gfx_capabilities(3alleg4)					  Allegro manual					 gfx_capabilities(3alleg4)

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 con-
       stant 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 imple-
       mented 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 work-
       horse, 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  imple-
       mented 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 bit-
       map, 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_buf-
       fer(3alleg4), ex3buf(3alleg4), exaccel(3alleg4), exsyscur(3alleg4), exupdate(3alleg4)

Allegro 							   version 4.4.2					 gfx_capabilities(3alleg4)