More than Two Sprites?

[jdrose]

The 2600 only supports two missiles, two sprites (players), playfield and a ball.

 

However, many games seem to suggest that a good number of (non-blinking) sprites can be displayed at the same time. Having trouble doing that myself without inducing serious blink.

 

I am trying to get 15 examples of the same round object to display on the screen at once:

 

Org $FF00

 

SpriteData

.binary %00111100

.binary %01111110

.binary %11111111

.binary %11111111

.binary %11111111

.binary %11111111

.binary %01111110

.binary %00111100

 

I can do it but the blinking is terrible.

 

What are some of the programming concepts that allow more than two sprites to be cleanly displayed at once?

 

Thanks.

[GroovyBee]

You need a sprite multiplexer. If more than two sprites occupy the same scan lines then they need to be alternated between frames.

[+SpiceWare]

You need to reposition and reuse the sprites as the screen is being drawn. Using Stella's fixed debug colors^* you can see how I do this in Frantic:

 

 

 

The maroon sprites are drawn using player 0, the other is player 1. At the bottom the 2 faint maroon ones are drawn using flicker as there's 3 sprites in the same area.

 

 

 

^* toggle it via COMMAND-Comma on Mac or ALT-Comma on Linux/Windows