diff --git a/src/hardware/hw_cache.c b/src/hardware/hw_cache.c
index 56f5416cf..f282ca891 100644
--- a/src/hardware/hw_cache.c
+++ b/src/hardware/hw_cache.c
@@ -450,15 +450,10 @@ static void HWR_GenerateTexture(INT32 texnum, GLMapTexture_t *grtex, GLMipmap_t
 
 	texture = textures[texnum];
 
-	mipmap->flags = TF_WRAPXY;
-	mipmap->width = (UINT16)texture->width;
-	mipmap->height = (UINT16)texture->height;
-	mipmap->format = textureformat;
-
 	blockwidth = texture->width;
 	blockheight = texture->height;
-	blocksize = (blockwidth * blockheight);
-	block = MakeBlock(&grtex->mipmap);
+	blocksize = blockwidth * blockheight;
+	block = MakeBlock(mipmap);
 
 	// Composite the columns together.
 	for (i = 0, patch = texture->patches; i < texture->patchcount; i++, patch++)
@@ -488,7 +483,7 @@ static void HWR_GenerateTexture(INT32 texnum, GLMapTexture_t *grtex, GLMipmap_t
 				realpatch = W_CachePatchNumPwad(wadnum, lumpnum, PU_PATCH);
 		}
 
-		HWR_DrawTexturePatchInCache(&grtex->mipmap, blockwidth, blockheight, texture, patch, realpatch);
+		HWR_DrawTexturePatchInCache(mipmap, blockwidth, blockheight, texture, patch, realpatch);
 
 		if (free_patch)
 			Patch_Free(realpatch);
@@ -680,25 +675,24 @@ void HWR_InitMapTextures(void)
 	gl_maptexturesloaded = false;
 }
 
-static void DeleteTextureMipmap(GLMipmap_t *grMipmap)
+static void DeleteTextureMipmap(GLMipmap_t *grMipmap, boolean delete_mipmap)
 {
 	HWD.pfnDeleteTexture(grMipmap);
 
-	// Chroma-keyed textures do not own their texture data, so do not free it
-	if (!(grMipmap->flags & TF_CHROMAKEYED))
+	if (delete_mipmap)
 		Z_Free(grMipmap->data);
 }
 
-static void FreeMapTexture(GLMapTexture_t *tex)
+static void FreeMapTexture(GLMapTexture_t *tex, boolean delete_chromakeys)
 {
 	if (tex->mipmap.nextcolormap)
 	{
-		DeleteTextureMipmap(tex->mipmap.nextcolormap);
+		DeleteTextureMipmap(tex->mipmap.nextcolormap, delete_chromakeys);
 		free(tex->mipmap.nextcolormap);
 		tex->mipmap.nextcolormap = NULL;
 	}
 
-	DeleteTextureMipmap(&tex->mipmap);
+	DeleteTextureMipmap(&tex->mipmap, true);
 }
 
 void HWR_FreeMapTextures(void)
@@ -707,8 +701,8 @@ void HWR_FreeMapTextures(void)
 
 	for (i = 0; i < gl_numtextures; i++)
 	{
-		FreeMapTexture(&gl_textures[i]);
-		FreeMapTexture(&gl_flats[i]);
+		FreeMapTexture(&gl_textures[i], true);
+		FreeMapTexture(&gl_flats[i], false);
 	}
 
 	// now the heap don't have any 'user' pointing to our
@@ -741,22 +735,7 @@ void HWR_LoadMapTextures(size_t pnumtextures)
 // --------------------------------------------------------------------------
 // Make sure texture is downloaded and set it as the source
 // --------------------------------------------------------------------------
-static void GetMapTexture(INT32 tex, GLMapTexture_t *grtex, GLMipmap_t *mipmap)
-{
-	// Generate texture if missing from the cache
-	if (!mipmap->data && !mipmap->downloaded)
-		HWR_GenerateTexture(tex, grtex, mipmap);
-
-	// If hardware does not have the texture, then call pfnSetTexture to upload it
-	if (!mipmap->downloaded)
-		HWD.pfnSetTexture(mipmap);
-	HWR_SetCurrentTexture(mipmap);
-
-	// The system-memory data can be purged now.
-	Z_ChangeTag(mipmap->data, PU_HWRCACHE_UNLOCKED);
-}
-
-GLMapTexture_t *HWR_GetTexture(INT32 tex)
+GLMapTexture_t *HWR_GetTexture(INT32 tex, boolean chromakeyed)
 {
 	if (tex < 0 || tex >= (signed)gl_numtextures)
 	{
@@ -769,7 +748,46 @@ GLMapTexture_t *HWR_GetTexture(INT32 tex)
 
 	GLMapTexture_t *grtex = &gl_textures[tex];
 
-	GetMapTexture(tex, grtex, &grtex->mipmap);
+	GLMipmap_t *grMipmap = &grtex->mipmap;
+	GLMipmap_t *originalMipmap = grMipmap;
+
+	if (!originalMipmap->downloaded)
+	{
+		originalMipmap->flags = TF_WRAPXY;
+		originalMipmap->width = (UINT16)textures[tex]->width;
+		originalMipmap->height = (UINT16)textures[tex]->height;
+		originalMipmap->format = textureformat;
+	}
+
+	// If chroma-keyed, create or use a different mipmap for the variant
+	if (chromakeyed && !textures[tex]->transparency)
+	{
+		// Allocate it if it wasn't already
+		if (!originalMipmap->nextcolormap)
+		{
+			GLMipmap_t *newMipmap = calloc(1, sizeof (*grMipmap));
+			if (newMipmap == NULL)
+				I_Error("%s: Out of memory", "HWR_GetTexture");
+
+			newMipmap->flags = originalMipmap->flags | TF_CHROMAKEYED;
+			newMipmap->width = originalMipmap->width;
+			newMipmap->height = originalMipmap->height;
+			newMipmap->format = originalMipmap->format;
+			originalMipmap->nextcolormap = newMipmap;
+		}
+
+		// Generate, upload and bind the variant texture instead of the original one
+		grMipmap = originalMipmap->nextcolormap;
+	}
+
+	if (!grMipmap->data)
+		HWR_GenerateTexture(tex, grtex, grMipmap);
+
+	if (!grMipmap->downloaded)
+		HWD.pfnSetTexture(grMipmap);
+	HWR_SetCurrentTexture(grMipmap);
+
+	Z_ChangeTag(grMipmap->data, PU_HWRCACHE_UNLOCKED);
 
 	return grtex;
 }
diff --git a/src/hardware/hw_glob.h b/src/hardware/hw_glob.h
index 807c70989..5678cd593 100644
--- a/src/hardware/hw_glob.h
+++ b/src/hardware/hw_glob.h
@@ -120,7 +120,7 @@ void HWR_GetPatch(patch_t *patch);
 void HWR_GetMappedPatch(patch_t *patch, const UINT8 *colormap);
 void HWR_GetFadeMask(lumpnum_t fademasklumpnum);
 
-GLMapTexture_t *HWR_GetTexture(INT32 tex);
+GLMapTexture_t *HWR_GetTexture(INT32 tex, boolean chromakeyed);
 void HWR_GetLevelFlat(levelflat_t *levelflat, boolean chromakeyed);
 void HWR_GetRawFlat(lumpnum_t flatlumpnum);
 
diff --git a/src/hardware/hw_main.c b/src/hardware/hw_main.c
index 4e651891d..a4b8b15ed 100644
--- a/src/hardware/hw_main.c
+++ b/src/hardware/hw_main.c
@@ -978,7 +978,7 @@ static void HWR_RenderMidtexture(INT32 gl_midtexture, float cliplow, float cliph
 	else
 		repeats = 1;
 
-	GLMapTexture_t *grTex = HWR_GetTexture(gl_midtexture);
+	GLMapTexture_t *grTex = HWR_GetTexture(gl_midtexture, true);
 	float xscale = FixedToFloat(gl_sidedef->scalex_mid);
 	float yscale = FixedToFloat(gl_sidedef->scaley_mid);
 
@@ -1237,7 +1237,7 @@ static void HWR_ProcessSeg(void)
 		// check TOP TEXTURE
 		if ((worldhighslope < worldtopslope || worldhigh < worldtop) && gl_toptexture)
 		{
-			grTex = HWR_GetTexture(gl_toptexture);
+			grTex = HWR_GetTexture(gl_toptexture, false);
 			xscale = FixedToFloat(abs(gl_sidedef->scalex_top));
 			yscale = FixedToFloat(abs(gl_sidedef->scaley_top));
 
@@ -1327,7 +1327,7 @@ static void HWR_ProcessSeg(void)
 		// check BOTTOM TEXTURE
 		if ((worldlowslope > worldbottomslope || worldlow > worldbottom) && gl_bottomtexture)
 		{
-			grTex = HWR_GetTexture(gl_bottomtexture);
+			grTex = HWR_GetTexture(gl_bottomtexture, false);
 			xscale = FixedToFloat(abs(gl_sidedef->scalex_bottom));
 			yscale = FixedToFloat(abs(gl_sidedef->scaley_bottom));
 
@@ -1441,7 +1441,7 @@ static void HWR_ProcessSeg(void)
 		// Single sided line... Deal only with the middletexture (if one exists)
 		if (gl_midtexture && gl_linedef->special != SPECIAL_HORIZON_LINE) // (Ignore horizon line for OGL)
 		{
-			grTex = HWR_GetTexture(gl_midtexture);
+			grTex = HWR_GetTexture(gl_midtexture, false);
 			xscale = FixedToFloat(gl_sidedef->scalex_mid);
 			yscale = FixedToFloat(gl_sidedef->scaley_mid);
 
@@ -1615,7 +1615,7 @@ static void HWR_ProcessSeg(void)
 					// -- Monster Iestyn 26/06/18
 					fixed_t texturevpeg = side->rowoffset + side->offsety_mid;
 
-					grTex = HWR_GetTexture(texnum);
+					grTex = HWR_GetTexture(texnum, true);
 					xscale = FixedToFloat(side->scalex_mid);
 					yscale = FixedToFloat(side->scaley_mid);
 
@@ -1772,7 +1772,7 @@ static void HWR_ProcessSeg(void)
 					// -- Monster Iestyn 26/06/18
 					fixed_t texturevpeg = side->rowoffset + side->offsety_mid;
 
-					grTex = HWR_GetTexture(texnum);
+					grTex = HWR_GetTexture(texnum, true);
 					xscale = FixedToFloat(side->scalex_mid);
 					yscale = FixedToFloat(side->scaley_mid);
 
@@ -4113,7 +4113,7 @@ static void HWR_CreateDrawNodes(void)
 		else if (sortnode[sortindex[i]].wall)
 		{
 			if (!(sortnode[sortindex[i]].wall->blend & PF_NoTexture))
-				HWR_GetTexture(sortnode[sortindex[i]].wall->texnum);
+				HWR_GetTexture(sortnode[sortindex[i]].wall->texnum, true);
 			HWR_RenderWall(sortnode[sortindex[i]].wall->wallVerts, &sortnode[sortindex[i]].wall->Surf, sortnode[sortindex[i]].wall->blend, sortnode[sortindex[i]].wall->fogwall,
 				sortnode[sortindex[i]].wall->lightlevel, sortnode[sortindex[i]].wall->wallcolormap);
 		}
@@ -5093,6 +5093,8 @@ static void HWR_DrawSkyBackground(player_t *player)
 
 	HWD.pfnSetBlend(PF_Translucent|PF_NoDepthTest|PF_Modulated);
 
+	HWR_GetTexture(texturetranslation[skytexture], false);
+
 	if (cv_glskydome.value)
 	{
 		FTransform dometransform;
@@ -5108,8 +5110,6 @@ static void HWR_DrawSkyBackground(player_t *player)
 		HWR_SetTransformAiming(&dometransform, player, false);
 		dometransform.angley = (float)((viewangle-ANGLE_270)>>ANGLETOFINESHIFT)*(360.0f/(float)FINEANGLES);
 
-		HWR_GetTexture(texturetranslation[skytexture]);
-
 		if (gl_sky.texture != texturetranslation[skytexture])
 		{
 			HWR_ClearSkyDome();
@@ -5129,7 +5129,6 @@ static void HWR_DrawSkyBackground(player_t *player)
 		float aspectratio;
 		float angleturn;
 
-		HWR_GetTexture(texturetranslation[skytexture]);
 		aspectratio = (float)vid.width/(float)vid.height;
 
 		//Hurdler: the sky is the only texture who need 4.0f instead of 1.0
diff --git a/src/m_menu.c b/src/m_menu.c
index 38165472e..c4fccb372 100644
--- a/src/m_menu.c
+++ b/src/m_menu.c
@@ -140,6 +140,7 @@ static char *char_notes = NULL;
 
 boolean menuactive = false;
 boolean fromlevelselect = false;
+tic_t shieldprompt_timer = 0; // Show a prompt about the new Shield button for old configs // TODO: 2.3: Remove
 
 typedef enum
 {
@@ -3161,6 +3162,7 @@ static void Command_Manual_f(void)
 	if (modeattacking)
 		return;
 	M_StartControlPanel();
+	if (shieldprompt_timer) return; // TODO: 2.3: Delete this line
 	currentMenu = &MISC_HelpDef;
 	itemOn = 0;
 }
@@ -3340,6 +3342,7 @@ boolean M_Responder(event_t *ev)
 				if (modeattacking)
 					return true;
 				M_StartControlPanel();
+				if (shieldprompt_timer) return true; // TODO: 2.3: Delete this line
 				M_Options(0);
 				// Uncomment the below if you want the menu to reset to the top each time like before. M_SetupNextMenu will fix it automatically.
 				//OP_SoundOptionsDef.lastOn = 0;
@@ -3350,6 +3353,7 @@ boolean M_Responder(event_t *ev)
 				if (modeattacking)
 					return true;
 				M_StartControlPanel();
+				if (shieldprompt_timer) return true; // TODO: 2.3: Delete this line
 				M_Options(0);
 				M_VideoModeMenu(0);
 				return true;
@@ -3361,6 +3365,7 @@ boolean M_Responder(event_t *ev)
 				if (modeattacking)
 					return true;
 				M_StartControlPanel();
+				if (shieldprompt_timer) return true; // TODO: 2.3: Delete this line
 				M_Options(0);
 				M_SetupNextMenu(&OP_MainDef);
 				return true;
@@ -3631,6 +3636,230 @@ void M_Drawer(void)
 	}
 }
 
+// Handle the "Do you want to assign Shield Ability now?" pop-up for old configs // TODO: 2.3: Remove this line...
+static UINT8 shieldprompt_currentchoice = 0; // ...and this line...
+
+static void M_ShieldPromptUseDefaults(void) // ...and this function
+{
+	// With a default config from v2.2.10 to v2.2.13, the B button will be set to Custom 1,
+	// and Controls per Key defaults to "One", so it will override the default Shield button.
+	// A default config from v2.2.0 to v2.2.9 has Next Weapon on B, so it suffers from this too.
+
+	// So for "Use default Shield Ability buttons", we should update old configs to mitigate gamepad conflicts
+	// (even with "Several" Controls per Key!), and show a message with the default bindings
+
+	for (setupcontrols = gamecontrol; true; setupcontrols = gamecontrolbis) // Do stuff for both P1 and P2
+	{
+		INT32 JOY1 = (setupcontrols == gamecontrol) ? KEY_JOY1 : KEY_2JOY1; // Is this for P1 or for P2?
+
+		if ((setupcontrols[GC_CUSTOM1][0] == JOY1+1 || setupcontrols[GC_CUSTOM1][1] == JOY1+1)
+		&&  (setupcontrols[GC_CUSTOM2][0] == JOY1+3 || setupcontrols[GC_CUSTOM2][1] == JOY1+3)
+		&&  (setupcontrols[GC_CUSTOM3][0] == JOY1+8 || setupcontrols[GC_CUSTOM3][1] == JOY1+8))
+		{
+			// If the player has v2.2.13's default gamepad Custom 1/2/3 buttons,
+			// shuffle Custom 1/2/3 around to make room for Shield Ability on B
+			UINT8 shield_slot  = (setupcontrols[GC_SHIELD ][0] == KEY_NULL  ) ? 0 : 1;
+			UINT8 custom1_slot = (setupcontrols[GC_CUSTOM1][0] == JOY1+1) ? 0 : 1;
+			UINT8 custom2_slot = (setupcontrols[GC_CUSTOM2][0] == JOY1+3) ? 0 : 1;
+			UINT8 custom3_slot = (setupcontrols[GC_CUSTOM3][0] == JOY1+8) ? 0 : 1;
+
+			setupcontrols[GC_SHIELD ][shield_slot ] = JOY1+1; // Assign Shield Ability to B
+			setupcontrols[GC_CUSTOM1][custom1_slot] = JOY1+3; // Move Custom 1 from B to Y
+			setupcontrols[GC_CUSTOM2][custom2_slot] = JOY1+8; // Move Custom 2 from Y to LS
+			setupcontrols[GC_CUSTOM3][custom3_slot] = KEY_NULL; // Unassign Custom 3 from LS...
+			// (The alternative would be to check and update the ENTIRE gamepad layout.
+			// That'd be nice, but it would mess with people that are used to the old defaults.)
+		}
+		else if ((setupcontrols[GC_WEAPONNEXT][0] == JOY1+1 || setupcontrols[GC_WEAPONNEXT][1] == JOY1+1)
+		&&       (setupcontrols[GC_WEAPONPREV][0] == JOY1+2 || setupcontrols[GC_WEAPONPREV][1] == JOY1+2))
+		{
+			// Or if the user has a default config from v2.2.0 to v2.2.9,
+			// the B button will be Next Weapon, and X will be Previous Weapon.
+			// It's "safe" to discard one of them, you just have to press X multiple times to select in the other direction
+			UINT8 shield_slot  = (setupcontrols[GC_SHIELD    ][0] == KEY_NULL  ) ? 0 : 1;
+			UINT8 nweapon_slot = (setupcontrols[GC_WEAPONNEXT][0] == JOY1+1) ? 0 : 1;
+			UINT8 pweapon_slot = (setupcontrols[GC_WEAPONPREV][0] == JOY1+2) ? 0 : 1;
+
+			setupcontrols[GC_SHIELD    ][shield_slot ] = JOY1+1; // Assign Shield Ability to B
+			setupcontrols[GC_WEAPONNEXT][nweapon_slot] = JOY1+3; // Move Next Weapon from B to X
+			setupcontrols[GC_WEAPONPREV][pweapon_slot] = KEY_NULL; // Unassign Previous Weapon from X
+		}
+
+		if (setupcontrols == gamecontrolbis) // If we've already updated both players, break out
+			break;
+	}
+
+
+	// Now, show a message about the default Shield Ability bindings
+	if ((gamecontrol[GC_SHIELD][0] == KEY_LALT && gamecontrol[GC_SHIELD][1] == KEY_JOY1+1)
+	||  (gamecontrol[GC_SHIELD][0] == KEY_JOY1+1 && gamecontrol[GC_SHIELD][1] == KEY_LALT))
+	{
+		// Left Alt and the B button are both assigned
+		M_StartMessage(M_GetText("Shield Ability defaults to\nthe \x82""Left Alt\x80"" key on keyboard,\nand the \x85""B button\x80"" on gamepads."
+		"\n\nYou can always reassign it\nin the Options menu later."
+		"\n\n\nPress 'Enter' to continue\n"),
+			NULL, MM_NOTHING);
+		MessageDef.x = 43; // Change the pop-up message's background position/width
+		MessageDef.lastOn = (MessageDef.lastOn & ~0xFF) | 27;
+	}
+	else if (gamecontrol[GC_SHIELD][0] == KEY_LALT || gamecontrol[GC_SHIELD][1] == KEY_LALT)
+	{
+		// Left Alt is assigned, but the B button isn't.
+		M_StartMessage(M_GetText("Shield Ability defaults to\nthe \x82""Left Alt\x80"" key on keyboard.\nThe \x85""B button\x80"" on gamepads was taken."
+		"\n\nYou can always reassign it\nin the Options menu later."
+		"\n\n\nPress 'Enter' to continue\n"),
+			NULL, MM_NOTHING);
+		MessageDef.x = 24; // Change the pop-up message's background position/width
+		MessageDef.lastOn = (MessageDef.lastOn & ~0xFF) | 32;
+	}
+	else if (gamecontrol[GC_SHIELD][0] == KEY_JOY1+1 || gamecontrol[GC_SHIELD][1] == KEY_JOY1+1)
+	{
+		// The B button is assigned, but Left Alt isn't
+		M_StartMessage(M_GetText("Shield Ability defaults to\nthe \x85""B button\x80"" on gamepads.\nThe \x82""Left Alt\x80"" key on keyboard was taken."
+		"\n\nYou can always reassign it\nin the Options menu later."
+		"\n\n\nPress 'Enter' to continue\n"),
+			NULL, MM_NOTHING);
+		MessageDef.x = 8; // Change the pop-up message's background position/width
+		MessageDef.lastOn = (MessageDef.lastOn & ~0xFF) | 36;
+	}
+	else if (gamecontrol[GC_SHIELD][0] == KEY_NULL && gamecontrol[GC_SHIELD][1] == KEY_NULL)
+	{
+		// Neither Left Alt nor the B button are assigned
+		M_StartMessage(M_GetText("Shield Ability is unassigned!\nThe \x82""Left Alt\x80"" key on keyboard and\nthe \x85""B button\x80"" on gamepads were taken."
+		"\n\nYou should assign Shield Ability\nin the Options menu later."
+		"\n\n\nPress 'Enter' to continue\n"),
+			NULL, MM_NOTHING);
+		MessageDef.x = 19; // Change the pop-up message's background position/width
+		MessageDef.lastOn = (MessageDef.lastOn & ~0xFF) | 33;
+	}
+	else
+	{
+		// Neither Left Alt nor the B button are assigned... but something else is???
+		// (This can technically happen if you edit your config or use setcontrol in the console before opening the menu)
+		char keystr[16+16+2+7+1]; // Two 16-char keys + two colour codes + "' and '" + null
+
+		if (gamecontrol[GC_SHIELD][0] != KEY_NULL && gamecontrol[GC_SHIELD][1] != KEY_NULL)
+			STRBUFCPY(keystr, va("%s\x80""' and '\x82""%s",
+				G_KeyNumToName(gamecontrol[GC_SHIELD][0]),
+				G_KeyNumToName(gamecontrol[GC_SHIELD][1])));
+		else if (gamecontrol[GC_SHIELD][0] != KEY_NULL)
+			STRBUFCPY(keystr, G_KeyNumToName(gamecontrol[GC_SHIELD][0]));
+		else //if (gamecontrol[GC_SHIELD][1] != KEY_NULL)
+			STRBUFCPY(keystr, G_KeyNumToName(gamecontrol[GC_SHIELD][1]));
+
+		M_StartMessage(va("Shield Ability is assigned to\n'\x82""%s\x80""'."
+		"\n\nYou can always reassign it\nin the Options menu later."
+		"\n\n\nPress 'Enter' to continue\n",
+			keystr), NULL, MM_NOTHING);
+		MessageDef.x = 23; // Change the pop-up message's background position/width
+		MessageDef.lastOn = (MessageDef.lastOn & ~0xFF) | 32;
+	}
+}
+
+static void M_HandleShieldPromptMenu(INT32 choice) // TODO: 2.3: Remove
+{
+	switch (choice)
+	{
+		case KEY_ESCAPE:
+			if (I_GetTime() <= shieldprompt_timer) // Don't mash past the pop-up by accident!
+				break;
+
+			S_StartSound(NULL, sfx_menu1);
+			noFurtherInput = true;
+			shieldprompt_timer = 0;
+			M_ShieldPromptUseDefaults();
+			break;
+
+		case KEY_ENTER:
+			if (I_GetTime() <= shieldprompt_timer) // Don't mash past the pop-up by accident!
+				break;
+
+			S_StartSound(NULL, sfx_menu1);
+			noFurtherInput = true;
+			shieldprompt_timer = 0;
+
+			if (shieldprompt_currentchoice == 0)
+			{
+				OP_ChangeControlsDef.lastOn = 8; // Highlight Shield Ability in the controls menu
+				M_Setup1PControlsMenu(0); // Set up P1's controls menu and call M_SetupNextMenu
+			}
+			else if (shieldprompt_currentchoice == 1) // Copy the Spin buttons to the Shield buttons
+			{
+				CV_SetValue(&cv_controlperkey, 2); // Make sure that Controls per Key is "Several"
+
+				gamecontrol   [GC_SHIELD][0] = gamecontrol   [GC_SPIN][0];
+				gamecontrol   [GC_SHIELD][1] = gamecontrol   [GC_SPIN][1];
+				gamecontrolbis[GC_SHIELD][0] = gamecontrolbis[GC_SPIN][0];
+				gamecontrolbis[GC_SHIELD][1] = gamecontrolbis[GC_SPIN][1];
+				CV_SetValue(&cv_shieldaxis,  cv_spinaxis.value);
+				CV_SetValue(&cv_shieldaxis2, cv_spinaxis2.value);
+
+				M_StartMessage(M_GetText("Spin and Shield Ability are now\nthe same button."
+				"\n\nYou can always reassign them\nin the Options menu later."
+				"\n\n\nPress 'Enter' to continue\n"),
+					NULL, MM_NOTHING);
+				MessageDef.x = 36; // Change the pop-up message's background position/width
+				MessageDef.lastOn = (MessageDef.lastOn & ~0xFF) | 29;
+			}
+			else
+				M_ShieldPromptUseDefaults();
+			break;
+
+		case KEY_UPARROW:
+			S_StartSound(NULL, sfx_menu1);
+			shieldprompt_currentchoice = (shieldprompt_currentchoice+2)%3;
+			break;
+
+		case KEY_DOWNARROW:
+			S_StartSound(NULL, sfx_menu1);
+			shieldprompt_currentchoice = (shieldprompt_currentchoice+1)%3;
+			break;
+	}
+
+	MessageDef.prevMenu = &MainDef;
+}
+
+static void M_DrawShieldPromptMenu(void) // TODO: 2.3: Remove
+{
+	INT16 cursorx = (BASEVIDWIDTH/2) - 24;
+
+	V_DrawFill(10-3, 68-3, 300+6, 40+6, 159);
+	// V_DrawCenteredString doesn't centre newlines, so we have to draw each line separately
+	V_DrawCenteredString(BASEVIDWIDTH/2, 68, V_ALLOWLOWERCASE, "Welcome back! Since you last played,");
+	V_DrawCenteredString(BASEVIDWIDTH/2, 76, V_ALLOWLOWERCASE, "Spin has been split into separate");
+	V_DrawCenteredString(BASEVIDWIDTH/2, 84, V_ALLOWLOWERCASE, "\"Spin\" and \"Shield Ability\" controls.");
+
+	V_DrawCenteredString(BASEVIDWIDTH/2, 98, V_ALLOWLOWERCASE, "Do you want to assign Shield Ability now?");
+
+
+	V_DrawCenteredString(BASEVIDWIDTH/2, 164,
+		(shieldprompt_currentchoice == 0) ? V_YELLOWMAP : 0, "Open Control Setup");
+	V_DrawCenteredString(BASEVIDWIDTH/2, 172,
+		(shieldprompt_currentchoice == 1) ? V_YELLOWMAP : 0, "Keep the old behaviour");
+	V_DrawCenteredString(BASEVIDWIDTH/2, 180,
+		(shieldprompt_currentchoice == 2) ? V_YELLOWMAP : 0, "Use default Shield Ability buttons");
+
+	switch (shieldprompt_currentchoice)
+	{
+		case 0:  cursorx -= V_StringWidth("Open Control Setup",                 0)/2; break;
+		case 1:  cursorx -= V_StringWidth("Keep the old behaviour",             0)/2; break;
+		default: cursorx -= V_StringWidth("Use default Shield Ability buttons", 0)/2; break;
+	}
+	V_DrawScaledPatch(cursorx, 164 + (shieldprompt_currentchoice*8), 0, W_CachePatchName("M_CURSOR", PU_PATCH));
+}
+
+static menuitem_t OP_ShieldPromptMenu[] = {{IT_KEYHANDLER | IT_NOTHING, NULL, "", M_HandleShieldPromptMenu, 0}}; // TODO: 2.3: Remove
+
+menu_t OP_ShieldPromptDef = { // TODO: 2.3: Remove
+	MN_SPECIAL,
+	NULL,
+	1,
+	&MainDef,
+	OP_ShieldPromptMenu,
+	M_DrawShieldPromptMenu,
+	0, 0, 0, NULL
+};
+
 //
 // M_StartControlPanel
 //
@@ -3662,6 +3891,15 @@ void M_StartControlPanel(void)
 		currentMenu = &MainDef;
 		itemOn = singleplr;
 		M_UpdateItemOn();
+
+		if (shieldprompt_timer) // For old configs, show a pop-up about the new Shield button // TODO: 2.3: Remove
+		{
+			S_StartSound(NULL, sfx_strpst);
+			noFurtherInput = true;
+			shieldprompt_timer = I_GetTime() + TICRATE; // Don't mash past the pop-up by accident!
+
+			M_SetupNextMenu(&OP_ShieldPromptDef);
+		}
 	}
 	else if (modeattacking)
 	{
diff --git a/src/m_menu.h b/src/m_menu.h
index 99a5b6de4..55c0b4060 100644
--- a/src/m_menu.h
+++ b/src/m_menu.h
@@ -176,6 +176,7 @@ typedef struct
 extern menupres_t menupres[NUMMENUTYPES];
 extern UINT32 prevMenuId;
 extern UINT32 activeMenuId;
+extern tic_t shieldprompt_timer; // Show a prompt about the new Shield button for old configs // TODO: 2.3: Remove
 
 void M_InitMenuPresTables(void);
 UINT8 M_GetYoungestChildMenu(void);
diff --git a/src/m_misc.c b/src/m_misc.c
index a60bbea98..724717aa6 100644
--- a/src/m_misc.c
+++ b/src/m_misc.c
@@ -560,6 +560,11 @@ void M_FirstLoadConfig(void)
 	COM_BufInsertText(va("exec \"%s\"\n", configfile));
 	// no COM_BufExecute() needed; that does it right away
 
+	// For configs loaded at startup only, check for pre-Shield-button configs // TODO: 2.3: Remove
+	if (GETMAJOREXECVERSION(cv_execversion.value) < 55 // Pre-v2.2.14 configs
+	&& cv_execversion.value != 25) // Make sure that the config exists, too
+		shieldprompt_timer = 1;
+
 	// don't filter anymore vars and don't let this convsvar be changed
 	COM_BufInsertText(va("%s \"%d\"\n", cv_execversion.name, EXECVERSION));
 	CV_ToggleExecVersion(false);
diff --git a/src/m_vector.c b/src/m_vector.c
index 3132a869d..1b04f8ae1 100644
--- a/src/m_vector.c
+++ b/src/m_vector.c
@@ -21,6 +21,32 @@ void DVector3_Load(dvector3_t *vec, double x, double y, double z)
 	vec->z = z;
 }
 
+void DVector3_Copy(dvector3_t *a_o, const dvector3_t *a_i)
+{
+	memcpy(a_o, a_i, sizeof(dvector3_t));
+}
+
+void DVector3_Add(const dvector3_t *a_i, const dvector3_t *a_c, dvector3_t *a_o)
+{
+	a_o->x = a_i->x + a_c->x;
+	a_o->y = a_i->y + a_c->y;
+	a_o->z = a_i->z + a_c->z;
+}
+
+void DVector3_Subtract(const dvector3_t *a_i, const dvector3_t *a_c, dvector3_t *a_o)
+{
+	a_o->x = a_i->x - a_c->x;
+	a_o->y = a_i->y - a_c->y;
+	a_o->z = a_i->z - a_c->z;
+}
+
+void DVector3_Multiply(const dvector3_t *a_i, double a_c, dvector3_t *a_o)
+{
+	a_o->x = a_i->x * a_c;
+	a_o->y = a_i->y * a_c;
+	a_o->z = a_i->z * a_c;
+}
+
 double DVector3_Magnitude(const dvector3_t *a_normal)
 {
 	double xs = a_normal->x * a_normal->x;
diff --git a/src/m_vector.h b/src/m_vector.h
index 55669be03..1395744f2 100644
--- a/src/m_vector.h
+++ b/src/m_vector.h
@@ -19,6 +19,10 @@ typedef struct
 } dvector3_t;
 
 void DVector3_Load(dvector3_t *vec, double x, double y, double z);
+void DVector3_Copy(dvector3_t *a_o, const dvector3_t *a_i);
+void DVector3_Add(const dvector3_t *a_i, const dvector3_t *a_c, dvector3_t *a_o);
+void DVector3_Subtract(const dvector3_t *a_i, const dvector3_t *a_c, dvector3_t *a_o);
+void DVector3_Multiply(const dvector3_t *a_i, double a_c, dvector3_t *a_o);
 double DVector3_Magnitude(const dvector3_t *a_normal);
 double DVector3_Normalize(dvector3_t *a_normal);
 void DVector3_Negate(dvector3_t *a_o);
diff --git a/src/r_defs.h b/src/r_defs.h
index 17f94bc1b..51cc08646 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -60,6 +60,8 @@ typedef UINT8 lighttable_t;
 #define CMF_FADEFULLBRIGHTSPRITES  1
 #define CMF_FOG 4
 
+#define TEXTURE_255_IS_TRANSPARENT
+
 // ExtraColormap type. Use for extra_colormaps from now on.
 typedef struct extracolormap_s
 {
diff --git a/src/r_draw.h b/src/r_draw.h
index 77588d7de..6a6ab2db1 100644
--- a/src/r_draw.h
+++ b/src/r_draw.h
@@ -154,9 +154,11 @@ void R_VideoErase(size_t ofs, INT32 count);
 
 void R_DrawColumn_8(void);
 void R_DrawColumnClamped_8(void);
+void R_Draw2sMultiPatchColumn_8(void);
 void R_DrawShadeColumn_8(void);
 void R_DrawTranslucentColumn_8(void);
 void R_DrawTranslucentColumnClamped_8(void);
+void R_Draw2sMultiPatchTranslucentColumn_8(void);
 void R_DrawDropShadowColumn_8(void);
 void R_DrawTranslatedColumn_8(void);
 void R_DrawTranslatedTranslucentColumn_8(void);
diff --git a/src/r_draw8.c b/src/r_draw8.c
index 735127f88..2011e4640 100644
--- a/src/r_draw8.c
+++ b/src/r_draw8.c
@@ -192,6 +192,189 @@ void R_DrawColumnClamped_8(void)
 	}
 }
 
+void R_Draw2sMultiPatchColumn_8(void)
+{
+	INT32 count;
+	register UINT8 *dest;
+	register fixed_t frac;
+	fixed_t fracstep;
+
+	count = dc_yh - dc_yl;
+
+	if (count < 0) // Zero length, column does not exceed a pixel.
+		return;
+
+#ifdef RANGECHECK
+	if ((unsigned)dc_x >= (unsigned)vid.width || dc_yl < 0 || dc_yh >= vid.height)
+		return;
+#endif
+
+	// Framebuffer destination address.
+	dest = &topleft[dc_yl*vid.width + dc_x];
+
+	count++;
+
+	// Determine scaling, which is the only mapping to be done.
+	fracstep = dc_iscale;
+	frac = dc_texturemid + FixedMul((dc_yl << FRACBITS) - centeryfrac, fracstep);
+
+	// Inner loop that does the actual texture mapping, e.g. a DDA-like scaling.
+	// This is as fast as it gets.
+	{
+		register const UINT8 *source = dc_source;
+		register const lighttable_t *colormap = dc_colormap;
+		register INT32 heightmask = dc_texheight-1;
+		register UINT8 val;
+		if (dc_texheight & heightmask)   // not a power of 2 -- killough
+		{
+			heightmask++;
+			heightmask <<= FRACBITS;
+
+			if (frac < 0)
+				while ((frac += heightmask) <  0);
+			else
+				while (frac >= heightmask)
+					frac -= heightmask;
+
+			do
+			{
+				// Re-map color indices from wall texture column
+				//  using a lighting/special effects LUT.
+				// heightmask is the Tutti-Frutti fix
+				val = source[frac>>FRACBITS];
+
+				if (val != TRANSPARENTPIXEL)
+					*dest = colormap[val];
+
+				dest += vid.width;
+
+				// Avoid overflow.
+				if (fracstep > 0x7FFFFFFF - frac)
+					frac += fracstep - heightmask;
+				else
+					frac += fracstep;
+
+				while (frac >= heightmask)
+					frac -= heightmask;
+			} while (--count);
+		}
+		else
+		{
+			while ((count -= 2) >= 0) // texture height is a power of 2
+			{
+				val = source[(frac>>FRACBITS) & heightmask];
+				if (val != TRANSPARENTPIXEL)
+					*dest = colormap[val];
+				dest += vid.width;
+				frac += fracstep;
+				val = source[(frac>>FRACBITS) & heightmask];
+				if (val != TRANSPARENTPIXEL)
+					*dest = colormap[val];
+				dest += vid.width;
+				frac += fracstep;
+			}
+			if (count & 1)
+			{
+				val = source[(frac>>FRACBITS) & heightmask];
+				if (val != TRANSPARENTPIXEL)
+					*dest = colormap[val];
+			}
+		}
+	}
+}
+
+void R_Draw2sMultiPatchTranslucentColumn_8(void)
+{
+	INT32 count;
+	register UINT8 *dest;
+	register fixed_t frac;
+	fixed_t fracstep;
+
+	count = dc_yh - dc_yl;
+
+	if (count < 0) // Zero length, column does not exceed a pixel.
+		return;
+
+#ifdef RANGECHECK
+	if ((unsigned)dc_x >= (unsigned)vid.width || dc_yl < 0 || dc_yh >= vid.height)
+		return;
+#endif
+
+	// Framebuffer destination address.
+	dest = &topleft[dc_yl*vid.width + dc_x];
+
+	count++;
+
+	// Determine scaling, which is the only mapping to be done.
+	fracstep = dc_iscale;
+	frac = dc_texturemid + FixedMul((dc_yl << FRACBITS) - centeryfrac, fracstep);
+
+	// Inner loop that does the actual texture mapping, e.g. a DDA-like scaling.
+	// This is as fast as it gets.
+	{
+		register const UINT8 *source = dc_source;
+		register const UINT8 *transmap = dc_transmap;
+		register const lighttable_t *colormap = dc_colormap;
+		register INT32 heightmask = dc_texheight-1;
+		register UINT8 val;
+		if (dc_texheight & heightmask)   // not a power of 2 -- killough
+		{
+			heightmask++;
+			heightmask <<= FRACBITS;
+
+			if (frac < 0)
+				while ((frac += heightmask) <  0);
+			else
+				while (frac >= heightmask)
+					frac -= heightmask;
+
+			do
+			{
+				// Re-map color indices from wall texture column
+				//  using a lighting/special effects LUT.
+				// heightmask is the Tutti-Frutti fix
+				val = source[frac>>FRACBITS];
+
+				if (val != TRANSPARENTPIXEL)
+					*dest = *(transmap + (colormap[val]<<8) + (*dest));
+
+				dest += vid.width;
+
+				// Avoid overflow.
+				if (fracstep > 0x7FFFFFFF - frac)
+					frac += fracstep - heightmask;
+				else
+					frac += fracstep;
+
+				while (frac >= heightmask)
+					frac -= heightmask;
+			} while (--count);
+		}
+		else
+		{
+			while ((count -= 2) >= 0) // texture height is a power of 2
+			{
+				val = source[(frac>>FRACBITS) & heightmask];
+				if (val != TRANSPARENTPIXEL)
+					*dest = *(transmap + (colormap[val]<<8) + (*dest));
+				dest += vid.width;
+				frac += fracstep;
+				val = source[(frac>>FRACBITS) & heightmask];
+				if (val != TRANSPARENTPIXEL)
+					*dest = *(transmap + (colormap[val]<<8) + (*dest));
+				dest += vid.width;
+				frac += fracstep;
+			}
+			if (count & 1)
+			{
+				val = source[(frac>>FRACBITS) & heightmask];
+				if (val != TRANSPARENTPIXEL)
+					*dest = *(transmap + (colormap[val]<<8) + (*dest));
+			}
+		}
+	}
+}
+
 /**	\brief The R_DrawShadeColumn_8 function
 	Experiment to make software go faster. Taken from the Boom source
 */
diff --git a/src/r_fps.c b/src/r_fps.c
index 0773f228d..7f1f2bb30 100644
--- a/src/r_fps.c
+++ b/src/r_fps.c
@@ -120,6 +120,19 @@ static vector3_t *R_LerpVector3(const vector3_t *from, const vector3_t *to, fixe
 	return out;
 }
 
+static double R_LerpDouble(double from, double to, double frac)
+{
+	return from + (frac * (to - from));
+}
+
+static dvector3_t *R_LerpDVector3(const dvector3_t *from, const dvector3_t *to, double frac, dvector3_t *out)
+{
+	DVector3_Subtract(to, from, out);
+	DVector3_Multiply(out, frac, out);
+	DVector3_Add(from, out, out);
+	return out;
+}
+
 // recalc necessary stuff for mouseaiming
 // slopes are already calculated for the full possible view (which is 4*viewheight).
 // 18/08/18: (No it's actually 16*viewheight, thanks Jimita for finding this out)
@@ -497,6 +510,14 @@ void R_CreateInterpolator_DynSlope(thinker_t *thinker, pslope_t *slope)
 	FV2_Copy(&interp->dynslope.bakd, &slope->d);
 
 	interp->dynslope.oldzdelta = interp->dynslope.bakzdelta = slope->zdelta;
+
+	DVector3_Copy(&interp->dynslope.oldorigin, &slope->dorigin);
+	DVector3_Copy(&interp->dynslope.bakorigin, &slope->dorigin);
+
+	DVector3_Copy(&interp->dynslope.oldnormdir, &slope->dnormdir);
+	DVector3_Copy(&interp->dynslope.baknormdir, &slope->dnormdir);
+
+	interp->dynslope.olddzdelta = interp->dynslope.bakdzdelta = slope->dzdelta;
 }
 
 void R_InitializeLevelInterpolators(void)
@@ -561,6 +582,21 @@ static void UpdateLevelInterpolatorState(levelinterpolator_t *interp)
 		FV3_Copy(&interp->dynslope.bako, &interp->dynslope.slope->o);
 		FV2_Copy(&interp->dynslope.bakd, &interp->dynslope.slope->d);
 		interp->dynslope.bakzdelta = interp->dynslope.slope->zdelta;
+
+		DVector3_Copy(&interp->dynslope.oldorigin, &interp->dynslope.bakorigin);
+		DVector3_Copy(&interp->dynslope.oldnormdir, &interp->dynslope.baknormdir);
+		interp->dynslope.olddzdelta = interp->dynslope.bakdzdelta;
+
+		if (interp->dynslope.slope->moved)
+		{
+			P_CalculateSlopeVectors(interp->dynslope.slope);
+
+			interp->dynslope.slope->moved = false;
+		}
+
+		DVector3_Copy(&interp->dynslope.bakorigin, &interp->dynslope.slope->dorigin);
+		DVector3_Copy(&interp->dynslope.baknormdir, &interp->dynslope.slope->dnormdir);
+		interp->dynslope.bakdzdelta = interp->dynslope.slope->dzdelta;
 		break;
 	}
 }
@@ -646,7 +682,13 @@ void R_ApplyLevelInterpolators(fixed_t frac)
 			R_LerpVector3(&interp->dynslope.oldo, &interp->dynslope.bako, frac, &interp->dynslope.slope->o);
 			R_LerpVector2(&interp->dynslope.oldd, &interp->dynslope.bakd, frac, &interp->dynslope.slope->d);
 			interp->dynslope.slope->zdelta = R_LerpFixed(interp->dynslope.oldzdelta, interp->dynslope.bakzdelta, frac);
-			interp->dynslope.slope->moved = true;
+			if (rendermode == render_soft)
+			{
+				double dfrac = FixedToDouble(frac);
+				R_LerpDVector3(&interp->dynslope.oldorigin, &interp->dynslope.bakorigin, dfrac, &interp->dynslope.slope->dorigin);
+				R_LerpDVector3(&interp->dynslope.oldnormdir, &interp->dynslope.baknormdir, dfrac, &interp->dynslope.slope->dnormdir);
+				interp->dynslope.slope->dzdelta = R_LerpDouble(interp->dynslope.olddzdelta, interp->dynslope.bakdzdelta, dfrac);
+			}
 			break;
 		}
 	}
@@ -704,6 +746,10 @@ void R_RestoreLevelInterpolators(void)
 			FV3_Copy(&interp->dynslope.slope->o, &interp->dynslope.bako);
 			FV2_Copy(&interp->dynslope.slope->d, &interp->dynslope.bakd);
 			interp->dynslope.slope->zdelta = interp->dynslope.bakzdelta;
+
+			DVector3_Copy(&interp->dynslope.slope->dorigin, &interp->dynslope.bakorigin);
+			DVector3_Copy(&interp->dynslope.slope->dnormdir, &interp->dynslope.baknormdir);
+			interp->dynslope.slope->dzdelta = interp->dynslope.bakdzdelta;
 			break;
 		}
 	}
diff --git a/src/r_fps.h b/src/r_fps.h
index cd40b0a9a..33224a83a 100644
--- a/src/r_fps.h
+++ b/src/r_fps.h
@@ -115,6 +115,9 @@ typedef struct levelinterpolator_s {
 			vector3_t oldo, bako;
 			vector2_t oldd, bakd;
 			fixed_t oldzdelta, bakzdelta;
+			dvector3_t oldorigin, bakorigin;
+			dvector3_t oldnormdir, baknormdir;
+			double olddzdelta, bakdzdelta;
 		} dynslope;
 	};
 } levelinterpolator_t;
diff --git a/src/r_segs.c b/src/r_segs.c
index 51487d242..8e2a72ccc 100644
--- a/src/r_segs.c
+++ b/src/r_segs.c
@@ -120,6 +120,98 @@ static INT16 R_BottomLightLevel(side_t *side, UINT8 base_lightlevel)
 }
 */
 
+// If we have a multi-patch texture on a 2sided wall (rare) then we draw
+//  it using R_DrawColumn, else we draw it using R_DrawMaskedColumn, this
+//  way we don't have to store extra post_t info with each column for
+//  multi-patch textures. They are not normally needed as multi-patch
+//  textures don't have holes in it. At least not for now.
+static void R_Render2sidedMultiPatchColumn(column_t *column, unsigned lengthcol)
+{
+	INT32 topscreen, bottomscreen;
+
+	post_t *post = &column->posts[0];
+	if (!post->length)
+		return;
+
+	topscreen = sprtopscreen;
+	bottomscreen = topscreen + spryscale * lengthcol;
+
+	dc_yl = (sprtopscreen+FRACUNIT-1)>>FRACBITS;
+	dc_yh = (bottomscreen-1)>>FRACBITS;
+
+	if (windowtop != INT32_MAX && windowbottom != INT32_MAX)
+	{
+		dc_yl = ((windowtop + FRACUNIT)>>FRACBITS);
+		dc_yh = (windowbottom - 1)>>FRACBITS;
+	}
+
+	if (dc_yh >= mfloorclip[dc_x])
+		dc_yh =  mfloorclip[dc_x] - 1;
+	if (dc_yl <= mceilingclip[dc_x])
+		dc_yl =  mceilingclip[dc_x] + 1;
+
+	if (dc_yl >= vid.height || dc_yh < 0)
+		return;
+
+	if (dc_yl <= dc_yh && dc_yh < vid.height && dc_yh > 0)
+	{
+		dc_source = column->pixels + post->data_offset;
+		dc_postlength = post->length;
+
+		if (colfunc == colfuncs[BASEDRAWFUNC])
+			(colfuncs[COLDRAWFUNC_TWOSMULTIPATCH])();
+		else if (colfunc == colfuncs[COLDRAWFUNC_FUZZY])
+			(colfuncs[COLDRAWFUNC_TWOSMULTIPATCHTRANS])();
+		else
+			colfunc();
+	}
+}
+
+static void R_RenderFlipped2sidedMultiPatchColumn(column_t *column, unsigned lengthcol)
+{
+	INT32 topscreen, bottomscreen;
+
+	void (*localcolfunc)(void);
+
+	post_t *post = &column->posts[0];
+	if (!post->length)
+		return;
+
+	topscreen = sprtopscreen;
+	bottomscreen = topscreen + spryscale * lengthcol;
+
+	dc_yl = (sprtopscreen+FRACUNIT-1)>>FRACBITS;
+	dc_yh = (bottomscreen-1)>>FRACBITS;
+
+	if (windowtop != INT32_MAX && windowbottom != INT32_MAX)
+	{
+		dc_yl = ((windowtop + FRACUNIT)>>FRACBITS);
+		dc_yh = (windowbottom - 1)>>FRACBITS;
+	}
+
+	if (dc_yh >= mfloorclip[dc_x])
+		dc_yh =  mfloorclip[dc_x] - 1;
+	if (dc_yl <= mceilingclip[dc_x])
+		dc_yl =  mceilingclip[dc_x] + 1;
+
+	if (dc_yl >= vid.height || dc_yh < 0)
+		return;
+
+	if (dc_yl <= dc_yh && dc_yh < vid.height && dc_yh > 0)
+	{
+		dc_postlength = post->length;
+
+		if (colfunc == colfuncs[BASEDRAWFUNC])
+			localcolfunc = colfuncs[COLDRAWFUNC_TWOSMULTIPATCH];
+		else if (colfunc == colfuncs[COLDRAWFUNC_FUZZY])
+			localcolfunc = colfuncs[COLDRAWFUNC_TWOSMULTIPATCHTRANS];
+		else
+			localcolfunc = colfunc;
+
+		R_DrawFlippedPost(column->pixels + post->data_offset, post->length, localcolfunc);
+	}
+}
+
 void R_RenderMaskedSegRange(drawseg_t *ds, INT32 x1, INT32 x2)
 {
 	size_t pindex;
@@ -207,7 +299,16 @@ void R_RenderMaskedSegRange(drawseg_t *ds, INT32 x1, INT32 x2)
 	// Texture must be cached
 	R_CheckTextureCache(texnum);
 
-	if (vertflip) // vertically flipped?
+	// handle case where multipatch texture is drawn on a 2sided wall, multi-patch textures
+	// are not stored per-column with post info in SRB2
+	if (!textures[texnum]->transparency)
+	{
+		if (vertflip) // vertically flipped?
+			colfunc_2s = R_RenderFlipped2sidedMultiPatchColumn;
+		else
+			colfunc_2s = R_Render2sidedMultiPatchColumn;
+	}
+	else if (vertflip) // vertically flipped?
 		colfunc_2s = R_DrawFlippedMaskedColumn;
 	else
 		colfunc_2s = R_DrawMaskedColumn; // render the usual 2sided single-patch packed texture
@@ -836,7 +937,16 @@ void R_RenderThickSideRange(drawseg_t *ds, INT32 x1, INT32 x2, ffloor_t *pfloor)
 	// Texture must be cached
 	R_CheckTextureCache(texnum);
 
-	if (vertflip) // vertically flipped?
+	// handle case where multipatch texture is drawn on a 2sided wall, multi-patch textures
+	// are not stored per-column with post info in SRB2
+	if (!textures[texnum]->transparency)
+	{
+		if (vertflip) // vertically flipped?
+			colfunc_2s = R_RenderFlipped2sidedMultiPatchColumn;
+		else
+			colfunc_2s = R_Render2sidedMultiPatchColumn;
+	}
+	else if (vertflip) // vertically flipped?
 		colfunc_2s = R_DrawRepeatFlippedMaskedColumn;
 	else
 		colfunc_2s = R_DrawRepeatMaskedColumn;
@@ -919,21 +1029,25 @@ void R_RenderThickSideRange(drawseg_t *ds, INT32 x1, INT32 x2, ffloor_t *pfloor)
 		{
 			dc_iscale = 0xffffffffu / (unsigned)spryscale;
 
-			// Column has a single post and it matches the texture height, use regular column drawers
-			if (col->num_posts == 1 && col->posts[0].topdelta == 0 && col->posts[0].length == (unsigned)dc_texheight)
+			// Skip if texture is multipatch
+			if (textures[texnum]->transparency)
 			{
-				if (fuzzy)
-					colfunc = colfuncs[COLDRAWFUNC_FUZZY];
+				// Column has a single post and it matches the texture height, use regular column drawers
+				if (col->num_posts == 1 && col->posts[0].topdelta == 0 && col->posts[0].length == (unsigned)dc_texheight)
+				{
+					if (fuzzy)
+						colfunc = colfuncs[COLDRAWFUNC_FUZZY];
+					else
+						colfunc = colfuncs[BASEDRAWFUNC];
+				}
 				else
-					colfunc = colfuncs[BASEDRAWFUNC];
-			}
-			else
-			{
-				// Otherwise use column drawers with extra checks
-				if (fuzzy)
-					colfunc = R_DrawTranslucentColumnClamped_8;
-				else
-					colfunc = R_DrawColumnClamped_8;
+				{
+					// Otherwise use column drawers with extra checks
+					if (fuzzy)
+						colfunc = colfuncs[COLDRAWFUNC_CLAMPEDTRANS];
+					else
+						colfunc = colfuncs[COLDRAWFUNC_CLAMPED];
+				}
 			}
 		}
 
diff --git a/src/r_textures.c b/src/r_textures.c
index 5d3fe24db..6e01d5641 100644
--- a/src/r_textures.c
+++ b/src/r_textures.c
@@ -147,9 +147,9 @@ static void R_DrawFlippedColumnInCache(column_t *column, UINT8 *cache, texpatch_
 
 		if (count > 0)
 		{
-			for (; dest < cache + position + count; --source, is_opaque++)
+			for (; dest < cache + position + count; --source, dest++, is_opaque++)
 			{
-				*dest++ = *source;
+				*dest = *source;
 				*is_opaque = true;
 			}
 		}
@@ -295,7 +295,6 @@ UINT8 *R_GenerateTexture(size_t texnum)
 		UINT16 lumpnum = patch->lump;
 		UINT8 *pdata;
 		softwarepatch_t *realpatch;
-		boolean holey = false;
 
 #ifndef NO_PNG_LUMPS
 		UINT8 header[PNG_HEADER_SIZE];
@@ -310,9 +309,11 @@ UINT8 *R_GenerateTexture(size_t texnum)
 		pdata = W_CacheLumpNumPwad(wadnum, lumpnum, PU_CACHE);
 		realpatch = (softwarepatch_t *)pdata;
 
+		texture->transparency = false;
+
 		// Check the patch for holes.
 		if (texture->width > SHORT(realpatch->width) || texture->height > SHORT(realpatch->height))
-			holey = true;
+			texture->transparency = true;
 		else
 		{
 			UINT8 *colofs = (UINT8 *)realpatch->columnofs;
@@ -332,12 +333,12 @@ UINT8 *R_GenerateTexture(size_t texnum)
 					col = (doompost_t *)((UINT8 *)col + col->length + 4);
 				}
 				if (y < texture->height)
-					holey = true; // this texture is HOLEy! D:
+					texture->transparency = true; // this texture is HOLEy! D:
 			}
 		}
 
 		// If the patch uses transparency, we have to save it this way.
-		if (holey)
+		if (texture->transparency)
 		{
 			texture->flip = patch->flip;
 
@@ -378,6 +379,15 @@ UINT8 *R_GenerateTexture(size_t texnum)
 	temp_columns = Z_Calloc(sizeof(column_t) * texture->width, PU_STATIC, NULL);
 	temp_block = Z_Calloc(total_pixels, PU_STATIC, NULL);
 
+#ifdef TEXTURE_255_IS_TRANSPARENT
+	texture->transparency = false;
+
+	// Transparency hack
+	memset(temp_block, TRANSPARENTPIXEL, total_pixels);
+#else
+	texture->transparency = true;
+#endif
+
 	for (x = 0; x < texture->width; x++)
 	{
 		column_t *column = &temp_columns[x];
@@ -474,13 +484,27 @@ UINT8 *R_GenerateTexture(size_t texnum)
 	// Now write the columns
 	column_posts = Z_Calloc(sizeof(unsigned) * texture->width, PU_STATIC, NULL);
 
+#ifdef TEXTURE_255_IS_TRANSPARENT
+	total_posts = texture->width;
+	temp_posts = Z_Realloc(temp_posts, sizeof(post_t) * total_posts, PU_CACHE, NULL);
+#endif
+
 	for (x = 0; x < texture->width; x++)
 	{
 		post_t *post = NULL;
-		boolean was_opaque = false;
 
 		column_t *column = &temp_columns[x];
 
+#ifdef TEXTURE_255_IS_TRANSPARENT
+		post = &temp_posts[x];
+		post->topdelta = 0;
+		post->length = texture->height;
+		post->data_offset = 0;
+		column_posts[x] = x;
+		column->num_posts = 1;
+#else
+		boolean was_opaque = false;
+
 		column_posts[x] = (unsigned)-1;
 
 		for (INT32 y = 0; y < texture->height; y++)
@@ -510,6 +534,7 @@ UINT8 *R_GenerateTexture(size_t texnum)
 
 			post->length++;
 		}
+#endif
 	}
 
 	blocksize = (sizeof(column_t) * texture->width) + (sizeof(post_t) * total_posts) + (sizeof(UINT8) * total_pixels);
diff --git a/src/r_textures.h b/src/r_textures.h
index eb68ec09f..7e1588851 100644
--- a/src/r_textures.h
+++ b/src/r_textures.h
@@ -54,6 +54,7 @@ typedef struct
 	char name[8];
 	UINT32 hash;
 	UINT8 type; // TEXTURETYPE_*
+	boolean transparency;
 	INT16 width, height;
 	UINT8 flip; // 1 = flipx, 2 = flipy, 3 = both
 	void *flat; // The texture, as a flat.
diff --git a/src/screen.c b/src/screen.c
index 9a82a1561..014a20117 100644
--- a/src/screen.c
+++ b/src/screen.c
@@ -112,6 +112,10 @@ void SCR_SetDrawFuncs(void)
 		colfuncs[COLDRAWFUNC_SHADE] = R_DrawShadeColumn_8;
 		colfuncs[COLDRAWFUNC_SHADOWED] = R_DrawColumnShadowed_8;
 		colfuncs[COLDRAWFUNC_TRANSTRANS] = R_DrawTranslatedTranslucentColumn_8;
+		colfuncs[COLDRAWFUNC_CLAMPED] = R_DrawColumnClamped_8;
+		colfuncs[COLDRAWFUNC_CLAMPEDTRANS] = R_DrawTranslucentColumnClamped_8;
+		colfuncs[COLDRAWFUNC_TWOSMULTIPATCH] = R_Draw2sMultiPatchColumn_8;
+		colfuncs[COLDRAWFUNC_TWOSMULTIPATCHTRANS] = R_Draw2sMultiPatchTranslucentColumn_8;
 		colfuncs[COLDRAWFUNC_FOG] = R_DrawFogColumn_8;
 
 		spanfuncs[SPANDRAWFUNC_TRANS] = R_DrawTranslucentSpan_8;
diff --git a/src/screen.h b/src/screen.h
index 8b952e553..e23e8cbd6 100644
--- a/src/screen.h
+++ b/src/screen.h
@@ -97,6 +97,10 @@ enum
 	COLDRAWFUNC_SHADE,
 	COLDRAWFUNC_SHADOWED,
 	COLDRAWFUNC_TRANSTRANS,
+	COLDRAWFUNC_CLAMPED,
+	COLDRAWFUNC_CLAMPEDTRANS,
+	COLDRAWFUNC_TWOSMULTIPATCH,
+	COLDRAWFUNC_TWOSMULTIPATCHTRANS,
 	COLDRAWFUNC_FOG,
 
 	COLDRAWFUNC_MAX
diff --git a/src/snake.c b/src/snake.c
index 2349d5fdb..4219d5b8f 100644
--- a/src/snake.c
+++ b/src/snake.c
@@ -582,7 +582,7 @@ boolean Snake_JoyGrabber(void *opaque, event_t *ev)
 {
 	snake_t *snake = opaque;
 
-	if (ev->type == ev_joystick  && ev->key == 0)
+	if (snake != NULL && ev->type == ev_joystick  && ev->key == 0)
 	{
 		snake->joyevents[snake->joyeventcount] = ev;
 		snake->joyeventcount++;