From 66dffef936e084b5f3f94b43198f69ab9d5b60aa Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Wed, 7 Dec 2011 15:31:33 +0900
Subject: [PATCH] Get trace_to_leaf working a little better.

I think the recursion decision needs a little more work, but this gets the
current tests working (though there's still a failure due to fp math).
---
 libs/models/test/testclip.c |  7 +++++--
 libs/models/trace.c         | 20 ++++++++++++++------
 2 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/libs/models/test/testclip.c b/libs/models/test/testclip.c
index 4b560c2f8..d7d4db31d 100644
--- a/libs/models/test/testclip.c
+++ b/libs/models/test/testclip.c
@@ -44,8 +44,9 @@ typedef struct {
 	}           expect;
 } test_t;
 
-box_t point = { {0, 0, 0} };
-box_t box =   { {8, 8, 8} };
+box_t point =  { { 0,  0,  0} };
+box_t box =    { { 8,  8,  8} };
+box_t bigbox = { { 8,  8, 24} };
 box_t player = { {16, 16, 28} };
 
 test_t tests[] = {
@@ -195,6 +196,8 @@ test_t tests[] = {
 		{ 54, 0, -16}, { 54, 0, 56}, { 0.5, 0, 1, 1, 0, 14}},
 	{"Box,  cave", &box, &hull_cave,
 		{ 54, 0,  12}, { 54, 0, 28}, { 0.5, 0, 0, 1, 0, 14}},
+	{"Big Box,  cave. start solid", &bigbox, &hull_cave,
+		{ 54, 0,   0}, { 54, 0, 8}, { 0.5, 0, 1, 1, 0, 14}},
 };
 #define num_tests (sizeof (tests) / sizeof (tests[0]))
 
diff --git a/libs/models/trace.c b/libs/models/trace.c
index a3e66dc21..398dc9857 100644
--- a/libs/models/trace.c
+++ b/libs/models/trace.c
@@ -667,10 +667,10 @@ trace_to_leaf (const hull_t *hull, clipleaf_t *leaf,
 			   const trace_t *trace, const trace_state_t *state, vec3_t stop)
 {
 	clipport_t *portal;
+	plane_t    *plane;
 	int         side;
 	vec_t       frac = 1;
-	plane_t    *plane;
-	vec_t       f;
+	vec_t       t1, t2, offset, f;
 	qboolean    clipped = false;
 	clipleaf_t *l;
 	trace_state_t lstate = *state;
@@ -684,13 +684,21 @@ trace_to_leaf (const hull_t *hull, clipleaf_t *leaf,
 		if (!trace_hits_portal (hull, trace, portal,
 								state->start_point, state->dist))
 			continue;
-		lstate.split_plane = plane;
-		f = box_portal_dist (hull, portal, &lstate);
 		l = portal->leafs[side^1];
+		if (l->test_count == test_count)
+			continue;
+		t1 = PlaneDiff (state->start_point, plane);
+		t2 = PlaneDiff (state->end_point, plane);
+		offset = calc_offset (trace, plane);
+		f = (t1 + (t1 < 0 ? offset : -offset)) / (t1 - t2);
 		if (f < 0 && l->contents != CONTENTS_SOLID
-			&& l->test_count != test_count)
+			&& l->test_count != test_count) {
 			f = trace_to_leaf (hull, l, trace, state, 0);
-		if (f > 0) {
+		} else {
+			lstate.split_plane = plane;
+			f = box_portal_dist (hull, portal, &lstate);
+		}
+		if (f >= 0) {
 			clipped = true;
 			if (f < frac)
 				frac = f;