Convert r_clipsegment into a class

src/swrenderer/line/r_line.cpp

@@ -91,7 +91,7 @@ namespace swrenderer
 
 		if (line->linedef == NULL)
 		{
-			if (R_CheckClipWallSegment(WallC.sx1, WallC.sx2))
+			if (RenderClipSegment::Instance()->Check(WallC.sx1, WallC.sx2))
 			{
 				InSubsector->flags |= SSECF_DRAWN;
 			}
@@ -257,7 +257,7 @@ namespace swrenderer
 				// mark their subsectors as visible for automap texturing.
 				if (hasglnodes && !(InSubsector->flags & SSECF_DRAWN))
 				{
-					if (R_CheckClipWallSegment(WallC.sx1, WallC.sx2))
+					if (RenderClipSegment::Instance()->Check(WallC.sx1, WallC.sx2))
 					{
 						InSubsector->flags |= SSECF_DRAWN;
 					}
@@ -298,7 +298,7 @@ namespace swrenderer
 		}
 
 		static SWRenderLine *self = this;
-		bool visible = R_ClipWallSegment(WallC.sx1, WallC.sx2, solid, [](int x1, int x2) -> bool
+		bool visible = RenderClipSegment::Instance()->Clip(WallC.sx1, WallC.sx2, solid, [](int x1, int x2) -> bool
 		{
 			return self->RenderWallSegment(x1, x2);
 		});

src/swrenderer/scene/r_opaque_pass.cpp

@@ -378,7 +378,7 @@ namespace swrenderer
 		// Find the first clippost that touches the source post
 		//	(adjacent pixels are touching).
 
-		return R_IsWallSegmentVisible(sx1, sx2);
+		return RenderClipSegment::Instance()->IsVisible(sx1, sx2);
 	}
 
 	void RenderOpaquePass::AddPolyobjs(subsector_t *sub)

src/swrenderer/scene/r_portal.cpp

@@ -179,7 +179,7 @@ namespace swrenderer
 			validcount++;	// Make sure we see all sprites
 
 			planes->Clear(false);
-			R_ClearClipSegs(pl->left, pl->right);
+			RenderClipSegment::Instance()->Clear(pl->left, pl->right);
 			WindowLeft = pl->left;
 			WindowRight = pl->right;
 
@@ -429,7 +429,7 @@ namespace swrenderer
 		CurrentPortal = pds;
 
 		VisiblePlaneList::Instance()->Clear(false);
-		R_ClearClipSegs(pds->x1, pds->x2);
+		RenderClipSegment::Instance()->Clear(pds->x1, pds->x2);
 
 		WindowLeft = pds->x1;
 		WindowRight = pds->x2;

src/swrenderer/scene/r_scene.cpp

@@ -131,7 +131,7 @@ namespace swrenderer
 		RenderPortal::Instance()->CopyStackedViewParameters();
 
 		// Clear buffers.
-		R_ClearClipSegs(0, viewwidth);
+		RenderClipSegment::Instance()->Clear(0, viewwidth);
 		R_ClearDrawSegs();
 		VisiblePlaneList::Instance()->Clear(true);
 		RenderTranslucentPass::Clear();

src/swrenderer/segments/r_clipsegment.cpp

@@ -34,18 +34,13 @@
 
 namespace swrenderer
 {
-	namespace
+	RenderClipSegment *RenderClipSegment::Instance()
 	{
-		struct cliprange_t
-		{
-			short first, last;
-		};
-
-		cliprange_t *newend; // newend is one past the last valid seg
-		cliprange_t solidsegs[MAXWIDTH / 2 + 2];
+		static RenderClipSegment instance;
+		return &instance;
 	}
 
-	void R_ClearClipSegs(short left, short right)
+	void RenderClipSegment::Clear(short left, short right)
 	{
 		solidsegs[0].first = -0x7fff;
 		solidsegs[0].last = left;
@@ -54,7 +49,7 @@ namespace swrenderer
 		newend = solidsegs+2;
 	}
 
-	bool R_CheckClipWallSegment(int first, int last)
+	bool RenderClipSegment::Check(int first, int last)
 	{
 		cliprange_t *start;
 
@@ -78,7 +73,7 @@ namespace swrenderer
 		return false;
 	}
 
-	bool R_IsWallSegmentVisible(int sx1, int sx2)
+	bool RenderClipSegment::IsVisible(int sx1, int sx2)
 	{
 		// Does not cross a pixel.
 		if (sx2 <= sx1)
@@ -97,7 +92,7 @@ namespace swrenderer
 		return true;
 	}
 
-	bool R_ClipWallSegment(int first, int last, bool solid, VisibleSegmentCallback callback)
+	bool RenderClipSegment::Clip(int first, int last, bool solid, VisibleSegmentCallback callback)
 	{
 		cliprange_t *next, *start;
 		int i, j;

src/swrenderer/segments/r_clipsegment.h

@@ -17,8 +17,23 @@ namespace swrenderer
 {
 	typedef bool(*VisibleSegmentCallback)(int x1, int x2);
 
-	void R_ClearClipSegs(short left, short right);
-	bool R_ClipWallSegment(int x1, int x2, bool solid, VisibleSegmentCallback callback);
-	bool R_CheckClipWallSegment(int first, int last);
-	bool R_IsWallSegmentVisible(int x1, int x2);
+	class RenderClipSegment
+	{
+	public:
+		static RenderClipSegment *Instance();
+
+		void Clear(short left, short right);
+		bool Clip(int x1, int x2, bool solid, VisibleSegmentCallback callback);
+		bool Check(int first, int last);
+		bool IsVisible(int x1, int x2);
+		
+	private:
+		struct cliprange_t
+		{
+			short first, last;
+		};
+
+		cliprange_t *newend; // newend is one past the last valid seg
+		cliprange_t solidsegs[MAXWIDTH / 2 + 2];
+	};
 }