From 094ef39d5f1a9d017cc454dd178fd534c1e8d7ce Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Wed, 26 Dec 2018 14:26:57 +0100
Subject: [PATCH] - dynamically update polyobj lines

---
 src/hwrenderer/dynlights/hw_aabbtree.cpp  | 78 +++++++++++++++++++++++
 src/hwrenderer/dynlights/hw_aabbtree.h    |  6 ++
 src/hwrenderer/dynlights/hw_shadowmap.cpp |  8 ++-
 3 files changed, 89 insertions(+), 3 deletions(-)

diff --git a/src/hwrenderer/dynlights/hw_aabbtree.cpp b/src/hwrenderer/dynlights/hw_aabbtree.cpp
index 3d2365bf94..a3b68109c9 100644
--- a/src/hwrenderer/dynlights/hw_aabbtree.cpp
+++ b/src/hwrenderer/dynlights/hw_aabbtree.cpp
@@ -44,6 +44,8 @@ LevelAABBTree::LevelAABBTree()
 	{
 		if (!level.lines[i].backsector)
 		{
+			if (level.lines[i].sidedef[0] && (level.lines[i].sidedef[0]->Flags & WALLF_POLYOBJ))
+				polylines.Push(i);
 			line_elements.Push(i);
 		}
 	}
@@ -69,6 +71,82 @@ LevelAABBTree::LevelAABBTree()
 	}
 }
 
+bool LevelAABBTree::Update()
+{
+	bool modified = false;
+	for (unsigned int ii = 0; ii < polylines.Size(); ii++)
+	{
+		int i = polylines[ii];
+		const auto &line = level.lines[i];
+
+		AABBTreeLine treeline;
+		treeline.x = (float)line.v1->fX();
+		treeline.y = (float)line.v1->fY();
+		treeline.dx = (float)line.v2->fX() - treeline.x;
+		treeline.dy = (float)line.v2->fY() - treeline.y;
+
+		if (memcmp(&lines[i], &treeline, sizeof(AABBTreeLine)))
+		{
+			TArray<int> path = FindNodePath(i, nodes.Size() - 1);
+			if (path.Size())
+			{
+				float x1 = (float)level.lines[i].v1->fX();
+				float y1 = (float)level.lines[i].v1->fY();
+				float x2 = (float)level.lines[i].v2->fX();
+				float y2 = (float)level.lines[i].v2->fY();
+
+				int nodeIndex = path[0];
+				nodes[nodeIndex].aabb_left = MIN(x1, x2);
+				nodes[nodeIndex].aabb_right = MAX(x1, x2);
+				nodes[nodeIndex].aabb_top = MIN(y1, y2);
+				nodes[nodeIndex].aabb_bottom = MAX(y1, y2);
+
+				for (unsigned int j = 1; j < path.Size(); j++)
+				{
+					auto &cur = nodes[path[j]];
+					const auto &left = nodes[cur.left_node];
+					const auto &right = nodes[cur.right_node];
+					cur.aabb_left = MIN(left.aabb_left, right.aabb_left);
+					cur.aabb_top = MIN(left.aabb_top, right.aabb_top);
+					cur.aabb_right = MAX(left.aabb_right, right.aabb_right);
+					cur.aabb_bottom = MAX(left.aabb_bottom, right.aabb_bottom);
+				}
+
+				lines[i] = treeline;
+				modified = true;
+			}
+		}
+	}
+	return modified;
+}
+
+TArray<int> LevelAABBTree::FindNodePath(unsigned int line, unsigned int node)
+{
+	const AABBTreeNode &n = nodes[node];
+
+	if (n.aabb_left > lines[line].x || n.aabb_right < lines[line].x ||
+		n.aabb_top > lines[line].y || n.aabb_bottom < lines[line].y)
+	{
+		return {};
+	}
+
+	TArray<int> path;
+	if (n.line_index == -1)
+	{
+		path = FindNodePath(line, n.left_node);
+		if (path.Size() == 0)
+			path = FindNodePath(line, n.right_node);
+
+		if (path.Size())
+			path.Push(node);
+	}
+	else if (n.line_index == line)
+	{
+		path.Push(node);
+	}
+	return path;
+}
+
 double LevelAABBTree::RayTest(const DVector3 &ray_start, const DVector3 &ray_end)
 {
 	// Precalculate some of the variables used by the ray/line intersection test
diff --git a/src/hwrenderer/dynlights/hw_aabbtree.h b/src/hwrenderer/dynlights/hw_aabbtree.h
index 2d820c5e2b..5e6978d213 100644
--- a/src/hwrenderer/dynlights/hw_aabbtree.h
+++ b/src/hwrenderer/dynlights/hw_aabbtree.h
@@ -51,6 +51,8 @@ public:
 	// Shoot a ray from ray_start to ray_end and return the closest hit as a fractional value between 0 and 1. Returns 1 if no line was hit.
 	double RayTest(const DVector3 &ray_start, const DVector3 &ray_end);
 
+	bool Update();
+
 private:
 	// Test if a ray overlaps an AABB node or not
 	bool OverlapRayAABB(const DVector2 &ray_start2d, const DVector2 &ray_end2d, const AABBTreeNode &node);
@@ -60,6 +62,10 @@ private:
 
 	// Generate a tree node and its children recursively
 	int GenerateTreeNode(int *lines, int num_lines, const FVector2 *centroids, int *work_buffer);
+
+	TArray<int> FindNodePath(unsigned int line, unsigned int node);
+
+	TArray<int> polylines;
 };
 
 } // namespace
diff --git a/src/hwrenderer/dynlights/hw_shadowmap.cpp b/src/hwrenderer/dynlights/hw_shadowmap.cpp
index 024a5cc975..fda7f9561f 100644
--- a/src/hwrenderer/dynlights/hw_shadowmap.cpp
+++ b/src/hwrenderer/dynlights/hw_shadowmap.cpp
@@ -156,7 +156,7 @@ bool IShadowMap::ValidateAABBTree()
 	}
 
 	if (mAABBTree)
-		return true;
+		return mAABBTree->Update();
 
 	mAABBTree.reset(new hwrenderer::LevelAABBTree());
 	return false;
@@ -197,10 +197,12 @@ void IShadowMap::UploadAABBTree()
 {
 	if (!ValidateAABBTree())
 	{
-		mNodesBuffer = screen->CreateDataBuffer(2, true);
+		if (!mNodesBuffer)
+			mNodesBuffer = screen->CreateDataBuffer(2, true);
 		mNodesBuffer->SetData(sizeof(hwrenderer::AABBTreeNode) * mAABBTree->nodes.Size(), &mAABBTree->nodes[0]);
 
-		mLinesBuffer = screen->CreateDataBuffer(3, true);
+		if (!mLinesBuffer)
+			mLinesBuffer = screen->CreateDataBuffer(3, true);
 		mLinesBuffer->SetData(sizeof(hwrenderer::AABBTreeLine) * mAABBTree->lines.Size(), &mAABBTree->lines[0]);
 	}
 }