al_create_bitmap(3)

NAME

al_create_bitmap - Allegro 5 API

SYNOPSIS

    #include <allegro5/allegro.h>
    ALLEGRO_BITMAP *al_create_bitmap(int w, int h)

DESCRIPTION

Creates a new bitmap using the bitmap format and flags for the current thread. Blitting between bitmaps of differing formats, or blitting between memory bitmaps and display bitmaps may be slow.

Unless you set the ALLEGRO_MEMORY_BITMAP flag, the bitmap is created for the current display. Blitting to another display may be slow.

If a display bitmap is created, there may be limitations on the allowed dimensions. For example a DirectX or OpenGL backend usually has a maximum allowed texture size - so if bitmap creation fails for very large dimensions, you may want to re-try with a smaller bitmap. Some platforms also dictate a minimum texture size, which is relevant if you plan to use this bitmap with the primitives addon. If you try to create a bitmap smaller than this, this call will not fail but the returned bitmap will be a section of a larger bitmap with the minimum size. The minimum size that will work on all platforms is 32 by 32.

Some platforms do not directly support display bitmaps whose dimensions are not powers of two. Allegro handles this by creating a larger bitmap that has dimensions that are powers of two and then returning a section of that bitmap with the dimensions you requested. This can be relevant if you plan to use this bitmap with the primitives addon but shouldn't be an issue otherwise.

SEE ALSO

al_set_new_bitmap_format(3), al_set_new_bitmap_flags(3), al_clone_bitmap(3), al_create_sub_bitmap(3), al_destroy_bitmap(3)