SA-1 Murmuration Demo — 128 dots in Lissajous sine patterns. More...

#include <snes.h>
#include <snes/sa1.h>

Macros
#define	NBIRDS 128

#define	SA1_STAR_BUF ((volatile u8*)0x3010)

#define	SA1_SYNC ((volatile u8)0x3001)

Functions
int	main (void)

Variables
static const u8	dot_tile []

static const u16	pal []

Detailed Description

SA-1 Murmuration Demo — 128 dots in Lissajous sine patterns.

The SA-1 computes 128 "bird" positions using overlapping Lissajous sine patterns at 10.74 MHz. The main CPU reads positions from I-RAM and displays them as pixel sprites. No assets — generated in code.

Each bird's position is the sum of two sine harmonics per axis, with prime-number phase multipliers creating organic flock spread: X = sin[bird*3 + frame]/2 + sin[bird*7 + frame*2]/4 + 32 Y = sin[bird*5 + frame+64]/2 + sin[bird*11 + frame*3]/4 + 16

What to Observe

128 dots moving in smooth, coordinated flock-like patterns
The pattern resembles a murmuration (starling flock)
All math computed by SA-1 coprocessor at 10.74 MHz

Modules Used: console, sprite, dma, background, input, sa1

Macro Definition Documentation

◆ NBIRDS

#define NBIRDS 128

◆ SA1_STAR_BUF

#define SA1_STAR_BUF ((volatile u8*)0x3010)

◆ SA1_SYNC

#define SA1_SYNC (*(volatile u8*)0x3001)

Function Documentation

◆ main()

int main ( void )

Variable Documentation

◆ dot_tile

const u8 dot_tile[]

static

Initial value:

= {
    
    0x00, 0x00,  
    0x00, 0x00,  
    0x00, 0x00,  
    0x18, 0x18,  
    0x18, 0x18,  
    0x00, 0x00,  
    0x00, 0x00,  
    0x00, 0x00,  
    
    0x00, 0x00,
    0x00, 0x00,
    0x00, 0x00,
    0x18, 0x18,  
    0x18, 0x18,
    0x00, 0x00,
    0x00, 0x00,
    0x00, 0x00,
}

2x2 pixel dot tile (4bpp, 8x8, pixels 3-4 on rows 3-4)

◆ pal

const u16 pal[]