About This Cliapter; Forming A Sprite; Screen Position - Commodore Amiga Hardware Reference Manual

Sprite DMA channels can be reused several times within the same display field. Thus,
you are not limited to having only eight sprites on the screen at the same time.
ABOUT THIS CHAPTER
This chapter discusses the following topics:
o Defining the size, shape, color, and screen position of sprites.
o Displaying and moving sprites.
o Combining sprites for more complex Images, additional width, or additional
colors.
o Reusing a sprite DMA channel multiple times within a display field to create
more than eight sprites on the screen at one time.
Forming a Sprite
To form a sprite, you must first define it and then create a formal data structure in
memory. You define a sprite by specifying its characteristics:
o On-screen wid th of up to 16 pixels.
o Unlimited height.
o Any shape.
o A combination of three colors, plus transparent.
o Any position on the screen.
'SCREEN POSITION
A sprite's screen position is defined as a set of X,Y coordinates. Position (0,0), where
X
=
0 and Y
=
0, is the upper left-hand corner of the display. You define a sprite's
location by specifying the coordinates of its upper left-hand pixel. Sprite position is
always defined as though the display modes were low-resolution and non-interlaced. The
X,Y coordinate system and definition of a sprite's position are graphically represented in
92 Sprite Hardware