FPS Drop (probably an easy fix)

FPS Drop (probably an easy fix)

VMaximus

Member #15,613

May 2014

I'll preface this by saying I'm pretty new to allegro, and a pretty bad programmer overall. The attatched code has been created expressly to reproduce my issue, and isn't currently in use in any project. I'm using the current stable release (5.0.10). I'm statically linking the -static-mt files with MinGW.

Description of my issue:
When I compile and run the attatched code, the game will run as normal (40fps) for around 4 seconds, and then suddenly drop down to 14fps, and remain like that for the rest of the time the game is running. I'm trying to figure out if this is an issue with my computer, or with the way I am coding... Hopfully someone can help me with this issue.

Neil Roy

Member #2,229

April 2002

You should use

<code>

my code here

</code>

and past examples directly into messages in here in the future, makes life easier = faster replies... here's the code for other's convenience...

#SelectExpand
  1#include <allegro.h>
  2#include <allegro_image.h>
  3#include <allegro_font.h>
  4#include <allegro_ttf.h>
  5
  6int MAXIMAGES = 2; //only 2 images used in this test
  7int MAXFONTS = 1; //font used to draw the fps
  8int ScrW = 800; //display width
  9int ScrH = 640; //display height
 10
 11int main (int argc, char *argv[])
 12{
 13
 14ALLEGRO_DISPLAY *gamedisp;//display
 15ALLEGRO_BITMAP* images [MAXIMAGES];//array of images
 16ALLEGRO_FONT* fonts [MAXFONTS];//same but for fonts
 17
 18al_init();
 19al_init_image_addon();
 20
 21ALLEGRO_PATH *path = al_get_standard_path(ALLEGRO_RESOURCES_PATH);
 22al_set_path_filename(path,"/bin/images/title.png");
 23images[0]=al_load_bitmap(al_path_cstr(path,'/'));
 24al_set_path_filename(path,"/bin/images/byval.png");
 25images[1]=al_load_bitmap(al_path_cstr(path,'/'));
 26
 27gamedisp=al_create_display(ScrW,ScrH);
 28
 29al_init_font_addon();
 30al_init_ttf_addon();
 31al_set_path_filename(path,"/bin/fonts/font.ttf");
 32fonts[0]=al_load_font(al_path_cstr(path,'/'),14,0);
 33
 34float fps=0; //fps is 0 before any frames are rendered
 35double fpstime = al_get_time(); // used to compare frame times and give FPS
 36
 37    while (1)
 38    {
 39  al_clear_to_color(al_map_rgb(0,0,0));
 40    al_draw_bitmap(images[0],259,248,0); //draws image 1 so its centered
 41  al_draw_bitmap(images[1],(ScrW/2),(ScrH/2)+30,0); //draws image 2 so it fits with image 1
 42  al_draw_textf(fonts[0],al_map_rgb(255,255,255),0,0,0,"FPS: %f",fps);//print fps
 43    al_flip_display();//flip
 44
 45    double new_time = al_get_time();
 46    fps = 1.0f/(new_time-fpstime);
 47    fpstime = new_time;//new fps
 48    }
 49
 50
 51
 52return 0;
 53}

---
“I love you too.” - last words of Wanda Roy

Edgar Reynaldo

Major Reynaldo

May 2007

One thing I see is that you are loading your bitmaps before you create your display. Without a display set as the current context you cannot create video bitmaps, so they are being created as memory bitmaps. Load your bitmaps after you create your display and see if that fixes things.

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VMaximus

Member #15,613

May 2014

That ended up doing the trick, thanks a lot.