diff --git a/source/blood/src/view.cpp b/source/blood/src/view.cpp
index c2d53e426..df65ee724 100644
--- a/source/blood/src/view.cpp
+++ b/source/blood/src/view.cpp
@@ -3450,17 +3450,20 @@ RORHACK:
             {
                 if (videoGetRenderMode() == REND_POLYMOST && gDeliriumBlur)
                 {
+					// todo: Implement using modern techniques instead of relying on deprecated old stuff that isn't well supported anymore.
+					/* names broken up so that searching for GL keywords won't find them anymore
                     if (!bDeliriumOld)
                     {
-                        glAccum(GL_LOAD, 1.f);
+                        g lAccum(GL_LOAD, 1.f);
                     }
                     else
                     {
                         const float fBlur = pow(1.f/3.f, 30.f/g_frameRate);
-                        glAccum(GL_MULT, fBlur);
-                        glAccum(GL_ACCUM, 1.f-fBlur);
-                        glAccum(GL_RETURN, 1.f);
+                        g lAccum(GL _MULT, fBlur);
+                        g lAccum(GL _ACCUM, 1.f-fBlur);
+                        g lAccum(GL _RETURN, 1.f);
                     }
+					*/
                 }
             }
 #endif
diff --git a/source/build/include/baselayer.h b/source/build/include/baselayer.h
index b7cb42dc6..ccc48fe41 100644
--- a/source/build/include/baselayer.h
+++ b/source/build/include/baselayer.h
@@ -78,20 +78,7 @@ extern float g_videoGamma, g_videoContrast, g_videoBrightness;
 extern int32_t (*baselayer_osdcmd_vidmode_func)(osdcmdptr_t parm);
 extern int osdcmd_glinfo(osdcmdptr_t parm);
 
-struct glinfo_t {
-    const char *vendor;
-    const char *renderer;
-    const char *version;
-    const char *extensions;
 
-    float maxanisotropy;
-    char debugoutput;
-    char bufferstorage;
-    char sync;
-    char dumped;
-};
-
-extern struct glinfo_t glinfo;
 #endif
 
 vec2_t CONSTEXPR const g_defaultVideoModes []
@@ -231,6 +218,9 @@ void joySetDeadZone(int32_t axis, uint16_t dead, uint16_t satur);
 void joyGetDeadZone(int32_t axis, uint16_t *dead, uint16_t *satur);
 extern int32_t inputchecked;
 
+void getScreen(uint8_t* imgBuf);
+
+
 int32_t wm_msgbox(const char *name, const char *fmt, ...) ATTRIBUTE((format(printf,2,3)));
 int32_t wm_ynbox(const char *name, const char *fmt, ...) ATTRIBUTE((format(printf,2,3)));
 void wm_setapptitle(const char *name);
diff --git a/source/build/src/2d.cpp b/source/build/src/2d.cpp
index 0e4b6d853..b083030a9 100644
--- a/source/build/src/2d.cpp
+++ b/source/build/src/2d.cpp
@@ -50,7 +50,7 @@ static void drawlinegl(int32_t x1, int32_t y1, int32_t x2, int32_t y2, palette_t
         if (y1 > wy2) x1 += scale(wy2-y1, dx, dy), y1 = wy2;
     }
 
-    glViewport(0, 0, xdim, ydim);
+    GLInterface.SetViewport(0, 0, xdim, ydim);
 	VSMatrix proj(0);
 	proj.ortho(0, xdim, ydim, 0, -1, 1);
 	GLInterface.SetMatrix(Matrix_Projection, &proj);
@@ -115,7 +115,7 @@ void polymostSet2dView(void)
 #ifdef USE_OPENGL
     if (videoGetRenderMode() < REND_POLYMOST) return;
 
-    glViewport(0, 0, xdim, ydim);
+	GLInterface.SetViewport(0, 0, xdim, ydim);
 
 	VSMatrix proj(0);
 	proj.ortho(0, xdim, ydim, 0, -1, 1);
diff --git a/source/build/src/animvpx.cpp b/source/build/src/animvpx.cpp
index 9aba6b4de..f71a206ae 100644
--- a/source/build/src/animvpx.cpp
+++ b/source/build/src/animvpx.cpp
@@ -412,7 +412,7 @@ void animvpx_setup_glstate(int32_t animvpx_flags)
     ////////// GL STATE //////////
 
     //Force fullscreen (glox1=-1 forces it to restore afterwards)
-    glViewport(0,0,xdim,ydim); glox1 = -1;
+	GLInterface.SetViewport(0,0,xdim,ydim); glox1 = -1;
 
 	VSMatrix identity(0);
 	GLInterface.SetMatrix(Matrix_ModelView, &identity);
@@ -439,8 +439,7 @@ void animvpx_setup_glstate(int32_t animvpx_flags)
     texuploaded = 0;
     ////////////////////
 
-    glClearColor(0.0,0.0,0.0,1.0);
-    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
+	GLInterface.ClearScreen(0, 0, 0, true);
 }
 
 void animvpx_restore_glstate(void)
diff --git a/source/build/src/baselayer.cpp b/source/build/src/baselayer.cpp
index ecea6dcfb..cbad7a8af 100644
--- a/source/build/src/baselayer.cpp
+++ b/source/build/src/baselayer.cpp
@@ -8,6 +8,7 @@
 #include "a.h"
 #include "polymost.h"
 #include "cache1d.h"
+#include "../../glbackend/glbackend.h"
 
 // video
 #ifdef _WIN32
@@ -304,21 +305,8 @@ int osdcmd_glinfo(osdcmdptr_t UNUSED(parm))
 {
     UNREFERENCED_CONST_PARAMETER(parm);
 
-    if (bpp == 8)
-    {
-        initprintf("glinfo: not in OpenGL mode!\n");
-        return OSDCMD_OK;
-    }
-
     initprintf("OpenGL information\n %s %s %s\n",
-               glinfo.vendor, glinfo.renderer, glinfo.version);
-
-    if (!glinfo.dumped)
-        return OSDCMD_OK;
-
-    char const *s[] = { "supported", "not supported" };
-
-    initprintf(" Extensions:\n%s", glinfo.extensions);
+               GLInterface.glinfo.vendor, GLInterface.glinfo.renderer, GLInterface.glinfo.version);
 
     return OSDCMD_OK;
 }
diff --git a/source/build/src/common.cpp b/source/build/src/common.cpp
index e8abac183..2608b5b23 100644
--- a/source/build/src/common.cpp
+++ b/source/build/src/common.cpp
@@ -249,29 +249,36 @@ int32_t FindDistance3D(int32_t x, int32_t y, int32_t z)
 // Clear OSD background
 void COMMON_doclearbackground(int numcols, int height)
 {
-    UNREFERENCED_PARAMETER(numcols);
+    polymost_setFogEnabled(false);
+    polymost_useColorOnly(true);
 
-# ifdef USE_OPENGL
-    if (videoGetRenderMode() >= REND_POLYMOST && in3dmode())
-    {
-        polymost_setFogEnabled(false);
-        polymost_useColorOnly(true);
+	polymostSet2dView();
 
-        polymostSet2dView();
-        GLInterface.SetColor(0.f, 0.f, 0.f, 0.67f);
-        GLInterface.EnableBlend(true);
-        glRecti(0, 0, xdim, height);
-        GLInterface.SetColor(0.f, 0.f, 0.f, 1.f);
-        glRecti(0, height-4, xdim, height);
+	VSMatrix identity(0);
+	GLInterface.SetMatrix(Matrix_ModelView, &identity);
+	auto vert = GLInterface.AllocVertices(8);
+	auto vt = vert.second;
 
-        polymost_useColorOnly(false);
-        polymost_setFogEnabled(true);
+	auto h4 = height - 4;
 
-        return;
-    }
-# endif
+	GLInterface.EnableBlend(true);
 
-    CLEARLINES2D(0, min(ydim, height), editorcolors[16]);
+	vt[0].Set(0, 0); //top-left
+	vt[1].Set(0, h4); //bottom-left
+	vt[2].Set(xdim, 0); //top-right
+	vt[3].Set(xdim, h4);  //bottom-right
+	GLInterface.SetColor(0.f, 0.f, 0.f, 0.67f);
+	GLInterface.Draw(DT_TRIANGLE_STRIP, vert.first, 4);
+
+	vt[0].Set(0, h4); //top-left
+	vt[1].Set(0, height); //bottom-left
+	vt[2].Set(xdim, h4); //top-right
+	vt[3].Set(xdim, height);  //bottom-right
+	GLInterface.SetColor(0.f, 0.f, 0.f, 1.f);
+	GLInterface.Draw(DT_TRIANGLE_STRIP, vert.first+4, 4);
+
+    polymost_useColorOnly(false);
+    polymost_setFogEnabled(true);
 }
 
 void COMMON_clearbackground(int numcols, int numrows)
diff --git a/source/build/src/engine.cpp b/source/build/src/engine.cpp
index 1991ea201..67783dabd 100644
--- a/source/build/src/engine.cpp
+++ b/source/build/src/engine.cpp
@@ -1002,8 +1002,8 @@ void yax_drawrooms(void (*SpriteAnimFunc)(int32_t,int32_t,int32_t,int32_t,int32_
 #ifdef USE_OPENGL
     if (videoGetRenderMode() == REND_POLYMOST)
     {
-        glClear(GL_DEPTH_BUFFER_BIT);
-        yax_polymostclearzbuffer = 0;
+		GLInterface.ClearScreen(0, 0, 0, true);
+		yax_polymostclearzbuffer = 0;
     }
 #endif
 
@@ -12081,11 +12081,10 @@ void videoClearViewableArea(int32_t dacol)
     {
         palette_t const p = paletteGetColor(dacol);
 
-        glClearColor((float)p.r * (1.f/255.f),
+        GLInterface.ClearScreen((float)p.r * (1.f/255.f),
                       (float)p.g * (1.f/255.f),
                       (float)p.b * (1.f/255.f),
-                      0);
-        glClear(GL_COLOR_BUFFER_BIT);
+                      false);
         return;
     }
 #endif
@@ -12119,12 +12118,11 @@ void videoClearScreen(int32_t dacol)
     {
         palette_t const p = paletteGetColor(dacol);
 
-        glViewport(0,0,xdim,ydim); glox1 = -1;
-        glClearColor((float)p.r * (1.f/255.f),
+		GLInterface.SetViewport(0,0,xdim,ydim); glox1 = -1;
+        GLInterface.ClearScreen((float)p.r * (1.f/255.f),
                       (float)p.g * (1.f/255.f),
                       (float)p.b * (1.f/255.f),
-                      0);
-        glClear(GL_COLOR_BUFFER_BIT);
+                      false);
         return;
     }
 #endif
diff --git a/source/build/src/glsurface.cpp b/source/build/src/glsurface.cpp
index 3f26e5c77..73eb88950 100644
--- a/source/build/src/glsurface.cpp
+++ b/source/build/src/glsurface.cpp
@@ -59,8 +59,6 @@ bool glsurface_initialize(vec2_t bufferResolution)
     if (buffer)
         glsurface_destroy();
 
-    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
-
     bufferRes = bufferResolution;
     buffer    = Xaligned_alloc(16, bufferRes.x * bufferRes.y);
 
diff --git a/source/build/src/mdsprite.cpp b/source/build/src/mdsprite.cpp
index 17712e0f4..c54239fae 100644
--- a/source/build/src/mdsprite.cpp
+++ b/source/build/src/mdsprite.cpp
@@ -1992,8 +1992,8 @@ static int32_t polymost_md3draw(md3model_t *m, tspriteptr_t tspr)
 		GLInterface.SetDepthFunc(Depth_LessEqual);
     }
 
-    if ((grhalfxdown10x >= 0) ^((globalorientation&8) != 0) ^((globalorientation&4) != 0)) glFrontFace(GL_CW); else glFrontFace(GL_CCW);
-	GLInterface.SetCull(Cull_Back);
+	int winding = ((grhalfxdown10x >= 0) ^((globalorientation&8) != 0) ^((globalorientation&4) != 0))? Winding_CW : Winding_CCW;
+	GLInterface.SetCull(Cull_Back, winding);
 
     // tinting
     pc[0] = pc[1] = pc[2] = ((float)numshades - min(max((globalshade * shadescale) + m->shadeoff, 0.f), (float)numshades)) / (float)numshades;
@@ -2022,7 +2022,7 @@ static int32_t polymost_md3draw(md3model_t *m, tspriteptr_t tspr)
             al=alphahackarray[globalpicnum] * (1.f/255.f);
         GLInterface.EnableBlend(true);
         GLInterface.EnableAlphaTest(true);
-        glAlphaFunc(GL_GREATER,al);
+		GLInterface.SetAlphaThreshold(al);
     }
     else
     {
diff --git a/source/build/src/polymost.cpp b/source/build/src/polymost.cpp
index f5697ddac..45a09ab1d 100644
--- a/source/build/src/polymost.cpp
+++ b/source/build/src/polymost.cpp
@@ -49,8 +49,6 @@ static float dxb1[MAXWALLSB], dxb2[MAXWALLSB];
 float shadescale = 1.0f;
 int32_t shadescale_unbounded = 0;
 
-int32_t r_polymostDebug = 0;
-int32_t r_enablepolymost2 = 0;
 int32_t r_pogoDebug = 0;
 int32_t r_usenewshading = 4;
 int32_t r_npotwallmode = 2;
@@ -228,25 +226,6 @@ hitdata_t polymost_hitdata;
 
 void polymost_outputGLDebugMessage(uint8_t severity, const char* format, ...)
 {
-    static char msg[8192];
-    va_list vArgs;
-
-    if (!glinfo.debugoutput ||
-        r_polymostDebug < severity)
-    {
-        return;
-    }
-
-    va_start(vArgs, format);
-    Bvsnprintf(msg, sizeof(msg), format, vArgs);
-    va_end(vArgs);
-
-    glDebugMessageInsertARB(GL_DEBUG_SOURCE_APPLICATION_ARB,
-                            GL_DEBUG_TYPE_OTHER_ARB,
-                            0,
-                            GL_DEBUG_SEVERITY_HIGH_ARB+severity-1,
-                            -1,
-                            msg);
 }
 
 void gltexinvalidate(int32_t dapicnum, int32_t dapalnum, int32_t dameth)
@@ -296,10 +275,10 @@ void gltexapplyprops(void)
     if (videoGetRenderMode() == REND_CLASSIC)
         return;
 
-	if (glinfo.maxanisotropy > 1.f)
+	if (GLInterface.glinfo.maxanisotropy > 1.f)
 	{
-		if (glanisotropy <= 0 || glanisotropy > glinfo.maxanisotropy)
-			glanisotropy = (int32_t)glinfo.maxanisotropy;
+		if (glanisotropy <= 0 || glanisotropy > GLInterface.glinfo.maxanisotropy)
+			glanisotropy = (int32_t)GLInterface.glinfo.maxanisotropy;
 	}
 
 
@@ -1029,21 +1008,11 @@ static void resizeglcheck(void)
     if (lastglpolygonmode != r_polygonmode)
     {
         lastglpolygonmode = r_polygonmode;
-        switch (r_polygonmode)
-        {
-        default:
-        case 0:
-            glPolygonMode(GL_FRONT_AND_BACK,GL_FILL); break;
-        case 1:
-            glPolygonMode(GL_FRONT_AND_BACK,GL_LINE); break;
-        case 2:
-            glPolygonMode(GL_FRONT_AND_BACK,GL_POINT); break;
-        }
+		GLInterface.SetWireframe(r_polygonmode == 1);
     }
     if (r_polygonmode) //FUK
     {
-        glClearColor(1.0,1.0,1.0,0.0);
-        glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
+		GLInterface.ClearScreen(1, 1, 1, true);
     }
 
     if ((glox1 != windowxy1.x) || (gloy1 != windowxy1.y) || (glox2 != windowxy2.x) || (gloy2 != windowxy2.y) || (gloxyaspect != gxyaspect) || (gloyxscale != gyxscale) || (glohoriz2 != ghoriz2) || (glohorizcorrect != ghorizcorrect) || (glotang != gtang))
@@ -1057,7 +1026,7 @@ static void resizeglcheck(void)
         glox1 = (float)windowxy1.x; gloy1 = (float)windowxy1.y;
         glox2 = (float)windowxy2.x; gloy2 = (float)windowxy2.y;
 
-        glViewport(windowxy1.x-(fovcorrect/2), ydim-(windowxy2.y+1),
+		GLInterface.SetViewport(windowxy1.x-(fovcorrect/2), ydim-(windowxy2.y+1),
                     ourxdimen+fovcorrect, windowxy2.y-windowxy1.y+1);
 
         float m[4][4];
@@ -2152,7 +2121,7 @@ static void polymost_drawpoly(vec2f_t const * const dpxy, int32_t const n, int32
         float const al = alphahackarray[globalpicnum] != 0 ? alphahackarray[globalpicnum] * (1.f/255.f) :
                          (pth->hicr && pth->hicr->alphacut >= 0.f ? pth->hicr->alphacut : 0.f);
 
-        glAlphaFunc(GL_GREATER, al);
+		GLInterface.SetAlphaThreshold(al);
         handle_blend((method & DAMETH_MASKPROPS) > DAMETH_MASK, drawpoly_blend, (method & DAMETH_MASKPROPS) == DAMETH_TRANS2);
     }
 
@@ -5252,10 +5221,11 @@ void polymost_drawrooms()
     frameoffset = frameplace + windowxy1.y*bytesperline + windowxy1.x;
 
 #ifdef YAX_ENABLE
-    if (yax_polymostclearzbuffer)
+	if (yax_polymostclearzbuffer)
 #endif
-    glClear(GL_DEPTH_BUFFER_BIT);
-
+	{
+		GLInterface.ClearDepth();
+	}
     GLInterface.EnableBlend(false);
     GLInterface.EnableAlphaTest(false);
     GLInterface.EnableDepthTest(true);
@@ -6653,12 +6623,12 @@ void polymost_dorotatespritemodel(int32_t sx, int32_t sy, int32_t z, int16_t a,
 
     if ((dastat&(RS_AUTO|RS_NOCLIP)) == RS_AUTO)
     {
-        glViewport(windowxy1.x, ydim-(windowxy2.y+1), windowxy2.x-windowxy1.x+1, windowxy2.y-windowxy1.y+1);
+		GLInterface.SetViewport(windowxy1.x, ydim-(windowxy2.y+1), windowxy2.x-windowxy1.x+1, windowxy2.y-windowxy1.y+1);
         glox1 = -1;
     }
     else
     {
-        glViewport(0, 0, xdim, ydim);
+		GLInterface.SetViewport(0, 0, xdim, ydim);
         glox1 = -1; //Force fullscreen (glox1=-1 forces it to restore)
     }
 
@@ -6706,8 +6676,8 @@ void polymost_dorotatespritemodel(int32_t sx, int32_t sy, int32_t z, int16_t a,
         if (onumframes != numframes)
         {
             onumframes = numframes;
-            glClear(GL_DEPTH_BUFFER_BIT);
-        }
+			GLInterface.ClearDepth();
+		}
     }
 
     spriteext[tspr.owner].alpha = daalpha * (1.0f / 255.0f);
@@ -6746,7 +6716,7 @@ void polymost_dorotatesprite(int32_t sx, int32_t sy, int32_t z, int16_t a, int16
     polymost_outputGLDebugMessage(3, "polymost_dorotatesprite(sx:%d, sy:%d, z:%d, a:%hd, picnum:%hd, dashade:%hhd, dapalnum:%hhu, dastat:%d, daalpha:%hhu, dablend:%hhu, cx1:%d, cy1:%d, cx2:%d, cy2:%d, uniqid:%d)",
                                   sx, sy, z, a, picnum, dashade, dapalnum, dastat, daalpha, dablend, cx1, cy1, cx2, cy2, uniqid);
 
-    glViewport(0,0,xdim,ydim); glox1 = -1; //Force fullscreen (glox1=-1 forces it to restore)
+	GLInterface.SetViewport(0,0,xdim,ydim); glox1 = -1; //Force fullscreen (glox1=-1 forces it to restore)
 	auto oldproj = GLInterface.GetMatrix(Matrix_Projection);
 	auto oldmv = GLInterface.GetMatrix(Matrix_ModelView);
 	
@@ -7295,8 +7265,8 @@ int32_t polymost_printext256(int32_t xpos, int32_t ypos, int16_t col, int16_t ba
     // XXX: Don't fogify the OSD text in Mapster32 with r_usenewshading >= 2.
     polymost_setFogEnabled(false);
     // We want to have readable text in wireframe mode, too:
-    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
-    lastglpolygonmode = 0;
+	GLInterface.SetWireframe(false);
+	lastglpolygonmode = 0;
 
     if (backcol >= 0)
     {
@@ -7481,7 +7451,6 @@ void polymost_initosdfuncs(void)
 
     static osdcvardata_t cvars_polymost[] =
     {
-        { "r_polymostDebug","Set the verbosity of Polymost GL debug messages",(void *) &r_polymostDebug, CVAR_INT, 0, 3 },
 #ifdef USE_GLEXT
         { "r_detailmapping","enable/disable detail mapping",(void *) &r_detailmapping, CVAR_BOOL, 0, 1 },
         { "r_glowmapping","enable/disable glow mapping",(void *) &r_glowmapping, CVAR_BOOL, 0, 1 },
diff --git a/source/build/src/screenshot.cpp b/source/build/src/screenshot.cpp
index b4e1e1129..1d00673ee 100644
--- a/source/build/src/screenshot.cpp
+++ b/source/build/src/screenshot.cpp
@@ -5,6 +5,7 @@
 #include "pngwrite.h"
 
 #include "vfs.h"
+#include "../../glbackend/glbackend.h"
 
 //
 // screencapture
@@ -54,6 +55,11 @@ static void screencapture_end(char *fn, buildvfs_FILE * filptr)
 #  define HICOLOR 0
 # endif
 
+void getScreen(uint8_t* imgBuf)
+{
+	GLInterface.ReadPixels(xdim, ydim, imgBuf);
+}
+
 int videoCaptureScreen(const char *filename, char inverseit)
 {
     char *fn = Xstrdup(filename);
@@ -72,7 +78,7 @@ int videoCaptureScreen(const char *filename, char inverseit)
 #ifdef USE_OPENGL
     if (HICOLOR)
     {
-        glReadPixels(0, 0, xdim, ydim, GL_RGB, GL_UNSIGNED_BYTE, imgBuf);
+        getScreen(imgBuf);
         int const bytesPerLine = xdim * 3;
 
         if (inverseit)
@@ -200,7 +206,7 @@ int videoCaptureScreenTGA(const char *filename, char inverseit)
         int const size = xdim * ydim * 3;
         uint8_t *inversebuf = (uint8_t *) Xmalloc(size);
 
-        glReadPixels(0, 0, xdim, ydim, GL_RGB, GL_UNSIGNED_BYTE, inversebuf);
+        getScreen(inversebuf);
 
         for (i = 0; i < size; i += 3)
             swapchar(&inversebuf[i], &inversebuf[i + 2]);
diff --git a/source/build/src/sdlayer.cpp b/source/build/src/sdlayer.cpp
index 78b55b783..ddef3f14b 100644
--- a/source/build/src/sdlayer.cpp
+++ b/source/build/src/sdlayer.cpp
@@ -1323,39 +1323,6 @@ void sdlayer_setvideomode_opengl(void)
     glsurface_destroy();
     polymost_glreset();
 
-    glinfo.vendor = (const char *) glGetString(GL_VENDOR);
-    glinfo.renderer = (const char *) glGetString(GL_RENDERER);
-    glinfo.version = (const char *) glGetString(GL_VERSION);
-    glinfo.extensions = (const char *) glGetString(GL_EXTENSIONS);
-
-    // process the extensions string and flag stuff we recognize
-
-    glinfo.debugoutput = !!Bstrstr(glinfo.extensions, "GL_ARB_debug_output");
-    glinfo.bufferstorage = !!Bstrstr(glinfo.extensions, "GL_ARB_buffer_storage");
-    glinfo.sync = !!Bstrstr(glinfo.extensions, "GL_ARB_sync");
-
-    if (Bstrstr(glinfo.extensions, "WGL_3DFX_gamma_control"))
-    {
-        static int32_t warnonce;
-        // 3dfx cards have issues with fog
-        nofog = 1;
-        if (!(warnonce & 1))
-            initprintf("3dfx card detected: OpenGL fog disabled\n");
-        warnonce |= 1;
-    }
-
-//    if (Bstrstr(glinfo.extensions, "GL_EXT_texture_filter_anisotropic"))
-    glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &glinfo.maxanisotropy);
-
-    if (!glinfo.dumped)
-    {
-        int32_t oldbpp = bpp;
-        bpp = 32;
-        osdcmd_glinfo(NULL);
-        glinfo.dumped = 1;
-        bpp = oldbpp;
-    }
-
 	GLInterface.Deinit();
 	GLInterface.Init();
 	GLInterface.InitGLState(r_usenewshading, glmultisample);
diff --git a/source/build/src/texcache.cpp b/source/build/src/texcache.cpp
index 10f4c501d..249be4703 100644
--- a/source/build/src/texcache.cpp
+++ b/source/build/src/texcache.cpp
@@ -13,7 +13,6 @@
 #include "vfs.h"
 
 
-#define CLEAR_GL_ERRORS() while(glGetError() != GL_NO_ERROR) { }
 #define TEXCACHE_FREEBUFS() { Xfree(pic), Xfree(packbuf), Xfree(midbuf); }
 
 globaltexcache texcache;
diff --git a/source/build/src/voxmodel.cpp b/source/build/src/voxmodel.cpp
index f0d0da26c..2549bd27b 100644
--- a/source/build/src/voxmodel.cpp
+++ b/source/build/src/voxmodel.cpp
@@ -1085,12 +1085,8 @@ int32_t polymost_voxdraw(voxmodel_t *m, tspriteptr_t const tspr)
 	}
 
 
-    if ((grhalfxdown10x >= 0) ^ ((globalorientation&8) != 0) ^ ((globalorientation&4) != 0))
-        glFrontFace(GL_CW);
-    else
-        glFrontFace(GL_CCW);
-
-	GLInterface.SetCull(Cull_Back);
+	int winding = ((grhalfxdown10x >= 0) ^ ((globalorientation & 8) != 0) ^ ((globalorientation & 4) != 0)) ? Winding_CW : Winding_CCW;
+	GLInterface.SetCull(Cull_Back, winding);
 
     float pc[4];
 
diff --git a/source/duke3d/src/game.cpp b/source/duke3d/src/game.cpp
index b5c97e423..77ed26744 100644
--- a/source/duke3d/src/game.cpp
+++ b/source/duke3d/src/game.cpp
@@ -713,7 +713,6 @@ static void G_ClearGotMirror()
 static void G_ReadGLFrame(void)
 {
     // Save OpenGL screenshot with Duke3D palette
-    // NOTE: maybe need to move this to the engine...
     palette_t *const frame = (palette_t *)Xcalloc(xdim * ydim, sizeof(palette_t));
     char *const pic = (char *) waloff[TILE_SAVESHOT];
 
@@ -731,8 +730,8 @@ static void G_ReadGLFrame(void)
     }
 
     videoBeginDrawing();
-    glReadPixels(0, 0, xdim, ydim, GL_RGBA, GL_UNSIGNED_BYTE, frame);
-    videoEndDrawing();
+	getScreen((uint8_t*)frame);
+	videoEndDrawing();
 
     for (y = 0; y < 200; y++)
     {
diff --git a/source/duke3d/src/menus.cpp b/source/duke3d/src/menus.cpp
index 50aeff037..09f0ed2ad 100644
--- a/source/duke3d/src/menus.cpp
+++ b/source/duke3d/src/menus.cpp
@@ -31,6 +31,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include "osdcmds.h"
 #include "savegame.h"
 #include "xxhash.h"
+#include "../../glbackend/glbackend.h"
 
 BEGIN_DUKE_NS
 
@@ -2041,7 +2042,7 @@ static void Menu_Pre(MenuID_t cm)
 
             for (i = (int32_t) ARRAY_SIZE(MEOSV_DISPLAYSETUP_ANISOTROPY) - 1; i >= 0; --i)
             {
-                if (MEOSV_DISPLAYSETUP_ANISOTROPY[i] <= glinfo.maxanisotropy)
+                if (MEOSV_DISPLAYSETUP_ANISOTROPY[i] <= GLInterface.glinfo.maxanisotropy)
                 {
                     MEOS_DISPLAYSETUP_ANISOTROPY.numOptions = i + 1;
                     break;
diff --git a/source/glbackend/glbackend.cpp b/source/glbackend/glbackend.cpp
index 4924e2e4d..3c18d8014 100644
--- a/source/glbackend/glbackend.cpp
+++ b/source/glbackend/glbackend.cpp
@@ -2,6 +2,7 @@
 #include "glad/glad.h"
 #include "gl_samplers.h"
 
+#include "baselayer.h"
 
 GLInstance GLInterface;
 
@@ -12,12 +13,24 @@ void GLInstance::Init()
 		mSamplers = new FSamplerManager;
 		memset(LastBoundTextures, 0, sizeof(LastBoundTextures));
 	}
+
+	glinfo.vendor = (const char*)glGetString(GL_VENDOR);
+	glinfo.renderer = (const char*)glGetString(GL_RENDERER);
+	glinfo.version = (const char*)glGetString(GL_VERSION);
+	glinfo.extensions = (const char*)glGetString(GL_EXTENSIONS);
+	glinfo.bufferstorage = !!strstr(glinfo.extensions, "GL_ARB_buffer_storage");
+	glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &glinfo.maxanisotropy);
+	if (!glinfo.dumped)
+	{
+		osdcmd_glinfo(NULL);
+		glinfo.dumped = 1;
+	}
+
 }
 
 void GLInstance::InitGLState(int fogmode, int multisample)
 {
 	glShadeModel(GL_SMOOTH);  // GL_FLAT
-	glClearColor(0, 0, 0, 1.0);  // Black Background
 	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
 	glDisable(GL_DITHER);
 	glEnable(GL_TEXTURE_2D);
@@ -178,7 +191,7 @@ void GLInstance::DisableStencil()
 	glDisable(GL_STENCIL_TEST);
 }
 
-void GLInstance::SetCull(int type)
+void GLInstance::SetCull(int type, int winding)
 {
 	if (type == Cull_None)
 	{
@@ -186,11 +199,13 @@ void GLInstance::SetCull(int type)
 	}
 	else if (type == Cull_Front)
 	{
+		glFrontFace(winding == Winding_CW ? GL_CW : GL_CCW);
 		glEnable(GL_CULL_FACE);
 		glCullFace(GL_FRONT);
 	}
 	else if (type == Cull_Back)
 	{
+		glFrontFace(winding == Winding_CW ? GL_CW : GL_CCW);
 		glEnable(GL_CULL_FACE);
 		glCullFace(GL_BACK);
 	}
@@ -245,3 +260,34 @@ void GLInstance::SetBlendOp(int op)
 {
 	glBlendEquation(renderops[op]);
 }
+
+void GLInstance::ClearScreen(float r, float g, float b, bool depth)
+{
+	glClearColor(r, g, b, 1.f);
+	glClear(depth ? GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT : GL_COLOR_BUFFER_BIT);
+}
+
+void GLInstance::ClearDepth()
+{
+	glClear(GL_DEPTH_BUFFER_BIT);
+}
+
+void GLInstance::SetAlphaThreshold(float al)
+{
+	glAlphaFunc(GL_GREATER, al);
+}
+
+void GLInstance::SetViewport(int x, int y, int w, int h)
+{
+	glViewport(x, y, w, h);
+}
+
+void GLInstance::SetWireframe(bool on)
+{
+	glPolygonMode(GL_FRONT_AND_BACK,on? GL_LINE : GL_FILL); 
+}
+
+void GLInstance::ReadPixels(int xdim, int ydim, uint8_t* buffer)
+{
+	glReadPixels(0, 0, xdim, ydim, GL_RGB, GL_UNSIGNED_BYTE, buffer);
+}
\ No newline at end of file
diff --git a/source/glbackend/glbackend.h b/source/glbackend/glbackend.h
index 46acf3e5c..2442977d8 100644
--- a/source/glbackend/glbackend.h
+++ b/source/glbackend/glbackend.h
@@ -9,6 +9,17 @@
 
 class FSamplerManager;
 
+struct glinfo_t {
+	const char* vendor;
+	const char* renderer;
+	const char* version;
+	const char* extensions;
+
+	float maxanisotropy;
+	char bufferstorage;
+	char dumped;
+};
+
 struct BaseVertex
 {
 	float x, y, z;
@@ -97,6 +108,12 @@ enum ERenderOp
 	STYLEOP_Sub,			// Subtract source from destination
 	STYLEOP_RevSub,			// Subtract destination from source
 };
+
+enum EWinding
+{
+	Winding_CCW,
+	Winding_CW
+};
 class GLInstance
 {
 	enum
@@ -114,6 +131,7 @@ class GLInstance
 	
 	
 public:
+	glinfo_t glinfo;
 	FSamplerManager *mSamplers;
 	
 	void Init();
@@ -147,7 +165,7 @@ public:
 	{
 		SetMatrix(num, reinterpret_cast<const VSMatrix*>(mat));
 	}
-	void SetCull(int type);
+	void SetCull(int type, int winding = Winding_CCW);
 
 	void EnableStencilWrite(int value);
 	void EnableStencilTest(int value);
@@ -165,6 +183,13 @@ public:
 	void SetDepthMask(bool on);
 	void SetBlendFunc(int src, int dst);
 	void SetBlendOp(int op);
+	void ClearScreen(float r, float g, float b, bool depth);
+	void ClearDepth();
+	void SetViewport(int x, int y, int w, int h);
+	void SetAlphaThreshold(float al);
+	void SetWireframe(bool on);
+
+	void ReadPixels(int w, int h, uint8_t* buffer);
 };
 
 extern GLInstance GLInterface;
diff --git a/source/rr/src/game.cpp b/source/rr/src/game.cpp
index fb9c08ed7..6a8f57c9f 100644
--- a/source/rr/src/game.cpp
+++ b/source/rr/src/game.cpp
@@ -915,7 +915,6 @@ void G_HandleMirror(int32_t x, int32_t y, int32_t z, fix16_t a, fix16_t q16horiz
 static void G_ReadGLFrame(void)
 {
     // Save OpenGL screenshot with Duke3D palette
-    // NOTE: maybe need to move this to the engine...
     palette_t *const frame = (palette_t *)Xcalloc(xdim * ydim, sizeof(palette_t));
     char *const pic = (char *) waloff[TILE_SAVESHOT];
 
@@ -933,7 +932,7 @@ static void G_ReadGLFrame(void)
     }
 
     videoBeginDrawing();
-    glReadPixels(0, 0, xdim, ydim, GL_RGBA, GL_UNSIGNED_BYTE, frame);
+    getScreen((uint8_t*)frame);
     videoEndDrawing();
 
     for (y = 0; y < 200; y++)
diff --git a/source/rr/src/menus.cpp b/source/rr/src/menus.cpp
index b675a3f2a..15a922a65 100644
--- a/source/rr/src/menus.cpp
+++ b/source/rr/src/menus.cpp
@@ -30,6 +30,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include "input.h"
 #include "menus.h"
 #include "cheats.h"
+#include "../../glbackend/glbackend.h"
 
 BEGIN_RR_NS
 
@@ -2012,7 +2013,7 @@ static void Menu_Pre(MenuID_t cm)
 
             for (i = (int32_t) ARRAY_SIZE(MEOSV_DISPLAYSETUP_ANISOTROPY) - 1; i >= 0; --i)
             {
-                if (MEOSV_DISPLAYSETUP_ANISOTROPY[i] <= glinfo.maxanisotropy)
+                if (MEOSV_DISPLAYSETUP_ANISOTROPY[i] <= GLInterface.glinfo.maxanisotropy)
                 {
                     MEOS_DISPLAYSETUP_ANISOTROPY.numOptions = i + 1;
                     break;