[PATCH] Allow up to 65520 clipnodes
The BSP file format's original design limits us to having 32767 clipnodes by
having the offsets stored as 16-bit signed values. Negative values are to
signify leaf nodes and refer to the CONTENTS_xxx flags defined in bspfile.h.
Since only a handful of values are required for the CONTENTS_xxx flags, we can
make use of all the space on the negative side be being a bit more careful
about how we handle these offsets.
Essentially, we can treat the offset as unsigned and instead of checking for a
value < 0 to signify contents, we check that the value large enough to be
contents. This is binary compatible with existing maps.
I added a helper function clipnode_child() to extract a 32-bit signed integer
value from the dclipnode_t structure. If the child index is large enough to be
a contents flag, we return the negative value. Otherwise, we return the index
between 0 and 65520 (0xfff0).
Hopefully my attempt at updating the asm code looks okay - this part of the
patch is the result of a 1-day crash course in x86 asm.
diff -urN a/NQ/world.c head/NQ/world.c
--- a/NQ/world.c 2005-01-29 11:16:40.000000000 +1030
+++ head/NQ/world.c 2006-03-09 17:56:23.000000000 +1030
@@ -482,9 +482,12 @@
dclipnode_t *node;
mplane_t *plane;
- while (num >= 0) {
+ if (num < 0)
+ return num;
+
+ while (num < 0xfff0) {
if (num < hull->firstclipnode || num > hull->lastclipnode)
- Sys_Error("%s: bad node number", __func__);
+ Sys_Error("%s: bad node number (%i)", __func__, num);
node = hull->clipnodes + num;
plane = hull->planes + node->planenum;
@@ -494,12 +497,13 @@
else
d = DotProduct(plane->normal, p) - plane->dist;
if (d < 0)
- num = node->children[1];
+ num = *(uint16_t *)&node->children[1];
else
- num = node->children[0];
+ num = *(uint16_t *)&node->children[0];
}
- return num;
+ /* Convert back to negative contents */
+ return num - 0x10000;
}
#endif // !id386
@@ -614,19 +618,23 @@
}
#if 1
- if (t1 >= 0 && t2 >= 0)
- return SV_RecursiveHullCheck(hull, node->children[0], p1f, p2f, p1,
- p2, trace);
- if (t1 < 0 && t2 < 0)
- return SV_RecursiveHullCheck(hull, node->children[1], p1f, p2f, p1,
- p2, trace);
+ if (t1 >= 0 && t2 >= 0) {
+ i = clipnode_child(node, 0);
+ return SV_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
+ if (t1 < 0 && t2 < 0) {
+ i = clipnode_child(node, 1);
+ return SV_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
#else
- if ((t1 >= DIST_EPSILON && t2 >= DIST_EPSILON) || (t2 > t1 && t1 >= 0))
- return SV_RecursiveHullCheck(hull, node->children[0], p1f, p2f, p1,
- p2, trace);
- if ((t1 <= -DIST_EPSILON && t2 <= -DIST_EPSILON) || (t2 < t1 && t1 <= 0))
- return SV_RecursiveHullCheck(hull, node->children[1], p1f, p2f, p1,
- p2, trace);
+ if ((t1 >= DIST_EPSILON && t2 >= DIST_EPSILON) || (t2 > t1 && t1 >= 0)) {
+ i = clipnode_child(node, 0);
+ return SV_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
+ if ((t1 <= -DIST_EPSILON && t2 <= -DIST_EPSILON) || (t2 < t1 && t1 <= 0)) {
+ i = clipnode_child(node, 1);
+ return SV_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
#endif
// put the crosspoint DIST_EPSILON pixels on the near side
@@ -646,23 +654,21 @@
side = (t1 < 0);
// move up to the node
- if (!SV_RecursiveHullCheck
- (hull, node->children[side], p1f, midf, p1, mid, trace))
+ i = clipnode_child(node, side);
+ if (!SV_RecursiveHullCheck(hull, i, p1f, midf, p1, mid, trace))
return false;
#ifdef PARANOID
- if (SV_HullPointContents(sv_hullmodel, mid, node->children[side])
- == CONTENTS_SOLID) {
+ if (SV_HullPointContents(sv_hullmodel, mid, i) == CONTENTS_SOLID) {
Con_Printf("mid PointInHullSolid\n");
return false;
}
#endif
- if (SV_HullPointContents(hull, node->children[side ^ 1], mid)
- != CONTENTS_SOLID)
-// go past the node
- return SV_RecursiveHullCheck(hull, node->children[side ^ 1], midf,
- p2f, mid, p2, trace);
+ i = clipnode_child(node, side ^ 1);
+ if (SV_HullPointContents(hull, i, mid) != CONTENTS_SOLID)
+ /* go past the node */
+ return SV_RecursiveHullCheck(hull, i, midf, p2f, mid, p2, trace);
if (trace->allsolid)
return false; // never got out of the solid area
diff -urN a/NQ/worlda.S head/NQ/worlda.S
--- a/NQ/worlda.S 2004-08-04 21:21:25.000000000 +0930
+++ head/NQ/worlda.S 2006-03-09 19:25:51.000000000 +1030
@@ -71,7 +71,7 @@
// %edi: hull->clipnodes
// %ebp: hull->planes
-// while (num >= 0)
+// while (num < 0xfff0)
// {
Lhloop:
@@ -111,8 +111,9 @@
fsubrs (%edx,%ebx,4)
Lsub:
- sarl $16,%eax
- sarl $16,%esi
+// Note: treating children as unsigned
+ shrl $16,%eax
+ shrl $16,%esi
// if (d < 0)
// num = node->children[1];
@@ -125,7 +126,13 @@
xorl $0xFFFFFFFF,%ecx
andl %ecx,%eax
orl %esi,%eax
- jns Lhloop
+
+ cmpl $0x0000FFF0,%eax
+ jb Lhloop
+
+// Re-interpret sign bit and extend
+ shll $16,%eax
+ sarl $16,%eax
// return num;
Lhdone:
diff -urN a/QW/common/pmovetst.c head/QW/common/pmovetst.c
--- a/QW/common/pmovetst.c 2004-07-25 15:59:58.000000000 +0930
+++ head/QW/common/pmovetst.c 2006-03-09 17:59:40.000000000 +1030
@@ -115,7 +115,10 @@
dclipnode_t *node;
mplane_t *plane;
- while (num >= 0) {
+ if (num < 0)
+ return num;
+
+ while (num < 0xfff0) {
if (num < hull->firstclipnode || num > hull->lastclipnode)
Sys_Error("PM_HullPointContents: bad node number");
@@ -127,12 +130,13 @@
else
d = DotProduct(plane->normal, p) - plane->dist;
if (d < 0)
- num = node->children[1];
+ num = *(uint16_t *)&node->children[1];
else
- num = node->children[0];
+ num = *(uint16_t *)&node->children[0];
}
- return num;
+ /* Convert back to negative contents */
+ return num - 0x10000;
}
/*
@@ -151,10 +155,12 @@
int num;
hull = &pmove.physents[0].model->hulls[0];
-
num = hull->firstclipnode;
- while (num >= 0) {
+ if (num < 0)
+ return num;
+
+ while (num < 0xfff0) {
if (num < hull->firstclipnode || num > hull->lastclipnode)
Sys_Error("PM_HullPointContents: bad node number");
@@ -166,12 +172,13 @@
else
d = DotProduct(plane->normal, p) - plane->dist;
if (d < 0)
- num = node->children[1];
+ num = *(uint16_t *)&node->children[1];
else
- num = node->children[0];
+ num = *(uint16_t *)&node->children[0];
}
- return num;
+ /* Convert back to negative contents */
+ return num - 0x10000;
}
/*
@@ -235,19 +242,23 @@
}
#if 1
- if (t1 >= 0 && t2 >= 0)
- return PM_RecursiveHullCheck(hull, node->children[0], p1f, p2f, p1,
- p2, trace);
- if (t1 < 0 && t2 < 0)
- return PM_RecursiveHullCheck(hull, node->children[1], p1f, p2f, p1,
- p2, trace);
+ if (t1 >= 0 && t2 >= 0) {
+ i = clipnode_child(node, 0);
+ return PM_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
+ if (t1 < 0 && t2 < 0) {
+ i = clipnode_child(node, 1);
+ return PM_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
#else
- if ((t1 >= DIST_EPSILON && t2 >= DIST_EPSILON) || (t2 > t1 && t1 >= 0))
- return PM_RecursiveHullCheck(hull, node->children[0], p1f, p2f, p1,
- p2, trace);
- if ((t1 <= -DIST_EPSILON && t2 <= -DIST_EPSILON) || (t2 < t1 && t1 <= 0))
- return PM_RecursiveHullCheck(hull, node->children[1], p1f, p2f, p1,
- p2, trace);
+ if ((t1 >= DIST_EPSILON && t2 >= DIST_EPSILON) || (t2 > t1 && t1 >= 0)) {
+ i = clipnode_child(node, 0);
+ return PM_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
+ if ((t1 <= -DIST_EPSILON && t2 <= -DIST_EPSILON) || (t2 < t1 && t1 <= 0)) {
+ i = clipnode_child(node, 1);
+ return PM_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
#endif
// put the crosspoint DIST_EPSILON pixels on the near side
@@ -267,23 +278,21 @@
side = (t1 < 0);
// move up to the node
- if (!PM_RecursiveHullCheck
- (hull, node->children[side], p1f, midf, p1, mid, trace))
+ i = clipnode_child(node, side);
+ if (!PM_RecursiveHullCheck(hull, i, p1f, midf, p1, mid, trace))
return false;
#ifdef PARANOID
- if (PM_HullPointContents(pm_hullmodel, mid, node->children[side])
- == CONTENTS_SOLID) {
+ if (PM_HullPointContents(pm_hullmodel, i, mid) == CONTENTS_SOLID) {
Con_Printf("mid PointInHullSolid\n");
return false;
}
#endif
- if (PM_HullPointContents(hull, node->children[side ^ 1], mid)
- != CONTENTS_SOLID)
-// go past the node
- return PM_RecursiveHullCheck(hull, node->children[side ^ 1], midf,
- p2f, mid, p2, trace);
+ i = clipnode_child(node, side ^ 1);
+ if (PM_HullPointContents(hull, i, mid) != CONTENTS_SOLID)
+ /* go past the node */
+ return PM_RecursiveHullCheck(hull, i, midf, p2f, mid, p2, trace);
if (trace->allsolid)
return false; // never got out of the solid area
diff -urN a/QW/server/world.c head/QW/server/world.c
--- a/QW/server/world.c 2004-08-01 02:34:40.000000000 +0930
+++ head/QW/server/world.c 2006-03-09 17:56:16.000000000 +1030
@@ -467,9 +467,12 @@
dclipnode_t *node;
mplane_t *plane;
- while (num >= 0) {
+ if (num < 0)
+ return num;
+
+ while (num < 0xfff0) {
if (num < hull->firstclipnode || num > hull->lastclipnode)
- SV_Error("SV_HullPointContents: bad node number");
+ SV_Error("%s: bad node number (%i)", __func__, num);
node = hull->clipnodes + num;
plane = hull->planes + node->planenum;
@@ -479,12 +482,13 @@
else
d = DotProduct(plane->normal, p) - plane->dist;
if (d < 0)
- num = node->children[1];
+ num = *(uint16_t *)&node->children[1];
else
- num = node->children[0];
+ num = *(uint16_t *)&node->children[0];
}
- return num;
+ /* Convert back to negative contents */
+ return num - 0x10000;
}
#endif // !id386
@@ -588,19 +592,23 @@
}
#if 1
- if (t1 >= 0 && t2 >= 0)
- return SV_RecursiveHullCheck(hull, node->children[0], p1f, p2f, p1,
- p2, trace);
- if (t1 < 0 && t2 < 0)
- return SV_RecursiveHullCheck(hull, node->children[1], p1f, p2f, p1,
- p2, trace);
+ if (t1 >= 0 && t2 >= 0) {
+ i = clipnode_child(node, 0);
+ return SV_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
+ if (t1 < 0 && t2 < 0) {
+ i = clipnode_child(node, 1);
+ return SV_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
#else
- if ((t1 >= DIST_EPSILON && t2 >= DIST_EPSILON) || (t2 > t1 && t1 >= 0))
- return SV_RecursiveHullCheck(hull, node->children[0], p1f, p2f, p1,
- p2, trace);
- if ((t1 <= -DIST_EPSILON && t2 <= -DIST_EPSILON) || (t2 < t1 && t1 <= 0))
- return SV_RecursiveHullCheck(hull, node->children[1], p1f, p2f, p1,
- p2, trace);
+ if ((t1 >= DIST_EPSILON && t2 >= DIST_EPSILON) || (t2 > t1 && t1 >= 0)) {
+ i = clipnode_child(node, 0);
+ return SV_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
+ if ((t1 <= -DIST_EPSILON && t2 <= -DIST_EPSILON) || (t2 < t1 && t1 <= 0)) {
+ i = clipnode_child(node, 1);
+ return SV_RecursiveHullCheck(hull, i, p1f, p2f, p1, p2, trace);
+ }
#endif
// put the crosspoint DIST_EPSILON pixels on the near side
@@ -620,23 +628,21 @@
side = (t1 < 0);
// move up to the node
- if (!SV_RecursiveHullCheck
- (hull, node->children[side], p1f, midf, p1, mid, trace))
+ i = clipnode_child(node, side);
+ if (!SV_RecursiveHullCheck(hull, i, p1f, midf, p1, mid, trace))
return false;
#ifdef PARANOID
- if (SV_HullPointContents(sv_hullmodel, mid, node->children[side])
- == CONTENTS_SOLID) {
+ if (SV_HullPointContents(sv_hullmodel, mid, i) == CONTENTS_SOLID) {
Con_Printf("mid PointInHullSolid\n");
return false;
}
#endif
- if (SV_HullPointContents(hull, node->children[side ^ 1], mid)
- != CONTENTS_SOLID)
-// go past the node
- return SV_RecursiveHullCheck(hull, node->children[side ^ 1], midf,
- p2f, mid, p2, trace);
+ i = clipnode_child(node, side ^ 1);
+ if (SV_HullPointContents(hull, i, mid) != CONTENTS_SOLID)
+ /* go past the node */
+ return SV_RecursiveHullCheck(hull, i, midf, p2f, mid, p2, trace);
if (trace->allsolid)
return false; // never got out of the solid area
diff -urN a/include/bspfile.h head/include/bspfile.h
--- a/include/bspfile.h 2004-07-25 16:00:01.000000000 +0930
+++ head/include/bspfile.h 2006-03-09 16:50:43.000000000 +1030
@@ -157,11 +157,30 @@
uint16_t numfaces; // counting both sides
} dnode_t;
+/*
+ * Note that children are interpreted as unsigned values now, so that we can
+ * handle > 32k clipnodes. Values > 0xFFF0 can be assumed to be CONTENTS
+ * values and can be read as the signed value to be compatible with the above
+ * (i.e. simply subtract 65536).
+ *
+ * I should probably change the type here to uint16_t eventaully and fix up
+ * the rest of the code.
+ */
typedef struct {
int32_t planenum;
- int16_t children[2]; // negative numbers are contents
+ int16_t children[2];
} dclipnode_t;
+static inline int
+clipnode_child(dclipnode_t *node, int child)
+{
+ int ret = *(uint16_t *)&node->children[child];
+ if (ret > 0xfff0)
+ ret -= 0x10000;
+
+ return ret;
+}
+
typedef struct texinfo_s {
float vecs[2][4]; // [s/t][xyz offset]