crsn/examples/life.csn

(
    ; simple GOL with screen and a buffer

    (sc-init 400 400)
    (sc-opt SCREEN_UPSCALE 10)
    (sc-opt SCREEN_AUTO_BLIT 0)
    (def W 40)
    (def H 40)
    (def XMAX 39) ; W-1
    (def YMAX 39) ; H-1
    (def NCELLS 1600) ; W*H
    
    (sc-erase 0) ; all black
    (sym ng g15)
    (mkbf ng NCELLS)
    
    ; one glider
    (bfwr @ng 1 1)
    (bfwr @ng 42 1)
    (bfwr @ng 80 1)
    (bfwr @ng 81 1)
    (bfwr @ng 82 1)
    
    ; another glider
    (bfwr @ng 16 1)
    (bfwr @ng 55 1)
    (bfwr @ng 95 1)
    (bfwr @ng 96 1)
    (bfwr @ng 97 1)
                
    (:loop)
        (sc-poll)
        ; TODO interactivity?
        (call Display)
        (sc-blit)
        (mslp 200)
        (j :loop)
    
    (proc CountNeighbors x y
        (sym xx r4)
        (sym yy r5)
        (sym i r6)
        (sym count r7)     
        
        ; yeah this sucks. it's correct, though
        
        (:a)
            (add yy y -1 (neg? (j :d)))        
            (add xx x -1 (neg? (j :b)))
            (mul i yy W)
            (add i xx)
            (bfrd r0 @ng i)
            (and r0 0xFF (nz? (inc count)))
            
        (:b)
            (mul i yy W)
            (add i x)
            (bfrd r0 @ng i)
            (and r0 0xFF (nz? (inc count)))
        
        (:c)
            (add xx x 1)
            (cmp xx W (ge? (j :d)))
            (mul i yy W)
            (add i xx)
            (bfrd r0 @ng i)
            (and r0 0xFF (nz? (inc count)))
        
        (:d)     
            (add xx x -1 (neg? (j :f)))
            (mul i y W)
            (add i xx)
            (bfrd r0 @ng i)
            (and r0 0xFF (nz? (inc count)))
            
        ; there is no E
            
        (:f)
            (add xx x 1)
            (cmp xx W (ge? (j :g)))
            (mul i y W)
            (add i xx)
            (bfrd r0 @ng i)
            (and r0 0xFF (nz? (inc count)))
                 
        (:g)
            (add yy y 1)        
            (cmp yy H (ge? (j :end)))
            (add xx x -1 (neg? (j :h)))
            (mul i yy W)
            (add i xx)
            (bfrd r0 @ng i)
            (and r0 0xFF (nz? (inc count)))
            
        (:h)
            (add yy y 1)        
            (cmp yy H (ge? (j :end)))
            (mul i yy W)
            (add i x)
            (bfrd r0 @ng i)
            (and r0 0xFF (nz? (inc count)))
        
        (:i)
            (add yy y 1)        
            (cmp yy H (ge? (j :end)))
            (add xx x 1)
            (cmp xx W (ge? (j :end)))
            (mul i yy W)
            (add i xx)
            (bfrd r0 @ng i)
            (and r0 0xFF (nz? (inc count)))
        
        (:end)
        (ret count)
    )
    
    (proc Display
        ; display and calc next gen
        (sym x r4)
        (sym y r5)
        (sym i r6)        
        (:next)
            ; The lower byte contains 0 or 1
            ; the second byte will be filled with the next gen
            
            (bfrd r0 @ng i)
            
            ; Show this gen
            (and r0 0xFF 
                (nz? (sc-wr x y 0xffffff))
                (z? (sc-wr x y 0x000000)))
            
            (call CountNeighbors x y)
            
            ; stay: 2,3
            ; die:  >3
            ; born: 3
            
            (cmp res0 2 
                (eq? (ld8 r0:8 r0)) ; stasis
                (ne?
                    (tst r0 
                        (z? 
                            (cmp res0 3 (eq? (ld8 r0:8 1))) ; birth                
                        ) 
                        (nz? 
                            (cmp res0 3 (eq? (ld8 r0:8 1))) ; stay alive                
                        )
                    )
                )
            )
            
            (bfwr @ng i r0)
            
            (inc i)
            (inc x)
            (cmp x W
                (ne? (j :next)))
            (ld x 0)
            (inc y)
            (cmp y H 
                (eq? (j :next2)))
            (j :next)
                   
        ; Shift all by 8 to the right (generation shift)
        (:next2)
            (dec i)
            (bfrd r0 @ng i)
            (lsr r0 8)
            (bfwr @ng i r0)
            (tst i)
            (j.nz :next2)
            (ret)
    )
)