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/* Reduced from linuxdoom-1.10's p_maputl.c (GPLv2). */
typedef int fixed_t;
enum
{
BOXTOP,
BOXBOTTOM,
BOXLEFT,
BOXRIGHT
};
typedef struct
{
fixed_t x;
fixed_t y;
} vertex_t;
typedef enum
{
ST_HORIZONTAL,
ST_VERTICAL,
ST_POSITIVE,
ST_NEGATIVE
} slopetype_t;
typedef struct line_s
{
vertex_t* v1;
/* [...snip...] */
fixed_t dx;
fixed_t dy;
/* [...snip...] */
slopetype_t slopetype;
/* [...snip...] */
} line_t;
int P_PointOnLineSide (fixed_t x, fixed_t y, line_t* line);
int
P_BoxOnLineSide
( fixed_t* tmbox,
line_t* ld )
{
int p1;
int p2;
switch (ld->slopetype)
{
case ST_HORIZONTAL:
p1 = tmbox[BOXTOP] > ld->v1->y;
p2 = tmbox[BOXBOTTOM] > ld->v1->y;
if (ld->dx < 0)
{
p1 ^= 1;
p2 ^= 1;
}
break;
case ST_VERTICAL:
p1 = tmbox[BOXRIGHT] < ld->v1->x;
p2 = tmbox[BOXLEFT] < ld->v1->x;
if (ld->dy < 0)
{
p1 ^= 1;
p2 ^= 1;
}
break;
case ST_POSITIVE:
p1 = P_PointOnLineSide (tmbox[BOXLEFT], tmbox[BOXTOP], ld);
p2 = P_PointOnLineSide (tmbox[BOXRIGHT], tmbox[BOXBOTTOM], ld);
break;
case ST_NEGATIVE:
p1 = P_PointOnLineSide (tmbox[BOXRIGHT], tmbox[BOXTOP], ld);
p2 = P_PointOnLineSide (tmbox[BOXLEFT], tmbox[BOXBOTTOM], ld);
break;
}
if (p1 == p2) /* { dg-bogus "use of uninitialized value" } */
return p1; /* { dg-bogus "use of uninitialized value" } */
return -1;
}
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