Thread: Allegro slowdown problem!?

Code:

while(1)
{
blit(maplayer[0], screenbuffer, 0, 0, 0, 0 , 640 ,480);

Draw_Sprite(player.posx, player.posy, screenbuffer);

for(i = 0; i < enemy_mem+1; i++)                                                   //draw the other sprites
{
Draw_Sprite(enemy[i].posx, enemy[i].posy, screenbuffer);
}

blit(screenbuffer, screen, 0, 0, 0, 0 , 640 ,480);
}

This is basicly the part i am having issues with... now the game runs at a decent speed if i comment out that first blit, however that blit copys the background onto to screen buffer then the sprites are drawn ontop... but by drawing the background makes the program run at a speed of about 2 frames a second, whats the deal with that!? Is this a timer issue because i currently don't have one set up...

cheers matty

Is your background bitmap the identical pixel format to the screen?

Because if it isn't, there's a hell of a lot of conversion work being done per frame.

You mean like colour depth? and pallete?
the bitmaps I am loading are 24bit, and i have my set_color_depth(24);

Ive just done some test and relized that the tiles are comming out strange colours!? so it has got something to do with that... but im not sure how to fix it

> You mean like colour depth? and pallete?
> the bitmaps I am loading are 24bit, and i have my set_color_depth(24);
Yes, something like that.
Whatever it is, it doesn't sound optimal.

The best-case blit() should be a thinly disguised memcpy(), which should take no time at all.

If you've compiled your allegro from source, then try using the debugger to step into the blit code. See if you can work out which "expensive" choice it is making, then try to address that in your code so it picks a cheaper alternative.

Is the color depth the same as your desktop? That might have an effect on it, although it is just speculation.

Ahh i figgured it out, I was setting my colour depth and my graphics mode in the wrong order at the start of the program.

Thanks for pointing me in the right direction