Draws a copy of the sprite bitmap onto the destination bitmap at the
specified position. This is almost the same as blit(sprite, bmp, 0, 0, x,
y, sprite->w, sprite->h), but it uses a masked drawing mode where
transparent pixels are skipped, so the background image will show through
the masked parts of the sprite. Transparent pixels are marked by a zero
in 256-color modes or bright pink for truecolor data (maximum red and
blue, zero green). Example:
BITMAP *spaceship;
...
draw_sprite(screen, spaceship, x, y);
If the GFX_HW_VRAM_BLIT_MASKED bit in the gfx_capabilities flag is set,
the current driver supports hardware accelerated sprite drawing when the
source image is a video memory bitmap or a sub-bitmap of the screen. This
is extremely fast, so when this flag is set it may be worth storing some
of your more frequently used sprites in an offscreen portion of the video
memory.
Warning: if the hardware acceleration flag is not set, draw_sprite() will
not work correctly when used with a sprite image in system or video
memory so the latter must be a memory bitmap.
Although generally not supporting graphics of mixed color depths, as a
special case this function can be used to draw 256-color source images
onto truecolor destination bitmaps, so you can use palette effects on
specific sprites within a truecolor program.
