Heretic/Doom alpha sight checks with fixes by RH

Makefile

@@ -71,6 +71,7 @@ OBJS = \
 	p_base.o \
 	p_user.o \
 	p_sight.o \
+	p_sight2.o \
 	p_shoot.o \
 	p_move.o \
 	p_change.o \

p_local.h

@@ -329,6 +329,51 @@ typedef struct
 
 void P_SlideMove (pslidemove_t *sm);
 
+
+
+/*
+===============================================================================
+
+							P_SIGHT
+
+===============================================================================
+*/
+
+#define MAXINTERCEPTS 32
+
+// CALICO: removed type punning by bringing back intercept_t
+typedef struct
+{
+    union
+    {
+        mobj_t* mo;
+        line_t* line;
+    } d;
+    fixed_t frac;
+	sector_t *front, *back; // a line if front != NULL
+} intercept_t;
+
+typedef struct 
+{
+   int16_t x, y, dx, dy;
+} i16divline_t;
+
+typedef struct
+{
+   int numintercepts;
+   intercept_t intercepts[MAXINTERCEPTS];
+
+   fixed_t sightzstart;           // eye z of looker
+   fixed_t topslope, bottomslope; // slopes to top and bottom of target
+
+   i16divline_t strace; // from t1 to t2
+   fixed_t t2x, t2y;
+} sightWork_t;
+
+boolean PTR_SightTraverse(sightWork_t *sw, intercept_t * in);
+boolean PS_SightBlockLinesIterator(sightWork_t *sw, int x, int y);
+boolean PS_SightPathTraverse(sightWork_t *sw);
+
 #endif	/* __P_LOCAL__ */
 
 

p_shoot.c

@@ -35,18 +35,6 @@
 // tracing.  If no thing is targeted along the entire range, the first line
 // that blocks the midpoint of the shootdiv will be hit.
 
-// CALICO: removed type punning by bringing back intercept_t
-typedef struct intercept_s
-{
-    union ptr_u
-    {
-        mobj_t* mo;
-        line_t* line;
-    } d;
-    fixed_t frac;
-    boolean isaline;
-} intercept_t;
-
 typedef struct
 {
    mobj_t    *shooter;
@@ -256,7 +244,7 @@ static boolean PA_ShootThing(shootWork_t *sw, mobj_t *th, fixed_t interceptfrac)
 //
 // Process an intercept
 //
-#define COPY_INTERCEPT(dst,src) do { (dst)->d.line = (src)->d.line, (dst)->frac = (src)->frac, (dst)->isaline = (src)->isaline; } while(0)
+#define COPY_INTERCEPT(dst,src) do { (dst)->d.line = (src)->d.line, (dst)->frac = (src)->frac, (dst)->front = (src)->front; } while(0)
 static boolean PA_DoIntercept(shootWork_t *sw, intercept_t *in)
 {
    intercept_t temp;
@@ -271,7 +259,7 @@ static boolean PA_DoIntercept(shootWork_t *sw, intercept_t *in)
    if(in->frac == 0 || in->frac >= FRACUNIT)
       return true;
 
-   if(in->isaline)
+   if(in->front)
       return PA_ShootLine(sw, in->d.line, in->frac);
    return PA_ShootThing(sw, in->d.mo, in->frac);
 }
@@ -320,7 +308,7 @@ static boolean PA_CrossSubsector(shootWork_t *sw, int bspnum)
          continue;
 
       in.d.mo    = thing;
-      in.isaline = false;
+      in.front   = NULL;
       in.frac    = frac;
 
       if(!PA_DoIntercept(sw, &in))
@@ -353,7 +341,7 @@ static boolean PA_CrossSubsector(shootWork_t *sw, int bspnum)
          continue;
 
       in.d.line  = line;
-      in.isaline = true;
+      in.front   = (void*)1;
       in.frac    = frac;
 
       if(!PA_DoIntercept(sw, &in))
@@ -436,7 +424,7 @@ void P_Shoot2(lineattack_t *la)
    // cross everything
    sw.old_intercept.d.line  = NULL;
    sw.old_intercept.frac    = 0;
-   sw.old_intercept.isaline = false;
+   sw.old_intercept.front   = NULL;
 
    PA_CrossBSPNode(&sw, numnodes - 1);
 
@@ -445,7 +433,7 @@ void P_Shoot2(lineattack_t *la)
    {
       intercept_t in;
       in.d.mo    = NULL;
-      in.isaline = false;
+      in.front   = NULL;
       in.frac    = FRACUNIT;
       PA_DoIntercept(&sw, &in);
    }