From 9d13e6b7eca7c687af6d8154a711066ed8e395fe Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 00:31:00 +0200
Subject: [PATCH 01/12] - gl_colormap.h is no longer needed.

---
 src/gl/renderer/gl_colormap.h | 30 ------------------------------
 1 file changed, 30 deletions(-)
 delete mode 100644 src/gl/renderer/gl_colormap.h

diff --git a/src/gl/renderer/gl_colormap.h b/src/gl/renderer/gl_colormap.h
deleted file mode 100644
index 46e36431e..000000000
--- a/src/gl/renderer/gl_colormap.h
+++ /dev/null
@@ -1,30 +0,0 @@
-#ifndef __GL_COLORMAP
-#define __GL_COLORMAP
-
-#include "doomtype.h"
-#include "v_palette.h"
-#include "r_data/colormaps.h"
-
-struct lightlist_t;
-
-enum EColorManipulation
-{
-	CM_SPECIAL2D = -3,			// the special colormaps get passed as color pair from the 2D drawer so they need a different value here.
-	CM_PLAIN2D = -2,			// regular 2D drawing.
-	CM_INVALID=-1,
-	CM_DEFAULT=0,					// untranslated
-	CM_FIRSTSPECIALCOLORMAP,		// first special fixed colormap
-	CM_FIRSTSPECIALCOLORMAPFORCED= 0x08000000,	// first special fixed colormap, application forced (for 2D overlays)
-
-	CM_FOGLAYER = 0x10000000,	// Sprite shaped fog layer
-
-	// These are not to be passed to the texture manager
-	CM_LITE	= 0x20000000,		// special values to handle these items without excessive hacking
-	CM_TORCH= 0x20000010,		// These are not real color manipulations
-};
-
-#define CM_MAXCOLORMAP int(CM_FIRSTSPECIALCOLORMAP + SpecialColormaps.Size())
-#define CM_MAXCOLORMAPFORCED int(CM_FIRSTSPECIALCOLORMAPFORCED + SpecialColormaps.Size())
-
-
-#endif

From 0dc82fe75556ddfb5cd4a4d1eadcdde523660cb7 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 00:53:58 +0200
Subject: [PATCH 02/12] - header cleanup for gl_swscene.

---
 src/gl/scene/gl_swscene.cpp | 8 ++++----
 src/gl/scene/gl_swscene.h   | 9 ---------
 2 files changed, 4 insertions(+), 13 deletions(-)

diff --git a/src/gl/scene/gl_swscene.cpp b/src/gl/scene/gl_swscene.cpp
index 4281a2cc9..965a2f8dd 100644
--- a/src/gl/scene/gl_swscene.cpp
+++ b/src/gl/scene/gl_swscene.cpp
@@ -25,17 +25,17 @@
 **
 */
 
-#include "gl/system/gl_system.h"
-#include "gl/system/gl_debug.h"
-#include "gl/data/gl_vertexbuffer.h"
-#include "gl/shaders/gl_shader.h"
 #include "hwrenderer/textures/hw_ihwtexture.h"
+#include "hwrenderer/textures/hw_material.h"
+#include "r_renderer.h"
 #include "gl_swscene.h"
 #include "w_wad.h"
 #include "d_player.h"
 #include "textures/bitmap.h"
 #include "swrenderer/scene/r_light.h"
 
+#include "gl/renderer/gl_renderer.h"
+
 // [RH] Base blending values (for e.g. underwater)
 int BaseBlendR, BaseBlendG, BaseBlendB;
 float BaseBlendA;
diff --git a/src/gl/scene/gl_swscene.h b/src/gl/scene/gl_swscene.h
index f4fbb00a3..f54b2f3ed 100644
--- a/src/gl/scene/gl_swscene.h
+++ b/src/gl/scene/gl_swscene.h
@@ -4,9 +4,6 @@
 #include "r_defs.h"
 #include "m_fixed.h"
 #include "hwrenderer/scene/hw_clipper.h"
-#include "gl_portal.h"
-#include "gl/renderer/gl_lightdata.h"
-#include "gl/renderer/gl_renderer.h"
 #include "r_utility.h"
 #include "c_cvars.h"
 
@@ -18,12 +15,6 @@ class SWSceneDrawer
 	FSWSceneTexture *FBTexture = nullptr;
 	bool FBIsTruecolor = false;
 
-	
-	void BlendView (player_t *CPlayer, float blend[4]);
-	bool CreateResources();
-	void BindFBBuffer();
-
-
 public:
 	SWSceneDrawer();
 	~SWSceneDrawer();

From 286846a8ec7ab33e69ea25abc285a8048ac7f5f9 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 08:59:59 +0200
Subject: [PATCH 03/12] 2D must consider brightmaps.

---
 wadsrc/static/shaders/glsl/main.fp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/wadsrc/static/shaders/glsl/main.fp b/wadsrc/static/shaders/glsl/main.fp
index a90141d0d..ddd1f1439 100644
--- a/wadsrc/static/shaders/glsl/main.fp
+++ b/wadsrc/static/shaders/glsl/main.fp
@@ -504,7 +504,7 @@ void main()
 		
 		case 4:	// simple 2D (reuses a uniform for the special colormap for the color overlay.)
 		{
-			frag = frag * vColor;
+			frag = frag * ProcessLight(vColor);
 			frag.rgb = frag.rgb + uFixedColormapStart.rgb;
 			break;
 		}

From fbcf2033c609134b4a445e32a4d233ca7cd8dd84 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 09:34:02 +0200
Subject: [PATCH 04/12] Corrected render style definition

---
 src/r_data/renderstyle.cpp | 3 ++-
 src/r_data/renderstyle.h   | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/r_data/renderstyle.cpp b/src/r_data/renderstyle.cpp
index 9b0569ea4..7c27e822c 100644
--- a/src/r_data/renderstyle.cpp
+++ b/src/r_data/renderstyle.cpp
@@ -58,7 +58,8 @@ FRenderStyle LegacyRenderStyles[STYLE_Count] =
 	{ { STYLEOP_RevSub, STYLEALPHA_Src, STYLEALPHA_One, 0 } },											/* STYLE_Subtract*/
 	{ { STYLEOP_Add, STYLEALPHA_Src, STYLEALPHA_One, STYLEF_ColorIsFixed } },							/* STYLE_AddStencil */
 	{ { STYLEOP_Add, STYLEALPHA_Src, STYLEALPHA_One, STYLEF_RedIsAlpha | STYLEF_ColorIsFixed } },		/* STYLE_AddShaded */
-	{ { STYLEOP_Add, STYLEALPHA_InvDstCol, STYLEALPHA_Zero, 0 } },										/* STYLE_Multiply */
+	{ { STYLEOP_Add, STYLEALPHA_DstCol, STYLEALPHA_Zero, 0 } },											/* STYLE_Multiply */
+	{ { STYLEOP_Add, STYLEALPHA_InvDstCol, STYLEALPHA_Zero, 0 } },										/* STYLE_InverseMultiply */
 };
 
 double GetAlpha(int type, double alpha)
diff --git a/src/r_data/renderstyle.h b/src/r_data/renderstyle.h
index d5393f487..04970f962 100644
--- a/src/r_data/renderstyle.h
+++ b/src/r_data/renderstyle.h
@@ -62,6 +62,7 @@ enum ERenderStyle
 	STYLE_AddStencil,		// Fill image interior with alphacolor
 	STYLE_AddShaded,		// Treat patch data as alpha values for alphacolor
 	STYLE_Multiply,			// Multiply source with destination (HW renderer only.)
+	STYLE_InverseMultiply,	// Multiply source with inverse of destination (HW renderer only.)
 
 	STYLE_Count
 };

From 90a1614ac8e7e3f19c865f4eb2b9676d79acb502 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 09:34:43 +0200
Subject: [PATCH 05/12] The intermission drawer doesn't need to check the
 return of Begin2D anymore

---
 src/intermission/intermission.cpp | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/src/intermission/intermission.cpp b/src/intermission/intermission.cpp
index 615f79fae..115084637 100644
--- a/src/intermission/intermission.cpp
+++ b/src/intermission/intermission.cpp
@@ -229,21 +229,14 @@ void DIntermissionScreenFader::Drawer ()
 		if (mType == FADE_In) factor = 1.0 - factor;
 		int color = MAKEARGB(int(factor*255), 0,0,0);
 
-		if (screen->Begin2D(false))
+		screen->Begin2D(false);
+		screen->DrawTexture (TexMan[mBackground], 0, 0, DTA_Fullscreen, true, DTA_ColorOverlay, color, TAG_DONE);
+		for (unsigned i=0; i < mOverlays.Size(); i++)
 		{
-			screen->DrawTexture (TexMan[mBackground], 0, 0, DTA_Fullscreen, true, DTA_ColorOverlay, color, TAG_DONE);
-			for (unsigned i=0; i < mOverlays.Size(); i++)
-			{
-				if (CheckOverlay(i))
-					screen->DrawTexture (TexMan[mOverlays[i].mPic], mOverlays[i].x, mOverlays[i].y, DTA_320x200, true, DTA_ColorOverlay, color, TAG_DONE);
-			}
-			screen->FillBorder (NULL);
-		}
-		else
-		{
-			V_SetBlend (0,0,0,int(256*factor));
-			Super::Drawer();
+			if (CheckOverlay(i))
+				screen->DrawTexture (TexMan[mOverlays[i].mPic], mOverlays[i].x, mOverlays[i].y, DTA_320x200, true, DTA_ColorOverlay, color, TAG_DONE);
 		}
+		screen->FillBorder (NULL);
 	}
 }
 

From bbea6e7e3ca2aab2cfbd6a4f0fa7309845ecfdf8 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 09:58:19 +0200
Subject: [PATCH 06/12] Begin2D doesn't need a return type anymore

This was to tell the caller that software 2D was in use, but that doesn't exist anymore
---
 src/gl/scene/gl_wall.h                | 2 ++
 src/gl/scene/gl_walls_draw.cpp        | 2 +-
 src/gl/system/gl_framebuffer.cpp      | 4 +---
 src/gl/system/gl_framebuffer.h        | 2 +-
 src/hwrenderer/scene/hw_drawstructs.h | 2 ++
 src/v_video.cpp                       | 3 +--
 src/v_video.h                         | 2 +-
 7 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/gl/scene/gl_wall.h b/src/gl/scene/gl_wall.h
index 38ff975ab..504c6f21c 100644
--- a/src/gl/scene/gl_wall.h
+++ b/src/gl/scene/gl_wall.h
@@ -11,7 +11,9 @@
 #include "r_data/colormaps.h"
 #include "hwrenderer/scene/hw_drawstructs.h"
 
+#ifdef _MSC_VER
 #pragma warning(disable:4244)
+#endif
 
 struct GLHorizonInfo;
 struct F3DFloor;
diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index 33d050805..de2e9a657 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -153,7 +153,7 @@ bool GLWall::SetupLights(FDynLightData &lightdata)
 
 void FDrawInfo::RenderWall(GLWall *wall, int textured)
 {
-	assert(vertcount > 0);
+	assert(wall->vertcount > 0);
 	gl_RenderState.Apply();
 	gl_RenderState.ApplyLightIndex(wall->dynlightindex);
 	GLRenderer->mVBO->RenderArray(GL_TRIANGLE_FAN, wall->vertindex, wall->vertcount);
diff --git a/src/gl/system/gl_framebuffer.cpp b/src/gl/system/gl_framebuffer.cpp
index a66f10291..e7844a219 100644
--- a/src/gl/system/gl_framebuffer.cpp
+++ b/src/gl/system/gl_framebuffer.cpp
@@ -481,10 +481,9 @@ void OpenGLFrameBuffer::SetClearColor(int color)
 //
 //
 //==========================================================================
-bool OpenGLFrameBuffer::Begin2D(bool copy3d)
+void OpenGLFrameBuffer::Begin2D(bool copy3d)
 {
 	Super::Begin2D(copy3d);
-	ClearClipRect();
 	gl_RenderState.mViewMatrix.loadIdentity();
 	gl_RenderState.mProjectionMatrix.ortho(0, GetWidth(), GetHeight(), 0, -1.0f, 1.0f);
 	gl_RenderState.ApplyMatrices();
@@ -503,7 +502,6 @@ bool OpenGLFrameBuffer::Begin2D(bool copy3d)
 
 	if (GLRenderer != NULL)
 			GLRenderer->Begin2D();
-	return true;
 }
 
 //===========================================================================
diff --git a/src/gl/system/gl_framebuffer.h b/src/gl/system/gl_framebuffer.h
index 6410a3443..0be4428f2 100644
--- a/src/gl/system/gl_framebuffer.h
+++ b/src/gl/system/gl_framebuffer.h
@@ -34,7 +34,7 @@ public:
 	PalEntry *GetPalette () override;
 	bool SetFlash(PalEntry rgb, int amount) override;
 	void GetFlash(PalEntry &rgb, int &amount) override;
-	bool Begin2D(bool copy3d) override;
+	void Begin2D(bool copy3d) override;
 	void GameRestart() override;
 	void InitForLevel() override;
 	void SetClearColor(int color) override;
diff --git a/src/hwrenderer/scene/hw_drawstructs.h b/src/hwrenderer/scene/hw_drawstructs.h
index 56f9d9389..262e5ed05 100644
--- a/src/hwrenderer/scene/hw_drawstructs.h
+++ b/src/hwrenderer/scene/hw_drawstructs.h
@@ -9,7 +9,9 @@
 #include "textures/textures.h"
 #include "r_data/colormaps.h"
 
+#ifdef _MSC_VER
 #pragma warning(disable:4244)
+#endif
 
 struct GLHorizonInfo;
 struct GLSkyInfo;
diff --git a/src/v_video.cpp b/src/v_video.cpp
index b6d8a1213..5c0395331 100644
--- a/src/v_video.cpp
+++ b/src/v_video.cpp
@@ -859,11 +859,10 @@ void DFrameBuffer::SetBlendingRect (int x1, int y1, int x2, int y2)
 //
 //==========================================================================
 
-bool DFrameBuffer::Begin2D (bool copy3d)
+void DFrameBuffer::Begin2D (bool copy3d)
 {
 	isIn2D = true;
 	ClearClipRect();
-	return false;
 }
 
 //==========================================================================
diff --git a/src/v_video.h b/src/v_video.h
index f2c8a711b..b976e5415 100644
--- a/src/v_video.h
+++ b/src/v_video.h
@@ -385,7 +385,7 @@ public:
 
 	// Begin 2D drawing operations.
 	// Returns true if hardware-accelerated 2D has been entered, false if not.
-	virtual bool Begin2D(bool copy3d);
+	virtual void Begin2D(bool copy3d);
 	void End2D() { isIn2D = false; }
 
 	// Returns true if Begin2D has been called and 2D drawing is now active

From 200848a4873702f2b9ec83ac18b7cf5feda39004 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 11:40:23 +0200
Subject: [PATCH 07/12] Decal work. Not finished yet.

---
 src/gl/compatibility/gl_20.cpp        |   1 +
 src/gl/scene/gl_decal.cpp             | 297 ++++++++++++++------------
 src/gl/scene/gl_wall.h                |   2 +-
 src/gl/scene/gl_walls_draw.cpp        |   2 +
 src/hwrenderer/scene/hw_drawinfo.h    |   2 +
 src/hwrenderer/scene/hw_drawstructs.h |   2 +
 6 files changed, 173 insertions(+), 133 deletions(-)

diff --git a/src/gl/compatibility/gl_20.cpp b/src/gl/compatibility/gl_20.cpp
index 57405e4ab..1c99b1825 100644
--- a/src/gl/compatibility/gl_20.cpp
+++ b/src/gl/compatibility/gl_20.cpp
@@ -555,6 +555,7 @@ bool FDrawInfo::PutWallCompat(GLWall *wall, int passflag)
 	int list = list_indices[masked][foggy];
 	auto newwall = dldrawlists[list].NewWall();
 	*newwall = *wall;
+	if (!masked) newwall->ProcessDecals(this);
 	return true;
 
 }
diff --git a/src/gl/scene/gl_decal.cpp b/src/gl/scene/gl_decal.cpp
index 0dd0b91f3..fa6f3dbba 100644
--- a/src/gl/scene/gl_decal.cpp
+++ b/src/gl/scene/gl_decal.cpp
@@ -46,143 +46,141 @@ struct DecalVertex
 	float u,v;
 };
 
-//==========================================================================
-//
-//
-//
-//==========================================================================
-void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
+struct GLDecal
+{
+	unsigned int vertindex;
+	FMaterial *gltexture;
+	GLWall *wall;
+	DBaseDecal *decal;
+	DecalVertex dv[4];
+	float zcenter;
+
+	int light;
+	int rel;
+	float a;
+	FColormap colormap;
+
+};
+
+void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 {
-	auto seg = wall->seg;
 	line_t * line = seg->linedef;
 	side_t * side = seg->sidedef;
 	int i;
 	float zpos;
-	int light;
-	int rel;
-	float a;
 	bool flipx, flipy;
-	DecalVertex dv[4];
 	FTextureID decalTile;
-
-
+	GLDecal gldecal;
+	
+	
 	if (decal->RenderFlags & RF_INVISIBLE) return;
-	if (wall->type == RENDERWALL_FFBLOCK && wall->gltexture->isMasked()) return;	// No decals on 3D floors with transparent textures.
-
-	//if (decal->sprite != 0xffff)
-	{
-		decalTile = decal->PicNum;
-		flipx = !!(decal->RenderFlags & RF_XFLIP);
-		flipy = !!(decal->RenderFlags & RF_YFLIP);
-	}
-	/*
-	else
-	{
-	decalTile = SpriteFrames[sprites[decal->sprite].spriteframes + decal->frame].lump[0];
-	flipx = SpriteFrames[sprites[decal->sprite].spriteframes + decal->frame].flip & 1;
-	}
-	*/
+	if (type == RENDERWALL_FFBLOCK && gltexture->isMasked()) return;	// No decals on 3D floors with transparent textures.
+	
+	
+	decalTile = decal->PicNum;
+	flipx = !!(decal->RenderFlags & RF_XFLIP);
+	flipy = !!(decal->RenderFlags & RF_YFLIP);
 
+	
 	FTexture *texture = TexMan[decalTile];
 	if (texture == NULL) return;
 
-	FMaterial *tex;
-
-
-	tex = FMaterial::ValidateTexture(texture, true);
-
-
+	
 	// the sectors are only used for their texture origin coordinates
 	// so we don't need the fake sectors for deep water etc.
 	// As this is a completely split wall fragment no further splits are
 	// necessary for the decal.
 	sector_t *frontsector;
-
+	
 	// for 3d-floor segments use the model sector as reference
 	if ((decal->RenderFlags&RF_CLIPMASK) == RF_CLIPMID) frontsector = decal->Sector;
 	else frontsector = seg->frontsector;
-
+	
 	switch (decal->RenderFlags & RF_RELMASK)
 	{
-	default:
-		// No valid decal can have this type. If one is encountered anyway
-		// it is in some way invalid so skip it.
-		return;
-		//zpos = decal->z;
-		//break;
-
-	case RF_RELUPPER:
-		if (wall->type != RENDERWALL_TOP) return;
-		if (line->flags & ML_DONTPEGTOP)
-		{
-			zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::ceiling);
-		}
-		else
-		{
-			zpos = decal->Z + seg->backsector->GetPlaneTexZ(sector_t::ceiling);
-		}
-		break;
-	case RF_RELLOWER:
-		if (wall->type != RENDERWALL_BOTTOM) return;
-		if (line->flags & ML_DONTPEGBOTTOM)
-		{
-			zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::ceiling);
-		}
-		else
-		{
-			zpos = decal->Z + seg->backsector->GetPlaneTexZ(sector_t::floor);
-		}
-		break;
-	case RF_RELMID:
-		if (wall->type == RENDERWALL_TOP || wall->type == RENDERWALL_BOTTOM) return;
-		if (line->flags & ML_DONTPEGBOTTOM)
-		{
-			zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::floor);
-		}
-		else
-		{
-			zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::ceiling);
-		}
+		default:
+			// No valid decal can have this type. If one is encountered anyway
+			// it is in some way invalid so skip it.
+			return;
+			//zpos = decal->z;
+			//break;
+			
+		case RF_RELUPPER:
+			if (type != RENDERWALL_TOP) return;
+			if (line->flags & ML_DONTPEGTOP)
+			{
+				zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::ceiling);
+			}
+			else
+			{
+				zpos = decal->Z + seg->backsector->GetPlaneTexZ(sector_t::ceiling);
+			}
+			break;
+		case RF_RELLOWER:
+			if (type != RENDERWALL_BOTTOM) return;
+			if (line->flags & ML_DONTPEGBOTTOM)
+			{
+				zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::ceiling);
+			}
+			else
+			{
+				zpos = decal->Z + seg->backsector->GetPlaneTexZ(sector_t::floor);
+			}
+			break;
+		case RF_RELMID:
+			if (type == RENDERWALL_TOP || type == RENDERWALL_BOTTOM) return;
+			if (line->flags & ML_DONTPEGBOTTOM)
+			{
+				zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::floor);
+			}
+			else
+			{
+				zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::ceiling);
+			}
 	}
-
+	
+	memset(&gldecal, 0, sizeof(gldecal));
+	gldecal.gltexture = FMaterial::ValidateTexture(texture, true);
+	gldecal.wall = this;
+	gldecal.decal = decal;
+	
 	if (decal->RenderFlags & RF_FULLBRIGHT)
 	{
-		light = 255;
-		rel = 0;
+		gldecal.light = 255;
+		gldecal.rel = 0;
 	}
 	else
 	{
-		light = wall->lightlevel;
-		rel = wall->rellight + getExtraLight();
+		gldecal.light = lightlevel;
+		gldecal.rel = rellight + getExtraLight();
 	}
-
-	FColormap p = wall->Colormap;
-
+	
+	gldecal.colormap = Colormap;
+	
 	if (level.flags3 & LEVEL3_NOCOLOREDSPRITELIGHTING)
 	{
-		p.Decolorize();
+		gldecal.colormap.Decolorize();
 	}
-
-
-
-	a = decal->Alpha;
-
+	
+	gldecal.a = decal->Alpha;
+	
 	// now clip the decal to the actual polygon
+	FMaterial *tex = gldecal.gltexture;
+
 	float decalwidth = tex->TextureWidth()  * decal->ScaleX;
 	float decalheight = tex->TextureHeight() * decal->ScaleY;
 	float decallefto = tex->GetLeftOffset() * decal->ScaleX;
 	float decaltopo = tex->GetTopOffset()  * decal->ScaleY;
-
-	auto &glseg = wall->glseg;
+	
 	float leftedge = glseg.fracleft * side->TexelLength;
 	float linelength = glseg.fracright * side->TexelLength - leftedge;
-
+	
 	// texel index of the decal's left edge
 	float decalpixpos = (float)side->TexelLength * decal->LeftDistance - (flipx ? decalwidth - decallefto : decallefto) - leftedge;
-
+	
 	float left, right;
 	float lefttex, righttex;
-
+	
 	// decal is off the left edge
 	if (decalpixpos < 0)
 	{
@@ -194,7 +192,7 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 		left = decalpixpos;
 		lefttex = 0;
 	}
-
+	
 	// decal is off the right edge
 	if (decalpixpos + decalwidth > linelength)
 	{
@@ -207,36 +205,37 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 		righttex = decalwidth;
 	}
 	if (right <= left) return;	// nothing to draw
-
+	
 	// one texture unit on the wall as vector
 	float vx = (glseg.x2 - glseg.x1) / linelength;
 	float vy = (glseg.y2 - glseg.y1) / linelength;
-
+	
+	DecalVertex *dv = gldecal.dv;
 	dv[1].x = dv[0].x = glseg.x1 + vx * left;
 	dv[1].y = dv[0].y = glseg.y1 + vy * left;
-
+	
 	dv[3].x = dv[2].x = glseg.x1 + vx * right;
 	dv[3].y = dv[2].y = glseg.y1 + vy * right;
-
+	
 	zpos += (flipy ? decalheight - decaltopo : decaltopo);
-
+	
 	dv[1].z = dv[2].z = zpos;
 	dv[0].z = dv[3].z = dv[1].z - decalheight;
 	dv[1].v = dv[2].v = tex->GetVT();
-
+	
 	dv[1].u = dv[0].u = tex->GetU(lefttex / decal->ScaleX);
 	dv[3].u = dv[2].u = tex->GetU(righttex / decal->ScaleX);
 	dv[0].v = dv[3].v = tex->GetVB();
-
+	
 	// now clip to the top plane
-	float vzt = (wall->ztop[1] - wall->ztop[0]) / linelength;
-	float topleft = wall->ztop[0] + vzt * left;
-	float topright = wall->ztop[0] + vzt * right;
-
+	float vzt = (ztop[1] - ztop[0]) / linelength;
+	float topleft = ztop[0] + vzt * left;
+	float topright = ztop[0] + vzt * right;
+	
 	// completely below the wall
 	if (topleft < dv[0].z && topright < dv[3].z)
 		return;
-
+	
 	if (topleft < dv[1].z || topright < dv[2].z)
 	{
 		// decal has to be clipped at the top
@@ -246,16 +245,16 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 		dv[1].z = topleft;
 		dv[2].z = topright;
 	}
-
+	
 	// now clip to the bottom plane
-	float vzb = (wall->zbottom[1] - wall->zbottom[0]) / linelength;
-	float bottomleft = wall->zbottom[0] + vzb * left;
-	float bottomright = wall->zbottom[0] + vzb * right;
-
+	float vzb = (zbottom[1] - zbottom[0]) / linelength;
+	float bottomleft = zbottom[0] + vzb * left;
+	float bottomright = zbottom[0] + vzb * right;
+	
 	// completely above the wall
 	if (bottomleft > dv[1].z && bottomright > dv[2].z)
 		return;
-
+	
 	if (bottomleft > dv[0].z || bottomright > dv[3].z)
 	{
 		// decal has to be clipped at the bottom
@@ -265,8 +264,8 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 		dv[0].z = bottomleft;
 		dv[3].z = bottomright;
 	}
-
-
+	
+	
 	if (flipx)
 	{
 		float ur = tex->GetUR();
@@ -278,13 +277,56 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 		for (i = 0; i < 4; i++) dv[i].v = vb - dv[i].v;
 	}
 
+	gldecal.zcenter = zpos - decalheight * 0.5f;
+	
+	auto verts = gl_drawinfo->AllocVertices(4);
+	gldecal.vertindex = verts.second;
+	
+	for (i = 0; i < 4; i++)
+	{
+		verts.first[i].Set(dv[i].x, dv[i].z, dv[i].y, dv[i].u, dv[i].v);
+	}
+	di->AddDecal(&gldecal);
+}
+
+//==========================================================================
+//
+//
+//
+//==========================================================================
+void GLWall::ProcessDecals(HWDrawInfo *di)
+{
+	if (seg->sidedef != nullptr)
+	{
+		DBaseDecal *decal = seg->sidedef->AttachedDecals;
+		while (decal)
+		{
+			ProcessDecal(di, decal);
+			decal = decal->WallNext;
+		}
+	}
+}
+
+//==========================================================================
+//
+//
+//
+//==========================================================================
+void FDrawInfo::DrawDecal(GLWall *__wall, DBaseDecal *__decal)
+{
+	GLDecal *gldecal;
+	auto wall = gldecal->wall;
+	auto decal = gldecal->decal;
+	auto tex = gldecal->gltexture;
+	auto &seg = wall->seg;
+	
 	// calculate dynamic light effect.
 	if (gl_lights && GLRenderer->mLightCount && !mDrawer->FixedColormap && gl_light_sprites)
 	{
 		// Note: This should be replaced with proper shader based lighting.
 		double x, y;
 		decal->GetXY(seg->sidedef, x, y);
-		gl_SetDynSpriteLight(nullptr, x, y, zpos - decalheight * 0.5f, wall->sub);
+		gl_SetDynSpriteLight(nullptr, x, y, gldecal->zcenter, wall->sub);
 	}
 
 	// alpha color only has an effect when using an alpha texture.
@@ -293,9 +335,6 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 		gl_RenderState.SetObjectColor(decal->AlphaColor | 0xff000000);
 	}
 
-
-
-
 	gl_SetRenderStyle(decal->RenderStyle, false, false);
 	gl_RenderState.SetMaterial(tex, CLAMP_XY, decal->Translation, 0, !!(decal->RenderStyle.Flags & STYLEF_RedIsAlpha));
 
@@ -305,7 +344,7 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 	else gl_RenderState.AlphaFunc(GL_GREATER, 0.f);
 
 
-	mDrawer->SetColor(light, rel, p, a);
+	mDrawer->SetColor(gldecal->light, gldecal->rel, gldecal->colormap, gldecal->a);
 	// for additively drawn decals we must temporarily set the fog color to black.
 	PalEntry fc = gl_RenderState.GetFogColor();
 	if (decal->RenderStyle.BlendOp == STYLEOP_Add && decal->RenderStyle.DestAlpha == STYLEALPHA_One)
@@ -313,18 +352,12 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 		gl_RenderState.SetFog(0, -1);
 	}
 
-	gl_RenderState.SetNormal(glseg.Normal());
-
-	FQuadDrawer qd;
-	for (i = 0; i < 4; i++)
-	{
-		qd.Set(i, dv[i].x, dv[i].z, dv[i].y, dv[i].u, dv[i].v);
-	}
+	gl_RenderState.SetNormal(wall->glseg.Normal());
 
 	if (wall->lightlist == nullptr)
 	{
 		gl_RenderState.Apply();
-		qd.Render(GL_TRIANGLE_FAN);
+		GLRenderer->mVBO->RenderArray(GL_TRIANGLE_FAN, gldecal->vertindex, 4);
 	}
 	else
 	{
@@ -334,6 +367,7 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 		{
 			secplane_t &lowplane = k == lightlist.Size() - 1 ? wall->bottomplane : lightlist[k + 1].plane;
 
+			DecalVertex *dv = gldecal->dv;
 			float low1 = lowplane.ZatPoint(dv[1].x, dv[1].y);
 			float low2 = lowplane.ZatPoint(dv[2].x, dv[2].y);
 
@@ -343,13 +377,13 @@ void FDrawInfo::DrawDecal(GLWall *wall, DBaseDecal *decal)
 				FColormap thiscm;
 				thiscm.FadeColor = wall->Colormap.FadeColor;
 				thiscm.CopyFrom3DLight(&lightlist[k]);
-				mDrawer->SetColor(thisll, rel, thiscm, a);
+				mDrawer->SetColor(thisll, gldecal->rel, thiscm, gldecal->a);
 				if (level.flags3 & LEVEL3_NOCOLOREDSPRITELIGHTING) thiscm.Decolorize();
-				mDrawer->SetFog(thisll, rel, &thiscm, wall->RenderStyle == STYLE_Add);
+				mDrawer->SetFog(thisll, gldecal->rel, &thiscm, wall->RenderStyle == STYLE_Add);
 				gl_RenderState.SetSplitPlanes(lightlist[k].plane, lowplane);
 
 				gl_RenderState.Apply();
-				qd.Render(GL_TRIANGLE_FAN);
+				GLRenderer->mVBO->RenderArray(GL_TRIANGLE_FAN, gldecal->vertindex, 4);
 			}
 			if (low1 <= dv[0].z && low2 <= dv[3].z) break;
 		}
@@ -391,7 +425,6 @@ void FDrawInfo::DoDrawDecals(GLWall *wall)
 		{
 			gl_RenderState.EnableSplit(false);
 		}
-
 	}
 }
 
diff --git a/src/gl/scene/gl_wall.h b/src/gl/scene/gl_wall.h
index 504c6f21c..03cc9dadd 100644
--- a/src/gl/scene/gl_wall.h
+++ b/src/gl/scene/gl_wall.h
@@ -86,7 +86,7 @@ public:
 	void SetFrom3DFloor(F3DFloor *rover, bool top, bool underside);
 	void ProcessSector(sector_t * frontsector);
 	void Draw(int pass, bool trans);
-
+	
 	GLFlat(const GLFlat &other)
 	{
 		memcpy(this, &other, sizeof(GLFlat));
diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index de2e9a657..4a68d4ac6 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -461,6 +461,7 @@ void FDrawInfo::AddWall(GLWall *wall)
 		wall->MakeVertices(this, false);
 		auto newwall = drawlists[list].NewWall();
 		*newwall = *wall;
+		if (!masked) newwall->ProcessDecals(this);
 	}
 	wall->dynlightindex = -1;
 }
@@ -482,6 +483,7 @@ void FDrawInfo::AddMirrorSurface(GLWall *w)
 	tcs[GLWall::LOLFT].u = tcs[GLWall::LORGT].u = tcs[GLWall::UPLFT].u = tcs[GLWall::UPRGT].u = v.X;
 	tcs[GLWall::LOLFT].v = tcs[GLWall::LORGT].v = tcs[GLWall::UPLFT].v = tcs[GLWall::UPRGT].v = v.Z;
 	newwall->MakeVertices(this, false);
+	newwall->ProcessDecals(this);
 }
 
 //==========================================================================
diff --git a/src/hwrenderer/scene/hw_drawinfo.h b/src/hwrenderer/scene/hw_drawinfo.h
index 13533cbfc..e2db5f132 100644
--- a/src/hwrenderer/scene/hw_drawinfo.h
+++ b/src/hwrenderer/scene/hw_drawinfo.h
@@ -6,6 +6,7 @@ struct FSectorPortalGroup;
 struct FLinePortalSpan;
 struct FFlatVertex;
 class GLWall;
+struct GLDecal;
 
 //==========================================================================
 //
@@ -127,6 +128,7 @@ public:
     virtual void AddWall(GLWall *w) = 0;
 	virtual void AddPortal(GLWall *w, int portaltype) = 0;
     virtual void AddMirrorSurface(GLWall *w) = 0;
+    virtual void AddDecal(GLDecal *d) = 0;
     virtual void ProcessActorsInPortal(FLinePortalSpan *glport) = 0;
 	virtual std::pair<FFlatVertex *, unsigned int> AllocVertices(unsigned int count) = 0;
 
diff --git a/src/hwrenderer/scene/hw_drawstructs.h b/src/hwrenderer/scene/hw_drawstructs.h
index 262e5ed05..a508b2a81 100644
--- a/src/hwrenderer/scene/hw_drawstructs.h
+++ b/src/hwrenderer/scene/hw_drawstructs.h
@@ -236,6 +236,8 @@ public:
 					  float fch1, float fch2, float ffh1, float ffh2,
 					  float bch1, float bch2, float bfh1, float bfh2);
 
+    void ProcessDecal(HWDrawInfo *di, DBaseDecal *decal);
+    void ProcessDecals(HWDrawInfo *di);
 
 	void CreateVertices(FFlatVertex *&ptr, bool nosplit);
 	void SplitLeftEdge (FFlatVertex *&ptr);

From 58c0431396078d01ece5066d3b2cfbf1ae27e527 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 18:53:01 +0200
Subject: [PATCH 08/12] - copied gl_SetupLights to hw_walls.cpp.

---
 src/gl/scene/gl_walls_draw.cpp    | 99 -------------------------------
 src/hwrenderer/scene/hw_walls.cpp | 99 +++++++++++++++++++++++++++++++
 2 files changed, 99 insertions(+), 99 deletions(-)

diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index 33d050805..8c954acf6 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -44,105 +44,6 @@ EXTERN_CVAR(Bool, gl_seamless)
 
 FDynLightData lightdata;
 
-//==========================================================================
-//
-// Collect lights for shader
-//
-//==========================================================================
-
-bool GLWall::SetupLights(FDynLightData &lightdata)
-{
-	if (RenderStyle == STYLE_Add && !level.lightadditivesurfaces) return false;	// no lights on additively blended surfaces.
-
-	// check for wall types which cannot have dynamic lights on them (portal types never get here so they don't need to be checked.)
-	switch (type)
-	{
-	case RENDERWALL_FOGBOUNDARY:
-	case RENDERWALL_MIRRORSURFACE:
-	case RENDERWALL_COLOR:
-		return false;
-	}
-
-	float vtx[]={glseg.x1,zbottom[0],glseg.y1, glseg.x1,ztop[0],glseg.y1, glseg.x2,ztop[1],glseg.y2, glseg.x2,zbottom[1],glseg.y2};
-	Plane p;
-
-	lightdata.Clear();
-
-	auto normal = glseg.Normal();
-	p.Set(normal, -normal.X * glseg.x1 - normal.Z * glseg.y1);
-
-	FLightNode *node;
-	if (seg->sidedef == NULL)
-	{
-		node = NULL;
-	}
-	else if (!(seg->sidedef->Flags & WALLF_POLYOBJ))
-	{
-		node = seg->sidedef->lighthead;
-	}
-	else if (sub)
-	{
-		// Polobject segs cannot be checked per sidedef so use the subsector instead.
-		node = sub->lighthead;
-	}
-	else node = NULL;
-
-	// Iterate through all dynamic lights which touch this wall and render them
-	while (node)
-	{
-		if (!(node->lightsource->flags2&MF2_DORMANT))
-		{
-			iter_dlight++;
-
-			DVector3 posrel = node->lightsource->PosRelative(seg->frontsector);
-			float x = posrel.X;
-			float y = posrel.Y;
-			float z = posrel.Z;
-			float dist = fabsf(p.DistToPoint(x, z, y));
-			float radius = node->lightsource->GetRadius();
-			float scale = 1.0f / ((2.f * radius) - dist);
-			FVector3 fn, pos;
-
-			if (radius > 0.f && dist < radius)
-			{
-				FVector3 nearPt, up, right;
-
-				pos = { x, z, y };
-				fn = p.Normal();
-
-				fn.GetRightUp(right, up);
-
-				FVector3 tmpVec = fn * dist;
-				nearPt = pos + tmpVec;
-
-				FVector3 t1;
-				int outcnt[4]={0,0,0,0};
-				texcoord tcs[4];
-
-				// do a quick check whether the light touches this polygon
-				for(int i=0;i<4;i++)
-				{
-					t1 = FVector3(&vtx[i*3]);
-					FVector3 nearToVert = t1 - nearPt;
-					tcs[i].u = ((nearToVert | right) * scale) + 0.5f;
-					tcs[i].v = ((nearToVert | up) * scale) + 0.5f;
-
-					if (tcs[i].u<0) outcnt[0]++;
-					if (tcs[i].u>1) outcnt[1]++;
-					if (tcs[i].v<0) outcnt[2]++;
-					if (tcs[i].v>1) outcnt[3]++;
-
-				}
-				if (outcnt[0]!=4 && outcnt[1]!=4 && outcnt[2]!=4 && outcnt[3]!=4) 
-				{
-					lightdata.GetLight(seg->frontsector->PortalGroup, p, node->lightsource, true);
-				}
-			}
-		}
-		node = node->nextLight;
-	}
-	return true;
-}
 
 //==========================================================================
 //
diff --git a/src/hwrenderer/scene/hw_walls.cpp b/src/hwrenderer/scene/hw_walls.cpp
index 1df0a0efc..a9c0c0639 100644
--- a/src/hwrenderer/scene/hw_walls.cpp
+++ b/src/hwrenderer/scene/hw_walls.cpp
@@ -39,6 +39,105 @@
 #include "hwrenderer/scene/hw_portal.h"
 
 
+//==========================================================================
+//
+// Collect lights for shader
+//
+//==========================================================================
+
+bool GLWall::SetupLights(FDynLightData &lightdata)
+{
+	if (RenderStyle == STYLE_Add && !level.lightadditivesurfaces) return false;	// no lights on additively blended surfaces.
+
+	// check for wall types which cannot have dynamic lights on them (portal types never get here so they don't need to be checked.)
+	switch (type)
+	{
+	case RENDERWALL_FOGBOUNDARY:
+	case RENDERWALL_MIRRORSURFACE:
+	case RENDERWALL_COLOR:
+		return false;
+	}
+
+	float vtx[]={glseg.x1,zbottom[0],glseg.y1, glseg.x1,ztop[0],glseg.y1, glseg.x2,ztop[1],glseg.y2, glseg.x2,zbottom[1],glseg.y2};
+	Plane p;
+
+	lightdata.Clear();
+
+	auto normal = glseg.Normal();
+	p.Set(normal, -normal.X * glseg.x1 - normal.Z * glseg.y1);
+
+	FLightNode *node;
+	if (seg->sidedef == NULL)
+	{
+		node = NULL;
+	}
+	else if (!(seg->sidedef->Flags & WALLF_POLYOBJ))
+	{
+		node = seg->sidedef->lighthead;
+	}
+	else if (sub)
+	{
+		// Polobject segs cannot be checked per sidedef so use the subsector instead.
+		node = sub->lighthead;
+	}
+	else node = NULL;
+
+	// Iterate through all dynamic lights which touch this wall and render them
+	while (node)
+	{
+		if (!(node->lightsource->flags2&MF2_DORMANT))
+		{
+			iter_dlight++;
+
+			DVector3 posrel = node->lightsource->PosRelative(seg->frontsector);
+			float x = posrel.X;
+			float y = posrel.Y;
+			float z = posrel.Z;
+			float dist = fabsf(p.DistToPoint(x, z, y));
+			float radius = node->lightsource->GetRadius();
+			float scale = 1.0f / ((2.f * radius) - dist);
+			FVector3 fn, pos;
+
+			if (radius > 0.f && dist < radius)
+			{
+				FVector3 nearPt, up, right;
+
+				pos = { x, z, y };
+				fn = p.Normal();
+
+				fn.GetRightUp(right, up);
+
+				FVector3 tmpVec = fn * dist;
+				nearPt = pos + tmpVec;
+
+				FVector3 t1;
+				int outcnt[4]={0,0,0,0};
+				texcoord tcs[4];
+
+				// do a quick check whether the light touches this polygon
+				for(int i=0;i<4;i++)
+				{
+					t1 = FVector3(&vtx[i*3]);
+					FVector3 nearToVert = t1 - nearPt;
+					tcs[i].u = ((nearToVert | right) * scale) + 0.5f;
+					tcs[i].v = ((nearToVert | up) * scale) + 0.5f;
+
+					if (tcs[i].u<0) outcnt[0]++;
+					if (tcs[i].u>1) outcnt[1]++;
+					if (tcs[i].v<0) outcnt[2]++;
+					if (tcs[i].v>1) outcnt[3]++;
+
+				}
+				if (outcnt[0]!=4 && outcnt[1]!=4 && outcnt[2]!=4 && outcnt[3]!=4) 
+				{
+					lightdata.GetLight(seg->frontsector->PortalGroup, p, node->lightsource, true);
+				}
+			}
+		}
+		node = node->nextLight;
+	}
+	return true;
+}
 
 
 const char GLWall::passflag[] = {

From 0d7c2527f2f2c6486e36507f65ffd55bc7a52e08 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 20:18:52 +0200
Subject: [PATCH 09/12] - finished decal render refactoring.

Decals will now be processed into a list in the processing pass, allowing to use the vertex buffer even on GL3 hardware and to offload this part of the work to a multithreaded worker task.
---
 src/gl/scene/gl_decal.cpp               | 79 +++++++++++--------------
 src/gl/scene/gl_drawinfo.cpp            | 24 ++++----
 src/gl/scene/gl_drawinfo.h              |  9 +--
 src/gl/scene/gl_scene.cpp               | 13 +---
 src/gl/scene/gl_walls_draw.cpp          |  5 +-
 src/hwrenderer/scene/hw_drawinfo.h      |  2 +-
 src/hwrenderer/scene/hw_drawstructs.h   | 26 ++++++++
 src/hwrenderer/scene/hw_walls.cpp       |  1 +
 src/hwrenderer/textures/hw_ihwtexture.h |  2 +
 9 files changed, 85 insertions(+), 76 deletions(-)

diff --git a/src/gl/scene/gl_decal.cpp b/src/gl/scene/gl_decal.cpp
index fa6f3dbba..cf5aa1f5f 100644
--- a/src/gl/scene/gl_decal.cpp
+++ b/src/gl/scene/gl_decal.cpp
@@ -40,28 +40,6 @@
 #include "gl/scene/gl_scenedrawer.h"
 #include "gl/renderer/gl_quaddrawer.h"
 
-struct DecalVertex
-{
-	float x,y,z;
-	float u,v;
-};
-
-struct GLDecal
-{
-	unsigned int vertindex;
-	FMaterial *gltexture;
-	GLWall *wall;
-	DBaseDecal *decal;
-	DecalVertex dv[4];
-	float zcenter;
-
-	int light;
-	int rel;
-	float a;
-	FColormap colormap;
-
-};
-
 void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 {
 	line_t * line = seg->linedef;
@@ -70,11 +48,11 @@ void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 	float zpos;
 	bool flipx, flipy;
 	FTextureID decalTile;
-	GLDecal gldecal;
 	
 	
 	if (decal->RenderFlags & RF_INVISIBLE) return;
 	if (type == RENDERWALL_FFBLOCK && gltexture->isMasked()) return;	// No decals on 3D floors with transparent textures.
+	if (seg == nullptr) return;
 	
 	
 	decalTile = decal->PicNum;
@@ -138,8 +116,8 @@ void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 				zpos = decal->Z + frontsector->GetPlaneTexZ(sector_t::ceiling);
 			}
 	}
-	
-	memset(&gldecal, 0, sizeof(gldecal));
+
+	GLDecal &gldecal = *di->AddDecal(type == RENDERWALL_MIRRORSURFACE);
 	gldecal.gltexture = FMaterial::ValidateTexture(texture, true);
 	gldecal.wall = this;
 	gldecal.decal = decal;
@@ -286,7 +264,6 @@ void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 	{
 		verts.first[i].Set(dv[i].x, dv[i].z, dv[i].y, dv[i].u, dv[i].v);
 	}
-	di->AddDecal(&gldecal);
 }
 
 //==========================================================================
@@ -312,9 +289,8 @@ void GLWall::ProcessDecals(HWDrawInfo *di)
 //
 //
 //==========================================================================
-void FDrawInfo::DrawDecal(GLWall *__wall, DBaseDecal *__decal)
+void FDrawInfo::DrawDecal(GLDecal *gldecal)
 {
-	GLDecal *gldecal;
 	auto wall = gldecal->wall;
 	auto decal = gldecal->decal;
 	auto tex = gldecal->gltexture;
@@ -401,29 +377,42 @@ void FDrawInfo::DrawDecal(GLWall *__wall, DBaseDecal *__decal)
 //
 //
 //==========================================================================
-void FDrawInfo::DoDrawDecals(GLWall *wall)
+void FDrawInfo::DrawDecals()
 {
-	if (wall->seg->sidedef && wall->seg->sidedef->AttachedDecals)
+	GLWall *wall = nullptr;
+	for (auto gldecal : decals[0])
 	{
-		if (wall->lightlist != nullptr)
+		if (gldecal->wall != wall)
 		{
-			gl_RenderState.EnableSplit(true);
-		}
-		else
-		{
-			mDrawer->SetFog(wall->lightlevel, wall->rellight + getExtraLight(), &wall->Colormap, false);
+			wall = gldecal->wall;
+			if (wall->lightlist != nullptr)
+			{
+				gl_RenderState.EnableSplit(true);
+			}
+			else
+			{
+				gl_RenderState.EnableSplit(false);
+				mDrawer->SetFog(wall->lightlevel, wall->rellight + getExtraLight(), &wall->Colormap, false);
+			}
 		}
+		DrawDecal(gldecal);
+	}
+	if (wall && wall->lightlist != nullptr) gl_RenderState.EnableSplit(false);
+}
 
-		DBaseDecal *decal = wall->seg->sidedef->AttachedDecals;
-		while (decal)
+//==========================================================================
+//
+// This list will never get long, so this code should be ok.
+//
+//==========================================================================
+void FDrawInfo::DrawDecalsForMirror(GLWall *wall)
+{
+	mDrawer->SetFog(wall->lightlevel, wall->rellight + getExtraLight(), &wall->Colormap, false);
+	for (auto gldecal : decals[1])
+	{
+		if (gldecal->wall == wall)
 		{
-			DrawDecal(wall, decal);
-			decal = decal->WallNext;
-		}
-
-		if (wall->lightlist != nullptr)
-		{
-			gl_RenderState.EnableSplit(false);
+			DrawDecal(gldecal);
 		}
 	}
 }
diff --git a/src/gl/scene/gl_drawinfo.cpp b/src/gl/scene/gl_drawinfo.cpp
index 91c364544..8e04f7d8f 100644
--- a/src/gl/scene/gl_drawinfo.cpp
+++ b/src/gl/scene/gl_drawinfo.cpp
@@ -867,19 +867,6 @@ void GLDrawList::DrawFlats(int pass)
 	RenderFlat.Unclock();
 }
 
-//==========================================================================
-//
-//
-//
-//==========================================================================
-void GLDrawList::DrawDecals()
-{
-	for(unsigned i=0;i<drawitems.Size();i++)
-	{
-		gl_drawinfo->DoDrawDecals(walls[drawitems[i].index]);
-	}
-}
-
 //==========================================================================
 //
 // Sorting the drawitems first by texture and then by light level.
@@ -952,7 +939,6 @@ GLSprite *GLDrawList::NewSprite()
 	return sprite;
 }
 
-
 //==========================================================================
 //
 // Try to reuse the lists as often as possible as they contain resources that
@@ -1033,6 +1019,8 @@ void FDrawInfo::StartScene()
 	{
 		for (int i = 0; i < GLLDL_TYPES; i++) dldrawlists[i].Reset();
 	}
+	decals[0].Clear();
+	decals[1].Clear();
 }
 
 //==========================================================================
@@ -1323,3 +1311,11 @@ std::pair<FFlatVertex *, unsigned int> FDrawInfo::AllocVertices(unsigned int cou
 	auto p = GLRenderer->mVBO->Alloc(count, &index);
 	return std::make_pair(p, index);
 }
+
+GLDecal *FDrawInfo::AddDecal(bool onmirror)
+{
+	auto decal = (GLDecal*)RenderDataAllocator.Alloc(sizeof(GLDecal));
+	decals[onmirror ? 1 : 0].Push(decal);
+	return decal;
+}
+
diff --git a/src/gl/scene/gl_drawinfo.h b/src/gl/scene/gl_drawinfo.h
index ebedb94a2..32003d973 100644
--- a/src/gl/scene/gl_drawinfo.h
+++ b/src/gl/scene/gl_drawinfo.h
@@ -158,7 +158,6 @@ public:
 	void Draw(int pass, bool trans = false);
 	void DrawWalls(int pass);
 	void DrawFlats(int pass);
-	void DrawDecals();
 	
 	GLDrawList * next;
 } ;
@@ -172,6 +171,7 @@ struct FDrawInfo : public HWDrawInfo
 	
 	FDrawInfo * next;
 	GLDrawList drawlists[GLDL_TYPES];
+	TArray<GLDecal *> decals[2];	// the second slot is for mirrors which get rendered in a separate pass.
 	GLDrawList *dldrawlists = NULL;	// only gets allocated when needed.
 	
 	FDrawInfo();
@@ -179,6 +179,7 @@ struct FDrawInfo : public HWDrawInfo
 	
 	void AddWall(GLWall *wall) override;
     void AddMirrorSurface(GLWall *w) override;
+	GLDecal *AddDecal(bool onmirror) override;
 	void AddPortal(GLWall *w, int portaltype) override;
 
     void ProcessActorsInPortal(FLinePortalSpan *glport) override;
@@ -189,10 +190,10 @@ struct FDrawInfo : public HWDrawInfo
 	void RenderFogBoundaryCompat(GLWall *wall);
 	void RenderLightsCompat(GLWall *wall, int pass);
 
-	void DrawDecal(GLWall *wall, DBaseDecal *decal);
-	void DoDrawDecals(GLWall *wall);
+	void DrawDecal(GLDecal *gldecal);
+	void DrawDecals();
+	void DrawDecalsForMirror(GLWall *wall);
 
-	
 	void StartScene();
 	void SetupFloodStencil(wallseg * ws);
 	void ClearFloodStencil(wallseg * ws);
diff --git a/src/gl/scene/gl_scene.cpp b/src/gl/scene/gl_scene.cpp
index 9e897c122..11d53cd5d 100644
--- a/src/gl/scene/gl_scene.cpp
+++ b/src/gl/scene/gl_scene.cpp
@@ -375,15 +375,7 @@ void GLSceneDrawer::RenderScene(int recursion)
 	glEnable(GL_POLYGON_OFFSET_FILL);
 	glPolygonOffset(-1.0f, -128.0f);
 	glDepthMask(false);
-
-	// this is the only geometry type on which decals can possibly appear
-	gl_drawinfo->drawlists[GLDL_PLAINWALLS].DrawDecals();
-	if (gl.legacyMode)
-	{
-		// also process the render lists with walls and dynamic lights
-        gl_drawinfo->dldrawlists[GLLDL_WALLS_PLAIN].DrawDecals();
-        gl_drawinfo->dldrawlists[GLLDL_WALLS_FOG].DrawDecals();
-	}
+	gl_drawinfo->DrawDecals();
 
 	gl_RenderState.SetTextureMode(TM_MODULATE);
 
@@ -434,9 +426,10 @@ void GLSceneDrawer::RenderTranslucent()
 	gl_drawinfo->drawlists[GLDL_TRANSLUCENT].DrawSorted();
 	gl_RenderState.EnableBrightmap(false);
 
-	glDepthMask(true);
 
 	gl_RenderState.AlphaFunc(GL_GEQUAL, 0.5f);
+	glDepthMask(true);
+
 	RenderAll.Unclock();
 }
 
diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index 10318c425..5e17fffe0 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -139,13 +139,14 @@ void FDrawInfo::RenderMirrorSurface(GLWall *wall)
 	glDepthFunc(GL_LESS);
 
 	// This is drawn in the translucent pass which is done after the decal pass
-	// As a result the decals have to be drawn here.
+	// As a result the decals have to be drawn here, right after the wall they are on,
+	// because the depth buffer won't get set by translucent items.
 	if (wall->seg->sidedef->AttachedDecals)
 	{
 		glEnable(GL_POLYGON_OFFSET_FILL);
 		glPolygonOffset(-1.0f, -128.0f);
 		glDepthMask(false);
-		gl_drawinfo->DoDrawDecals(wall);
+		gl_drawinfo->DrawDecalsForMirror(wall);
 		glDepthMask(true);
 		glPolygonOffset(0.0f, 0.0f);
 		glDisable(GL_POLYGON_OFFSET_FILL);
diff --git a/src/hwrenderer/scene/hw_drawinfo.h b/src/hwrenderer/scene/hw_drawinfo.h
index e2db5f132..ec4aaa31f 100644
--- a/src/hwrenderer/scene/hw_drawinfo.h
+++ b/src/hwrenderer/scene/hw_drawinfo.h
@@ -128,7 +128,7 @@ public:
     virtual void AddWall(GLWall *w) = 0;
 	virtual void AddPortal(GLWall *w, int portaltype) = 0;
     virtual void AddMirrorSurface(GLWall *w) = 0;
-    virtual void AddDecal(GLDecal *d) = 0;
+    virtual GLDecal *AddDecal(bool onmirror) = 0;
     virtual void ProcessActorsInPortal(FLinePortalSpan *glport) = 0;
 	virtual std::pair<FFlatVertex *, unsigned int> AllocVertices(unsigned int count) = 0;
 
diff --git a/src/hwrenderer/scene/hw_drawstructs.h b/src/hwrenderer/scene/hw_drawstructs.h
index a508b2a81..e4e9a2507 100644
--- a/src/hwrenderer/scene/hw_drawstructs.h
+++ b/src/hwrenderer/scene/hw_drawstructs.h
@@ -281,6 +281,32 @@ public:
 
 };
 
+
+
+
+struct DecalVertex
+{
+	float x, y, z;
+	float u, v;
+};
+
+struct GLDecal
+{
+	FMaterial *gltexture;
+	GLWall *wall;
+	DBaseDecal *decal;
+	DecalVertex dv[4];
+	float zcenter;
+	unsigned int vertindex;
+
+	int light;
+	int rel;
+	float a;
+	FColormap colormap;
+
+};
+
+
 inline float Dist2(float x1,float y1,float x2,float y2)
 {
 	return sqrtf((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
diff --git a/src/hwrenderer/scene/hw_walls.cpp b/src/hwrenderer/scene/hw_walls.cpp
index a9c0c0639..0ee2af2ee 100644
--- a/src/hwrenderer/scene/hw_walls.cpp
+++ b/src/hwrenderer/scene/hw_walls.cpp
@@ -29,6 +29,7 @@
 #include "p_maputl.h"
 #include "doomdata.h"
 #include "g_levellocals.h"
+#include "actorinlines.h"
 #include "hwrenderer/dynlights/hw_dynlightdata.h"
 #include "hwrenderer/textures/hw_material.h"
 #include "hwrenderer/utility/hw_cvars.h"
diff --git a/src/hwrenderer/textures/hw_ihwtexture.h b/src/hwrenderer/textures/hw_ihwtexture.h
index 681d6cca6..ca9d5bfad 100644
--- a/src/hwrenderer/textures/hw_ihwtexture.h
+++ b/src/hwrenderer/textures/hw_ihwtexture.h
@@ -1,8 +1,10 @@
 #pragma once
 
 #include <stdint.h>
+#include "tarray.h"
 
 typedef TMap<int, bool> SpriteHits;
+class FTexture;
 
 class IHardwareTexture
 {

From 383ff0d8b8acf59c071776c1f818db01020cb337 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 20:21:22 +0200
Subject: [PATCH 10/12] - moved code around.

---
 src/gl/scene/gl_decal.cpp      | 133 --------------------------------
 src/gl/scene/gl_walls_draw.cpp | 134 +++++++++++++++++++++++++++++++++
 2 files changed, 134 insertions(+), 133 deletions(-)

diff --git a/src/gl/scene/gl_decal.cpp b/src/gl/scene/gl_decal.cpp
index cf5aa1f5f..fc0b9f5e6 100644
--- a/src/gl/scene/gl_decal.cpp
+++ b/src/gl/scene/gl_decal.cpp
@@ -284,136 +284,3 @@ void GLWall::ProcessDecals(HWDrawInfo *di)
 	}
 }
 
-//==========================================================================
-//
-//
-//
-//==========================================================================
-void FDrawInfo::DrawDecal(GLDecal *gldecal)
-{
-	auto wall = gldecal->wall;
-	auto decal = gldecal->decal;
-	auto tex = gldecal->gltexture;
-	auto &seg = wall->seg;
-	
-	// calculate dynamic light effect.
-	if (gl_lights && GLRenderer->mLightCount && !mDrawer->FixedColormap && gl_light_sprites)
-	{
-		// Note: This should be replaced with proper shader based lighting.
-		double x, y;
-		decal->GetXY(seg->sidedef, x, y);
-		gl_SetDynSpriteLight(nullptr, x, y, gldecal->zcenter, wall->sub);
-	}
-
-	// alpha color only has an effect when using an alpha texture.
-	if (decal->RenderStyle.Flags & STYLEF_RedIsAlpha)
-	{
-		gl_RenderState.SetObjectColor(decal->AlphaColor | 0xff000000);
-	}
-
-	gl_SetRenderStyle(decal->RenderStyle, false, false);
-	gl_RenderState.SetMaterial(tex, CLAMP_XY, decal->Translation, 0, !!(decal->RenderStyle.Flags & STYLEF_RedIsAlpha));
-
-
-	// If srcalpha is one it looks better with a higher alpha threshold
-	if (decal->RenderStyle.SrcAlpha == STYLEALPHA_One) gl_RenderState.AlphaFunc(GL_GEQUAL, gl_mask_sprite_threshold);
-	else gl_RenderState.AlphaFunc(GL_GREATER, 0.f);
-
-
-	mDrawer->SetColor(gldecal->light, gldecal->rel, gldecal->colormap, gldecal->a);
-	// for additively drawn decals we must temporarily set the fog color to black.
-	PalEntry fc = gl_RenderState.GetFogColor();
-	if (decal->RenderStyle.BlendOp == STYLEOP_Add && decal->RenderStyle.DestAlpha == STYLEALPHA_One)
-	{
-		gl_RenderState.SetFog(0, -1);
-	}
-
-	gl_RenderState.SetNormal(wall->glseg.Normal());
-
-	if (wall->lightlist == nullptr)
-	{
-		gl_RenderState.Apply();
-		GLRenderer->mVBO->RenderArray(GL_TRIANGLE_FAN, gldecal->vertindex, 4);
-	}
-	else
-	{
-		auto &lightlist = *wall->lightlist;
-
-		for (unsigned k = 0; k < lightlist.Size(); k++)
-		{
-			secplane_t &lowplane = k == lightlist.Size() - 1 ? wall->bottomplane : lightlist[k + 1].plane;
-
-			DecalVertex *dv = gldecal->dv;
-			float low1 = lowplane.ZatPoint(dv[1].x, dv[1].y);
-			float low2 = lowplane.ZatPoint(dv[2].x, dv[2].y);
-
-			if (low1 < dv[1].z || low2 < dv[2].z)
-			{
-				int thisll = lightlist[k].caster != NULL ? hw_ClampLight(*lightlist[k].p_lightlevel) : wall->lightlevel;
-				FColormap thiscm;
-				thiscm.FadeColor = wall->Colormap.FadeColor;
-				thiscm.CopyFrom3DLight(&lightlist[k]);
-				mDrawer->SetColor(thisll, gldecal->rel, thiscm, gldecal->a);
-				if (level.flags3 & LEVEL3_NOCOLOREDSPRITELIGHTING) thiscm.Decolorize();
-				mDrawer->SetFog(thisll, gldecal->rel, &thiscm, wall->RenderStyle == STYLE_Add);
-				gl_RenderState.SetSplitPlanes(lightlist[k].plane, lowplane);
-
-				gl_RenderState.Apply();
-				GLRenderer->mVBO->RenderArray(GL_TRIANGLE_FAN, gldecal->vertindex, 4);
-			}
-			if (low1 <= dv[0].z && low2 <= dv[3].z) break;
-		}
-	}
-
-	rendered_decals++;
-	gl_RenderState.SetTextureMode(TM_MODULATE);
-	gl_RenderState.SetObjectColor(0xffffffff);
-	gl_RenderState.SetFog(fc, -1);
-	gl_RenderState.SetDynLight(0, 0, 0);
-}
-
-//==========================================================================
-//
-//
-//
-//==========================================================================
-void FDrawInfo::DrawDecals()
-{
-	GLWall *wall = nullptr;
-	for (auto gldecal : decals[0])
-	{
-		if (gldecal->wall != wall)
-		{
-			wall = gldecal->wall;
-			if (wall->lightlist != nullptr)
-			{
-				gl_RenderState.EnableSplit(true);
-			}
-			else
-			{
-				gl_RenderState.EnableSplit(false);
-				mDrawer->SetFog(wall->lightlevel, wall->rellight + getExtraLight(), &wall->Colormap, false);
-			}
-		}
-		DrawDecal(gldecal);
-	}
-	if (wall && wall->lightlist != nullptr) gl_RenderState.EnableSplit(false);
-}
-
-//==========================================================================
-//
-// This list will never get long, so this code should be ok.
-//
-//==========================================================================
-void FDrawInfo::DrawDecalsForMirror(GLWall *wall)
-{
-	mDrawer->SetFog(wall->lightlevel, wall->rellight + getExtraLight(), &wall->Colormap, false);
-	for (auto gldecal : decals[1])
-	{
-		if (gldecal->wall == wall)
-		{
-			DrawDecal(gldecal);
-		}
-	}
-}
-
diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index 5e17fffe0..93cf8ceef 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -470,3 +470,137 @@ void FDrawInfo::AddPortal(GLWall *wall, int ptype)
 	}
 	wall->vertcount = 0;
 }
+
+//==========================================================================
+//
+//
+//
+//==========================================================================
+void FDrawInfo::DrawDecal(GLDecal *gldecal)
+{
+	auto wall = gldecal->wall;
+	auto decal = gldecal->decal;
+	auto tex = gldecal->gltexture;
+	auto &seg = wall->seg;
+	
+	// calculate dynamic light effect.
+	if (gl_lights && GLRenderer->mLightCount && !mDrawer->FixedColormap && gl_light_sprites)
+	{
+		// Note: This should be replaced with proper shader based lighting.
+		double x, y;
+		decal->GetXY(seg->sidedef, x, y);
+		gl_SetDynSpriteLight(nullptr, x, y, gldecal->zcenter, wall->sub);
+	}
+
+	// alpha color only has an effect when using an alpha texture.
+	if (decal->RenderStyle.Flags & STYLEF_RedIsAlpha)
+	{
+		gl_RenderState.SetObjectColor(decal->AlphaColor | 0xff000000);
+	}
+
+	gl_SetRenderStyle(decal->RenderStyle, false, false);
+	gl_RenderState.SetMaterial(tex, CLAMP_XY, decal->Translation, 0, !!(decal->RenderStyle.Flags & STYLEF_RedIsAlpha));
+
+
+	// If srcalpha is one it looks better with a higher alpha threshold
+	if (decal->RenderStyle.SrcAlpha == STYLEALPHA_One) gl_RenderState.AlphaFunc(GL_GEQUAL, gl_mask_sprite_threshold);
+	else gl_RenderState.AlphaFunc(GL_GREATER, 0.f);
+
+
+	mDrawer->SetColor(gldecal->light, gldecal->rel, gldecal->colormap, gldecal->a);
+	// for additively drawn decals we must temporarily set the fog color to black.
+	PalEntry fc = gl_RenderState.GetFogColor();
+	if (decal->RenderStyle.BlendOp == STYLEOP_Add && decal->RenderStyle.DestAlpha == STYLEALPHA_One)
+	{
+		gl_RenderState.SetFog(0, -1);
+	}
+
+	gl_RenderState.SetNormal(wall->glseg.Normal());
+
+	if (wall->lightlist == nullptr)
+	{
+		gl_RenderState.Apply();
+		GLRenderer->mVBO->RenderArray(GL_TRIANGLE_FAN, gldecal->vertindex, 4);
+	}
+	else
+	{
+		auto &lightlist = *wall->lightlist;
+
+		for (unsigned k = 0; k < lightlist.Size(); k++)
+		{
+			secplane_t &lowplane = k == lightlist.Size() - 1 ? wall->bottomplane : lightlist[k + 1].plane;
+
+			DecalVertex *dv = gldecal->dv;
+			float low1 = lowplane.ZatPoint(dv[1].x, dv[1].y);
+			float low2 = lowplane.ZatPoint(dv[2].x, dv[2].y);
+
+			if (low1 < dv[1].z || low2 < dv[2].z)
+			{
+				int thisll = lightlist[k].caster != NULL ? hw_ClampLight(*lightlist[k].p_lightlevel) : wall->lightlevel;
+				FColormap thiscm;
+				thiscm.FadeColor = wall->Colormap.FadeColor;
+				thiscm.CopyFrom3DLight(&lightlist[k]);
+				mDrawer->SetColor(thisll, gldecal->rel, thiscm, gldecal->a);
+				if (level.flags3 & LEVEL3_NOCOLOREDSPRITELIGHTING) thiscm.Decolorize();
+				mDrawer->SetFog(thisll, gldecal->rel, &thiscm, wall->RenderStyle == STYLE_Add);
+				gl_RenderState.SetSplitPlanes(lightlist[k].plane, lowplane);
+
+				gl_RenderState.Apply();
+				GLRenderer->mVBO->RenderArray(GL_TRIANGLE_FAN, gldecal->vertindex, 4);
+			}
+			if (low1 <= dv[0].z && low2 <= dv[3].z) break;
+		}
+	}
+
+	rendered_decals++;
+	gl_RenderState.SetTextureMode(TM_MODULATE);
+	gl_RenderState.SetObjectColor(0xffffffff);
+	gl_RenderState.SetFog(fc, -1);
+	gl_RenderState.SetDynLight(0, 0, 0);
+}
+
+//==========================================================================
+//
+//
+//
+//==========================================================================
+void FDrawInfo::DrawDecals()
+{
+	GLWall *wall = nullptr;
+	for (auto gldecal : decals[0])
+	{
+		if (gldecal->wall != wall)
+		{
+			wall = gldecal->wall;
+			if (wall->lightlist != nullptr)
+			{
+				gl_RenderState.EnableSplit(true);
+			}
+			else
+			{
+				gl_RenderState.EnableSplit(false);
+				mDrawer->SetFog(wall->lightlevel, wall->rellight + getExtraLight(), &wall->Colormap, false);
+			}
+		}
+		DrawDecal(gldecal);
+	}
+	if (wall && wall->lightlist != nullptr) gl_RenderState.EnableSplit(false);
+}
+
+//==========================================================================
+//
+// This list will never get long, so this code should be ok.
+//
+//==========================================================================
+void FDrawInfo::DrawDecalsForMirror(GLWall *wall)
+{
+	mDrawer->SetFog(wall->lightlevel, wall->rellight + getExtraLight(), &wall->Colormap, false);
+	for (auto gldecal : decals[1])
+	{
+		if (gldecal->wall == wall)
+		{
+			DrawDecal(gldecal);
+		}
+	}
+}
+

From 678ac40b72a4a69a7418cef4498cc8457e8cfbbe Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 20:28:59 +0200
Subject: [PATCH 11/12] - cleaned up includes for gl_decal.cpp

---
 src/gl/scene/gl_decal.cpp            | 20 ++++++++------------
 src/gl/scene/gl_scenedrawer.h        |  8 --------
 src/hwrenderer/utility/hw_lighting.h |  9 +++++++++
 3 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/src/gl/scene/gl_decal.cpp b/src/gl/scene/gl_decal.cpp
index fc0b9f5e6..3dd2972c8 100644
--- a/src/gl/scene/gl_decal.cpp
+++ b/src/gl/scene/gl_decal.cpp
@@ -1,7 +1,7 @@
 // 
 //---------------------------------------------------------------------------
 //
-// Copyright(C) 2003-2016 Christoph Oelckers
+// Copyright(C) 2003-2018 Christoph Oelckers
 // All rights reserved.
 //
 // This program is free software: you can redistribute it and/or modify
@@ -21,24 +21,20 @@
 //
 /*
 ** gl_decal.cpp
-** OpenGL decal rendering code
+** OpenGL decal processing code
 **
 */
 
 #include "doomdata.h"
-#include "gl/system/gl_system.h"
 #include "a_sharedglobal.h"
 #include "r_utility.h"
 #include "g_levellocals.h"
-
+#include "hwrenderer/textures/hw_material.h"
 #include "hwrenderer/utility/hw_cvars.h"
-#include "gl/data/gl_vertexbuffer.h"
-#include "gl/renderer/gl_renderer.h"
-#include "gl/renderer/gl_lightdata.h"
-#include "gl/renderer/gl_renderstate.h"
-#include "gl/scene/gl_drawinfo.h"
-#include "gl/scene/gl_scenedrawer.h"
-#include "gl/renderer/gl_quaddrawer.h"
+#include "hwrenderer/scene/hw_drawstructs.h"
+#include "hwrenderer/scene/hw_drawinfo.h"
+#include "hwrenderer/utility/hw_lighting.h"
+#include "hwrenderer/data/flatvertices.h"
 
 void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 {
@@ -257,7 +253,7 @@ void GLWall::ProcessDecal(HWDrawInfo *di, DBaseDecal *decal)
 
 	gldecal.zcenter = zpos - decalheight * 0.5f;
 	
-	auto verts = gl_drawinfo->AllocVertices(4);
+	auto verts = di->AllocVertices(4);
 	gldecal.vertindex = verts.second;
 	
 	for (i = 0; i < 4; i++)
diff --git a/src/gl/scene/gl_scenedrawer.h b/src/gl/scene/gl_scenedrawer.h
index 0d1759ff7..5520225f6 100644
--- a/src/gl/scene/gl_scenedrawer.h
+++ b/src/gl/scene/gl_scenedrawer.h
@@ -9,14 +9,6 @@
 #include "r_utility.h"
 #include "c_cvars.h"
 
-EXTERN_CVAR(Int, gl_weaponlight);
-
-inline	int getExtraLight()
-{
-	return r_viewpoint.extralight * gl_weaponlight;
-}
-
-
 class GLSceneDrawer
 {
 	fixed_t viewx, viewy;	// since the nodes are still fixed point, keeping the view position  also fixed point for node traversal is faster.
diff --git a/src/hwrenderer/utility/hw_lighting.h b/src/hwrenderer/utility/hw_lighting.h
index 43bceaf98..9acb1578d 100644
--- a/src/hwrenderer/utility/hw_lighting.h
+++ b/src/hwrenderer/utility/hw_lighting.h
@@ -1,7 +1,9 @@
 #pragma once
 
+#include "c_cvars.h"
 #include "v_palette.h"
 #include "templates.h"
+#include "r_utility.h"
 
 struct Colormap;
 
@@ -15,3 +17,10 @@ inline int hw_ClampLight(int lightlevel)
 	return clamp(lightlevel, 0, 255);
 }
 
+EXTERN_CVAR(Int, gl_weaponlight);
+
+inline	int getExtraLight()
+{
+	return r_viewpoint.extralight * gl_weaponlight;
+}
+

From fe2bfc6f11f37672ebe9de62a2babe45c0b8a88d Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Fri, 27 Apr 2018 20:34:20 +0200
Subject: [PATCH 12/12] - moved the API-independent parts of the decal code to
 hwrenderer/.

---
 src/CMakeLists.txt                                           | 2 +-
 src/{gl/scene/gl_decal.cpp => hwrenderer/scene/hw_decal.cpp} | 0
 2 files changed, 1 insertion(+), 1 deletion(-)
 rename src/{gl/scene/gl_decal.cpp => hwrenderer/scene/hw_decal.cpp} (100%)

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a7bedf0a6..7dc4606c2 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -813,7 +813,6 @@ set( FASTMATH_SOURCES
 	textures/hires/xbr/xbrz.cpp
 	textures/hires/xbr/xbrz_old.cpp
 	gl/scene/gl_bsp.cpp
-	gl/scene/gl_decal.cpp
 	gl/scene/gl_drawinfo.cpp
 	gl/scene/gl_flats.cpp
 	gl/scene/gl_sprite.cpp
@@ -828,6 +827,7 @@ set( FASTMATH_SOURCES
 	gl_load/gl_load.c
 	hwrenderer/dynlights/hw_dynlightdata.cpp
 	hwrenderer/scene/hw_fakeflat.cpp
+	hwrenderer/scene/hw_decal.cpp
 	hwrenderer/scene/hw_clipper.cpp
 	hwrenderer/scene/hw_renderhacks.cpp
 	hwrenderer/scene/hw_walls.cpp
diff --git a/src/gl/scene/gl_decal.cpp b/src/hwrenderer/scene/hw_decal.cpp
similarity index 100%
rename from src/gl/scene/gl_decal.cpp
rename to src/hwrenderer/scene/hw_decal.cpp