diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index eb0205a43..22a2a5e37 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -63,7 +63,7 @@ add_executable(SRB2SDL2 MACOSX_BUNDLE WIN32
 	p_user.c
 	p_slopes.c
 	tables.c
-	r_bsp.c
+	r_bsp.cpp
 	r_data.c
 	r_debug.cpp
 	r_debug_parser.cpp
diff --git a/src/r_bsp.c b/src/r_bsp.cpp
similarity index 96%
rename from src/r_bsp.c
rename to src/r_bsp.cpp
index f71dea646..4464646a5 100644
--- a/src/r_bsp.c
+++ b/src/r_bsp.cpp
@@ -11,6 +11,8 @@
 /// \file  r_bsp.c
 /// \brief BSP traversal, handling of LineSegs for rendering
 
+#include <algorithm>
+
 #include "doomdef.h"
 #include "g_game.h"
 #include "r_local.h"
@@ -271,11 +273,11 @@ sector_t *R_FakeFlat(sector_t *sec, sector_t *tempsec, INT32 *floorlightlevel,
 {
 	if (floorlightlevel)
 		*floorlightlevel = sec->floorlightsec == -1 ?
-			(sec->floorlightabsolute ? sec->floorlightlevel : max(0, min(255, sec->lightlevel + sec->floorlightlevel))) : sectors[sec->floorlightsec].lightlevel;
+			(sec->floorlightabsolute ? sec->floorlightlevel : std::max(0, std::min(255, sec->lightlevel + sec->floorlightlevel))) : sectors[sec->floorlightsec].lightlevel;
 
 	if (ceilinglightlevel)
 		*ceilinglightlevel = sec->ceilinglightsec == -1 ?
-			(sec->ceilinglightabsolute ? sec->ceilinglightlevel : max(0, min(255, sec->lightlevel + sec->ceilinglightlevel))) : sectors[sec->ceilinglightsec].lightlevel;
+			(sec->ceilinglightabsolute ? sec->ceilinglightlevel : std::max(0, std::min(255, sec->lightlevel + sec->ceilinglightlevel))) : sectors[sec->ceilinglightsec].lightlevel;
 
 	// if (sec->midmap != -1)
 	//	mapnum = sec->midmap;
@@ -341,11 +343,11 @@ sector_t *R_FakeFlat(sector_t *sec, sector_t *tempsec, INT32 *floorlightlevel,
 			tempsec->lightlevel = s->lightlevel;
 
 			if (floorlightlevel)
-				*floorlightlevel = s->floorlightsec == -1 ? (s->floorlightabsolute ? s->floorlightlevel : max(0, min(255, s->lightlevel + s->floorlightlevel)))
+				*floorlightlevel = s->floorlightsec == -1 ? (s->floorlightabsolute ? s->floorlightlevel : std::max(0, std::min(255, s->lightlevel + s->floorlightlevel)))
 					: sectors[s->floorlightsec].lightlevel;
 
 			if (ceilinglightlevel)
-				*ceilinglightlevel = s->ceilinglightsec == -1 ? (s->ceilinglightabsolute ? s->ceilinglightlevel : max(0, min(255, s->lightlevel + s->ceilinglightlevel)))
+				*ceilinglightlevel = s->ceilinglightsec == -1 ? (s->ceilinglightabsolute ? s->ceilinglightlevel : std::max(0, std::min(255, s->lightlevel + s->ceilinglightlevel)))
 					: sectors[s->ceilinglightsec].lightlevel;
 		}
 		else if (heightsec != -1 && viewz >= sectors[heightsec].ceilingheight
@@ -379,11 +381,11 @@ sector_t *R_FakeFlat(sector_t *sec, sector_t *tempsec, INT32 *floorlightlevel,
 			tempsec->lightlevel = s->lightlevel;
 
 			if (floorlightlevel)
-				*floorlightlevel = s->floorlightsec == -1 ? (s->floorlightabsolute ? s->floorlightlevel : max(0, min(255, s->lightlevel + s->floorlightlevel)))
+				*floorlightlevel = s->floorlightsec == -1 ? (s->floorlightabsolute ? s->floorlightlevel : std::max(0, std::min(255, s->lightlevel + s->floorlightlevel)))
 					: sectors[s->floorlightsec].lightlevel;
 
 			if (ceilinglightlevel)
-				*ceilinglightlevel = s->ceilinglightsec == -1 ? (s->ceilinglightabsolute ? s->ceilinglightlevel : max(0, min(255, s->lightlevel + s->ceilinglightlevel)))
+				*ceilinglightlevel = s->ceilinglightsec == -1 ? (s->ceilinglightabsolute ? s->ceilinglightlevel : std::max(0, std::min(255, s->lightlevel + s->ceilinglightlevel)))
 					: sectors[s->ceilinglightsec].lightlevel;
 		}
 		sec = tempsec;
@@ -760,8 +762,7 @@ void R_SortPolyObjects(subsector_t *sub)
 		{
 			// use free instead realloc since faster (thanks Lee ^_^)
 			free(po_ptrs);
-			po_ptrs = malloc((num_po_ptrs = numpolys*2)
-				* sizeof(*po_ptrs));
+			po_ptrs = static_cast<polyobj_t**>(malloc((num_po_ptrs = numpolys*2) * sizeof(*po_ptrs)));
 		}
 
 		po = sub->polyList;
@@ -805,8 +806,8 @@ static int R_PolysegCompare(const void *p1, const void *p2)
 	dist2v1 = vxdist(seg2->v1);
 	dist2v2 = vxdist(seg2->v2);
 
-	if (min(dist1v1, dist1v2) != min(dist2v1, dist2v2))
-		return min(dist1v1, dist1v2) - min(dist2v1, dist2v2);
+	if (std::min(dist1v1, dist1v2) != std::min(dist2v1, dist2v2))
+		return std::min(dist1v1, dist1v2) - std::min(dist2v1, dist2v2);
 
 	{ // That didn't work, so now let's try this.......
 		fixed_t delta1, delta2, x1, y1, x2, y2;
@@ -959,11 +960,11 @@ static void R_Subsector(size_t num)
 
 		light = R_GetPlaneLight(frontsector, floorcenterz, false);
 		if (frontsector->floorlightsec == -1 && !frontsector->floorlightabsolute)
-			floorlightlevel = max(0, min(255, *frontsector->lightlist[light].lightlevel + frontsector->floorlightlevel));
+			floorlightlevel = std::max(0, std::min(255, *frontsector->lightlist[light].lightlevel + frontsector->floorlightlevel));
 		floorcolormap = *frontsector->lightlist[light].extra_colormap;
 		light = R_GetPlaneLight(frontsector, ceilingcenterz, false);
 		if (frontsector->ceilinglightsec == -1 && !frontsector->ceilinglightabsolute)
-			ceilinglightlevel = max(0, min(255, *frontsector->lightlist[light].lightlevel + frontsector->ceilinglightlevel));
+			ceilinglightlevel = std::max(0, std::min(255, *frontsector->lightlist[light].lightlevel + frontsector->ceilinglightlevel));
 		ceilingcolormap = *frontsector->lightlist[light].extra_colormap;
 	}
 
@@ -1232,7 +1233,7 @@ void R_Prep3DFloors(sector_t *sector)
 	if (count != sector->numlights)
 	{
 		Z_Free(sector->lightlist);
-		sector->lightlist = Z_Calloc(sizeof (*sector->lightlist) * count, PU_LEVEL, NULL);
+		sector->lightlist = static_cast<lightlist_t*>(Z_Calloc(sizeof (*sector->lightlist) * count, PU_LEVEL, NULL));
 		sector->numlights = count;
 	}
 	else