double width = (1024 / cards) / 100.0;
int i;
for( i=0; i < cards; i++ )
{
// ...
str_cat_num(cardName, "%i", cardNumbers[i]);
str_cat(cardName, ".png");
deckImages[i] = bmap_create(cardName);
deckPanels[i] = pan_create("", 1);
deckPanels[i].bmap = deckImages[i];
deckPanels[i].size_x = screen_size.x * width;
deckPanels[i].pos_x = i*(1024/cards);
deckPanels[i].pos_y = screen_size.y - bmap_height(deckImages[i]);
set(deckPanels[i], SHOW | OUTLINE);