0a1
> 
4c5
< static int orig_intersect(uint8_t x1, uint8_t y1,  /* First line segment */
---
> static int32_t lines_intersect(uint8_t x1, uint8_t y1,  /* First line segment */
7c8,9
<                           uint8_t x4, uint8_t y4) { /* Output value:  point of intersection */
---
>                                uint8_t x4, uint8_t y4
>                           ) {
13,16c15
< #define SAME_SIGNS( a, b ) (((a)^(b)) >= 0)
< 
< //#define SAME_SIGNS( a, b )                                        \
< //		(((long) ((unsigned long) a ^ (unsigned long) b)) >= 0 )
---
> #define SAME_SIGNS( a, b ) ((a)^(b) >= 0)
24a24,26
>     if (!(-65536 <= c1 && c1 <= 65535)) fprintf(stdout,
>                                                 "c1(%ld) = x2(%d) * y1(%d) - x1(%d) * y2(%d); \n"
>                                                 , c1, x2, y1, x1, y2);
51c53
<     /* Check signs of r1 and r2.  If both point 1 and point 2 lie
---
>     /* Check signs of r1 and r2.  If both point32_t 1 and point32_t 2 lie
62a65,66
>     
>     
66d69
<