From 3644073bbd57161c571b666b0cdcade298637c8a Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@zdoom.fake>
Date: Sun, 15 Jun 2014 01:14:41 +0200
Subject: [PATCH] - use a software buffer for immediate mode rendering. This
 allows using the regular buffer code to collect data for both render modes
 and allows removal of a lot of duplicated code.

---
 src/gl/data/gl_vertexbuffer.cpp |  26 +++-
 src/gl/data/gl_vertexbuffer.h   |  27 +++-
 src/gl/renderer/gl_renderer.cpp | 229 +++++++++-----------------------
 src/gl/scene/gl_decal.cpp       |  24 +---
 src/gl/scene/gl_drawinfo.cpp    | 105 +++++----------
 src/gl/scene/gl_flats.cpp       |  73 +++-------
 src/gl/scene/gl_scene.cpp       |  32 ++---
 src/gl/scene/gl_sprite.cpp      |  68 ++--------
 src/gl/scene/gl_vertex.cpp      | 142 --------------------
 src/gl/scene/gl_wall.h          |   7 +-
 src/gl/scene/gl_walls_draw.cpp  | 103 +++++---------
 src/gl/scene/gl_weapon.cpp      |  32 ++---
 12 files changed, 232 insertions(+), 636 deletions(-)

diff --git a/src/gl/data/gl_vertexbuffer.cpp b/src/gl/data/gl_vertexbuffer.cpp
index f7b4bdbf29..8093a57a0e 100644
--- a/src/gl/data/gl_vertexbuffer.cpp
+++ b/src/gl/data/gl_vertexbuffer.cpp
@@ -53,7 +53,7 @@ CUSTOM_CVAR(Int, gl_usevbo, -1, CVAR_ARCHIVE | CVAR_GLOBALCONFIG | CVAR_NOINITCA
 {
 	if (self < -1 || self > 1 || !(gl.flags & RFL_BUFFER_STORAGE))
 	{
-		self = 0;
+		if (self != 0) self = 0;
 	}
 	else if (self == -1)
 	{
@@ -101,7 +101,8 @@ FFlatVertexBuffer::FFlatVertexBuffer()
 	}
 	else
 	{
-		map = NULL;
+		vbo_shadowdata.Reserve(BUFFER_SIZE);
+		map = &vbo_shadowdata[0];
 	}
 	mIndex = mCurIndex = 0;
 }
@@ -113,6 +114,25 @@ FFlatVertexBuffer::~FFlatVertexBuffer()
 	glBindBuffer(GL_ARRAY_BUFFER, 0);
 }
 
+//==========================================================================
+//
+// Renders the buffer's contents with immediate mode functions
+// This is here so that the immediate mode fallback does not need
+// to double all rendering code and can instead reuse the buffer-based version
+//
+//==========================================================================
+
+void FFlatVertexBuffer::ImmRenderBuffer(unsigned int primtype, unsigned int offset, unsigned int count)
+{
+	glBegin(primtype);
+	for (unsigned int i = 0; i < count; i++)
+	{
+		glTexCoord2fv(&map[offset + i].u);
+		glVertex3fv(&map[offset + i].x);
+	}
+	glEnd();
+}
+
 //==========================================================================
 //
 // Initialize a single vertex
@@ -369,7 +389,7 @@ void FFlatVertexBuffer::CheckPlanes(sector_t *sector)
 
 void FFlatVertexBuffer::CheckUpdate(sector_t *sector)
 {
-	if (vbo_arg == 2)
+	if (gl.flags & RFL_BUFFER_STORAGE)
 	{
 		CheckPlanes(sector);
 		sector_t *hs = sector->GetHeightSec();
diff --git a/src/gl/data/gl_vertexbuffer.h b/src/gl/data/gl_vertexbuffer.h
index 0862106d72..50ddd7d130 100644
--- a/src/gl/data/gl_vertexbuffer.h
+++ b/src/gl/data/gl_vertexbuffer.h
@@ -3,6 +3,7 @@
 
 #include "tarray.h"
 #include "gl/utility/gl_clock.h"
+#include "gl/system/gl_interface.h"
 
 struct vertex_t;
 struct secplane_t;
@@ -43,6 +44,7 @@ struct FFlatVertex
 class FFlatVertexBuffer : public FVertexBuffer
 {
 	FFlatVertex *map;
+	FFlatVertex mDrawBuffer[1000];
 	unsigned int mIndex;
 	unsigned int mCurIndex;
 
@@ -50,9 +52,10 @@ class FFlatVertexBuffer : public FVertexBuffer
 
 	const unsigned int BUFFER_SIZE = 2000000;
 
+	void ImmRenderBuffer(unsigned int primtype, unsigned int offset, unsigned int count);
+
 public:
-	int vbo_arg;
-	TArray<FFlatVertex> vbo_shadowdata;	// this is kept around for updating the actual (non-readable) buffer
+	TArray<FFlatVertex> vbo_shadowdata;	// this is kept around for updating the actual (non-readable) buffer and as stand-in for pre GL 4.x
 
 	FFlatVertexBuffer();
 	~FFlatVertexBuffer();
@@ -67,6 +70,7 @@ public:
 	}
 	unsigned int GetCount(FFlatVertex *newptr, unsigned int *poffset)
 	{
+
 		unsigned int newofs = (unsigned int)(newptr - map);
 		unsigned int diff = newofs - mCurIndex;
 		*poffset = mCurIndex;
@@ -75,16 +79,29 @@ public:
 		return diff;
 	}
 #ifdef __GL_PCH_H	// we need the system includes for this but we cannot include them ourselves without creating #define clashes. The affected files wouldn't try to draw anyway.
+	void RenderArray(unsigned int primtype, unsigned int offset, unsigned int count)
+	{
+		drawcalls.Clock();
+		if (gl.flags & RFL_BUFFER_STORAGE)
+		{
+			glDrawArrays(primtype, offset, count);
+		}
+		else
+		{
+			ImmRenderBuffer(primtype, offset, count);
+		}
+		drawcalls.Unclock();
+	}
+
 	void RenderCurrent(FFlatVertex *newptr, unsigned int primtype, unsigned int *poffset = NULL, unsigned int *pcount = NULL)
 	{
 		unsigned int offset;
 		unsigned int count = GetCount(newptr, &offset);
-		drawcalls.Clock();
-		glDrawArrays(primtype, offset, count);
-		drawcalls.Unclock();
+		RenderArray(primtype, offset, count);
 		if (poffset) *poffset = offset;
 		if (pcount) *pcount = count;
 	}
+
 #endif
 	void Reset()
 	{
diff --git a/src/gl/renderer/gl_renderer.cpp b/src/gl/renderer/gl_renderer.cpp
index 1d1535d9a0..78ec2e34e1 100644
--- a/src/gl/renderer/gl_renderer.cpp
+++ b/src/gl/renderer/gl_renderer.cpp
@@ -283,36 +283,17 @@ void FGLRenderer::ClearBorders()
 	gl_RenderState.EnableTexture(false);
 	gl_RenderState.Apply();
 
-	if (!gl_usevbo)
-	{
-		glBegin(GL_QUADS);
-		// upper quad
-		glVertex2i(0, borderHeight);
-		glVertex2i(0, 0);
-		glVertex2i(width, 0);
-		glVertex2i(width, borderHeight);
-
-		// lower quad
-		glVertex2i(0, trueHeight);
-		glVertex2i(0, trueHeight - borderHeight);
-		glVertex2i(width, trueHeight - borderHeight);
-		glVertex2i(width, trueHeight);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(0, borderHeight, 0, 0, 0); ptr++;
-		ptr->Set(0, 0, 0, 0, 0); ptr++;
-		ptr->Set(width, 0, 0, 0, 0); ptr++;
-		ptr->Set(width, borderHeight, 0, 0, 0); ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
-		ptr->Set(0, trueHeight, 0, 0, 0); ptr++;
-		ptr->Set(0, trueHeight - borderHeight, 0, 0, 0); ptr++;
-		ptr->Set(width, trueHeight - borderHeight, 0, 0, 0); ptr++;
-		ptr->Set(width, trueHeight, 0, 0, 0); ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
-	}
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(0, borderHeight, 0, 0, 0); ptr++;
+	ptr->Set(0, 0, 0, 0, 0); ptr++;
+	ptr->Set(width, 0, 0, 0, 0); ptr++;
+	ptr->Set(width, borderHeight, 0, 0, 0); ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
+	ptr->Set(0, trueHeight, 0, 0, 0); ptr++;
+	ptr->Set(0, trueHeight - borderHeight, 0, 0, 0); ptr++;
+	ptr->Set(width, trueHeight - borderHeight, 0, 0, 0); ptr++;
+	ptr->Set(width, trueHeight, 0, 0, 0); ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
 	gl_RenderState.EnableTexture(true);
 
 	glViewport(0, (trueHeight - height) / 2, width, height); 
@@ -412,28 +393,13 @@ void FGLRenderer::DrawTexture(FTexture *img, DCanvas::DrawParms &parms)
 	gl_RenderState.SetColor(color);
 	gl_RenderState.EnableAlphaTest(false);
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
-	{
-		glBegin(GL_TRIANGLE_STRIP);
-		glTexCoord2f(u1, v1);
-		glVertex2d(x, y);
-		glTexCoord2f(u1, v2);
-		glVertex2d(x, y + h);
-		glTexCoord2f(u2, v1);
-		glVertex2d(x + w, y);
-		glTexCoord2f(u2, v2);
-		glVertex2d(x + w, y + h);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(x, y, 0, u1, v1); ptr++;
-		ptr->Set(x, y + h, 0, u1, v2); ptr++;
-		ptr->Set(x + w, y, 0, u2, v1); ptr++;
-		ptr->Set(x + w, y + h, 0, u2, v2); ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
-	}
+
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(x, y, 0, u1, v1); ptr++;
+	ptr->Set(x, y + h, 0, u1, v2); ptr++;
+	ptr->Set(x + w, y, 0, u2, v1); ptr++;
+	ptr->Set(x + w, y + h, 0, u2, v2); ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
 
 	if (parms.colorOverlay)
 	{
@@ -443,28 +409,12 @@ void FGLRenderer::DrawTexture(FTexture *img, DCanvas::DrawParms &parms)
 		gl_RenderState.SetColor(PalEntry(parms.colorOverlay));
 		gl_RenderState.Apply();
 
-		if (!gl_usevbo)
-		{
-			glBegin(GL_TRIANGLE_STRIP);
-			glTexCoord2f(u1, v1);
-			glVertex2d(x, y);
-			glTexCoord2f(u1, v2);
-			glVertex2d(x, y + h);
-			glTexCoord2f(u2, v1);
-			glVertex2d(x + w, y);
-			glTexCoord2f(u2, v2);
-			glVertex2d(x + w, y + h);
-			glEnd();
-		}
-		else
-		{
-			FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-			ptr->Set(x, y, 0, u1, v1); ptr++;
-			ptr->Set(x, y + h, 0, u1, v2); ptr++;
-			ptr->Set(x + w, y, 0, u2, v1); ptr++;
-			ptr->Set(x + w, y + h, 0, u2, v2); ptr++;
-			GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
-		}
+		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+		ptr->Set(x, y, 0, u1, v1); ptr++;
+		ptr->Set(x, y + h, 0, u1, v2); ptr++;
+		ptr->Set(x + w, y, 0, u2, v1); ptr++;
+		ptr->Set(x + w, y + h, 0, u2, v2); ptr++;
+		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
 	}
 
 	gl_RenderState.EnableAlphaTest(true);
@@ -487,20 +437,12 @@ void FGLRenderer::DrawLine(int x1, int y1, int x2, int y2, int palcolor, uint32
 	gl_RenderState.EnableTexture(false);
 	gl_RenderState.SetColorAlpha(p, 1.f);
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
-	{
-		glBegin(GL_LINES);
-		glVertex2i(x1, y1);
-		glVertex2i(x2, y2);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(x1, y1, 0, 0, 0); ptr++;
-		ptr->Set(x2, y2, 0, 0, 0); ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_LINES);
-	}
+
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(x1, y1, 0, 0, 0); ptr++;
+	ptr->Set(x2, y2, 0, 0, 0); ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_LINES);
+	
 	gl_RenderState.EnableTexture(true);
 }
 
@@ -515,18 +457,11 @@ void FGLRenderer::DrawPixel(int x1, int y1, int palcolor, uint32 color)
 	gl_RenderState.EnableTexture(false);
 	gl_RenderState.SetColorAlpha(p, 1.f);
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
-	{
-		glBegin(GL_POINTS);
-		glVertex2i(x1, y1);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(x1, y1, 0, 0, 0); ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_POINTS);
-	}
+
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(x1, y1, 0, 0, 0); ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_POINTS);
+
 	gl_RenderState.EnableTexture(true);
 }
 
@@ -544,24 +479,13 @@ void FGLRenderer::Dim(PalEntry color, float damount, int x1, int y1, int w, int
 	gl_RenderState.SetColorAlpha(color, damount);
 	gl_RenderState.Apply();
 	
-	if (!gl_usevbo)
-	{
-		glBegin(GL_TRIANGLE_FAN);
-		glVertex2i(x1, y1);
-		glVertex2i(x1, y1 + h);
-		glVertex2i(x1 + w, y1 + h);
-		glVertex2i(x1 + w, y1);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(x1, y1, 0, 0, 0); ptr++;
-		ptr->Set(x1, y1+h, 0, 0, 0); ptr++;
-		ptr->Set(x1+w, y1+h, 0, 0, 0); ptr++;
-		ptr->Set(x1+w, y1, 0, 0, 0); ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
-	}
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(x1, y1, 0, 0, 0); ptr++;
+	ptr->Set(x1, y1+h, 0, 0, 0); ptr++;
+	ptr->Set(x1+w, y1+h, 0, 0, 0); ptr++;
+	ptr->Set(x1+w, y1, 0, 0, 0); ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
+
 	gl_RenderState.EnableTexture(true);
 }
 
@@ -597,24 +521,13 @@ void FGLRenderer::FlatFill (int left, int top, int right, int bottom, FTexture *
 	}
 	gl_RenderState.ResetColor();
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
-	{
-		glBegin(GL_TRIANGLE_STRIP);
-		glTexCoord2f(fU1, fV1); glVertex2f(left, top);
-		glTexCoord2f(fU1, fV2); glVertex2f(left, bottom);
-		glTexCoord2f(fU2, fV1); glVertex2f(right, top);
-		glTexCoord2f(fU2, fV2); glVertex2f(right, bottom);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(left, top, 0, fU1, fV1); ptr++;
-		ptr->Set(left, bottom, 0, fU1, fV2); ptr++;
-		ptr->Set(right, top, 0, fU2, fV1); ptr++;
-		ptr->Set(right, bottom, 0, fU2, fV2); ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
-	}
+
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(left, top, 0, fU1, fV1); ptr++;
+	ptr->Set(left, bottom, 0, fU1, fV2); ptr++;
+	ptr->Set(right, top, 0, fU2, fV1); ptr++;
+	ptr->Set(right, bottom, 0, fU2, fV2); ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
 }
 
 //==========================================================================
@@ -702,41 +615,21 @@ void FGLRenderer::FillSimplePoly(FTexture *texture, FVector2 *points, int npoint
 	float oy = float(originy);
 
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
+
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	for (i = 0; i < npoints; ++i)
 	{
-		glBegin(GL_TRIANGLE_FAN);
-		for (i = 0; i < npoints; ++i)
+		float u = points[i].X - 0.5f - ox;
+		float v = points[i].Y - 0.5f - oy;
+		if (dorotate)
 		{
-			float u = points[i].X - 0.5f - ox;
-			float v = points[i].Y - 0.5f - oy;
-			if (dorotate)
-			{
-				float t = u;
-				u = t * cosrot - v * sinrot;
-				v = v * cosrot + t * sinrot;
-			}
-			glTexCoord2f(u * uscale, v * vscale);
-			glVertex3f(points[i].X, points[i].Y /* + yoffs */, 0);
+			float t = u;
+			u = t * cosrot - v * sinrot;
+			v = v * cosrot + t * sinrot;
 		}
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		for (i = 0; i < npoints; ++i)
-		{
-			float u = points[i].X - 0.5f - ox;
-			float v = points[i].Y - 0.5f - oy;
-			if (dorotate)
-			{
-				float t = u;
-				u = t * cosrot - v * sinrot;
-				v = v * cosrot + t * sinrot;
-			}
-			ptr->Set(points[i].X, points[i].Y, 0, u*uscale, v*vscale);
-			ptr++;
-		}
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
+		ptr->Set(points[i].X, points[i].Y, 0, u*uscale, v*vscale);
+		ptr++;
 	}
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
 }
 
diff --git a/src/gl/scene/gl_decal.cpp b/src/gl/scene/gl_decal.cpp
index 8f2e7977ae..e6d5c144f2 100644
--- a/src/gl/scene/gl_decal.cpp
+++ b/src/gl/scene/gl_decal.cpp
@@ -337,26 +337,14 @@ void GLWall::DrawDecal(DBaseDecal *decal)
 	else gl_RenderState.AlphaFunc(GL_GREATER, 0.f);
 
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	for (i = 0; i < 4; i++)
 	{
-		glBegin(GL_TRIANGLE_FAN);
-		for (i = 0; i < 4; i++)
-		{
-			glTexCoord2f(dv[i].u, dv[i].v);
-			glVertex3f(dv[i].x, dv[i].z, dv[i].y);
-		}
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		for (i = 0; i < 4; i++)
-		{
-			ptr->Set(dv[i].x, dv[i].z, dv[i].y, dv[i].u, dv[i].v);
-			ptr++;
-		}
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
+		ptr->Set(dv[i].x, dv[i].z, dv[i].y, dv[i].u, dv[i].v);
+		ptr++;
 	}
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
+
 	rendered_decals++;
 	gl_RenderState.SetTextureMode(TM_MODULATE);
 	gl_RenderState.SetObjectColor(0xffffffff);
diff --git a/src/gl/scene/gl_drawinfo.cpp b/src/gl/scene/gl_drawinfo.cpp
index fc44c7896f..8c620d93e6 100644
--- a/src/gl/scene/gl_drawinfo.cpp
+++ b/src/gl/scene/gl_drawinfo.cpp
@@ -991,28 +991,17 @@ void FDrawInfo::SetupFloodStencil(wallseg * ws)
 	glDepthMask(true);
 
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
-	{
-		glBegin(GL_TRIANGLE_FAN);
-		glVertex3f(ws->x1, ws->z1, ws->y1);
-		glVertex3f(ws->x1, ws->z2, ws->y1);
-		glVertex3f(ws->x2, ws->z2, ws->y2);
-		glVertex3f(ws->x2, ws->z1, ws->y2);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(ws->x1, ws->z1, ws->y1, 0, 0);
-		ptr++;
-		ptr->Set(ws->x1, ws->z2, ws->y1, 0, 0);
-		ptr++;
-		ptr->Set(ws->x2, ws->z2, ws->y2, 0, 0);
-		ptr++;
-		ptr->Set(ws->x2, ws->z1, ws->y2, 0, 0);
-		ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
-	}
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(ws->x1, ws->z1, ws->y1, 0, 0);
+	ptr++;
+	ptr->Set(ws->x1, ws->z2, ws->y1, 0, 0);
+	ptr++;
+	ptr->Set(ws->x2, ws->z2, ws->y2, 0, 0);
+	ptr++;
+	ptr->Set(ws->x2, ws->z1, ws->y2, 0, 0);
+	ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
+
 
 	glStencilFunc(GL_EQUAL,recursion+1,~0);		// draw sky into stencil
 	glStencilOp(GL_KEEP,GL_KEEP,GL_KEEP);		// this stage doesn't modify the stencil
@@ -1033,28 +1022,16 @@ void FDrawInfo::ClearFloodStencil(wallseg * ws)
 	gl_RenderState.ResetColor();
 
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
-	{
-		glBegin(GL_TRIANGLE_FAN);
-		glVertex3f(ws->x1, ws->z1, ws->y1);
-		glVertex3f(ws->x1, ws->z2, ws->y1);
-		glVertex3f(ws->x2, ws->z2, ws->y2);
-		glVertex3f(ws->x2, ws->z1, ws->y2);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(ws->x1, ws->z1, ws->y1, 0, 0);
-		ptr++;
-		ptr->Set(ws->x1, ws->z2, ws->y1, 0, 0);
-		ptr++;
-		ptr->Set(ws->x2, ws->z2, ws->y2, 0, 0);
-		ptr++;
-		ptr->Set(ws->x2, ws->z1, ws->y2, 0, 0);
-		ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
-	}
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(ws->x1, ws->z1, ws->y1, 0, 0);
+	ptr++;
+	ptr->Set(ws->x1, ws->z2, ws->y1, 0, 0);
+	ptr++;
+	ptr->Set(ws->x2, ws->z2, ws->y2, 0, 0);
+	ptr++;
+	ptr->Set(ws->x2, ws->z1, ws->y2, 0, 0);
+	ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
 
 	// restore old stencil op.
 	glStencilOp(GL_KEEP,GL_KEEP,GL_KEEP);
@@ -1126,36 +1103,16 @@ void FDrawInfo::DrawFloodedPlane(wallseg * ws, float planez, sector_t * sec, boo
 	float px4 = fviewx + prj_fac1 * (ws->x2-fviewx);
 	float py4 = fviewy + prj_fac1 * (ws->y2-fviewy);
 
-	if (!gl_usevbo)
-	{
-		glBegin(GL_TRIANGLE_FAN);
-		glTexCoord2f(px1 / 64, -py1 / 64);
-		glVertex3f(px1, planez, py1);
-
-		glTexCoord2f(px2 / 64, -py2 / 64);
-		glVertex3f(px2, planez, py2);
-
-		glTexCoord2f(px3 / 64, -py3 / 64);
-		glVertex3f(px3, planez, py3);
-
-		glTexCoord2f(px4 / 64, -py4 / 64);
-		glVertex3f(px4, planez, py4);
-
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(px1, planez, py1, px1 / 64, -py1 / 64);
-		ptr++;
-		ptr->Set(px2, planez, py2, px2 / 64, -py2 / 64);
-		ptr++;
-		ptr->Set(px3, planez, py3, px3 / 64, -py3 / 64);
-		ptr++;
-		ptr->Set(px4, planez, py4, px4 / 64, -py4 / 64);
-		ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
-	}
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(px1, planez, py1, px1 / 64, -py1 / 64);
+	ptr++;
+	ptr->Set(px2, planez, py2, px2 / 64, -py2 / 64);
+	ptr++;
+	ptr->Set(px3, planez, py3, px3 / 64, -py3 / 64);
+	ptr++;
+	ptr->Set(px4, planez, py4, px4 / 64, -py4 / 64);
+	ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
 
 	if (pushed)
 	{
diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index 39731bf740..59d4192e70 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -239,64 +239,35 @@ bool GLFlat::SetupSubsectorLights(bool lightsapplied, subsector_t * sub)
 
 void GLFlat::DrawSubsector(subsector_t * sub)
 {
-	if (!gl_usevbo)
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	if (plane.plane.a | plane.plane.b)
 	{
-		glBegin(GL_TRIANGLE_FAN);
-
-		if (plane.plane.a | plane.plane.b)
+		for (unsigned int k = 0; k < sub->numlines; k++)
 		{
-			for (unsigned int k = 0; k < sub->numlines; k++)
-			{
-				vertex_t *vt = sub->firstline[k].v1;
-				glTexCoord2f(vt->fx / 64.f, -vt->fy / 64.f);
-				float zc = plane.plane.ZatPoint(vt->fx, vt->fy) + dz;
-				glVertex3f(vt->fx, zc, vt->fy);
-			}
+			vertex_t *vt = sub->firstline[k].v1;
+			ptr->x = vt->fx;
+			ptr->y = vt->fy;
+			ptr->z = plane.plane.ZatPoint(vt->fx, vt->fy) + dz;
+			ptr->u = vt->fx / 64.f;
+			ptr->v = -vt->fy / 64.f;
+			ptr++;
 		}
-		else
-		{
-			float zc = FIXED2FLOAT(plane.plane.Zat0()) + dz;
-			for (unsigned int k = 0; k < sub->numlines; k++)
-			{
-				vertex_t *vt = sub->firstline[k].v1;
-				glTexCoord2f(vt->fx / 64.f, -vt->fy / 64.f);
-				glVertex3f(vt->fx, zc, vt->fy);
-			}
-		}
-		glEnd();
 	}
 	else
 	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		if (plane.plane.a | plane.plane.b)
+		float zc = FIXED2FLOAT(plane.plane.Zat0()) + dz;
+		for (unsigned int k = 0; k < sub->numlines; k++)
 		{
-			for (unsigned int k = 0; k < sub->numlines; k++)
-			{
-				vertex_t *vt = sub->firstline[k].v1;
-				ptr->x = vt->fx;
-				ptr->y = vt->fy;
-				ptr->z = plane.plane.ZatPoint(vt->fx, vt->fy) + dz;
-				ptr->u = vt->fx / 64.f;
-				ptr->v = -vt->fy / 64.f;
-				ptr++;
-			}
+			vertex_t *vt = sub->firstline[k].v1;
+			ptr->x = vt->fx;
+			ptr->y = vt->fy;
+			ptr->z = zc;
+			ptr->u = vt->fx / 64.f;
+			ptr->v = -vt->fy / 64.f;
+			ptr++;
 		}
-		else
-		{
-			float zc = FIXED2FLOAT(plane.plane.Zat0()) + dz;
-			for (unsigned int k = 0; k < sub->numlines; k++)
-			{
-				vertex_t *vt = sub->firstline[k].v1;
-				ptr->x = vt->fx;
-				ptr->y = vt->fy;
-				ptr->z = zc;
-				ptr->u = vt->fx / 64.f;
-				ptr->v = -vt->fy / 64.f;
-				ptr++;
-			}
-		}
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
 	}
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
 
 	flatvertices += sub->numlines;
 	flatprimitives++;
@@ -332,9 +303,9 @@ void GLFlat::DrawSubsectors(int pass, bool istrans)
 				if (gl_drawinfo->ss_renderflags[sub-subsectors]&renderflags || istrans)
 				{
 					if (pass == GLPASS_ALL) lightsapplied = SetupSubsectorLights(lightsapplied, sub);
-					drawcalls.Clock();
+					//drawcalls.Clock();
 					glDrawArrays(GL_TRIANGLE_FAN, index, sub->numlines);
-					drawcalls.Unclock();
+					//drawcalls.Unclock();
 					flatvertices += sub->numlines;
 					flatprimitives++;
 				}
diff --git a/src/gl/scene/gl_scene.cpp b/src/gl/scene/gl_scene.cpp
index a05aadde40..8f8d505321 100644
--- a/src/gl/scene/gl_scene.cpp
+++ b/src/gl/scene/gl_scene.cpp
@@ -617,28 +617,16 @@ static void FillScreen()
 	gl_RenderState.EnableAlphaTest(false);
 	gl_RenderState.EnableTexture(false);
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
-	{
-		glBegin(GL_TRIANGLE_STRIP);
-		glVertex2f(0.0f, 0.0f);
-		glVertex2f(0.0f, (float)SCREENHEIGHT);
-		glVertex2f((float)SCREENWIDTH, 0.0f);
-		glVertex2f((float)SCREENWIDTH, (float)SCREENHEIGHT);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(0, 0, 0, 0, 0);
-		ptr++;
-		ptr->Set(0, (float)SCREENHEIGHT, 0, 0, 0);
-		ptr++;
-		ptr->Set((float)SCREENWIDTH, 0, 0, 0, 0);
-		ptr++;
-		ptr->Set((float)SCREENWIDTH, (float)SCREENHEIGHT, 0, 0, 0);
-		ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
-	}
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(0, 0, 0, 0, 0);
+	ptr++;
+	ptr->Set(0, (float)SCREENHEIGHT, 0, 0, 0);
+	ptr++;
+	ptr->Set((float)SCREENWIDTH, 0, 0, 0, 0);
+	ptr++;
+	ptr->Set((float)SCREENWIDTH, (float)SCREENHEIGHT, 0, 0, 0);
+	ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
 }
 
 //==========================================================================
diff --git a/src/gl/scene/gl_sprite.cpp b/src/gl/scene/gl_sprite.cpp
index e36dd4b0e8..00f2ccada0 100644
--- a/src/gl/scene/gl_sprite.cpp
+++ b/src/gl/scene/gl_sprite.cpp
@@ -269,39 +269,16 @@ void GLSprite::Draw(int pass)
 
 		FFlatVertex *ptr;
 		unsigned int offset, count;
-		if (!gl_usevbo)
-		{
-			glBegin(GL_TRIANGLE_STRIP);
-			if (gltexture)
-			{
-				glTexCoord2f(ul, vt); glVertex3fv(&v1[0]);
-				glTexCoord2f(ur, vt); glVertex3fv(&v2[0]);
-				glTexCoord2f(ul, vb); glVertex3fv(&v3[0]);
-				glTexCoord2f(ur, vb); glVertex3fv(&v4[0]);
-			}
-			else	// Particle
-			{
-				glVertex3fv(&v1[0]);
-				glVertex3fv(&v2[0]);
-				glVertex3fv(&v3[0]);
-				glVertex3fv(&v4[0]);
-			}
-
-			glEnd();
-		}
-		else
-		{
-			ptr = GLRenderer->mVBO->GetBuffer();
-			ptr->Set(v1[0], v1[1], v1[2], ul, vt);
-			ptr++;
-			ptr->Set(v2[0], v2[1], v2[2], ur, vt);
-			ptr++;
-			ptr->Set(v3[0], v3[1], v3[2], ul, vb);
-			ptr++;
-			ptr->Set(v4[0], v4[1], v4[2], ur, vb);
-			ptr++;
-			GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP, &offset, &count);
-		}
+		ptr = GLRenderer->mVBO->GetBuffer();
+		ptr->Set(v1[0], v1[1], v1[2], ul, vt);
+		ptr++;
+		ptr->Set(v2[0], v2[1], v2[2], ur, vt);
+		ptr++;
+		ptr->Set(v3[0], v3[1], v3[2], ul, vb);
+		ptr++;
+		ptr->Set(v4[0], v4[1], v4[2], ur, vb);
+		ptr++;
+		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP, &offset, &count);
 
 		if (foglayer)
 		{
@@ -311,30 +288,7 @@ void GLSprite::Draw(int pass)
 			gl_RenderState.BlendEquation(GL_FUNC_ADD);
 			gl_RenderState.BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 			gl_RenderState.Apply();
-
-			if (!gl_usevbo)
-			{
-				glBegin(GL_TRIANGLE_STRIP);
-				if (gltexture)
-				{
-					glTexCoord2f(ul, vt); glVertex3fv(&v1[0]);
-					glTexCoord2f(ur, vt); glVertex3fv(&v2[0]);
-					glTexCoord2f(ul, vb); glVertex3fv(&v3[0]);
-					glTexCoord2f(ur, vb); glVertex3fv(&v4[0]);
-				}
-				else	// Particle
-				{
-					glVertex3fv(&v1[0]);
-					glVertex3fv(&v2[0]);
-					glVertex3fv(&v3[0]);
-					glVertex3fv(&v4[0]);
-				}
-				glEnd();
-			}
-			else
-			{
-				glDrawArrays(GL_TRIANGLE_STRIP, offset, count);
-			}
+			GLRenderer->mVBO->RenderArray(GL_TRIANGLE_STRIP, offset, count);
 			gl_RenderState.SetFixedColormap(CM_DEFAULT);
 		}
 	}
diff --git a/src/gl/scene/gl_vertex.cpp b/src/gl/scene/gl_vertex.cpp
index b3ee9c8b5a..c0f21adce2 100644
--- a/src/gl/scene/gl_vertex.cpp
+++ b/src/gl/scene/gl_vertex.cpp
@@ -54,144 +54,6 @@
 #include "gl/utility/gl_templates.h"
 
 EXTERN_CVAR(Bool, gl_seamless)
-extern int vertexcount;
-
-//==========================================================================
-//
-// Split upper edge of wall
-//
-//==========================================================================
-
-void GLWall::SplitUpperEdge(texcoord * tcs)
-{
-	if (seg == NULL || seg->sidedef == NULL || (seg->sidedef->Flags & WALLF_POLYOBJ) || seg->sidedef->numsegs == 1) return;
-
-	side_t *sidedef = seg->sidedef;
-	float polyw = glseg.fracright - glseg.fracleft;
-	float facu = (tcs[2].u - tcs[1].u) / polyw;
-	float facv = (tcs[2].v - tcs[1].v) / polyw;
-	float fact = (ztop[1] - ztop[0]) / polyw;
-	float facc = (zceil[1] - zceil[0]) / polyw;
-	float facf = (zfloor[1] - zfloor[0]) / polyw;
-
-	for (int i=0; i < sidedef->numsegs - 1; i++)
-	{
-		seg_t *cseg = sidedef->segs[i];
-		float sidefrac = cseg->sidefrac;
-		if (sidefrac <= glseg.fracleft) continue;
-		if (sidefrac >= glseg.fracright) return;
-
-		float fracfac = sidefrac - glseg.fracleft;
-
-		glTexCoord2f(tcs[1].u + facu * fracfac, tcs[1].v + facv * fracfac);
-		glVertex3f(cseg->v2->fx, ztop[0] + fact * fracfac, cseg->v2->fy);
-	}
-	vertexcount += sidedef->numsegs-1;
-}
-
-//==========================================================================
-//
-// Split upper edge of wall
-//
-//==========================================================================
-
-void GLWall::SplitLowerEdge(texcoord * tcs)
-{
-	if (seg == NULL || seg->sidedef == NULL || (seg->sidedef->Flags & WALLF_POLYOBJ) || seg->sidedef->numsegs == 1) return;
-
-	side_t *sidedef = seg->sidedef;
-	float polyw = glseg.fracright - glseg.fracleft;
-	float facu = (tcs[3].u - tcs[0].u) / polyw;
-	float facv = (tcs[3].v - tcs[0].v) / polyw;
-	float facb = (zbottom[1] - zbottom[0]) / polyw;
-	float facc = (zceil[1] - zceil[0]) / polyw;
-	float facf = (zfloor[1] - zfloor[0]) / polyw;
-
-	for (int i = sidedef->numsegs-2; i >= 0; i--)
-	{
-		seg_t *cseg = sidedef->segs[i];
-		float sidefrac = cseg->sidefrac;
-		if (sidefrac >= glseg.fracright) continue;
-		if (sidefrac <= glseg.fracleft) return;
-
-		float fracfac = sidefrac - glseg.fracleft;
-
-		glTexCoord2f(tcs[0].u + facu * fracfac, tcs[0].v + facv * fracfac);
-		glVertex3f(cseg->v2->fx, zbottom[0] + facb * fracfac, cseg->v2->fy);
-	}
-	vertexcount += sidedef->numsegs-1;
-}
-
-//==========================================================================
-//
-// Split left edge of wall
-//
-//==========================================================================
-
-void GLWall::SplitLeftEdge(texcoord * tcs)
-{
-	if (vertexes[0]==NULL) return;
-
-	vertex_t * vi=vertexes[0];
-
-	if (vi->numheights)
-	{
-		int i=0;
-
-		float polyh1=ztop[0] - zbottom[0];
-		float factv1=polyh1? (tcs[1].v - tcs[0].v) / polyh1:0;
-		float factu1=polyh1? (tcs[1].u - tcs[0].u) / polyh1:0;
-
-		while (i<vi->numheights && vi->heightlist[i] <= zbottom[0] ) i++;
-		while (i<vi->numheights && vi->heightlist[i] < ztop[0])
-		{
-			glTexCoord2f(factu1*(vi->heightlist[i] - ztop[0]) + tcs[1].u,
-						 factv1*(vi->heightlist[i] - ztop[0]) + tcs[1].v);
-			glVertex3f(glseg.x1, vi->heightlist[i], glseg.y1);
-			i++;
-		}
-		vertexcount+=i;
-	}
-}
-
-//==========================================================================
-//
-// Split right edge of wall
-//
-//==========================================================================
-
-void GLWall::SplitRightEdge(texcoord * tcs)
-{
-	if (vertexes[1]==NULL) return;
-
-	vertex_t * vi=vertexes[1];
-
-	if (vi->numheights)
-	{
-		int i=vi->numheights-1;
-
-		float polyh2 = ztop[1] - zbottom[1];
-		float factv2 = polyh2? (tcs[2].v - tcs[3].v) / polyh2:0;
-		float factu2 = polyh2? (tcs[2].u - tcs[3].u) / polyh2:0;
-
-		while (i>0 && vi->heightlist[i] >= ztop[1]) i--;
-		while (i>0 && vi->heightlist[i] > zbottom[1])
-		{
-			glTexCoord2f(factu2 * (vi->heightlist[i] - ztop[1]) + tcs[2].u,
-						 factv2 * (vi->heightlist[i] - ztop[1]) + tcs[2].v);
-			glVertex3f(glseg.x2, vi->heightlist[i], glseg.y2);
-			i--;
-		}
-		vertexcount+=i;
-	}
-}
-
-
-//==========================================================================
-//
-// same for vertex buffer mode
-//
-//==========================================================================
 
 //==========================================================================
 //
@@ -227,7 +89,6 @@ void GLWall::SplitUpperEdge(texcoord * tcs, FFlatVertex *&ptr)
 		ptr->v = tcs[1].v + facv * fracfac;
 		ptr++;
 	}
-	vertexcount += sidedef->numsegs - 1;
 }
 
 //==========================================================================
@@ -264,7 +125,6 @@ void GLWall::SplitLowerEdge(texcoord * tcs, FFlatVertex *&ptr)
 		ptr->v = tcs[0].v + facv * fracfac;
 		ptr++;
 	}
-	vertexcount += sidedef->numsegs - 1;
 }
 
 //==========================================================================
@@ -298,7 +158,6 @@ void GLWall::SplitLeftEdge(texcoord * tcs, FFlatVertex *&ptr)
 			ptr++;
 			i++;
 		}
-		vertexcount += i;
 	}
 }
 
@@ -333,7 +192,6 @@ void GLWall::SplitRightEdge(texcoord * tcs, FFlatVertex *&ptr)
 			ptr++;
 			i--;
 		}
-		vertexcount += i;
 	}
 }
 
diff --git a/src/gl/scene/gl_wall.h b/src/gl/scene/gl_wall.h
index dd13651934..25815ab76a 100644
--- a/src/gl/scene/gl_wall.h
+++ b/src/gl/scene/gl_wall.h
@@ -159,7 +159,7 @@ private:
 
 	void SetupLights();
 	bool PrepareLight(texcoord * tcs, ADynamicLight * light);
-	void RenderWall(int textured, float * color2, ADynamicLight * light=NULL);
+	void RenderWall(int textured, ADynamicLight * light=NULL);
 	void GetPrimitive(unsigned int *store);
 
 	void FloodPlane(int pass);
@@ -212,11 +212,6 @@ private:
 	void RenderMirrorSurface();
 	void RenderTranslucentWall();
 
-	void SplitLeftEdge(texcoord * tcs);
-	void SplitRightEdge(texcoord * tcs);
-	void SplitUpperEdge(texcoord * tcs);
-	void SplitLowerEdge(texcoord * tcs);
-
 	void SplitLeftEdge(texcoord * tcs, FFlatVertex *&ptr);
 	void SplitRightEdge(texcoord * tcs, FFlatVertex *&ptr);
 	void SplitUpperEdge(texcoord * tcs, FFlatVertex *&ptr);
diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index 9c5baae6ae..1388eb7824 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -215,6 +215,7 @@ void GLWall::SetupLights()
 	}
 }
 
+
 //==========================================================================
 //
 // General purpose wall rendering function
@@ -222,7 +223,7 @@ void GLWall::SetupLights()
 //
 //==========================================================================
 
-void GLWall::RenderWall(int textured, float * color2, ADynamicLight * light)
+void GLWall::RenderWall(int textured, ADynamicLight * light)
 {
 	texcoord tcs[4];
 	bool split = (gl_seamless && !(textured&4) && seg->sidedef != NULL && !(seg->sidedef->Flags & WALLF_POLYOBJ));
@@ -249,64 +250,22 @@ void GLWall::RenderWall(int textured, float * color2, ADynamicLight * light)
 	gl_RenderState.Apply();
 
 	// the rest of the code is identical for textured rendering and lights
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
 
-
-	if (!gl_usevbo)
-	{
-		glBegin(GL_TRIANGLE_FAN);
-
-		// lower left corner
-		if (textured & 1) glTexCoord2f(tcs[0].u, tcs[0].v);
-		glVertex3f(glseg.x1, zbottom[0], glseg.y1);
-
-		if (split && glseg.fracleft == 0) SplitLeftEdge(tcs);
-
-		// upper left corner
-		if (textured & 1) glTexCoord2f(tcs[1].u, tcs[1].v);
-		glVertex3f(glseg.x1, ztop[0], glseg.y1);
-
-		if (split && !(flags & GLWF_NOSPLITUPPER)) SplitUpperEdge(tcs);
-
-		// color for right side (do not set in render state!)
-		if (color2) glColor4fv(color2);
-
-		// upper right corner
-		if (textured & 1) glTexCoord2f(tcs[2].u, tcs[2].v);
-		glVertex3f(glseg.x2, ztop[1], glseg.y2);
-
-		if (split && glseg.fracright == 1) SplitRightEdge(tcs);
-
-		// lower right corner
-		if (textured & 1) glTexCoord2f(tcs[3].u, tcs[3].v);
-		glVertex3f(glseg.x2, zbottom[1], glseg.y2);
-
-		if (split && !(flags & GLWF_NOSPLITLOWER)) SplitLowerEdge(tcs);
-
-		glEnd();
-
-		vertexcount += 4;
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-
-		ptr->Set(glseg.x1, zbottom[0], glseg.y1, tcs[0].u, tcs[0].v);
-		ptr++;
-		if (split && glseg.fracleft == 0) SplitLeftEdge(tcs, ptr);
-		ptr->Set(glseg.x1, ztop[0], glseg.y1, tcs[1].u, tcs[1].v);
-		ptr++;
-		if (split && !(flags & GLWF_NOSPLITUPPER)) SplitUpperEdge(tcs, ptr);
-		ptr->Set(glseg.x2, ztop[1], glseg.y2, tcs[2].u, tcs[2].v);
-		ptr++;
-		if (split && glseg.fracright == 1) SplitRightEdge(tcs, ptr);
-		ptr->Set(glseg.x2, zbottom[1], glseg.y2, tcs[3].u, tcs[3].v);
-		ptr++;
-		if (split && !(flags & GLWF_NOSPLITLOWER)) SplitLowerEdge(tcs, ptr);
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
-		vertexcount += 4;
-	}
-
-
+	ptr->Set(glseg.x1, zbottom[0], glseg.y1, tcs[0].u, tcs[0].v);
+	ptr++;
+	if (split && glseg.fracleft == 0) SplitLeftEdge(tcs, ptr);
+	ptr->Set(glseg.x1, ztop[0], glseg.y1, tcs[1].u, tcs[1].v);
+	ptr++;
+	if (split && !(flags & GLWF_NOSPLITUPPER)) SplitUpperEdge(tcs, ptr);
+	ptr->Set(glseg.x2, ztop[1], glseg.y2, tcs[2].u, tcs[2].v);
+	ptr++;
+	if (split && glseg.fracright == 1) SplitRightEdge(tcs, ptr);
+	ptr->Set(glseg.x2, zbottom[1], glseg.y2, tcs[3].u, tcs[3].v);
+	ptr++;
+	if (split && !(flags & GLWF_NOSPLITLOWER)) SplitLowerEdge(tcs, ptr);
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_FAN);
+	vertexcount += 4;
 }
 
 //==========================================================================
@@ -356,7 +315,7 @@ void GLWall::RenderFogBoundary()
 			gl_SetFog(lightlevel, rel, &Colormap, false);
 			gl_RenderState.SetEffect(EFF_FOGBOUNDARY);
 			gl_RenderState.EnableAlphaTest(false);
-			RenderWall(0, NULL);
+			RenderWall(0);
 			gl_RenderState.EnableAlphaTest(true);
 			gl_RenderState.SetEffect(EFF_NONE);
 		}
@@ -385,8 +344,17 @@ void GLWall::RenderFogBoundary()
 			glDepthFunc(GL_LEQUAL);
 			gl_RenderState.SetColor(fc[0], fc[1], fc[2], fogd1);
 
-			flags &= ~GLWF_GLOW;
-			RenderWall(4,fc);
+			// this case is special because it needs to change the color in the middle of the polygon so it cannot use the standard function
+			// This also needs no splits so it's relatively simple.
+			gl_RenderState.Apply();
+			glBegin(GL_TRIANGLE_FAN);
+			glVertex3f(glseg.x1, zbottom[0], glseg.y1);
+			glVertex3f(glseg.x1, ztop[0], glseg.y1);
+			glColor4fv(fc);
+			glVertex3f(glseg.x2, ztop[1], glseg.y2);
+			glVertex3f(glseg.x2, zbottom[1], glseg.y2);
+			glEnd();
+			vertexcount += 4;
 
 			glDepthFunc(GL_LESS);
 			gl_RenderState.EnableFog(true);
@@ -424,8 +392,7 @@ void GLWall::RenderMirrorSurface()
 	pat->BindPatch(0);
 
 	flags &= ~GLWF_GLOW;
-	//flags |= GLWF_NOSHADER;
-	RenderWall(0,NULL);
+	RenderWall(0);
 
 	gl_RenderState.SetEffect(EFF_NONE);
 
@@ -486,7 +453,7 @@ void GLWall::RenderTranslucentWall()
 	if (type!=RENDERWALL_M2SNF) gl_SetFog(lightlevel, extra, &Colormap, isadditive);
 	else gl_SetFog(255, 0, NULL, false);
 
-	RenderWall(5,NULL);
+	RenderWall(5);
 
 	// restore default settings
 	if (isadditive) gl_RenderState.BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
@@ -540,7 +507,7 @@ void GLWall::Draw(int pass)
 
 		gl_RenderState.EnableGlow(!!(flags & GLWF_GLOW));
 		gltexture->Bind(flags, 0);
-		RenderWall(3, NULL);
+		RenderWall(3);
 		gl_RenderState.EnableGlow(false);
 		gl_RenderState.EnableLight(false);
 		break;
@@ -561,14 +528,14 @@ void GLWall::Draw(int pass)
 		{
 			gltexture->Bind(flags, 0);
 		}
-		RenderWall(pass == GLPASS_BASE? 2:3, NULL);
+		RenderWall(pass == GLPASS_BASE? 2:3);
 		gl_RenderState.EnableGlow(false);
 		gl_RenderState.EnableLight(false);
 		break;
 
 	case GLPASS_TEXTURE:		// modulated texture
 		gltexture->Bind(flags, 0);
-		RenderWall(1, NULL);
+		RenderWall(1);
 		break;
 
 	case GLPASS_LIGHT:
@@ -597,7 +564,7 @@ void GLWall::Draw(int pass)
 			if (!(node->lightsource->flags2&MF2_DORMANT))
 			{
 				iter_dlight++;
-				RenderWall(1, NULL, node->lightsource);
+				RenderWall(1, node->lightsource);
 			}
 			node = node->nextLight;
 		}
diff --git a/src/gl/scene/gl_weapon.cpp b/src/gl/scene/gl_weapon.cpp
index a91fa252f1..8f76b0571a 100644
--- a/src/gl/scene/gl_weapon.cpp
+++ b/src/gl/scene/gl_weapon.cpp
@@ -154,28 +154,16 @@ void FGLRenderer::DrawPSprite (player_t * player,pspdef_t *psp,fixed_t sx, fixed
 		gl_RenderState.EnableAlphaTest(false);
 	}
 	gl_RenderState.Apply();
-	if (!gl_usevbo)
-	{
-		glBegin(GL_TRIANGLE_STRIP);
-		glTexCoord2f(fU1, fV1); glVertex2f(x1, y1);
-		glTexCoord2f(fU1, fV2); glVertex2f(x1, y2);
-		glTexCoord2f(fU2, fV1); glVertex2f(x2, y1);
-		glTexCoord2f(fU2, fV2); glVertex2f(x2, y2);
-		glEnd();
-	}
-	else
-	{
-		FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
-		ptr->Set(x1, y1, 0, fU1, fV1);
-		ptr++;
-		ptr->Set(x1, y2, 0, fU1, fV2);
-		ptr++;
-		ptr->Set(x2, y1, 0, fU2, fV1);
-		ptr++;
-		ptr->Set(x2, y2, 0, fU2, fV2);
-		ptr++;
-		GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
-	}
+	FFlatVertex *ptr = GLRenderer->mVBO->GetBuffer();
+	ptr->Set(x1, y1, 0, fU1, fV1);
+	ptr++;
+	ptr->Set(x1, y2, 0, fU1, fV2);
+	ptr++;
+	ptr->Set(x2, y1, 0, fU2, fV1);
+	ptr++;
+	ptr->Set(x2, y2, 0, fU2, fV2);
+	ptr++;
+	GLRenderer->mVBO->RenderCurrent(ptr, GL_TRIANGLE_STRIP);
 	if (tex->GetTransparent() || OverrideShader != 0)
 	{
 		gl_RenderState.EnableAlphaTest(true);