main_pan.scale_x = screen_size.x / bmap_width(main_tga);
 main_pan.scale_y = screen_size.y / bmap_height(main_tga);

// Scale bmap
var sx = screen_size.x / bmap_width(main_tga);
var sy = screen_size.y / bmap_height(main_tga);
      
var scale = minv(sx, sy);
main_pan.scale_x = main_pan.scale_y = scale;
main_pan.pos_x = (screen_size.x - (bmap_width(main_tga) * scale)) * 0.5;