diff --git a/src/lua_infolib.c b/src/lua_infolib.c
index 86ed88d5b..752c167f2 100644
--- a/src/lua_infolib.c
+++ b/src/lua_infolib.c
@@ -33,7 +33,7 @@ extern CV_PossibleValue_t Color_cons_t[];
 extern UINT8 skincolor_modified[];
 
 boolean LUA_CallAction(enum actionnum actionnum, mobj_t *actor);
-state_t *astate;
+state_t *astate = NULL;
 
 enum sfxinfo_read {
 	sfxinfor_name = 0,
diff --git a/src/lua_script.c b/src/lua_script.c
index f134c0d68..0144e09d8 100644
--- a/src/lua_script.c
+++ b/src/lua_script.c
@@ -45,31 +45,31 @@ boolean lua_compatmode = false;
 
 // List of internal libraries to load from SRB2
 static lua_CFunction liblist[] = {
-	LUA_EnumLib, // global metatable for enums
-	LUA_SOCLib, // A_Action functions, freeslot
-	LUA_BaseLib, // string concatination by +, CONS_Printf, p_local.h stuff (P_InstaThrust, P_Move), etc.
-	LUA_MathLib, // fixed_t and angle_t math functions
-	LUA_HookLib, // hookAdd and hook-calling functions
-	LUA_ConsoleLib, // console command/variable functions and structs
-	LUA_InfoLib, // info.h stuff: mobjinfo_t, mobjinfo[], state_t, states[]
-	LUA_MobjLib, // mobj_t, mapthing_t
-	LUA_PlayerLib, // player_t
-	LUA_SkinLib, // skin_t, skins[]
-	LUA_ThinkerLib, // thinker_t
-	LUA_MapLib, // line_t, side_t, sector_t, subsector_t
-	LUA_TagLib, // tags
-	LUA_PolyObjLib, // polyobj_t
-	LUA_BlockmapLib, // blockmap stuff
-	LUA_HudLib, // HUD stuff
-	LUA_FollowerLib, // follower_t, followers[]
-	LUA_BotVarsLib, // botvars_t
-	LUA_TerrainLib, // t_splash_t, t_footstep_t, t_overlay_t, terrain_t
-	LUA_WaypointLib, // waypoint_t
-	LUA_VectorLib, // vectors
-	LUA_MatrixLib, // matrices
-	LUA_QuaternionLib, // quaternions
-	LUA_VoiceLib, // kartvoice_t, skinvoices[]
-	LUA_ItemLib, // kartitem_t, kartresult_t, kartitemgraphics_t
+	LUA_EnumLib, 		// global metatable for enums
+	LUA_SOCLib, 		// A_Action functions, freeslot
+	LUA_BaseLib, 		// string concatination by +, CONS_Printf, p_local.h stuff (P_InstaThrust, P_Move), etc.
+	LUA_MathLib, 		// fixed_t and angle_t math functions
+	LUA_HookLib, 		// hookAdd and hook-calling functions
+	LUA_ConsoleLib, 	// console command/variable functions and structs
+	LUA_InfoLib, 		// info.h stuff: mobjinfo_t, mobjinfo[], state_t, states[]
+	LUA_MobjLib, 		// mobj_t, mapthing_t
+	LUA_PlayerLib, 		// player_t
+	LUA_SkinLib, 		// skin_t, skins[]
+	LUA_ThinkerLib, 	// thinker_t
+	LUA_MapLib, 		// line_t, side_t, sector_t, subsector_t
+	LUA_TagLib, 		// tags
+	LUA_PolyObjLib, 	// polyobj_t
+	LUA_BlockmapLib,	// blockmap stuff
+	LUA_HudLib, 		// HUD stuff
+	LUA_FollowerLib, 	// follower_t, followers[]
+	LUA_BotVarsLib, 	// botvars_t
+	LUA_TerrainLib, 	// t_splash_t, t_footstep_t, t_overlay_t, terrain_t
+	LUA_WaypointLib, 	// waypoint_t
+	LUA_VectorLib, 		// vectors
+	LUA_MatrixLib, 		// matrices
+	LUA_QuaternionLib, 	// quaternions
+	LUA_VoiceLib, 		// kartvoice_t, skinvoices[]
+	LUA_ItemLib, 		// kartitem_t, kartresult_t, kartitemgraphics_t
 	NULL
 };
 
@@ -77,12 +77,8 @@ static lua_CFunction liblist[] = {
 static void *LUA_Alloc(void *ud, void *ptr, size_t osize, size_t nsize)
 {
 	(void)ud;
-	if (nsize == 0) {
-		if (osize != 0)
-			Z_Free(ptr);
-		return NULL;
-	} else
-		return Z_Realloc(ptr, nsize, PU_LUA, NULL);
+	(void)osize;
+	return Z_Realloc(ptr, nsize, PU_LUA, NULL);
 }
 
 // Panic function Lua calls when there's an unprotected error.
@@ -690,7 +686,8 @@ void LUA_ClearState(void)
 	lua_setfield(L, LUA_REGISTRYINDEX, LREG_METATABLES);
 
 	// open srb2 libraries
-	for(i = 0; liblist[i]; i++) {
+	for (i = 0; liblist[i]; i++)
+	{
 		lua_pushcfunction(L, liblist[i]);
 		lua_call(L, 0, 0);
 	}
diff --git a/src/m_cheat.c b/src/m_cheat.c
index 7c2d1abc5..8dcd8d068 100644
--- a/src/m_cheat.c
+++ b/src/m_cheat.c
@@ -297,7 +297,7 @@ void Command_CheatGod_f(void)
 void Command_Scale_f(void)
 {
 	const double scaled = atof(COM_Argv(1));
-	fixed_t scale = FLOAT_TO_FIXED(scaled);
+	fixed_t scale = DoubleToFixed(scaled);
 
 	REQUIRE_DEVMODE;
 	REQUIRE_INLEVEL;
diff --git a/src/r_plane.cpp b/src/r_plane.cpp
index 60fba5854..1792b78f5 100644
--- a/src/r_plane.cpp
+++ b/src/r_plane.cpp
@@ -868,12 +868,12 @@ void R_SetSlopePlane(drawspandata_t* ds, pslope_t *slope, fixed_t xpos, fixed_t
 
 	// m is the v direction vector in view space
 	ang = ANG2RAD(ANGLE_180 - (angle + plangle));
-	m->x = cos(ang);
-	m->z = sin(ang);
+	m->x = cosf(ang);
+	m->z = sinf(ang);
 
 	// n is the u direction vector in view space
-	n->x = sin(ang);
-	n->z = -cos(ang);
+	n->x = sinf(ang);
+	n->z = -cosf(ang);
 
 	plangle >>= ANGLETOFINESHIFT;
 	temp = P_GetSlopeZAt(slope, xpos + FINESINE(plangle), ypos + FINECOSINE(plangle));
diff --git a/src/r_things.cpp b/src/r_things.cpp
index 9da9c674d..0a22076bd 100644
--- a/src/r_things.cpp
+++ b/src/r_things.cpp
@@ -100,7 +100,7 @@ static const char *spritename;
 
 typedef struct drawseg_xrange_item_s
 {
-	INT16 x1, x2;
+	INT32 x1, x2;
 	drawseg_t *user;
 } drawseg_xrange_item_t;
 
@@ -642,8 +642,8 @@ void R_InitSprites(void)
 	for (angle = 1; angle < ROTANGLES; angle++)
 	{
 		fa = ANG2RAD(FixedAngle((ROTANGDIFF * angle)<<FRACBITS));
-		rollcosang[angle] = FLOAT_TO_FIXED(cos(-fa));
-		rollsinang[angle] = FLOAT_TO_FIXED(sin(-fa));
+		rollcosang[angle] = FLOAT_TO_FIXED(cosf(-fa));
+		rollsinang[angle] = FLOAT_TO_FIXED(sinf(-fa));
 	}
 #endif
 
diff --git a/src/sdl/mixer_sound.c b/src/sdl/mixer_sound.c
index 983d34e3f..74067db68 100644
--- a/src/sdl/mixer_sound.c
+++ b/src/sdl/mixer_sound.c
@@ -1152,7 +1152,7 @@ UINT32 I_GetSongPosition(void)
 void
 I_UpdateSongLagThreshold (void)
 {
-	stutter_threshold_user = cv_music_resync_threshold.value/1000.0*(4*44100);
+	stutter_threshold_user = (UINT32)(cv_music_resync_threshold.value/1000.0*(4*44100));
 	I_UpdateSongLagConditions();
 }
 
diff --git a/src/v_video.c b/src/v_video.c
index faad604b6..33dc94faa 100644
--- a/src/v_video.c
+++ b/src/v_video.c
@@ -379,7 +379,7 @@ void V_CubeApply(UINT8 *red, UINT8 *green, UINT8 *blue)
 	if (!Cubeapply)
 		return;
 
-	linear = (*red/255.0);
+	linear = (*red/255.0f);
 #define dolerp(e1, e2) ((1 - linear)*e1 + linear*e2)
 	for (q = 0; q < 3; q++)
 	{
@@ -388,20 +388,20 @@ void V_CubeApply(UINT8 *red, UINT8 *green, UINT8 *blue)
 		working[2][q] = dolerp(Cubepal[0][0][1][q], Cubepal[1][0][1][q]);
 		working[3][q] = dolerp(Cubepal[0][1][1][q], Cubepal[1][1][1][q]);
 	}
-	linear = (*green/255.0);
+	linear = (*green/255.0f);
 	for (q = 0; q < 3; q++)
 	{
 		working[0][q] = dolerp(working[0][q], working[1][q]);
 		working[1][q] = dolerp(working[2][q], working[3][q]);
 	}
-	linear = (*blue/255.0);
+	linear = (*blue/255.0f);
 	for (q = 0; q < 3; q++)
 	{
 		working[0][q] = 255*dolerp(working[0][q], working[1][q]);
-		if (working[0][q] > 255.0)
-			working[0][q] = 255.0;
-		else if (working[0][q]  < 0.0)
-			working[0][q] = 0.0;
+		if (working[0][q] > 255.0f)
+			working[0][q] = 255.0f;
+		else if (working[0][q]  < 0.0f)
+			working[0][q] = 0.0f;
 	}
 #undef dolerp