From 5b375d0924147214e176402a04dafa7daeee0faf Mon Sep 17 00:00:00 2001
From: Kawe Mazidjatari <48657826+Mauler125@users.noreply.github.com>
Date: Sat, 10 Aug 2024 01:45:48 +0200
Subject: [PATCH] Recast: perform raycast tests before establishing traverse
 link

This results in very clean generation of jump links. Results are very close to Titanfall 2 single player navmeshes.
---
 src/naveditor/Editor.cpp | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/naveditor/Editor.cpp b/src/naveditor/Editor.cpp
index 2ac9fe96..27ac197b 100644
--- a/src/naveditor/Editor.cpp
+++ b/src/naveditor/Editor.cpp
@@ -576,6 +576,28 @@ void Editor::connectTileTraverseLinks(dtMeshTile* const tile)
 					if (rdIntersectSegSeg2D(startPolySpos, startPolyEpos, endPolySpos, endPolyEpos, t, s))
 						continue;
 
+					float raycastStartPos[3];
+					float raycastEndPos[3];
+
+					float hitTime;
+
+					rdVcopy(raycastStartPos, startPolyEdgeMid);
+					rdVcopy(raycastEndPos, endPolyEdgeMid);
+
+					// note(amos): offset the ray heights so we don't clip into
+					// ledges. Realistically, we need at least the height of the
+					// agent anyways to be able to properly perform a jump
+					// without clipping into geometry.
+					raycastStartPos[2] += m_agentHeight;
+					raycastEndPos[2] += m_agentHeight;
+
+					// note(amos): perform 2 raycasts as we have to take the
+					// face normal into account. Path must be clear from both
+					// directions.
+					if (m_geom->raycastMesh(raycastStartPos, raycastEndPos, hitTime) ||
+						m_geom->raycastMesh(raycastEndPos, raycastStartPos, hitTime))
+						continue;
+
 					const unsigned char distance = dtCalcLinkDistance(startPolyEdgeMid, endPolyEdgeMid);
 					const float slopeAngle = rdMathFabsf(rdCalcSlopeAngle(startPolyEdgeMid, endPolyEdgeMid));
 					const bool samePolyGroup = startPoly->groupId == endPoly->groupId;