diff --git a/source/CMakeLists.txt b/source/CMakeLists.txt
index 87cb52fda..6b2e3fb71 100644
--- a/source/CMakeLists.txt
+++ b/source/CMakeLists.txt
@@ -759,11 +759,9 @@ set (FASTMATH_SOURCES ${FASTMATH_SOURCES} ${POLYBACKEND_SOURCES})
 
 set (PCH_SOURCES
 
-	glbackend/gl_shader.cpp
 	glbackend/glbackend.cpp
 	glbackend/gl_palmanager.cpp
 	glbackend/gl_texture.cpp
-	glbackend/hw_draw2d.cpp
 
 	thirdparty/src/base64.cpp
 	thirdparty/src/fix16.cpp
diff --git a/source/build/src/polymost.cpp b/source/build/src/polymost.cpp
index f42fa18c8..ef8f1d1d9 100644
--- a/source/build/src/polymost.cpp
+++ b/source/build/src/polymost.cpp
@@ -122,12 +122,6 @@ float sectorVisibility(int sectnum)
 
 void gltexapplyprops(void)
 {
-	if (GLInterface.glinfo.maxanisotropy > 1.f)
-	{
-		if (gl_texture_filter_anisotropic <= 0 || gl_texture_filter_anisotropic > GLInterface.glinfo.maxanisotropy)
-			gl_texture_filter_anisotropic = (int32_t)GLInterface.glinfo.maxanisotropy;
-	}
-
 	screen->SetTextureFilterMode();
 }
 
diff --git a/source/common/rendering/gl/gl_framebuffer.cpp b/source/common/rendering/gl/gl_framebuffer.cpp
index ad390d84c..f2a66ef43 100644
--- a/source/common/rendering/gl/gl_framebuffer.cpp
+++ b/source/common/rendering/gl/gl_framebuffer.cpp
@@ -518,6 +518,7 @@ void OpenGLFrameBuffer::Draw2D()
 
 void OpenGLFrameBuffer::PostProcessScene(bool swscene, int fixedcm, float flash, const std::function<void()> &afterBloomDrawEndScene2D)
 {
+	if (!swscene) GLRenderer->mBuffers->BlitSceneToTexture(); // Copy the resulting scene to the current post process texture
 	GLRenderer->PostProcessScene(fixedcm, flash, afterBloomDrawEndScene2D);
 }
 
diff --git a/source/common/rendering/gl/gl_postprocess.cpp b/source/common/rendering/gl/gl_postprocess.cpp
index 03a5ae103..4beed0577 100644
--- a/source/common/rendering/gl/gl_postprocess.cpp
+++ b/source/common/rendering/gl/gl_postprocess.cpp
@@ -36,7 +36,6 @@
 #include "templates.h"
 #include "hw_vrmodes.h"
 #include "v_draw.h"
-#include "i_interface.h"
 
 extern bool vid_hdr_active;
 
diff --git a/source/common/rendering/hwrenderer/hw_draw2d.cpp b/source/common/rendering/hwrenderer/hw_draw2d.cpp
index e49663bb2..1d5c47773 100644
--- a/source/common/rendering/hwrenderer/hw_draw2d.cpp
+++ b/source/common/rendering/hwrenderer/hw_draw2d.cpp
@@ -96,17 +96,8 @@ public:
 
 CVAR(Bool, gl_aalines, false, CVAR_ARCHIVE) 
 
-EXTERN_CVAR(Bool, hw_use_backend);
-#include "glbackend/glbackend.h"
-
 void Draw2D(F2DDrawer *drawer, FRenderState &state)
 {
-	// This is still needed for testing until things are working.
-	if (!hw_use_backend)
-	{
-		GLInterface.Draw2D(drawer);
-		return;
-	}
 	twoD.Clock();
 
 	const auto &mScreenViewport = screen->mScreenViewport;
diff --git a/source/core/screenshot.cpp b/source/core/screenshot.cpp
index d40fae46e..06970a5ec 100644
--- a/source/core/screenshot.cpp
+++ b/source/core/screenshot.cpp
@@ -42,6 +42,7 @@
 #include "gamecontrol.h"
 #include "printf.h"
 #include "c_dispatch.h"
+#include "v_video.h"
 
 #include "../../glbackend/glbackend.h"
 
@@ -63,7 +64,7 @@ static FileWriter *opennextfile(const char *fn)
 
 void getScreen(uint8_t* imgBuf)
 {
-	GLInterface.ReadPixels(xdim, ydim, imgBuf);
+	screen->CopyScreenToBuffer(xdim, ydim, imgBuf);
 }
 
 
diff --git a/source/glbackend/gl_shader.cpp b/source/glbackend/gl_shader.cpp
deleted file mode 100644
index b4be8d217..000000000
--- a/source/glbackend/gl_shader.cpp
+++ /dev/null
@@ -1,176 +0,0 @@
-/*
-** gl_shader.cpp
-**
-** GLSL shader handling
-**
-**---------------------------------------------------------------------------
-** Copyright 2004-2019 Christoph Oelckers
-** All rights reserved.
-**
-** Redistribution and use in source and binary forms, with or without
-** modification, are permitted provided that the following conditions
-** are met:
-**
-** 1. Redistributions of source code must retain the above copyright
-**    notice, this list of conditions and the following disclaimer.
-** 2. Redistributions in binary form must reproduce the above copyright
-**    notice, this list of conditions and the following disclaimer in the
-**    documentation and/or other materials provided with the distribution.
-** 3. The name of the author may not be used to endorse or promote products
-**    derived from this software without specific prior written permission.
-**
-** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
-** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
-** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
-** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
-** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-**---------------------------------------------------------------------------
-**
-*/
-#include <memory>
-#include "gl_load.h"
-#include "glbackend.h"
-#include "gl_shader.h"
-#include "zstring.h"
-#include "shaderuniforms.h"
-
-#include "baselayer.h"
-
-//==========================================================================
-//
-//
-//
-//==========================================================================
-
-bool FShader::Load(const char * name, const char * vert_prog, const char * frag_prog)
-{
-	FString error;
-	static char buffer[10000];
-
-	hVertProg = glCreateShader(GL_VERTEX_SHADER);
-	hFragProg = glCreateShader(GL_FRAGMENT_SHADER);	
-
-	glShaderSource(hVertProg, 1, &vert_prog, nullptr);
-	glShaderSource(hFragProg, 1, &frag_prog, nullptr);
-
-	glCompileShader(hVertProg);
-	glCompileShader(hFragProg);
-
-	hShader = glCreateProgram();
-
-	glAttachShader(hShader, hVertProg);
-	glAttachShader(hShader, hFragProg);
-
-	glLinkProgram(hShader);
-
-	glGetShaderInfoLog(hVertProg, 10000, NULL, buffer);
-	if (*buffer) 
-	{
-		error << "Vertex shader:\n" << buffer << "\n";
-	}
-	glGetShaderInfoLog(hFragProg, 10000, NULL, buffer);
-	if (*buffer) 
-	{
-		error << "Fragment shader:\n" << buffer << "\n";
-	}
-
-	glGetProgramInfoLog(hShader, 10000, NULL, buffer);
-	if (*buffer) 
-	{
-		error << "Linking:\n" << buffer << "\n";
-	}
-	int linked;
-	glGetProgramiv(hShader, GL_LINK_STATUS, &linked);
-	if (linked == 0)
-	{
-		// only print message if there's an error.
-		I_Error("Init Shader '%s':\n%s\n", name, error.GetChars());
-	}
-	return true;
-}
-
-//==========================================================================
-//
-//
-//
-//==========================================================================
-
-FShader::~FShader()
-{
-	glDeleteProgram(hShader);
-	glDeleteShader(hVertProg);
-	glDeleteShader(hFragProg);
-}
-
-
-//==========================================================================
-//
-//
-//
-//==========================================================================
-
-bool FShader::Bind()
-{
-	glUseProgram(hShader);
-	return true;
-}
-
-
-//==========================================================================
-//
-//
-//
-//==========================================================================
-
-bool PolymostShader::Load(const char * name, const char * vert_prog, const char * frag_prog)
-{
-	if (!FShader::Load(name, vert_prog, frag_prog)) return false;
-	
-	int tempindex = glGetUniformBlockIndex(hShader, "ViewpointUBO");
-	if (tempindex != -1) glUniformBlockBinding(hShader, tempindex, VIEWPOINT_BINDINGPOINT);
-
-	Flags.Init(hShader, "u_flags");
-
-	NPOTEmulation.Init(hShader, "uNpotEmulation");
-	TextureMode.Init(hShader, "uTextureMode");
-	FogColor.Init(hShader, "uFogColor");
-	muFogEnabled.Init(hShader, "uFogEnabled");
-	muLightParms.Init(hShader, "uLightAttr");
-	AlphaThreshold.Init(hShader, "uAlphaThreshold");
-	DetailParms.Init(hShader, "uDetailParms");
-	ModelMatrix.Init(hShader, "ModelMatrix");
-	TextureMatrix.Init(hShader, "TextureMatrix");
-	muTextureAddColor.Init(hShader, "uTextureAddColor");
-	muTextureModulateColor.Init(hShader, "uTextureModulateColor");
-	muTextureBlendColor.Init(hShader, "uTextureBlendColor");
-
-
-    
-	glUseProgram(hShader);
-
-	VSMatrix identity(0);
-	TextureMatrix.Set(identity.get());
-
-	int SamplerLoc;
-    SamplerLoc = glGetUniformLocation(hShader, "s_texture");
-	glUniform1i(SamplerLoc, 0);
-	SamplerLoc = glGetUniformLocation(hShader, "brighttexture");
-	glUniform1i(SamplerLoc, 1);
-	SamplerLoc = glGetUniformLocation(hShader, "detailtexture");
-	glUniform1i(SamplerLoc, 2);
-	SamplerLoc = glGetUniformLocation(hShader, "glowtexture");
-	glUniform1i(SamplerLoc, 3);
-	SamplerLoc = glGetUniformLocation(hShader, "s_palette");
-	glUniform1i(SamplerLoc, 4);
-	SamplerLoc = glGetUniformLocation(hShader, "s_palswap");
-	glUniform1i(SamplerLoc, 5);
-
-	glUseProgram(0);
-	return true;
-}
-
diff --git a/source/glbackend/gl_shader.h b/source/glbackend/gl_shader.h
deleted file mode 100644
index 594a7fd0a..000000000
--- a/source/glbackend/gl_shader.h
+++ /dev/null
@@ -1,49 +0,0 @@
-#pragma once
-
-#include "gl_uniform.h"
-
-class FShader
-{
-	friend class FShaderManager;
-	friend class FRenderState;
-
-	unsigned int hVertProg = 0;
-	unsigned int hFragProg = 0;
-
-protected:
-	unsigned int hShader = 0;
-
-
-public:
-	FShader() = default;
-	virtual ~FShader();
-
-	virtual bool Load(const char * name, const char * vert_prog_lump, const char * fragprog); //, const char * fragprog2, const char *defines);
-	bool Bind();
-	unsigned int GetHandle() const { return hShader; }
-};
-
-class PolymostShader : public FShader
-{
-public:
-	FBufferedUniform1i Flags;
-    FBufferedUniform2f NPOTEmulation;
-    FBufferedUniformPalEntry FogColor;
-
-	FBufferedUniform1i TextureMode;
-	FBufferedUniform4f DetailParms;
-	FBufferedUniform1f AlphaThreshold;
-	FBufferedUniform1i muFogEnabled;
-	FBufferedUniform4f muLightParms;
-	FUniformMatrix4f   ModelMatrix;
-	FUniformMatrix4f   TextureMatrix;
-	FBufferedUniform4f muTextureBlendColor;
-	FBufferedUniform4f muTextureModulateColor;
-	FBufferedUniform4f muTextureAddColor;
-
-public:
-
-	PolymostShader() = default;
-	virtual bool Load(const char * name, const char * vert_prog_lump, const char * fragprog); //, const char * fragprog2, const char *defines);
-};
-
diff --git a/source/glbackend/gl_uniform.h b/source/glbackend/gl_uniform.h
deleted file mode 100644
index ff53d7adf..000000000
--- a/source/glbackend/gl_uniform.h
+++ /dev/null
@@ -1,146 +0,0 @@
-#pragma once
-
-class FBufferedUniform1i
-{
-	int mBuffer;
-	int mIndex;
-
-public:
-	void Init(GLuint hShader, const GLchar* name)
-	{
-		mIndex = glGetUniformLocation(hShader, name);
-		mBuffer = 0;
-	}
-
-	void Set(int newvalue)
-	{
-		if (newvalue != mBuffer)
-		{
-			mBuffer = newvalue;
-			glUniform1i(mIndex, newvalue);
-		}
-	}
-};
-
-
-class FBufferedUniform1f
-{
-	float mBuffer;
-	int mIndex;
-
-public:
-	void Init(GLuint hShader, const GLchar *name)
-	{
-		mIndex = glGetUniformLocation(hShader, name);
-		mBuffer = 0;
-	}
-
-	void Set(float newvalue)
-	{
-		if (newvalue != mBuffer)
-		{
-			mBuffer = newvalue;
-			glUniform1f(mIndex, newvalue);
-		}
-	}
-};
-
-class FBufferedUniform2f
-{
-	float mBuffer[2];
-	int mIndex;
-
-public:
-	void Init(GLuint hShader, const GLchar *name)
-	{
-		mIndex = glGetUniformLocation(hShader, name);
-		memset(mBuffer, 0, sizeof(mBuffer));
-	}
-
-	void Set(const float *newvalue)
-	{
-		if (memcmp(newvalue, mBuffer, sizeof(mBuffer)))
-		{
-			memcpy(mBuffer, newvalue, sizeof(mBuffer));
-			glUniform2fv(mIndex, 1, newvalue);
-		}
-	}
-
-	void Set(float f1, float f2)
-	{
-		if (mBuffer[0] != f1 || mBuffer[1] != f2)
-		{
-			mBuffer[0] = f1;
-			mBuffer[1] = f2;
-			glUniform2fv(mIndex, 1, mBuffer);
-		}
-	}
-
-};
-
-class FBufferedUniform4f
-{
-	float mBuffer[4];
-	int mIndex;
-
-public:
-	void Init(GLuint hShader, const GLchar *name)
-	{
-		mIndex = glGetUniformLocation(hShader, name);
-		memset(mBuffer, 0, sizeof(mBuffer));
-	}
-
-	void Set(const float *newvalue)
-	{
-		if (memcmp(newvalue, mBuffer, sizeof(mBuffer)))
-		{
-			memcpy(mBuffer, newvalue, sizeof(mBuffer));
-			glUniform4fv(mIndex, 1, newvalue);
-		}
-	}
-}; 
-
-class FBufferedUniformPalEntry
-{
-	PalEntry mBuffer;
-	int mIndex;
-
-public:
-	void Init(GLuint hShader, const GLchar* name)
-	{
-		mIndex = glGetUniformLocation(hShader, name);
-		mBuffer = 0;
-	}
-
-	void Set(PalEntry newvalue)
-	{
-		if (newvalue != mBuffer)
-		{
-			mBuffer = newvalue;
-			glUniform4f(mIndex,
-				newvalue.r * (1 / 255.f),
-				newvalue.g * (1 / 255.f),
-				newvalue.b * (1 / 255.f),
-				newvalue.a * (1 / 255.f));
-
-		}
-	}
-};
-
-
-
-class FUniformMatrix4f
-{
-	int mIndex;
-
-public:
-	void Init(GLuint hShader, const GLchar *name)
-	{
-		mIndex = glGetUniformLocation(hShader, name);
-	}
-
-	void Set(const float *newvalue)
-	{
-		glUniformMatrix4fv(mIndex, 1, false, newvalue);
-	}
-};
\ No newline at end of file
diff --git a/source/glbackend/glbackend.cpp b/source/glbackend/glbackend.cpp
index 5b869db12..24bda1989 100644
--- a/source/glbackend/glbackend.cpp
+++ b/source/glbackend/glbackend.cpp
@@ -34,40 +34,25 @@
 */
 #include <memory>
 #include <assert.h>
-#include "gl_load.h"
 #include "glbackend.h"
-#include "gl_samplers.h"
-#include "gl_shader.h"
 #include "textures.h"
 #include "palette.h"
-//#include "imgui.h"
 #include "gamecontrol.h"
-//#include "imgui_impl_sdl.h"
-//#include "imgui_impl_opengl3.h"
 #include "baselayer.h"
-#include "gl_interface.h"
 #include "v_2ddrawer.h"
 #include "v_video.h"
 #include "flatvertices.h"
-#include "gl_renderer.h"
 #include "build.h"
 #include "v_draw.h"
 #include "v_font.h"
 #include "hw_viewpointuniforms.h"
 #include "hw_viewpointbuffer.h"
-#include "gl_renderstate.h"
+#include "hw_renderstate.h"
 #include "hw_cvars.h"
 
 F2DDrawer twodpsp;
 static int BufferLock = 0;
 
-CVAR(Bool, hw_use_backend, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG);
-
-
-static int blendstyles[] = { GL_ZERO, GL_ONE, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR, GL_DST_COLOR, GL_ONE_MINUS_DST_COLOR, GL_DST_ALPHA, GL_ONE_MINUS_DST_ALPHA };
-static int renderops[] = { GL_FUNC_ADD, GL_FUNC_ADD, GL_FUNC_SUBTRACT, GL_FUNC_REVERSE_SUBTRACT };
-int depthf[] = { GL_ALWAYS, GL_LESS, GL_EQUAL, GL_LEQUAL };
-
 TArray<VSMatrix> matrixArray;
 
 FileReader GetResource(const char* fn)
@@ -95,95 +80,18 @@ TArray<uint8_t> ttf;
 
 void GLInstance::Init(int ydim)
 {
-	//glinfo.bufferstorage =  !!strstr(glinfo.extensions, "GL_ARB_buffer_storage");
-	glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &glinfo.maxanisotropy);
-
 	new(&renderState) PolymostRenderState;	// reset to defaults.
-	LoadPolymostShader();
-}
-
-auto i_data = R"(
-	#version 330
-	// This must match the HWViewpointUniforms struct
-	layout(std140) uniform ViewpointUBO {
-		mat4 ProjectionMatrix;
-		mat4 ViewMatrix;
-		mat4 NormalViewMatrix;
-
-		vec4 uCameraPos;
-		vec4 uClipLine;
-
-		float uGlobVis;			// uGlobVis = R_GetGlobVis(r_visibility) / 32.0
-		int uPalLightLevels;	
-		int uViewHeight;		// Software fuzz scaling
-		float uClipHeight;
-		float uClipHeightDirection;
-		int uShadowmapFilter;
-	};
-	uniform sampler2D detailtexture;
-	uniform sampler2D glowtexture;
-	uniform sampler2D brighttexture;
-
-	uniform mat4 ModelMatrix;
-	uniform mat4 NormalModelMatrix;
-	uniform mat4 TextureMatrix;
-	uniform vec4 uDetailParms;
-
-	uniform vec4 uTextureBlendColor;
-	uniform vec4 uTextureModulateColor;
-	uniform vec4 uTextureAddColor;
-
-	uniform float uAlphaThreshold;
-	uniform vec4 uLightAttr;
-	#define uLightLevel uLightAttr.a
-	#define uFogDensity uLightAttr.b
-	#define uLightFactor uLightAttr.g
-	#define uLightDist uLightAttr.r
-	uniform int uFogEnabled;
-	uniform vec4 uFogColor;
-	uniform int uTextureMode;
-	uniform vec2 uNpotEmulation;
-
-)";
-
-void GLInstance::LoadPolymostShader()
-{
-	auto fr1 = GetResource("engine/shaders/glsl/polymost.vp");
-	TArray<uint8_t> Vert = fr1.Read();
-	fr1 = GetResource("engine/shaders/glsl/polymost.fp");
-	TArray<uint8_t> Frag = fr1.Read();
-	// Zero-terminate both strings.
-	Vert.Push(0);
-	Frag.Push(0);
-	FStringf VertS("%s\n%s", i_data, Vert.Data());
-	FStringf FragS("%s\n%s", i_data, Frag.Data());
-	polymostShader = new PolymostShader();
-	polymostShader->Load("PolymostShader", (const char*)VertS.GetChars(), (const char*)FragS.GetChars());
-	SetPolymostShader();
 }
 
 void GLInstance::InitGLState(int fogmode, int multisample)
 {
-	glEnable(GL_TEXTURE_2D);
-
-    if (multisample > 0 )
-    {
-		//glHint(GL_MULTISAMPLE_FILTER_HINT_NV, GL_NICEST);
-        glEnable(GL_MULTISAMPLE);
-    }
 	// This is a bad place to call this but without deconstructing the entire render loops in all front ends there is no way to have a well defined spot for this stuff.
 	// Before doing that the backend needs to work in some fashion, so we have to make sure everything is set up when the first render call is performed.
 	screen->BeginFrame();	
-	bool useSSAO = (gl_ssao != 0);
-    OpenGLRenderer::GLRenderer->mBuffers->BindSceneFB(useSSAO);
-	ClearBufferState();
 }
 
 void GLInstance::Deinit()
 {
-	if (polymostShader) delete polymostShader;
-	polymostShader = nullptr;
-	activeShader = nullptr;
 	palmanager.DeleteAll();
 	lastPalswapIndex = -1;
 }
@@ -201,28 +109,6 @@ void GLInstance::ResetFrame()
 
 }
 
-void GLInstance::SetVertexBuffer(IVertexBuffer* vb, int offset1, int offset2)
-{
-	int o[] = { offset1, offset2 };
-	static_cast<OpenGLRenderer::GLVertexBuffer*>(vb)->Bind(o);
-}
-
-void GLInstance::SetIndexBuffer(IIndexBuffer* vb)
-{
-	if (vb) static_cast<OpenGLRenderer::GLIndexBuffer*>(vb)->Bind();
-	else glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
-}
-
-void GLInstance::ClearBufferState()
-{
-	SetVertexBuffer(screen->mVertexData->GetBufferObjects().first, 0, 0);
-	SetIndexBuffer(nullptr);
-}
-
-	
-static GLint primtypes[] ={ GL_POINTS, GL_LINES, GL_TRIANGLES, GL_TRIANGLE_FAN, GL_TRIANGLE_STRIP };
-	
-
 void GLInstance::Draw(EDrawType type, size_t start, size_t count)
 {
 	assert (BufferLock > 0);
@@ -235,41 +121,12 @@ void GLInstance::Draw(EDrawType type, size_t start, size_t count)
 	renderState.StateFlags &= ~(STF_CLEARCOLOR | STF_CLEARDEPTH | STF_VIEWPORTSET | STF_SCISSORSET);
 }
 
-void GLInstance::DrawElement(EDrawType type, size_t start, size_t count, PolymostRenderState &renderState)
-{
-	if (activeShader == polymostShader)
-	{
-		glVertexAttrib4fv(2, renderState.Color);
-		renderState.Apply(polymostShader, lastState);
-	}
-	if (type != DT_Lines)
-	{
-		glDrawElements(primtypes[type], count, GL_UNSIGNED_INT, (void*)(intptr_t)(start * sizeof(uint32_t)));
-	}
-	else
-	{
-		glDrawArrays(primtypes[type], start, count);
-	}
-}
-
 void GLInstance::DoDraw()
 {
-	if (hw_use_backend)
+	for (auto& rs : rendercommands)
 	{
-		for (auto& rs : rendercommands)
-		{
-			rs.Apply(*screen->RenderState(), lastState);
-			screen->RenderState()->Draw(rs.primtype, rs.vindex, rs.vcount);
-		}
-	}
-	else
-	{
-		for (auto& rs : rendercommands)
-		{
-			glVertexAttrib4fv(2, rs.Color);
-			rs.Apply(polymostShader, lastState);
-			glDrawArrays(primtypes[rs.primtype], rs.vindex, rs.vcount);
-		}
+		rs.Apply(*screen->RenderState(), lastState);
+		screen->RenderState()->Draw(rs.primtype, rs.vindex, rs.vcount);
 	}
 	rendercommands.Clear();
 	matrixArray.Resize(1);
@@ -290,17 +147,6 @@ void GLInstance::SetIdentityMatrix(int num)
 }
 
 
-void GLInstance::ReadPixels(int xdim, int ydim, uint8_t* buffer)
-{
-	glReadPixels(0, 0, xdim, ydim, GL_RGB, GL_UNSIGNED_BYTE, buffer);
-}
-
-void GLInstance::SetPolymostShader()
-{
-	polymostShader->Bind();
-	activeShader = polymostShader;
-}
-
 void GLInstance::SetPalette(int index)
 {
 	palmanager.BindPalette(index);
@@ -313,250 +159,6 @@ void GLInstance::SetPalswap(int index)
 	renderState.ShadeDiv = lookups.tables[index].ShadeFactor;
 }
 
-//===========================================================================
-// 
-//	Binds a texture to the renderer
-//
-//===========================================================================
-
-void PolymostRenderState::ApplyMaterial(FMaterial* mat, int clampmode, int translation, int overrideshader, PolymostShader* shader)
-{
-	auto tex = mat->Source();
-	clampmode = tex->GetClampMode(clampmode);
-
-	// avoid rebinding the same texture multiple times.
-	//if (mat == lastMaterial && lastClamp == clampmode && translation == lastTranslation) return;
-#if 0
-	lastMaterial = mat;
-	lastClamp = clampmode;
-	lastTranslation = translation;
-#endif
-
-	int scf = 0;
-	if (Flags & RF_UsePalette)
-	{
-		scf |= CTF_Indexed;
-		translation = -1;
-	}
-
-	int usebright = false;
-	int maxbound = 0;
-
- 	int numLayers = mat->NumLayers();
-	MaterialLayerInfo* layer;
-	auto base = static_cast<OpenGLRenderer::FHardwareTexture*>(mat->GetLayer(0, translation, &layer));
-	scf |= layer->scaleFlags;
-	if (base->BindOrCreate(layer->layerTexture, 0, layer->clampflags == -1? clampmode : layer->clampflags, translation, scf))
-	{
-		int LayerFlags = 0;
-		for (int i = 1; i < numLayers; i++)
-		{
-			auto systex = static_cast<OpenGLRenderer::FHardwareTexture*>(mat->GetLayer(i, 0, &layer));
-			// fixme: Upscale flags must be disabled for certain layers.
-			systex->BindOrCreate(layer->layerTexture, i, layer->clampflags == -1 ? clampmode : layer->clampflags, 0, layer->scaleFlags);
-			maxbound = i;
-			LayerFlags |= 32768 << i;
-		}
-		shader->TextureMode.Set(LayerFlags);
-	}
-
-}
-
-void PolymostRenderState::Apply(PolymostShader* shader, GLState& oldState)
-{
-	if (!OpenGLRenderer::GLRenderer) return;
-	auto sm = OpenGLRenderer::GLRenderer->mSamplerManager;
-
-	bool reset = false;
-	if (mMaterial.mChanged)
-	{
-		mMaterial.mChanged = false;
-		ApplyMaterial(mMaterial.mMaterial, mMaterial.mClampMode, mMaterial.mTranslation, mMaterial.mOverrideShader, shader);
-		float buffer[] = { mMaterial.mMaterial->GetDetailScale().X, mMaterial.mMaterial->GetDetailScale().Y, 1.f, 0.f };
-		shader->DetailParms.Set(buffer);
-	}
-
-	if (PaletteTexture != nullptr)
-	{
-		PaletteTexture->Bind(4, false);
-		sm->Bind(4, CLAMP_NOFILTER, -1);
-	}
-	if (LookupTexture != nullptr)
-	{
-		LookupTexture->Bind(5, false);
-		sm->Bind(5, CLAMP_NOFILTER, -1);
-	}
-	glActiveTexture(GL_TEXTURE0);
-
-
-	if (StateFlags != oldState.Flags)
-	{
-		if ((StateFlags ^ oldState.Flags) & STF_DEPTHTEST)
-		{
-			if (StateFlags & STF_DEPTHTEST) glEnable(GL_DEPTH_TEST);
-			else glDisable(GL_DEPTH_TEST);
-		}
-		if ((StateFlags ^ oldState.Flags) & STF_BLEND)
-		{
-			if (StateFlags & STF_BLEND) glEnable(GL_BLEND);
-			else glDisable(GL_BLEND);
-		}
-		if ((StateFlags ^ oldState.Flags) & STF_MULTISAMPLE)
-		{
-			if (StateFlags & STF_MULTISAMPLE) glEnable(GL_MULTISAMPLE);
-			else glDisable(GL_MULTISAMPLE);
-		}
-		if ((StateFlags ^ oldState.Flags) & (STF_STENCILTEST | STF_STENCILWRITE))
-		{
-			if (StateFlags & STF_STENCILWRITE)
-			{
-				glEnable(GL_STENCIL_TEST);
-				glClear(GL_STENCIL_BUFFER_BIT);
-				glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE);
-				glStencilFunc(GL_ALWAYS, 1/*value*/, 0xFF);
-			}
-			else if (StateFlags & STF_STENCILTEST)
-			{
-				glEnable(GL_STENCIL_TEST);
-				glStencilFunc(GL_EQUAL, 1/*value*/, 0xFF);
-				glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
-
-			}
-			else
-			{
-				glDisable(GL_STENCIL_TEST);
-			}
-		}
-		if ((StateFlags ^ oldState.Flags) & (STF_CULLCW | STF_CULLCCW))
-		{
-			if (StateFlags & (STF_CULLCW | STF_CULLCCW))
-			{
-				glFrontFace(StateFlags & STF_CULLCW ? GL_CW : GL_CCW);
-				glEnable(GL_CULL_FACE);
-				glCullFace(GL_BACK); // Cull_Front is not being used.
-			}
-			else
-			{
-				glDisable(GL_CULL_FACE);
-			}
-		}
-		if ((StateFlags ^ oldState.Flags) & STF_COLORMASK)
-		{
-			if (StateFlags & STF_COLORMASK) glColorMask(1, 1, 1, 1);
-			else glColorMask(0, 0, 0, 0);
-		}
-		if ((StateFlags ^ oldState.Flags) & STF_DEPTHMASK)
-		{
-			if (StateFlags & STF_DEPTHMASK) glDepthMask(1);
-			else glDepthMask(0);
-		}
-		if (StateFlags & (STF_CLEARCOLOR | STF_CLEARDEPTH))
-		{
-			glClearColor(ClearColor.r / 255.f, ClearColor.g / 255.f, ClearColor.b / 255.f, 1.f);
-			int bit = 0;
-			if (StateFlags & STF_CLEARCOLOR) bit |= GL_COLOR_BUFFER_BIT;
-			if (StateFlags & STF_CLEARDEPTH) bit |= GL_DEPTH_BUFFER_BIT;
-			glClear(bit);
-		}
-		if (StateFlags & STF_VIEWPORTSET)
-		{
-			glViewport(vp_x, vp_y, vp_w, vp_h);
-		}
-		if (StateFlags & STF_SCISSORSET)
-		{
-			if (sc_x > SHRT_MIN)
-			{
-				glScissor(sc_x, sc_y, sc_w, sc_h);
-				glEnable(GL_SCISSOR_TEST);
-			}
-			else
-				glDisable(GL_SCISSOR_TEST);
-		}
-		if (mBias.mChanged)
-		{
-			if (mBias.mFactor == 0 && mBias.mUnits == 0)
-			{
-				glDisable(GL_POLYGON_OFFSET_FILL);
-			}
-			else
-			{
-				glEnable(GL_POLYGON_OFFSET_FILL);
-			}
-			glPolygonOffset(mBias.mFactor, mBias.mUnits);
-			mBias.mChanged = false;
-		}
-
-		StateFlags &= ~(STF_CLEARCOLOR | STF_CLEARDEPTH | STF_VIEWPORTSET | STF_SCISSORSET);
-		oldState.Flags = StateFlags;
-	}
-	if (Style != oldState.Style)
-	{
-		glBlendFunc(blendstyles[Style.SrcAlpha], blendstyles[Style.DestAlpha]);
-		if (Style.BlendOp != oldState.Style.BlendOp) glBlendEquation(renderops[Style.BlendOp]);
-		oldState.Style = Style;
-		// Flags are not being checked yet, the current shader has no implementation for them.
-	}
-	if (DepthFunc != oldState.DepthFunc)
-	{
-		glDepthFunc(depthf[DepthFunc]);
-		oldState.DepthFunc = DepthFunc;
-	}
-	// Disable brightmaps if non-black fog is used.
-	if (!(Flags & RF_FogDisabled) && ShadeDiv >= 1 / 1000.f)
-	{
-		if (!FogColor.isBlack())
-		{
-			//Flags &= ~RF_Brightmapping;
-			shader->muFogEnabled.Set(-1);
-		}
-		else
-		{
-			shader->muFogEnabled.Set(1);
-		}
-	}
-	else shader->muFogEnabled.Set(0);
-
-	shader->Flags.Set(Flags);
-	shader->NPOTEmulation.Set(&NPOTEmulation.X);
-	shader->AlphaThreshold.Set(AlphaTest ? AlphaThreshold : -1.f);
-	shader->FogColor.Set((Flags& RF_MapFog)? PalEntry(0x999999) : FogColor);
-	float lightattr[] = { ShadeDiv / (numshades - 2), VisFactor, (Flags & RF_MapFog) ? -5.f : 0.f , ShadeDiv >= 1 / 1000.f? Shade : 0 };
-	shader->muLightParms.Set(lightattr);
-
-	FVector4 addcol(0, 0, 0, 0);
-	FVector4 modcol(fullscreenTint.r / 255.f, fullscreenTint.g / 255.f, fullscreenTint.b / 255.f, 0);
-	FVector4 blendcol(0, 0, 0, 0);
-	int flags = 0;
-	if (fullscreenTint != 0xffffff) flags |= 16;
-	if (hictint_flags != -1)
-	{
-		flags |= 16;
-		if (hictint_flags & TINTF_COLORIZE)
-		{
-			modcol.X *= hictint.r / 64.f;
-			modcol.Y *= hictint.g / 64.f;
-			modcol.Z *= hictint.b / 64.f;
-		}
-		if (hictint_flags & TINTF_GRAYSCALE)
-			modcol.W = 1.f;
-
-		if (hictint_flags & TINTF_INVERT)
-			flags |= 8;
-
-		if (hictint_flags & TINTF_BLENDMASK)
-			flags |= ((hictint_flags & TINTF_BLENDMASK) >> 6) + 1;
-
-		addcol.W = flags;
-	}
-	shader->muTextureAddColor.Set(&addcol[0]);
-	shader->muTextureModulateColor.Set(&modcol[0]);
-	shader->muTextureBlendColor.Set(&blendcol[0]);
-	if (matrixIndex[Matrix_Model] != -1)
-		shader->ModelMatrix.Set(matrixArray[matrixIndex[Matrix_Model]].get());
-
-	memset(matrixIndex, -1, sizeof(matrixIndex));
-}
-
 void PolymostRenderState::Apply(FRenderState& state, GLState& oldState)
 {
 	if (Flags & RF_ColorOnly)
@@ -714,7 +316,7 @@ void WriteSavePic(FileWriter* file, int width, int height)
 	auto& RenderState = *screen->RenderState();
 
 	// we must be sure the GPU finished reading from the buffer before we fill it with new data.
-	glFinish();
+	screen->WaitForCommands(false);
 	screen->mVertexData->Reset();
 
 	// Switch to render buffers dimensioned for the savepic
@@ -787,7 +389,7 @@ void renderBeginScene()
 	assert(BufferLock == 0);
 
 	vp.mPalLightLevels = numshades | (static_cast<int>(gl_fogmode) << 8) | ((int)5 << 16);
-	screen->mViewpoints->SetViewpoint(OpenGLRenderer::gl_RenderState, &vp);
+	screen->mViewpoints->SetViewpoint(*screen->RenderState(), &vp);
 
 	if (BufferLock++ == 0)
 	{
@@ -851,7 +453,6 @@ void videoShowFrame(int32_t w)
 
 	float Brightness = 8.f / (r_scenebrightness + 8.f);
 
-	OpenGLRenderer::GLRenderer->mBuffers->BlitSceneToTexture(); // Copy the resulting scene to the current post process texture
 	screen->PostProcessScene(false, 0, Brightness, []() {
 		Draw2D(&twodpsp, *screen->RenderState()); // draws the weapon sprites
 		});
diff --git a/source/glbackend/glbackend.h b/source/glbackend/glbackend.h
index f2d807796..d1a2b7101 100644
--- a/source/glbackend/glbackend.h
+++ b/source/glbackend/glbackend.h
@@ -13,7 +13,6 @@
 #include "pm_renderstate.h"
 
 class FShader;
-class PolymostShader;
 class FGameTexture;
 class GLInstance;
 class F2DDrawer;
@@ -79,7 +78,6 @@ struct GLState
 	int Flags = STF_COLORMASK | STF_DEPTHMASK;
 	FRenderStyle Style{};
 	int DepthFunc = -1;
-	int TexId[MAX_TEXTURES] = {}, SamplerId[MAX_TEXTURES] = {};
 };
 
 class GLInstance
@@ -96,18 +94,14 @@ public:
 	GLState lastState;
 
 	PolymostRenderState renderState;
-	FShader* activeShader;
 	
 	
 public:
 	float mProjectionM5 = 1.0f; // needed by ssao
-	PolymostShader* polymostShader;
 	glinfo_t glinfo;
 	
 	void Init(int y);
 	void InitGLState(int fogmode, int multisample);
-	void LoadPolymostShader();
-	void Draw2D(F2DDrawer* drawer);
 	void ResetFrame();
 
 	void Deinit();
@@ -121,14 +115,9 @@ public:
 	GLInstance();
 	void Draw(EDrawType type, size_t start, size_t count);
 	void DoDraw();
-	void DrawElement(EDrawType type, size_t start, size_t count, PolymostRenderState& renderState);
 
 	OpenGLRenderer::FHardwareTexture* NewTexture(int numchannels = 4);
 
-	void SetVertexBuffer(IVertexBuffer* vb, int offset1, int offset2);
-	void SetIndexBuffer(IIndexBuffer* vb);
-	void ClearBufferState();
-
 	float GetProjectionM5() { return mProjectionM5; }
 	int SetMatrix(int num, const VSMatrix *mat );
 	int SetMatrix(int num, const float *mat)
@@ -141,11 +130,8 @@ public:
 		renderState.matrixIndex[num] = index;
 	}
 
-	void SetPolymostShader();
 	void SetPalette(int palette);
 	
-	void ReadPixels(int w, int h, uint8_t* buffer);
-
 	void SetTextureMode(int m)
 	{
 		renderState.TextureMode = m;
diff --git a/source/glbackend/hw_draw2d.cpp b/source/glbackend/hw_draw2d.cpp
deleted file mode 100644
index f98404ff7..000000000
--- a/source/glbackend/hw_draw2d.cpp
+++ /dev/null
@@ -1,225 +0,0 @@
-/*
-** hw_draw2d.cpp
-** 2d drawer Renderer interface
-**
-**---------------------------------------------------------------------------
-** Copyright 2018-2019 Christoph Oelckers
-** All rights reserved.
-**
-** Redistribution and use in source and binary forms, with or without
-** modification, are permitted provided that the following conditions
-** are met:
-**
-** 1. Redistributions of source code must retain the above copyright
-**    notice, this list of conditions and the following disclaimer.
-** 2. Redistributions in binary form must reproduce the above copyright
-**    notice, this list of conditions and the following disclaimer in the
-**    documentation and/or other materials provided with the distribution.
-** 3. The name of the author may not be used to endorse or promote products
-**    derived from this software without specific prior written permission.
-**
-** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
-** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
-** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
-** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
-** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-**---------------------------------------------------------------------------
-**
-*/
-
-
-#include "gl_load.h"
-#include "cmdlib.h"
-#include "gl_buffers.h"
-#include "v_2ddrawer.h"
-#include "c_cvars.h"
-#include "glbackend.h"
-#include "v_draw.h"
-#include "palette.h"
-#include "flatvertices.h"
-#include "build.h"
-#include "v_video.h"
-#include "hw_renderstate.h"
-#include "hw_viewpointbuffer.h"
-#include "gl_renderstate.h"
-
-extern int16_t numshades;
-extern TArray<VSMatrix> matrixArray;
-
-//===========================================================================
-// 
-// Vertex buffer for 2D drawer
-//
-//===========================================================================
-
-class F2DVertexBuffer
-{
-	IVertexBuffer *mVertexBuffer;
-	IIndexBuffer *mIndexBuffer;
-
-
-public:
-
-	F2DVertexBuffer()
-	{
-		mVertexBuffer = new OpenGLRenderer::GLVertexBuffer();
-		mIndexBuffer = new OpenGLRenderer::GLIndexBuffer();
-
-		static const FVertexBufferAttribute format[] = {
-			{ 0, VATTR_VERTEX, VFmt_Float3, (int)myoffsetof(F2DDrawer::TwoDVertex, x) },
-			{ 0, VATTR_TEXCOORD, VFmt_Float2, (int)myoffsetof(F2DDrawer::TwoDVertex, u) },
-			{ 0, VATTR_COLOR, VFmt_Byte4, (int)myoffsetof(F2DDrawer::TwoDVertex, color0) }
-		};
-		mVertexBuffer->SetFormat(1, 3, sizeof(F2DDrawer::TwoDVertex), format);
-	}
-	~F2DVertexBuffer()
-	{
-		delete mIndexBuffer;
-		delete mVertexBuffer;
-	}
-
-	void UploadData(F2DDrawer::TwoDVertex *vertices, int vertcount, int *indices, int indexcount)
-	{
-		mVertexBuffer->SetData(vertcount * sizeof(*vertices), vertices, false);
-		mIndexBuffer->SetData(indexcount * sizeof(unsigned int), indices, false);
-	}
-
-	std::pair<IVertexBuffer *, IIndexBuffer *> GetBufferObjects() const
-	{
-		return std::make_pair(mVertexBuffer, mIndexBuffer);
-	}
-};
-
-//===========================================================================
-// 
-// Draws the 2D stuff. This is the version for OpenGL 3 and later.
-//
-//===========================================================================
-void polymost_dorotatesprite(int32_t sx, int32_t sy, int32_t z, int16_t a, int16_t picnum, int8_t dashade, uint8_t dapalnum, int32_t dastat, uint8_t daalpha, uint8_t dablend, int32_t cx1, int32_t cy1, int32_t cx2, int32_t cy2, int32_t uniqid);
-
-void GLInstance::Draw2D(F2DDrawer *drawer)
-{
-	VSMatrix mat(0);
-	screen->mViewpoints->Set2D(OpenGLRenderer::gl_RenderState, xdim, ydim, numshades);
-	SetViewport(0, 0, xdim, ydim);
-	EnableDepthTest(false);
-	EnableMultisampling(false);
-	EnableBlend(true);
-	EnableAlphaTest(true);
-	SetRenderStyle(LegacyRenderStyles[STYLE_Translucent]);
-
-	auto &vertices = drawer->mVertices;
-	auto &indices = drawer->mIndices;
-	auto &commands = drawer->mData;
-
-	if (commands.Size() == 0)
-	{
-		return;
-	}
-
-	if (drawer->mIsFirstPass)
-	{
-		for (auto &v : vertices)
-		{
-			// Change from BGRA to RGBA
-			std::swap(v.color0.r, v.color0.b);
-		}
-	}
-	F2DVertexBuffer vb;
-	vb.UploadData(&vertices[0], vertices.Size(), &indices[0], indices.Size());
-	assert(vb.GetBufferObjects().first && vb.GetBufferObjects().second);
-	SetVertexBuffer(vb.GetBufferObjects().first, 0, 0);
-	SetIndexBuffer(vb.GetBufferObjects().second);
-	SetFadeDisable(true);
-
-	for(auto &cmd : commands)
-	{
-
-
-		int gltrans = -1;
-
-		SetRenderStyle(cmd.mRenderStyle);
-		//state.EnableBrightmap(!(cmd.mRenderStyle.Flags & STYLEF_ColorIsFixed));
-		//state.SetTextureMode(cmd.mDrawMode);
-
-		if (cmd.mFlags & F2DDrawer::DTF_Scissor)
-		{
-			// scissor test doesn't use the current viewport for the coordinates, so use real screen coordinates
-			// Note that the origin here is the lower left corner!
-			int sciX = screen->ScreenToWindowX(cmd.mScissor[0]);
-			int sciY = screen->ScreenToWindowY(cmd.mScissor[3]);
-			int sciW = screen->ScreenToWindowX(cmd.mScissor[2]) - sciX;
-			int sciH = screen->ScreenToWindowY(cmd.mScissor[1]) - sciY;
-			if (sciX < 0) sciW += sciX, sciX = 0;
-			if (sciY < 0) sciH += sciY, sciY = 0;
-			SetScissor(sciX, sciY, sciW, sciH);
-		}
-		else
-		{
-			DisableScissor();
-		}
-
-		auto tex = cmd.mTexture;
-		if (tex != nullptr && tex->isValid())
-		{
-			auto tex = cmd.mTexture;
-
-			SetFadeDisable(cmd.mLightLevel == 0);
-			SetShade(cmd.mLightLevel, numshades);
-
-			SetTexture(TileFiles.GetTileIndex(tex), tex, cmd.mTranslationId, cmd.mFlags & F2DDrawer::DTF_Wrap ? CLAMP_NONE : CLAMP_XY);
-			EnableBlend(!(cmd.mRenderStyle.Flags & STYLEF_Alpha1));
-			UseColorOnly(false);
-		}
-		else
-		{
-			UseColorOnly(true);
-		}
-
-		switch (cmd.mType)
-		{
-		case F2DDrawer::DrawTypeTriangles:
-			DrawElement(DT_Triangles, cmd.mIndexIndex, cmd.mIndexCount, renderState);
-			break;
-
-		case F2DDrawer::DrawTypeLines:
-			DrawElement(DT_Lines, cmd.mVertIndex, cmd.mVertCount, renderState);
-			break;
-
-		case F2DDrawer::DrawTypePoints:
-			//Draw(DT_POINTS, cmd.mVertIndex, cmd.mVertCount);
-			break;
-
-		}
-		/*
-		state.SetObjectColor(0xffffffff);
-		state.SetObjectColor2(0);
-		state.SetAddColor(0);
-		state.EnableTextureMatrix(false);
-		state.SetEffect(EFF_NONE);
-		*/
-
-	}
-
-	//state.SetRenderStyle(STYLE_Translucent);
-	ClearBufferState();
-	UseColorOnly(false);
-	//state.EnableBrightmap(true);
-	//state.SetTextureMode(TM_NORMAL);
-	SetShade(0, numshades);
-	SetFadeDisable(false);
-	SetColor(1, 1, 1);
-	DisableScissor();
-	//drawer->mIsFirstPass = false;
-	EnableBlend(true);
-	EnableMultisampling(true);
-	matrixArray.Resize(1);
-	renderState.Apply(polymostShader, lastState);	// actually set the desired state before returning.
-}
-
-
diff --git a/source/glbackend/pm_renderstate.h b/source/glbackend/pm_renderstate.h
index d89c6e0d6..b890489ac 100644
--- a/source/glbackend/pm_renderstate.h
+++ b/source/glbackend/pm_renderstate.h
@@ -3,7 +3,6 @@
 #include "palentry.h"
 #include "gl_buffers.h"
 #include "renderstyle.h"
-class PolymostShader;
 struct GLState;
 class FMaterial;
 
@@ -74,7 +73,5 @@ struct PolymostRenderState
 
 	PalEntry FogColor;
 
-	void ApplyMaterial(FMaterial* mat, int clampmode, int translation, int overrideshader, PolymostShader *shader);
-	void Apply(PolymostShader *shader, GLState &oldstate);
 	void Apply(FRenderState & state, GLState& oldState);
 };
diff --git a/wadsrc/static/engine/shaders/glsl/polymost.fp b/wadsrc/static/engine/shaders/glsl/polymost.fp
deleted file mode 100644
index e83922462..000000000
--- a/wadsrc/static/engine/shaders/glsl/polymost.fp
+++ /dev/null
@@ -1,268 +0,0 @@
-const int RF_ColorOnly = 1;
-const int RF_UsePalette = 2;
-const int RF_ShadeInterpolate = 64;
-
-const int TEXF_Brightmap = 0x10000;
-const int TEXF_Detailmap = 0x20000;
-const int TEXF_Glowmap = 0x40000;
-
-
-struct Material
-{
-	vec4 Base;
-	vec4 Bright;
-	vec4 Glow;
-	vec3 Normal;
-	vec3 Specular;
-	float Glossiness;
-	float SpecularLevel;
-	float Metallic;
-	float Roughness;
-	float AO;
-};
-
-Material material;
- 
-
-//s_texture points to an indexed color texture
-uniform sampler2D s_texture;
-//s_palswap is the palette swap texture where u is the color index and v is the shade
-uniform sampler2D s_palswap;
-//s_palette is the base palette texture where u is the color index
-uniform sampler2D s_palette;
-
-uniform int u_flags;
-
-in vec4 v_color;
-in float v_distance;
-in vec4 v_texCoord;
-in vec4 v_detailCoord;
-in float v_fogCoord;
-in vec4 v_eyeCoordPosition;
-in vec4 v_worldPosition;
-
-layout(location=0) out vec4 fragColor;
-layout(location=1) out vec4 fragFog;
-layout(location=2) out vec4 fragNormal;
-
-//===========================================================================
-//
-// Color to grayscale
-//
-//===========================================================================
-
-float grayscale(vec4 color)
-{
-	return dot(color.rgb, vec3(0.3, 0.56, 0.14));
-}
-
-//===========================================================================
-//
-// Desaturate a color
-//
-//===========================================================================
-
-vec4 dodesaturate(vec4 texel, float factor)
-{
-	if (factor != 0.0)
-	{
-		float gray = grayscale(texel);
-		return mix (texel, vec4(gray,gray,gray,texel.a), factor);
-	}
-	else
-	{
-		return texel;
-	}
-}
-
-//===========================================================================
-//
-// Texture tinting code originally from JFDuke but with a few more options
-//
-//===========================================================================
-
-const int Tex_Blend_Alpha = 1;
-const int Tex_Blend_Screen = 2;
-const int Tex_Blend_Overlay = 3;
-const int Tex_Blend_Hardlight = 4;
- 
- vec4 ApplyTextureManipulation(vec4 texel, int blendflags)
- {
-	// Step 1: desaturate according to the material's desaturation factor. 
-	texel = dodesaturate(texel, uTextureModulateColor.a);
-	
-	// Step 2: Invert if requested
-	if ((blendflags & 8) != 0)
-	{
-		texel.rgb = vec3(1.0 - texel.r, 1.0 - texel.g, 1.0 - texel.b);
-	}
-	
-	// Step 3: Apply additive color
-	texel.rgb += uTextureAddColor.rgb;
-	
-	// Step 4: Colorization, including gradient if set.
-	texel.rgb *= uTextureModulateColor.rgb;
-	
-	// Before applying the blend the value needs to be clamped to [0..1] range.
-	texel.rgb = clamp(texel.rgb, 0.0, 1.0);
-	
-	// Step 5: Apply a blend. This may just be a translucent overlay or one of the blend modes present in current Build engines.
-	if ((blendflags & 7) != 0)
-	{
-		vec3 tcol = texel.rgb * 255.0;	// * 255.0 to make it easier to reuse the integer math.
-		vec4 tint = uTextureBlendColor * 255.0;
-
-		switch (blendflags & 7)
-		{
-			default:
-				tcol.b = tcol.b * (1.0 - uTextureBlendColor.a) + tint.b * uTextureBlendColor.a;
-				tcol.g = tcol.g * (1.0 - uTextureBlendColor.a) + tint.g * uTextureBlendColor.a;
-				tcol.r = tcol.r * (1.0 - uTextureBlendColor.a) + tint.r * uTextureBlendColor.a;
-				break;
-			// The following 3 are taken 1:1 from the Build engine
-			case Tex_Blend_Screen:
-				tcol.b = 255.0 - (((255.0 - tcol.b) * (255.0 - tint.r)) / 256.0);
-				tcol.g = 255.0 - (((255.0 - tcol.g) * (255.0 - tint.g)) / 256.0);
-				tcol.r = 255.0 - (((255.0 - tcol.r) * (255.0 - tint.b)) / 256.0);
-				break;
-			case Tex_Blend_Overlay:
-				tcol.b = tcol.b < 128.0? (tcol.b * tint.b) / 128.0 : 255.0 - (((255.0 - tcol.b) * (255.0 - tint.b)) / 128.0);
-				tcol.g = tcol.g < 128.0? (tcol.g * tint.g) / 128.0 : 255.0 - (((255.0 - tcol.g) * (255.0 - tint.g)) / 128.0);
-				tcol.r = tcol.r < 128.0? (tcol.r * tint.r) / 128.0 : 255.0 - (((255.0 - tcol.r) * (255.0 - tint.r)) / 128.0);
-				break;
-			case Tex_Blend_Hardlight:
-				tcol.b = tint.b < 128.0 ? (tcol.b * tint.b) / 128.0 : 255.0 - (((255.0 - tcol.b) * (255.0 - tint.b)) / 128.0);
-				tcol.g = tint.g < 128.0 ? (tcol.g * tint.g) / 128.0 : 255.0 - (((255.0 - tcol.g) * (255.0 - tint.g)) / 128.0);
-				tcol.r = tint.r < 128.0 ? (tcol.r * tint.r) / 128.0 : 255.0 - (((255.0 - tcol.r) * (255.0 - tint.r)) / 128.0);
-				break;
-		}
-		texel.rgb = tcol / 255.0;
-	}
-	return texel;
-}
-
-
-//===========================================================================
-//
-//
-//
-//===========================================================================
-
-void main()
-{
-	float fullbright = 0.0;
-	vec4 color;
-	if ((u_flags & RF_ColorOnly) == 0)
-	{
-		float coordX = v_texCoord.x;
-		float coordY = v_texCoord.y;
-		vec2 newCoord;
-		
-		// Coordinate adjustment for NPOT textures. It is somehow fitting that Build games exploited this texture wrapping quirk of the software rendering engine...
-		if (uNpotEmulation.y != 0.0)
-		{
-			float period = floor(coordY / uNpotEmulation.y);
-			coordX += uNpotEmulation.x * floor(mod(coordY, uNpotEmulation.y));
-			coordY = period + mod(coordY, uNpotEmulation.y);
-		}
-		newCoord = vec2(coordX, coordY);
-
-		color = texture(s_texture, newCoord);
-
-		float visibility = max(uGlobVis * uLightFactor * v_distance - ((u_flags & RF_ShadeInterpolate) != 0.0? 0.5 : 0.0), 0.0);
-		float numShades = float(uPalLightLevels & 255);
-		float shade = clamp((uLightLevel + visibility), 0.0, numShades - 1.0);
-		
-
-		if ((u_flags & RF_UsePalette) != 0)
-		{
-			int palindex = int(color.r * 255.0 + 0.1); // The 0.1 is for roundoff error compensation.
-			int shadeindex = int(floor(shade));
-			float colorIndexF = texelFetch(s_palswap, ivec2(palindex, shadeindex), 0).r;
-			int colorIndex = int(colorIndexF * 255.0 + 0.1); // The 0.1 is for roundoff error compensation.
-			vec4 palettedColor = texelFetch(s_palette, ivec2(colorIndex, 0), 0);
-			
-			if ((u_flags & RF_ShadeInterpolate) != 0)
-			{
-				// Get the next shaded palette index for interpolation
-				colorIndexF = texelFetch(s_palswap, ivec2(palindex, shadeindex+1), 0).r;
-				colorIndex = int(colorIndexF * 255.0 + 0.1); // The 0.1 is for roundoff error compensation.
-				vec4 palettedColorNext = texelFetch(s_palette, ivec2(colorIndex, 0), 0);
-				float shadeFrac = mod(shade, 1.0);
-				palettedColor.rgb = mix(palettedColor.rgb, palettedColorNext.rgb, shadeFrac);
-			}
-			
-	   		palettedColor.a = color.r == 0.0? 0.0 : 1.0;// 1.0-floor(color.r);
-	   		color.rgb = palettedColor.rgb * v_color.rgb;
-			color.a = palettedColor.a;
-		}
-		else
-		{
-			// This was further down but it really should be done before applying any kind of depth fading, not afterward.
-			if ((uTextureMode & TEXF_Detailmap) != 0)
-			{
-				vec4 detailColor = texture(detailtexture, newCoord * uDetailParms.xy) * uDetailParms.z;
-				detailColor = mix(vec4(1.0), 2.0 * detailColor, detailColor.a);
-				color.rgb *= detailColor.rgb;
-			}
-
-			// Apply the texture modification colors.
-			int blendflags = int(uTextureAddColor.a);	// this alpha is unused otherwise
-			if (blendflags != 0)	
-			{
-				// only apply the texture manipulation if it contains something.
-				color = ApplyTextureManipulation(color, blendflags);
-			}
-			
-			if (uFogEnabled != 0) // Right now this code doesn't care about the fog modes yet.
-			{
-				shade = clamp(shade * uLightDist, 0.0, 1.0);
-				vec3 lightcolor = v_color.rgb * (1.0 - shade);
-
-				if ((uTextureMode & TEXF_Brightmap) != 0)
-				{
-					lightcolor = clamp(lightcolor + texture(brighttexture, v_texCoord.xy).rgb, 0.0, 1.0);
-				}
-				color.rgb *= lightcolor;
-				if (uFogDensity == 0.0) color.rgb += uFogColor.rgb * shade;
-			}
-			else color.rgb *= v_color.rgb;
-
-			if ((uTextureMode & TEXF_Glowmap) != 0)
-			{
-				vec4 glowColor = texture(glowtexture, v_texCoord.xy);
-				color.rgb = mix(color.rgb, glowColor.rgb, glowColor.a);
-			}
-
-		}
-		if (uFogDensity != 0.0) // fog hack for RRRA E2L1. Needs to be done better, this is gross, but still preferable to the broken original implementation.
-		{
-			float fogfactor = 0.55 + 0.3 * exp2 (uFogDensity * v_fogCoord / 1024.0); 		
-			color.rgb = uFogColor.rgb * (1.0-fogfactor) + color.rgb * fogfactor;// mix(vec3(0.6), color.rgb, fogfactor);
-		}
-		if (color.a < uAlphaThreshold) discard;	// it's only here that we have the alpha value available to be able to perform the alpha test.
-		color.a *= v_color.a;
-	}
-	else
-	{
-		// untextured rendering
-		color = v_color;
-	}
-
-	
-	/*
-	int ix = int (v_worldPosition.x);
-	int iy = int (v_worldPosition.z);
-	int iz = int (v_worldPosition.y);
-	if ((ix & 64) == 1) color.r = 0;
-	if ((iy & 64) == 1) color.g = 0;
-	if ((iz & 64) == 1) color.b = 0;
-	*/
-	
-	fragColor = color;
-	fragFog = vec4(0.0, 0.0, 0.0, 1.0); // Does build have colored fog?
-	vec3 normal = normalize(cross(dFdx(v_eyeCoordPosition.xyz), dFdy(v_eyeCoordPosition.xyz)));
-	normal.x = -normal.x;
-	normal.y = -normal.y;
-	fragNormal = vec4(normal * 0.5 + 0.5, 1.0);
-}
diff --git a/wadsrc/static/engine/shaders/glsl/polymost.vp b/wadsrc/static/engine/shaders/glsl/polymost.vp
deleted file mode 100644
index 665c975b0..000000000
--- a/wadsrc/static/engine/shaders/glsl/polymost.vp
+++ /dev/null
@@ -1,30 +0,0 @@
-out vec4 v_color;
-out float v_distance;
-out vec4 v_texCoord;
-out float v_fogCoord;
-out vec4 v_eyeCoordPosition;
-out vec4 v_worldPosition;
-
-layout(location = 0) in vec4 i_vertPos;
-layout(location = 1) in vec4 i_texCoord;
-layout(location = 2) in vec4 i_color;
-
-
-
-void main()
-{
-   vec4 vertex = ModelMatrix * i_vertPos;
-   vec4 eyeCoordPosition = ViewMatrix * vertex;
-   v_eyeCoordPosition = eyeCoordPosition;
-   gl_Position = ProjectionMatrix * eyeCoordPosition;
-
-   eyeCoordPosition.xyz /= eyeCoordPosition.w;
-
-   v_texCoord = TextureMatrix * i_texCoord;
-
-   v_fogCoord = abs(eyeCoordPosition.z);
-
-   v_color = i_color;
-   v_distance = eyeCoordPosition.z;
-   v_worldPosition = vertex;
-}