bm875 Sprites - Extension

Sheet


 

bm898         sprite identity

bm899         move of all sprites in X direction

bm900         move of all sprites in Y direction

 

The move of all sprites commands induce an immediate move of the sprites by a specified increment. This increment may be both a positive and a negative number. During the move of all sprites the starting position and destination position of the sprite motion are readjusted independently on the sprite motion speed. During the move of all sprites the sprites keep on moving in the original direction, being shifted only by the increment specified. In practice, the result of this operation appears as if the window for viewing the sprites would be shifted.

 

bm901         left edge of sprites window

bm902         lower edge of sprites window

bm903         right edge of sprites window

bm904         upper edge of sprites window

 

The "sprites window" defines that portion of the window, in which the sprites are visible. As a default the sprites are visible in the entire window. By redefining the sprites window borders that sheet portion can be determined, in which the sprites are supposed to be visible. This feature is important above all in the case, when a cutout of a rather large sheet is displayed in the window, and if program commanding buttons, too, should be included in the window.