me worried there.

To prevent this from happening in the future, get into the habit of adding override when you override a method. It's a very useful C++11 feature.

"For in much wisdom is much grief: and he that increases knowledge increases sorrow."-Ecclesiastes 1:18
[SiegeLord's Abode][Codes]:[DAllegro5]:[RustAllegro]

agonvs
Member #15,917
March 2015

Thanks for the tip! 8-)

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