NAME

       gfx_capabilities - Bitfield describing video hardware capabilities. Allegro game programming library.

SYNOPSIS

       #include <allegro.h>

       extern int gfx_capabilities;

DESCRIPTION

       Bitfield  describing the capabilities of the current graphics driver and video hardware. This may contain
       combination any of the flags:

       GFX_CAN_SCROLL: Indicates that the scroll_screen() function may be used with this driver.

       GFX_CAN_TRIPLE_BUFFER: Indicates that the request_scroll() and poll_scroll() functions may be  used  with
       this driver. If this flag is not set, it is possible that the enable_triple_buffer() function may be able
       to activate it.

       GFX_HW_CURSOR:  Indicates  that  a  hardware mouse cursor is in use. When this flag is set, it is safe to
       draw onto the screen without hiding the mouse pointer first. Note that not every cursor  graphic  can  be
       implemented in hardware: in particular VBE/AF only supports 2-color images up to 32x32 in size, where the
       second  color  is  an  exact  inverse  of  the  first. This means that Allegro may need to switch between
       hardware and software cursors at any point during the execution of your program, so you should not assume
       that this flag will remain constant for long periods of time. It only tells you whether a hardware cursor
       is in use at the current time, and may change whenever you hide/redisplay the pointer.

       GFX_SYSTEM_CURSOR Indicates that the mouse cursor is the default  system  cursor,  not  Allegro's  custom
       cursor.

       GFX_HW_HLINE:  Indicates  that  the  normal opaque version of the hline() function is implemented using a
       hardware accelerator. This will improve the performance not only of hline()  itself,  but  also  of  many
       other functions that use it as a workhorse, for example circlefill(), triangle(), and floodfill().

       GFX_HW_HLINE_XOR:  Indicates  that  the XOR version of the hline() function, and any other functions that
       use it as a workhorse, are implemented using a hardware accelerator.

       GFX_HW_HLINE_SOLID_PATTERN: Indicates that the solid and masked pattern modes of  the  hline()  function,
       and  any  other  functions  that use it as a workhorse, are implemented using a hardware accelerator (see
       note below).

       GFX_HW_HLINE_COPY_PATTERN: Indicates that the copy pattern mode of the hline() function,  and  any  other
       functions that use it as a workhorse, are implemented using a hardware accelerator (see note below).

       GFX_HW_FILL:  Indicates  that  the opaque version of the rectfill() function, the clear_bitmap() routine,
       and clear_to_color(), are implemented using a hardware accelerator.

       GFX_HW_FILL_XOR: Indicates that the XOR version  of  the  rectfill()  function  is  implemented  using  a
       hardware accelerator.

       GFX_HW_FILL_SOLID_PATTERN:  Indicates  that the solid and masked pattern modes of the rectfill() function
       are implemented using a hardware accelerator (see note below).

       GFX_HW_FILL_COPY_PATTERN: Indicates that the copy pattern mode of the rectfill() function is  implemented
       using a hardware accelerator (see note below).

       GFX_HW_LINE: Indicates that the opaque mode line() and vline() functions are implemented using a hardware
       accelerator.

       GFX_HW_LINE_XOR: Indicates that the XOR version of the line() and vline() functions are implemented using
       a hardware accelerator.

       GFX_HW_TRIANGLE:  Indicates  that  the  opaque  mode  triangle() function is implemented using a hardware
       accelerator.

       GFX_HW_TRIANGLE_XOR: Indicates that the XOR version of the triangle() function  is  implemented  using  a
       hardware accelerator.

       GFX_HW_GLYPH:  Indicates  that  monochrome  character expansion (for text drawing) is implemented using a
       hardware accelerator.

       GFX_HW_VRAM_BLIT: Indicates that blitting from one part of the screen to another is implemented  using  a
       hardware  accelerator. If this flag is set, blitting within the video memory will almost certainly be the
       fastest possible way to display an image, so it may be worth storing some of your  more  frequently  used
       graphics in an offscreen portion of the video memory.

       GFX_HW_VRAM_BLIT_MASKED:  Indicates  that  the masked_blit() routine is capable of a hardware accelerated
       copy from one part of video memory to another, and that draw_sprite() will use a hardware copy when given
       a sub-bitmap of the screen or a video memory bitmap as the source image. If this  flag  is  set,  copying
       within  the video memory will almost certainly be the fastest possible way to display an image, so it may
       be worth storing some of your more frequently used sprites in an offscreen portion of the video memory.

       Warning: if this flag is not set, masked_blit() and draw_sprite() will not work correctly when used  with
       a  video memory source image! You must only try to use these functions to copy within the video memory if
       they are supported in hardware.

       GFX_HW_MEM_BLIT: Indicates that blitting from a memory bitmap onto the screen  is  being  accelerated  in
       hardware.

       GFX_HW_MEM_BLIT_MASKED:   Indicates   that  the  masked_blit()  and  draw_sprite()  functions  are  being
       accelerated in hardware when the source image is a memory bitmap and  the  destination  is  the  physical
       screen.

       GFX_HW_SYS_TO_VRAM_BLIT:  Indicates  that  blitting  from  a  system  bitmap  onto  the  screen  is being
       accelerated in hardware. Note that some acceleration may be present even if this flag is not set, because
       system bitmaps can benefit from normal memory to screen blitting as well. This flag will only be  set  if
       system bitmaps have further acceleration above and beyond what is provided by GFX_HW_MEM_BLIT.

       GFX_HW_SYS_TO_VRAM_BLIT_MASKED:  Indicates  that  the masked_blit() and draw_sprite() functions are being
       accelerated in hardware when the source image is a system bitmap and  the  destination  is  the  physical
       screen.  Note  that some acceleration may be present even if this flag is not set, because system bitmaps
       can benefit from normal memory to screen blitting as well. This flag will only be set if  system  bitmaps
       have further acceleration above and beyond what is provided by GFX_HW_MEM_BLIT_MASKED.

       GFX_HW_VRAM_STRETCH_BLIT:  Indicates  that  stretched  blitting  of  video  bitmaps  onto  the  screen is
       implemented using hardware acceleration.

       GFX_HW_SYS_STRETCH_BLIT: Indicates  that  stretched  blitting  of  system  bitmaps  onto  the  screen  is
       implemented using hardware acceleration.

       GFX_HW_VRAM_STRETCH_BLIT_MASKED:  Indicates  that masked stretched blitting (including stretch_sprite) of
       video bitmaps onto the screen is implemented using hardware acceleration.  NOTE: some display drivers may
       show artifacts when this function is used.  If the image does not look correct try  updating  your  video
       drivers.

       GFX_HW_SYS_STRETCH_BLIT_MASKED:  Indicates  that  masked stretched blitting (including stretch_sprite) of
       system bitmaps onto the screen is implemented using hardware acceleration.  NOTE:  some  display  drivers
       may  show  artefact's  when  this function is used.  If the image does not look correct try updating your
       video drivers.

       Note: even if the capabilities information says that patterned drawing is supported by the  hardware,  it
       will  not  be  possible  for  every  size of pattern. VBE/AF only supports patterns up to 8x8 in size, so
       Allegro will fall back on the original non-accelerated drawing routines whenever you use a pattern larger
       than this.

       Note2: these hardware acceleration features will only take effect when you are drawing directly onto  the
       screen  bitmap,  a video memory bitmap, or a sub-bitmap thereof. Accelerated hardware is most useful in a
       page flipping or triple buffering setup, and is unlikely to make any difference to the classic "draw onto
       a memory bitmap, then blit to the screen" system.

SEE ALSO

       screen(3alleg4),    create_video_bitmap(3alleg4),    scroll_screen(3alleg4),     request_scroll(3alleg4),
       show_mouse(3alleg4), enable_triple_buffer(3alleg4), ex3buf(3alleg4), exaccel(3alleg4), exsyscur(3alleg4),
       exupdate(3alleg4)

Allegro                                           version 4.4.3                        gfx_capabilities(3alleg4)