bionic (3) al_set_new_bitmap_flags.3alleg5.gz

NAME

       al_set_new_bitmap_flags - Allegro 5 API

SYNOPSIS

              #include <allegro5/allegro.h>

              void al_set_new_bitmap_flags(int flags)

DESCRIPTION

       Sets the flags to use for newly created bitmaps.  Valid flags are:

       ALLEGRO_MEMORY_BITMAP
              Create  a  bitmap  residing in system memory.  Operations on, and with, memory bitmaps will not be
              hardware accelerated.  However, direct pixel access can be  relatively  quick  compared  to  video
              bitmaps, which depend on the display driver in use.

              Note: Allegro's software rendering routines are currently somewhat unoptimised.

              Note: Combining ALLEGRO_VIDEO_BITMAP and ALLEGRO_MEMORY_BITMAP flags is invalid.

       ALLEGRO_VIDEO_BITMAP
              Creates  a  bitmap  that  resides  in  the  video card memory.  These types of bitmaps receive the
              greatest benefit from hardware acceleration.

              Note: Creating a video bitmap will fail if there is no current  display  or  the  current  display
              driver  cannot  create the bitmap.  The latter will happen if for example the format or dimensions
              are not supported.

              Note: Bitmaps created with this flag will be converted to memory bitmaps when the last display  is
              destroyed.  In most cases it is therefore easier to use the ALLEGRO_CONVERT_BITMAP flag instead.

              Note: Combining ALLEGRO_VIDEO_BITMAP and ALLEGRO_MEMORY_BITMAP flags is invalid.

       ALLEGRO_CONVERT_BITMAP
              This  is  the  default.   It  will  try to create a video bitmap and if that fails create a memory
              bitmap.  Bitmaps created with this flag when there is no active display will be converted to video
              bitmaps  next  time a display is created.  They also will remain video bitmaps if the last display
              is destroyed and then another is created again.  Since 5.1.0.

              Note: You can combine this flag with ALLEGRO_MEMORY_BITMAP or ALLEGRO_VIDEO_BITMAP  to  force  the
              initial type (and fail in the latter case if no video bitmap can be created) - but usually neither
              of those combinations is very useful.

              You can use the display option ALLEGRO_AUTO_CONVERT_BITMAPS to control which displays will try  to
              auto-convert bitmaps.

       ALLEGRO_FORCE_LOCKING
              Does nothing since 5.1.8.  Kept for backwards compatibility only.

       ALLEGRO_NO_PRESERVE_TEXTURE
              Normally,  every  effort  is  taken  to preserve the contents of bitmaps, since some platforms may
              forget them.  This can take extra processing time.  If you know it  doesn't  matter  if  a  bitmap
              keeps  its pixel data, for example when it's a temporary buffer, use this flag to tell Allegro not
              to attempt to preserve its contents.

       ALLEGRO_ALPHA_TEST
              This is a driver hint only.  It tells the graphics driver to do alpha  testing  instead  of  alpha
              blending on bitmaps created with this flag.  Alpha testing is usually faster and preferred if your
              bitmaps have only one level of alpha (0).  This flag is currently not  widely  implemented  (i.e.,
              only for memory bitmaps).

       ALLEGRO_MIN_LINEAR
              When  drawing  a  scaled  down  version  of  the bitmap, use linear filtering.  This usually looks
              better.  You can also combine it with the MIPMAP flag for even better quality.

       ALLEGRO_MAG_LINEAR
              When drawing a magnified version of a bitmap, use linear filtering.  This will cause  the  picture
              to  get  blurry  instead  of  creating a big rectangle for each pixel.  It depends on how you want
              things to look like whether you want to use this or not.

       ALLEGRO_MIPMAP
              This can only be used for bitmaps whose width and height is a power of two.  In that case, it will
              generate  mipmaps  and  use  them when drawing scaled down versions.  For example if the bitmap is
              64x64, then extra bitmaps of sizes 32x32, 16x16, 8x8, 4x4, 2x2 and  1x1  will  be  created  always
              containing a scaled down version of the original.

SEE ALSO

       al_get_new_bitmap_flags(3alleg5), al_get_bitmap_flags(3alleg5)