From b5f3f63b9327706fd92fe78a02da2903a354105b Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Fri, 16 Dec 2016 20:52:56 +0100
Subject: [PATCH] Minor bug fixes

---
 src/r_poly.cpp       |  2 +-
 src/r_poly.h         |  2 ++
 src/r_poly_cull.cpp  | 30 ++++++++++++++++++++++++++----
 src/r_poly_scene.cpp |  2 +-
 4 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/src/r_poly.cpp b/src/r_poly.cpp
index 2e100b395..f7fa33979 100644
--- a/src/r_poly.cpp
+++ b/src/r_poly.cpp
@@ -74,7 +74,7 @@ void PolyRenderer::RenderActorView(AActor *actor, bool dontmaplines)
 {
 	NetUpdate();
 	
-	//swrenderer::r_dontmaplines = dontmaplines;
+	DontMapLines = dontmaplines;
 	
 	P_FindParticleSubsectors();
 	PO_LinkToSubsectors();
diff --git a/src/r_poly.h b/src/r_poly.h
index f34106a4b..10d2e92aa 100644
--- a/src/r_poly.h
+++ b/src/r_poly.h
@@ -50,6 +50,8 @@ public:
 	bool InsertSeenLinePortal(FLinePortal *portal);
 	bool InsertSeenMirror(line_t *mirrorLine);
 
+	bool DontMapLines = false;
+
 private:
 	void ClearBuffers();
 	void SetSceneViewport();
diff --git a/src/r_poly_cull.cpp b/src/r_poly_cull.cpp
index 59b7c0c5a..02a0f2fc5 100644
--- a/src/r_poly_cull.cpp
+++ b/src/r_poly_cull.cpp
@@ -239,10 +239,31 @@ LineSegmentRange PolyCull::GetSegmentRangeForLine(double x1, double y1, double x
 {
 	double znear = 5.0;
 	double updownnear = -400.0;
+	double sidenear = 400.0;
 
-	// Cull if entirely behind the portal clip plane (tbd: should we clip the segment?)
-	if (Vec4f::dot(PortalClipPlane, Vec4f((float)x1, (float)y1, 0.0f, 1.0f)) < 0.0f && Vec4f::dot(PortalClipPlane, Vec4f((float)x2, (float)y2, 0.0f, 1.0f)) < 0.0f)
+	// Clip line to the portal clip plane
+	float distance1 = Vec4f::dot(PortalClipPlane, Vec4f((float)x1, (float)y1, 0.0f, 1.0f));
+	float distance2 = Vec4f::dot(PortalClipPlane, Vec4f((float)x2, (float)y2, 0.0f, 1.0f));
+	if (distance1 < 0.0f && distance2 < 0.0f)
+	{
 		return LineSegmentRange::NotVisible;
+	}
+	else if (distance1 < 0.0f || distance2 < 0.0f)
+	{
+		double t1 = 0.0f, t2 = 1.0f;
+		if (distance1 < 0.0f)
+			t1 = clamp(distance1 / (distance1 - distance2), 0.0f, 1.0f);
+		else
+			t2 = clamp(distance2 / (distance1 - distance2), 0.0f, 1.0f);
+		double nx1 = x1 * (1.0 - t1) + x2 * t1;
+		double ny1 = y1 * (1.0 - t1) + y2 * t1;
+		double nx2 = x1 * (1.0 - t2) + x2 * t2;
+		double ny2 = y1 * (1.0 - t2) + y2 * t2;
+		x1 = nx1;
+		x2 = nx2;
+		y1 = ny1;
+		y2 = ny2;
+	}
 
 	// Transform to 2D view space:
 	x1 = x1 - ViewPos.X;
@@ -255,7 +276,8 @@ LineSegmentRange PolyCull::GetSegmentRangeForLine(double x1, double y1, double x
 	double ry2 = x2 * ViewCos + y2 * ViewSin;
 
 	// Is it potentially visible when looking straight up or down?
-	if (!(ry1 < updownnear && ry2 < updownnear) && !(ry1 > znear && ry2 > znear))
+	if (!(ry1 < updownnear && ry2 < updownnear) && !(ry1 > znear && ry2 > znear) &&
+		!(rx1 < -sidenear && rx2 < -sidenear) && !(rx1 > sidenear && rx2 > sidenear))
 		return LineSegmentRange::AlwaysVisible;
 
 	// Cull if line is entirely behind view
@@ -267,7 +289,7 @@ LineSegmentRange PolyCull::GetSegmentRangeForLine(double x1, double y1, double x
 	if (ry1 < znear)
 		t1 = clamp((znear - ry1) / (ry2 - ry1), 0.0, 1.0);
 	if (ry2 < znear)
-		t2 = clamp((znear - ry1) / (ry2 - ry1), 0.0, 1.0);
+		t2 = clamp((znear - ry2) / (ry2 - ry1), 0.0, 1.0);
 	if (t1 != 0.0 || t2 != 1.0)
 	{
 		double nx1 = rx1 * (1.0 - t1) + rx2 * t1;
diff --git a/src/r_poly_scene.cpp b/src/r_poly_scene.cpp
index cfb858e0b..8bf6d1ce9 100644
--- a/src/r_poly_scene.cpp
+++ b/src/r_poly_scene.cpp
@@ -198,7 +198,7 @@ void RenderPolyScene::RenderLine(subsector_t *sub, seg_t *line, sector_t *fronts
 		return;
 
 	// Tell automap we saw this
-	if (!swrenderer::r_dontmaplines && line->linedef && segmentRange != LineSegmentRange::AlwaysVisible)
+	if (!PolyRenderer::Instance()->DontMapLines && line->linedef && segmentRange != LineSegmentRange::AlwaysVisible)
 	{
 		line->linedef->flags |= ML_MAPPED;
 		sub->flags |= SSECF_DRAWN;