maybe

mandel.s

@@ -226,26 +226,31 @@ positive_result:
 
 .proc iter
     ; (cx and cy should be pre-scaled to 6.26 fixed point)
-
     ; zx = 0
-    ; zx_2 = 0
     ; zy = 0
     ; zx_2 = 0
+    ; zy_2 = 0
+    ; zx_zy = 0
 
 loop:
     ; iters++
 
-    ; zx_next = zx_2 + zy_2 + cx
-    ; zy_next = 2 * zx * zy + cy
-    ; (detect overflows to -4 or +4 and break if necessary)
-    ; (re-downshift into zx and zy as 3.13 fixed point; round.)
+    ; 6.26:
+    ; zx = zx_2 + zy_2 + cx
+    ; zy = zx_zy + zx_zy + cy
+    ; round to 6.10.
 
+    ; 12.20:
     ; zx_2 = zx * zx
     ; zy_2 = zy * zy
     ; dist = zx_2 + zy_2
-
     ; if dist >= 4 break, else continue iterating
 
+    ; round zx_2, zy_2, dist to 6.26
+
+    ; if may be in the lake, look for looping output with a small buffer
+    ; as an optimization vs running to max iters
+
 .endproc
 
 .proc start