Cleanup GPU: get rid of some extremely legacy draw code.

Basically this commit gets rid of most of the derived mesh immediate mode
drawing (cases such as subsurf excluded). Even when VBO is turned off
in user preferences, we still use vertex arrays, which are very similar to
VBOs but memory is client side. Vertex arrays are OpenGL 1.1 so compatibility
is not an issue here.

Reviewers: campbellbarton, sergey, jwilkins

Differential Revision: https://developer.blender.org/D919

5 files changed, 451 insertions, 771 deletions

diff --git a/source/blender/blenkernel/intern/cdderivedmesh.c b/source/blender/blenkernel/intern/cdderivedmesh.c
index 7f49fc60bde..e3950567d80 100644
--- a/source/blender/blenkernel/intern/cdderivedmesh.c
+++ b/source/blender/blenkernel/intern/cdderivedmesh.c
@@ -343,106 +343,64 @@ static void cdDM_update_normals_from_pbvh(DerivedMesh *dm)
 
 static void cdDM_drawVerts(DerivedMesh *dm)
 {
-	CDDerivedMesh *cddm = (CDDerivedMesh *) dm;
-	MVert *mv = cddm->mvert;
-	int i;
-
-	if (GPU_buffer_legacy(dm)) {
-		glBegin(GL_POINTS);
-		for (i = 0; i < dm->numVertData; i++, mv++)
-			glVertex3fv(mv->co);
-		glEnd();
-	}
-	else {  /* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
-		GPU_vertex_setup(dm);
-		if (!GPU_buffer_legacy(dm)) {
-			if (dm->drawObject->tot_triangle_point)
-				glDrawArrays(GL_POINTS, 0, dm->drawObject->tot_triangle_point);
-			else
-				glDrawArrays(GL_POINTS, 0, dm->drawObject->tot_loose_point);
-		}
-		GPU_buffer_unbind();
-	}
+	GPU_vertex_setup(dm);
+	if (dm->drawObject->tot_triangle_point)
+		glDrawArrays(GL_POINTS, 0, dm->drawObject->tot_triangle_point);
+	else
+		glDrawArrays(GL_POINTS, 0, dm->drawObject->tot_loose_point);
+	GPU_buffer_unbind();
 }
 
 static void cdDM_drawUVEdges(DerivedMesh *dm)
 {
 	CDDerivedMesh *cddm = (CDDerivedMesh *) dm;
 	MFace *mf = cddm->mface;
-	MTFace *tf = DM_get_tessface_data_layer(dm, CD_MTFACE);
 	int i;
 
 	if (mf) {
-		if (GPU_buffer_legacy(dm)) {
-			glBegin(GL_LINES);
-			for (i = 0; i < dm->numTessFaceData; i++, mf++, tf++) {
-				if (!(mf->flag & ME_HIDE)) {
-					glVertex2fv(tf->uv[0]);
-					glVertex2fv(tf->uv[1]);
-
-					glVertex2fv(tf->uv[1]);
-					glVertex2fv(tf->uv[2]);
-
-					if (!mf->v4) {
-						glVertex2fv(tf->uv[2]);
-						glVertex2fv(tf->uv[0]);
-					}
-					else {
-						glVertex2fv(tf->uv[2]);
-						glVertex2fv(tf->uv[3]);
-
-						glVertex2fv(tf->uv[3]);
-						glVertex2fv(tf->uv[0]);
-					}
-				}
+		int prevstart = 0;
+		int prevdraw = 1;
+		int draw = 1;
+		int curpos = 0;
+		
+		GPU_uvedge_setup(dm);
+		for (i = 0; i < dm->numTessFaceData; i++, mf++) {
+			if (!(mf->flag & ME_HIDE)) {
+				draw = 1;
 			}
-			glEnd();
-		}
-		else {
-			int prevstart = 0;
-			int prevdraw = 1;
-			int draw = 1;
-			int curpos = 0;
-
-			GPU_uvedge_setup(dm);
-			if (!GPU_buffer_legacy(dm)) {
-				for (i = 0; i < dm->numTessFaceData; i++, mf++) {
-					if (!(mf->flag & ME_HIDE)) {
-						draw = 1;
-					}
-					else {
-						draw = 0;
-					}
-					if (prevdraw != draw) {
-						if (prevdraw > 0 && (curpos - prevstart) > 0) {
-							glDrawArrays(GL_LINES, prevstart, curpos - prevstart);
-						}
-						prevstart = curpos;
-					}
-					if (mf->v4) {
-						curpos += 8;
-					}
-					else {
-						curpos += 6;
-					}
-					prevdraw = draw;
-				}
+			else {
+				draw = 0;
+			}
+			if (prevdraw != draw) {
 				if (prevdraw > 0 && (curpos - prevstart) > 0) {
 					glDrawArrays(GL_LINES, prevstart, curpos - prevstart);
 				}
+				prevstart = curpos;
+			}
+			if (mf->v4) {
+				curpos += 8;
 			}
-			GPU_buffer_unbind();
+			else {
+				curpos += 6;
+			}
+			prevdraw = draw;
+		}
+		if (prevdraw > 0 && (curpos - prevstart) > 0) {
+			glDrawArrays(GL_LINES, prevstart, curpos - prevstart);
 		}
+		GPU_buffer_unbind();
 	}
 }
 
 static void cdDM_drawEdges(DerivedMesh *dm, bool drawLooseEdges, bool drawAllEdges)
 {
 	CDDerivedMesh *cddm = (CDDerivedMesh *) dm;
-	MVert *mvert = cddm->mvert;
 	MEdge *medge = cddm->medge;
 	int i;
-
+	int prevstart = 0;
+	int prevdraw = 1;
+	bool draw = true;
+	
 	if (cddm->pbvh && cddm->pbvh_draw &&
 	    BKE_pbvh_type(cddm->pbvh) == PBVH_BMESH)
 	{
@@ -451,97 +409,60 @@ static void cdDM_drawEdges(DerivedMesh *dm, bool drawLooseEdges, bool drawAllEdg
 		return;
 	}
 	
-	if (GPU_buffer_legacy(dm)) {
-		DEBUG_VBO("Using legacy code. cdDM_drawEdges\n");
-		glBegin(GL_LINES);
-		for (i = 0; i < dm->numEdgeData; i++, medge++) {
-			if ((drawAllEdges || (medge->flag & ME_EDGEDRAW)) &&
-			    (drawLooseEdges || !(medge->flag & ME_LOOSEEDGE)))
-			{
-				glVertex3fv(mvert[medge->v1].co);
-				glVertex3fv(mvert[medge->v2].co);
-			}
+	GPU_edge_setup(dm);
+	for (i = 0; i < dm->numEdgeData; i++, medge++) {
+		if ((drawAllEdges || (medge->flag & ME_EDGEDRAW)) &&
+		        (drawLooseEdges || !(medge->flag & ME_LOOSEEDGE)))
+		{
+			draw = true;
 		}
-		glEnd();
-	}
-	else {  /* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
-		int prevstart = 0;
-		int prevdraw = 1;
-		bool draw = true;
-
-		GPU_edge_setup(dm);
-		if (!GPU_buffer_legacy(dm)) {
-			for (i = 0; i < dm->numEdgeData; i++, medge++) {
-				if ((drawAllEdges || (medge->flag & ME_EDGEDRAW)) &&
-				    (drawLooseEdges || !(medge->flag & ME_LOOSEEDGE)))
-				{
-					draw = true;
-				}
-				else {
-					draw = false;
-				}
-				if (prevdraw != draw) {
-					if (prevdraw > 0 && (i - prevstart) > 0) {
-						GPU_buffer_draw_elements(dm->drawObject->edges, GL_LINES, prevstart * 2, (i - prevstart) * 2);
-					}
-					prevstart = i;
-				}
-				prevdraw = draw;
-			}
+		else {
+			draw = false;
+		}
+		if (prevdraw != draw) {
 			if (prevdraw > 0 && (i - prevstart) > 0) {
 				GPU_buffer_draw_elements(dm->drawObject->edges, GL_LINES, prevstart * 2, (i - prevstart) * 2);
 			}
+			prevstart = i;
 		}
-		GPU_buffer_unbind();
+		prevdraw = draw;
 	}
+	if (prevdraw > 0 && (i - prevstart) > 0) {
+		GPU_buffer_draw_elements(dm->drawObject->edges, GL_LINES, prevstart * 2, (i - prevstart) * 2);
+	}
+	GPU_buffer_unbind();
 }
 
 static void cdDM_drawLooseEdges(DerivedMesh *dm)
 {
 	CDDerivedMesh *cddm = (CDDerivedMesh *) dm;
-	MVert *mvert = cddm->mvert;
 	MEdge *medge = cddm->medge;
 	int i;
-
-	if (GPU_buffer_legacy(dm)) {
-		DEBUG_VBO("Using legacy code. cdDM_drawLooseEdges\n");
-		glBegin(GL_LINES);
-		for (i = 0; i < dm->numEdgeData; i++, medge++) {
-			if (medge->flag & ME_LOOSEEDGE) {
-				glVertex3fv(mvert[medge->v1].co);
-				glVertex3fv(mvert[medge->v2].co);
-			}
+	
+	int prevstart = 0;
+	int prevdraw = 1;
+	int draw = 1;
+	
+	GPU_edge_setup(dm);
+	for (i = 0; i < dm->numEdgeData; i++, medge++) {
+		if (medge->flag & ME_LOOSEEDGE) {
+			draw = 1;
 		}
-		glEnd();
-	}
-	else {  /* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
-		int prevstart = 0;
-		int prevdraw = 1;
-		int draw = 1;
-
-		GPU_edge_setup(dm);
-		if (!GPU_buffer_legacy(dm)) {
-			for (i = 0; i < dm->numEdgeData; i++, medge++) {
-				if (medge->flag & ME_LOOSEEDGE) {
-					draw = 1;
-				}
-				else {
-					draw = 0;
-				}
-				if (prevdraw != draw) {
-					if (prevdraw > 0 && (i - prevstart) > 0) {
-						GPU_buffer_draw_elements(dm->drawObject->edges, GL_LINES, prevstart * 2, (i - prevstart) * 2);
-					}
-					prevstart = i;
-				}
-				prevdraw = draw;
-			}
+		else {
+			draw = 0;
+		}
+		if (prevdraw != draw) {
 			if (prevdraw > 0 && (i - prevstart) > 0) {
 				GPU_buffer_draw_elements(dm->drawObject->edges, GL_LINES, prevstart * 2, (i - prevstart) * 2);
 			}
+			prevstart = i;
 		}
-		GPU_buffer_unbind();
+		prevdraw = draw;
+	}
+	if (prevdraw > 0 && (i - prevstart) > 0) {
+		GPU_buffer_draw_elements(dm->drawObject->edges, GL_LINES, prevstart * 2, (i - prevstart) * 2);
 	}
+	GPU_buffer_unbind();
 }
 
 static void cdDM_drawFacesSolid(DerivedMesh *dm,
@@ -549,11 +470,7 @@ static void cdDM_drawFacesSolid(DerivedMesh *dm,
                                 bool UNUSED(fast), DMSetMaterial setMaterial)
 {
 	CDDerivedMesh *cddm = (CDDerivedMesh *) dm;
-	MVert *mvert = cddm->mvert;
-	MFace *mface = cddm->mface;
-	const float *nors = dm->getTessFaceDataArray(dm, CD_NORMAL);
-	const short (*lnors)[4][3] = dm->getTessFaceDataArray(dm, CD_TESSLOOPNORMAL);
-	int a, glmode = -1, shademodel = -1, matnr = -1, drawCurrentMat = 1;
+	int a;
 
 	if (cddm->pbvh && cddm->pbvh_draw) {
 		if (dm->numTessFaceData) {
@@ -566,101 +483,17 @@ static void cdDM_drawFacesSolid(DerivedMesh *dm,
 
 		return;
 	}
-
-	if (GPU_buffer_legacy(dm)) {
-		DEBUG_VBO("Using legacy code. cdDM_drawFacesSolid\n");
-		glBegin(glmode = GL_QUADS);
-		for (a = 0; a < dm->numTessFaceData; a++, mface++) {
-			int new_glmode, new_matnr, new_shademodel;
-
-			new_glmode = mface->v4 ? GL_QUADS : GL_TRIANGLES;
-			new_matnr = mface->mat_nr + 1;
-			new_shademodel = (lnors || (mface->flag & ME_SMOOTH)) ? GL_SMOOTH : GL_FLAT;
-
-
-			if ((new_glmode != glmode) || (new_shademodel != shademodel) ||
-			    (setMaterial && (new_matnr != matnr)))
-			{
-				glEnd();
-
-				if (setMaterial) {
-					drawCurrentMat = setMaterial(matnr = new_matnr, NULL);
-				}
-
-				glShadeModel(shademodel = new_shademodel);
-				glBegin(glmode = new_glmode);
-			}
-			
-			if (drawCurrentMat) {
-				if (lnors) {
-					glNormal3sv((const GLshort *)lnors[0][0]);
-					glVertex3fv(mvert[mface->v1].co);
-					glNormal3sv((const GLshort *)lnors[0][1]);
-					glVertex3fv(mvert[mface->v2].co);
-					glNormal3sv((const GLshort *)lnors[0][2]);
-					glVertex3fv(mvert[mface->v3].co);
-					if (mface->v4) {
-						glNormal3sv((const GLshort *)lnors[0][3]);
-						glVertex3fv(mvert[mface->v4].co);
-					}
-				}
-				else if (shademodel == GL_FLAT) {
-					if (nors) {
-						glNormal3fv(nors);
-					}
-					else {
-						/* TODO make this better (cache facenormals as layer?) */
-						float nor[3];
-						if (mface->v4) {
-							normal_quad_v3(nor, mvert[mface->v1].co, mvert[mface->v2].co, mvert[mface->v3].co, mvert[mface->v4].co);
-						}
-						else {
-							normal_tri_v3(nor, mvert[mface->v1].co, mvert[mface->v2].co, mvert[mface->v3].co);
-						}
-						glNormal3fv(nor);
-					}
-					glVertex3fv(mvert[mface->v1].co);
-					glVertex3fv(mvert[mface->v2].co);
-					glVertex3fv(mvert[mface->v3].co);
-					if (mface->v4) {
-						glVertex3fv(mvert[mface->v4].co);
-					}
-				}
-				else {  /* shademodel == GL_SMOOTH */
-					glNormal3sv(mvert[mface->v1].no);
-					glVertex3fv(mvert[mface->v1].co);
-					glNormal3sv(mvert[mface->v2].no);
-					glVertex3fv(mvert[mface->v2].co);
-					glNormal3sv(mvert[mface->v3].no);
-					glVertex3fv(mvert[mface->v3].co);
-					if (mface->v4) {
-						glNormal3sv(mvert[mface->v4].no);
-						glVertex3fv(mvert[mface->v4].co);
-					}
-				}
-			}
-
-			if (nors)
-				nors += 3;
-			if (lnors)
-				lnors++;
-		}
-		glEnd();
-	}
-	else {  /* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
-		GPU_vertex_setup(dm);
-		GPU_normal_setup(dm);
-		if (!GPU_buffer_legacy(dm)) {
-			glShadeModel(GL_SMOOTH);
-			for (a = 0; a < dm->drawObject->totmaterial; a++) {
-				if (!setMaterial || setMaterial(dm->drawObject->materials[a].mat_nr + 1, NULL)) {
-					glDrawArrays(GL_TRIANGLES, dm->drawObject->materials[a].start,
-					             dm->drawObject->materials[a].totpoint);
-				}
-			}
+	
+	GPU_vertex_setup(dm);
+	GPU_normal_setup(dm);
+	glShadeModel(GL_SMOOTH);
+	for (a = 0; a < dm->drawObject->totmaterial; a++) {
+		if (!setMaterial || setMaterial(dm->drawObject->materials[a].mat_nr + 1, NULL)) {
+			glDrawArrays(GL_TRIANGLES, dm->drawObject->materials[a].start,
+			             dm->drawObject->materials[a].totpoint);
 		}
-		GPU_buffer_unbind();
 	}
+	GPU_buffer_unbind();
 
 	glShadeModel(GL_FLAT);
 }
@@ -672,15 +505,15 @@ static void cdDM_drawFacesTex_common(DerivedMesh *dm,
                                      void *userData, DMDrawFlag uvflag)
 {
 	CDDerivedMesh *cddm = (CDDerivedMesh *) dm;
-	MVert *mv = cddm->mvert;
 	const MFace *mf = DM_get_tessface_data_layer(dm, CD_MFACE);
-	const float *nors = dm->getTessFaceDataArray(dm, CD_NORMAL);
-	const short (*lnors)[4][3] = dm->getTessFaceDataArray(dm, CD_TESSLOOPNORMAL);
 	MTFace *tf = DM_get_tessface_data_layer(dm, CD_MTFACE);
 	MCol *mcol;
 	int i, orig;
 	int colType, startFace = 0;
 	bool use_tface = (uvflag & DM_DRAW_USE_ACTIVE_UV) != 0;
+	int tottri;
+	int next_actualFace;
+	
 
 	/* double lookup */
 	const int *index_mf_to_mpoly = dm->getTessFaceDataArray(dm, CD_ORIGINDEX);
@@ -717,208 +550,81 @@ static void cdDM_drawFacesTex_common(DerivedMesh *dm,
 	}
 
 	cdDM_update_normals_from_pbvh(dm);
-
-	if (GPU_buffer_legacy(dm)) {
-		int mat_nr_cache = -1;
-		MTFace *tf_base = DM_get_tessface_data_layer(dm, CD_MTFACE);
-		MTFace *tf_stencil_base = NULL;
-		MTFace *tf_stencil = NULL;
-
-		if (uvflag & DM_DRAW_USE_TEXPAINT_UV) {
-			int stencil = CustomData_get_stencil_layer(&dm->faceData, CD_MTFACE);
-			tf_stencil_base = CustomData_get_layer_n(&dm->faceData, CD_MTFACE, stencil);
+	
+	GPU_vertex_setup(dm);
+	GPU_normal_setup(dm);
+	if (uvflag & DM_DRAW_USE_TEXPAINT_UV)
+		GPU_texpaint_uv_setup(dm);
+	else
+		GPU_uv_setup(dm);
+	if (mcol) {
+		GPU_color_setup(dm, colType);
+	}
+	
+	tottri = dm->drawObject->tot_triangle_point / 3;
+	next_actualFace = dm->drawObject->triangle_to_mface[0];
+	
+	glShadeModel(GL_SMOOTH);
+	/* lastFlag = 0; */ /* UNUSED */
+	for (i = 0; i < tottri; i++) {
+		int actualFace = next_actualFace;
+		DMDrawOption draw_option = DM_DRAW_OPTION_NORMAL;
+		int flush = 0;
+		
+		if (i != tottri - 1)
+			next_actualFace = dm->drawObject->triangle_to_mface[i + 1];
+		
+		if (drawParams) {
+			draw_option = drawParams(use_tface && tf ? &tf[actualFace] : NULL, (mcol != NULL), mf[actualFace].mat_nr);
 		}
-
-		DEBUG_VBO("Using legacy code. cdDM_drawFacesTex_common\n");
-		for (i = 0; i < dm->numTessFaceData; i++, mf++) {
-			MVert *mvert;
-			DMDrawOption draw_option;
-			unsigned char *cp = NULL;
-
-			if (uvflag & DM_DRAW_USE_TEXPAINT_UV) {
-				if (mf->mat_nr != mat_nr_cache) {
-					tf_base = DM_paint_uvlayer_active_get(dm, mf->mat_nr);
-
-					mat_nr_cache = mf->mat_nr;
-				}
-			}
-
-			tf = tf_base ? tf_base + i : NULL;
-			tf_stencil = tf_stencil_base ? tf_stencil_base + i : NULL;
-
-			if (drawParams) {
-				draw_option = drawParams(use_tface ? tf : NULL, (mcol != NULL), mf->mat_nr);
-			}
-			else {
-				if (index_mf_to_mpoly) {
-					orig = DM_origindex_mface_mpoly(index_mf_to_mpoly, index_mp_to_orig, i);
-					if (orig == ORIGINDEX_NONE) {
-						/* XXX, this is not really correct
-						 * it will draw the previous faces context for this one when we don't know its settings.
-						 * but better then skipping it altogether. - campbell */
-						draw_option = DM_DRAW_OPTION_NORMAL;
-					}
-					else if (drawParamsMapped) {
-						draw_option = drawParamsMapped(userData, orig, i);
-					}
-					else {
-						if (nors) {
-							nors += 3;
-						}
-						continue;
-					}
+		else {
+			if (index_mf_to_mpoly) {
+				orig = DM_origindex_mface_mpoly(index_mf_to_mpoly, index_mp_to_orig, actualFace);
+				if (orig == ORIGINDEX_NONE) {
+					/* XXX, this is not really correct
+							 * it will draw the previous faces context for this one when we don't know its settings.
+							 * but better then skipping it altogether. - campbell */
+					draw_option = DM_DRAW_OPTION_NORMAL;
 				}
 				else if (drawParamsMapped) {
-					draw_option = drawParamsMapped(userData, i, i);
-				}
-				else {
-					if (nors) {
-						nors += 3;
-					}
-					continue;
+					draw_option = drawParamsMapped(userData, orig, mf[actualFace].mat_nr);
 				}
 			}
-			
-			if (draw_option != DM_DRAW_OPTION_SKIP) {
-				if (draw_option != DM_DRAW_OPTION_NO_MCOL && mcol)
-					cp = (unsigned char *) &mcol[i * 4];
-
-				if (!(lnors || (mf->flag & ME_SMOOTH))) {
-					if (nors) {
-						glNormal3fv(nors);
-					}
-					else {
-						float nor[3];
-						if (mf->v4) {
-							normal_quad_v3(nor, mv[mf->v1].co, mv[mf->v2].co, mv[mf->v3].co, mv[mf->v4].co);
-						}
-						else {
-							normal_tri_v3(nor, mv[mf->v1].co, mv[mf->v2].co, mv[mf->v3].co);
-						}
-						glNormal3fv(nor);
-					}
-				}
-
-				glBegin(mf->v4 ? GL_QUADS : GL_TRIANGLES);
-				if (tf) glTexCoord2fv(tf->uv[0]);
-				if (tf_stencil) glMultiTexCoord2fv(GL_TEXTURE2, tf->uv[0]);
-				if (cp) glColor3ub(cp[3], cp[2], cp[1]);
-				mvert = &mv[mf->v1];
-				if (lnors) glNormal3sv((const GLshort *)lnors[0][0]);
-				else if (mf->flag & ME_SMOOTH) glNormal3sv(mvert->no);
-				glVertex3fv(mvert->co);
-
-				if (tf) glTexCoord2fv(tf->uv[1]);
-				if (tf_stencil) glMultiTexCoord2fv(GL_TEXTURE2, tf->uv[1]);
-				if (cp) glColor3ub(cp[7], cp[6], cp[5]);
-				mvert = &mv[mf->v2];
-				if (lnors) glNormal3sv((const GLshort *)lnors[0][1]);
-				else if (mf->flag & ME_SMOOTH) glNormal3sv(mvert->no);
-				glVertex3fv(mvert->co);
-
-				if (tf) glTexCoord2fv(tf->uv[2]);
-				if (tf_stencil) glMultiTexCoord2fv(GL_TEXTURE2, tf->uv[2]);
-				if (cp) glColor3ub(cp[11], cp[10], cp[9]);
-				mvert = &mv[mf->v3];
-				if (lnors) glNormal3sv((const GLshort *)lnors[0][2]);
-				else if (mf->flag & ME_SMOOTH) glNormal3sv(mvert->no);
-				glVertex3fv(mvert->co);
-
-				if (mf->v4) {
-					if (tf) glTexCoord2fv(tf->uv[3]);
-					if (tf_stencil) glMultiTexCoord2fv(GL_TEXTURE2, tf->uv[3]);
-					if (cp) glColor3ub(cp[15], cp[14], cp[13]);
-					mvert = &mv[mf->v4];
-					if (lnors) glNormal3sv((const GLshort *)lnors[0][3]);
-					else if (mf->flag & ME_SMOOTH) glNormal3sv(mvert->no);
-					glVertex3fv(mvert->co);
-				}
-				glEnd();
+			else if (drawParamsMapped) {
+				draw_option = drawParamsMapped(userData, actualFace, mf[actualFace].mat_nr);
 			}
-			
-			if (nors)
-				nors += 3;
-			if (lnors)
-				lnors++;
-		}
-	}
-	else { /* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
-		GPU_vertex_setup(dm);
-		GPU_normal_setup(dm);
-		if (uvflag & DM_DRAW_USE_TEXPAINT_UV)
-			GPU_texpaint_uv_setup(dm);
-		else
-			GPU_uv_setup(dm);
-		if (mcol) {
-			GPU_color_setup(dm, colType);
 		}
-
-		if (!GPU_buffer_legacy(dm)) {
-			int tottri = dm->drawObject->tot_triangle_point / 3;
-			int next_actualFace = dm->drawObject->triangle_to_mface[0];
-
-			glShadeModel(GL_SMOOTH);
-			/* lastFlag = 0; */ /* UNUSED */
-			for (i = 0; i < tottri; i++) {
-				int actualFace = next_actualFace;
-				DMDrawOption draw_option = DM_DRAW_OPTION_NORMAL;
-				int flush = 0;
-
-				if (i != tottri - 1)
-					next_actualFace = dm->drawObject->triangle_to_mface[i + 1];
-
-				if (drawParams) {
-					draw_option = drawParams(use_tface && tf ? &tf[actualFace] : NULL, (mcol != NULL), mf[actualFace].mat_nr);
-				}
-				else {
-					if (index_mf_to_mpoly) {
-						orig = DM_origindex_mface_mpoly(index_mf_to_mpoly, index_mp_to_orig, actualFace);
-						if (orig == ORIGINDEX_NONE) {
-							/* XXX, this is not really correct
-							 * it will draw the previous faces context for this one when we don't know its settings.
-							 * but better then skipping it altogether. - campbell */
-							draw_option = DM_DRAW_OPTION_NORMAL;
-						}
-						else if (drawParamsMapped) {
-							draw_option = drawParamsMapped(userData, orig, mf[actualFace].mat_nr);
-						}
-					}
-					else if (drawParamsMapped) {
-						draw_option = drawParamsMapped(userData, actualFace, mf[actualFace].mat_nr);
-					}
-				}
-
-				/* flush buffer if current triangle isn't drawable or it's last triangle */
-				flush = (draw_option == DM_DRAW_OPTION_SKIP) || (i == tottri - 1);
-
-				if (!flush && compareDrawOptions) {
-					/* also compare draw options and flush buffer if they're different
+		
+		/* flush buffer if current triangle isn't drawable or it's last triangle */
+		flush = (draw_option == DM_DRAW_OPTION_SKIP) || (i == tottri - 1);
+		
+		if (!flush && compareDrawOptions) {
+			/* also compare draw options and flush buffer if they're different
 					 * need for face selection highlight in edit mode */
-					flush |= compareDrawOptions(userData, actualFace, next_actualFace) == 0;
-				}
-
-				if (flush) {
-					int first = startFace * 3;
-					/* Add one to the length if we're drawing at the end of the array */
-					int count = (i - startFace + (draw_option != DM_DRAW_OPTION_SKIP ? 1 : 0)) * 3;
-
-					if (count) {
-						if (mcol && draw_option != DM_DRAW_OPTION_NO_MCOL)
-							GPU_color_switch(1);
-						else
-							GPU_color_switch(0);
-
-						glDrawArrays(GL_TRIANGLES, first, count);
-					}
-
-					startFace = i + 1;
-				}
+			flush |= compareDrawOptions(userData, actualFace, next_actualFace) == 0;
+		}
+		
+		if (flush) {
+			int first = startFace * 3;
+			/* Add one to the length if we're drawing at the end of the array */
+			int count = (i - startFace + (draw_option != DM_DRAW_OPTION_SKIP ? 1 : 0)) * 3;
+			
+			if (count) {
+				if (mcol && draw_option != DM_DRAW_OPTION_NO_MCOL)
+					GPU_color_switch(1);
+				else
+					GPU_color_switch(0);
+				
+				glDrawArrays(GL_TRIANGLES, first, count);
 			}
+			
+			startFace = i + 1;
 		}
-
-		GPU_buffer_unbind();
-		glShadeModel(GL_FLAT);
 	}
+	
+	GPU_buffer_unbind();
+	glShadeModel(GL_FLAT);
+	
 }
 
 static void cdDM_drawFacesTex(DerivedMesh *dm,
@@ -968,7 +674,7 @@ static void cdDM_drawMappedFaces(DerivedMesh *dm,
 
 	/* back-buffer always uses legacy since VBO's would need the
 	 * color array temporarily overwritten for drawing, then reset. */
-	if (GPU_buffer_legacy(dm) || G.f & G_BACKBUFSEL) {
+	if (G.f & G_BACKBUFSEL) {
 		DEBUG_VBO("Using legacy code. cdDM_drawMappedFaces\n");
 		for (i = 0; i < dm->numTessFaceData; i++, mf++) {
 			int drawSmooth = ((flag & DM_DRAW_ALWAYS_SMOOTH) || lnors) ? 1 : (mf->flag & ME_SMOOTH);
@@ -1070,85 +776,85 @@ static void cdDM_drawMappedFaces(DerivedMesh *dm,
 	}
 	else { /* use OpenGL VBOs or Vertex Arrays instead for better, faster rendering */
 		int prevstart = 0;
+		int tottri;
+		
 		GPU_vertex_setup(dm);
 		GPU_normal_setup(dm);
 		if (useColors && mcol) {
 			GPU_color_setup(dm, colType);
 		}
-		if (!GPU_buffer_legacy(dm)) {
-			int tottri = dm->drawObject->tot_triangle_point / 3;
-			glShadeModel(GL_SMOOTH);
+		tottri = dm->drawObject->tot_triangle_point / 3;
+		glShadeModel(GL_SMOOTH);
+		
+		if (tottri == 0) {
+			/* avoid buffer problems in following code */
+		}
+		if (setDrawOptions == NULL) {
+			/* just draw the entire face array */
+			glDrawArrays(GL_TRIANGLES, 0, (tottri) * 3);
+		}
+		else {
+			/* we need to check if the next material changes */
+			int next_actualFace = dm->drawObject->triangle_to_mface[0];
+			int prev_mat_nr = -1;
 			
-			if (tottri == 0) {
-				/* avoid buffer problems in following code */
-			}
-			if (setDrawOptions == NULL) {
-				/* just draw the entire face array */
-				glDrawArrays(GL_TRIANGLES, 0, (tottri) * 3);
-			}
-			else {
-				/* we need to check if the next material changes */
-				int next_actualFace = dm->drawObject->triangle_to_mface[0];
-				int prev_mat_nr = -1;
+			for (i = 0; i < tottri; i++) {
+				//int actualFace = dm->drawObject->triangle_to_mface[i];
+				int actualFace = next_actualFace;
+				MFace *mface = mf + actualFace;
+				/*int drawSmooth = (flag & DM_DRAW_ALWAYS_SMOOTH) ? 1 : (mface->flag & ME_SMOOTH);*/ /* UNUSED */
+				DMDrawOption draw_option = DM_DRAW_OPTION_NORMAL;
+				int flush = 0;
 				
-				for (i = 0; i < tottri; i++) {
-					//int actualFace = dm->drawObject->triangle_to_mface[i];
-					int actualFace = next_actualFace;
-					MFace *mface = mf + actualFace;
-					/*int drawSmooth = (flag & DM_DRAW_ALWAYS_SMOOTH) ? 1 : (mface->flag & ME_SMOOTH);*/ /* UNUSED */
-					DMDrawOption draw_option = DM_DRAW_OPTION_NORMAL;
-					int flush = 0;
-
-					if (i != tottri - 1)
-						next_actualFace = dm->drawObject->triangle_to_mface[i + 1];
-
-					orig = (index_mf_to_mpoly) ? DM_origindex_mface_mpoly(index_mf_to_mpoly, index_mp_to_orig, actualFace) : actualFace;
-
-					if (mface->mat_nr != prev_mat_nr) {
-						if (setMaterial)
-							draw_option = setMaterial(mface->mat_nr + 1, NULL);
-
-						prev_mat_nr = mface->mat_nr;
-					}
+				if (i != tottri - 1)
+					next_actualFace = dm->drawObject->triangle_to_mface[i + 1];
+				
+				orig = (index_mf_to_mpoly) ? DM_origindex_mface_mpoly(index_mf_to_mpoly, index_mp_to_orig, actualFace) : actualFace;
+				
+				if (mface->mat_nr != prev_mat_nr) {
+					if (setMaterial)
+						draw_option = setMaterial(mface->mat_nr + 1, NULL);
 					
-					if (setDrawOptions != NULL && (orig != ORIGINDEX_NONE))
-						draw_option = setDrawOptions(userData, orig);
-
-					if (draw_option == DM_DRAW_OPTION_STIPPLE) {
-						glEnable(GL_POLYGON_STIPPLE);
-						glPolygonStipple(stipple_quarttone);
-					}
-	
-					/* Goal is to draw as long of a contiguous triangle
+					prev_mat_nr = mface->mat_nr;
+				}
+				
+				if (setDrawOptions != NULL && (orig != ORIGINDEX_NONE))
+					draw_option = setDrawOptions(userData, orig);
+				
+				if (draw_option == DM_DRAW_OPTION_STIPPLE) {
+					glEnable(GL_POLYGON_STIPPLE);
+					glPolygonStipple(stipple_quarttone);
+				}
+				
+				/* Goal is to draw as long of a contiguous triangle
 					 * array as possible, so draw when we hit either an
 					 * invisible triangle or at the end of the array */
-
-					/* flush buffer if current triangle isn't drawable or it's last triangle... */
-					flush = (ELEM(draw_option, DM_DRAW_OPTION_SKIP, DM_DRAW_OPTION_STIPPLE)) || (i == tottri - 1);
-
-					/* ... or when material setting is dissferent  */
-					flush |= mf[actualFace].mat_nr != mf[next_actualFace].mat_nr;
-
-					if (!flush && compareDrawOptions) {
-						flush |= compareDrawOptions(userData, actualFace, next_actualFace) == 0;
-					}
-
-					if (flush) {
-						int first = prevstart * 3;
-						/* Add one to the length if we're drawing at the end of the array */
-						int count = (i - prevstart + (draw_option != DM_DRAW_OPTION_SKIP ? 1 : 0)) * 3;
-
-						if (count)
-							glDrawArrays(GL_TRIANGLES, first, count);
-
-						prevstart = i + 1;
-
-						if (draw_option == DM_DRAW_OPTION_STIPPLE)
-							glDisable(GL_POLYGON_STIPPLE);
-					}
+				
+				/* flush buffer if current triangle isn't drawable or it's last triangle... */
+				flush = (ELEM(draw_option, DM_DRAW_OPTION_SKIP, DM_DRAW_OPTION_STIPPLE)) || (i == tottri - 1);
+				
+				/* ... or when material setting is dissferent  */
+				flush |= mf[actualFace].mat_nr != mf[next_actualFace].mat_nr;
+				
+				if (!flush && compareDrawOptions) {
+					flush |= compareDrawOptions(userData, actualFace, next_actualFace) == 0;
+				}
+				
+				if (flush) {
+					int first = prevstart * 3;
+					/* Add one to the length if we're drawing at the end of the array */
+					int count = (i - prevstart + (draw_option != DM_DRAW_OPTION_SKIP ? 1 : 0)) * 3;
+					
+					if (count)
+						glDrawArrays(GL_TRIANGLES, first, count);
+					
+					prevstart = i + 1;
+					
+					if (draw_option == DM_DRAW_OPTION_STIPPLE)
+						glDisable(GL_POLYGON_STIPPLE);
 				}
 			}
-
+			
 			glShadeModel(GL_FLAT);
 		}
 		GPU_buffer_unbind();
@@ -1276,7 +982,7 @@ static void cdDM_drawMappedFacesGLSL(DerivedMesh *dm,
 
 	glShadeModel(GL_SMOOTH);
 
-	if (GPU_buffer_legacy(dm) || setDrawOptions != NULL) {
+	if (setDrawOptions != NULL) {
 		DEBUG_VBO("Using legacy code. cdDM_drawMappedFacesGLSL\n");
 		memset(&attribs, 0, sizeof(attribs));
 
@@ -1335,11 +1041,11 @@ static void cdDM_drawMappedFacesGLSL(DerivedMesh *dm,
 				ln3 = &lnors[a][2];
 				ln4 = &lnors[a][3];
 			}
-
+			
 			cddm_draw_attrib_vertex(&attribs, mvert, a, mface->v1, 0, ln1, smoothnormal);
 			cddm_draw_attrib_vertex(&attribs, mvert, a, mface->v2, 1, ln2, smoothnormal);
 			cddm_draw_attrib_vertex(&attribs, mvert, a, mface->v3, 2, ln3, smoothnormal);
-
+			
 			if (mface->v4)
 				cddm_draw_attrib_vertex(&attribs, mvert, a, mface->v4, 3, ln4, smoothnormal);
 			else
@@ -1353,214 +1059,213 @@ static void cdDM_drawMappedFacesGLSL(DerivedMesh *dm,
 		int numdata = 0, elementsize = 0, offset;
 		int start = 0, numfaces = 0 /* , prevdraw = 0 */ /* UNUSED */, curface = 0;
 		int i;
-
+		
 		const MFace *mf = mface;
 		GPUAttrib datatypes[GPU_MAX_ATTRIB]; /* TODO, messing up when switching materials many times - [#21056]*/
 		memset(&attribs, 0, sizeof(attribs));
-
+		
 		GPU_vertex_setup(dm);
 		GPU_normal_setup(dm);
-
-		if (!GPU_buffer_legacy(dm)) {
-			for (i = 0; i < dm->drawObject->tot_triangle_point / 3; i++) {
-
-				a = dm->drawObject->triangle_to_mface[i];
-
-				mface = mf + a;
-				new_matnr = mface->mat_nr + 1;
-
-				if (new_matnr != matnr) {
-					numfaces = curface - start;
-					if (numfaces > 0) {
-
-						if (do_draw) {
-
-							if (numdata != 0) {
-
-								GPU_buffer_unlock(buffer);
-
-								GPU_interleaved_attrib_setup(buffer, datatypes, numdata);
-							}
-
-							glDrawArrays(GL_TRIANGLES, start * 3, numfaces * 3);
-
-							if (numdata != 0) {
-
-								GPU_buffer_free(buffer);
-
-								buffer = NULL;
-							}
-
+		
+		for (i = 0; i < dm->drawObject->tot_triangle_point / 3; i++) {
+			
+			a = dm->drawObject->triangle_to_mface[i];
+			
+			mface = mf + a;
+			new_matnr = mface->mat_nr + 1;
+			
+			if (new_matnr != matnr) {
+				numfaces = curface - start;
+				if (numfaces > 0) {
+					
+					if (do_draw) {
+						
+						if (numdata != 0) {
+							
+							GPU_buffer_unlock(buffer);
+							
+							GPU_interleaved_attrib_setup(buffer, datatypes, numdata);
+						}
+						
+						glDrawArrays(GL_TRIANGLES, start * 3, numfaces * 3);
+						
+						if (numdata != 0) {
+							
+							GPU_buffer_free(buffer);
+							
+							buffer = NULL;
 						}
+						
 					}
-					numdata = 0;
-					start = curface;
-					/* prevdraw = do_draw; */ /* UNUSED */
-					do_draw = setMaterial(matnr = new_matnr, &gattribs);
-					if (do_draw) {
-						DM_vertex_attributes_from_gpu(dm, &gattribs, &attribs);
-
-						if (attribs.totorco && attribs.orco.array) {
-							datatypes[numdata].index = attribs.orco.gl_index;
-							datatypes[numdata].size = 3;
+				}
+				numdata = 0;
+				start = curface;
+				/* prevdraw = do_draw; */ /* UNUSED */
+				do_draw = setMaterial(matnr = new_matnr, &gattribs);
+				if (do_draw) {
+					DM_vertex_attributes_from_gpu(dm, &gattribs, &attribs);
+					
+					if (attribs.totorco && attribs.orco.array) {
+						datatypes[numdata].index = attribs.orco.gl_index;
+						datatypes[numdata].size = 3;
+						datatypes[numdata].type = GL_FLOAT;
+						numdata++;
+					}
+					for (b = 0; b < attribs.tottface; b++) {
+						if (attribs.tface[b].array) {
+							datatypes[numdata].index = attribs.tface[b].gl_index;
+							datatypes[numdata].size = 2;
 							datatypes[numdata].type = GL_FLOAT;
 							numdata++;
 						}
-						for (b = 0; b < attribs.tottface; b++) {
-							if (attribs.tface[b].array) {
-								datatypes[numdata].index = attribs.tface[b].gl_index;
-								datatypes[numdata].size = 2;
-								datatypes[numdata].type = GL_FLOAT;
-								numdata++;
-							}
-						}
-						for (b = 0; b < attribs.totmcol; b++) {
-							if (attribs.mcol[b].array) {
-								datatypes[numdata].index = attribs.mcol[b].gl_index;
-								datatypes[numdata].size = 4;
-								datatypes[numdata].type = GL_UNSIGNED_BYTE;
-								numdata++;
-							}
-						}
-						if (attribs.tottang && attribs.tang.array) {
-							datatypes[numdata].index = attribs.tang.gl_index;
+					}
+					for (b = 0; b < attribs.totmcol; b++) {
+						if (attribs.mcol[b].array) {
+							datatypes[numdata].index = attribs.mcol[b].gl_index;
 							datatypes[numdata].size = 4;
-							datatypes[numdata].type = GL_FLOAT;
+							datatypes[numdata].type = GL_UNSIGNED_BYTE;
 							numdata++;
 						}
-						if (numdata != 0) {
-							elementsize = GPU_attrib_element_size(datatypes, numdata);
-							buffer = GPU_buffer_alloc(elementsize * dm->drawObject->tot_triangle_point);
-							if (buffer == NULL) {
-								GPU_buffer_unbind();
-								dm->drawObject->legacy = 1;
-								return;
-							}
-							varray = GPU_buffer_lock_stream(buffer);
-							if (varray == NULL) {
-								GPU_buffer_unbind();
-								GPU_buffer_free(buffer);
-								dm->drawObject->legacy = 1;
-								return;
-							}
+					}
+					if (attribs.tottang && attribs.tang.array) {
+						datatypes[numdata].index = attribs.tang.gl_index;
+						datatypes[numdata].size = 4;
+						datatypes[numdata].type = GL_FLOAT;
+						numdata++;
+					}
+					if (numdata != 0) {
+						elementsize = GPU_attrib_element_size(datatypes, numdata);
+						buffer = GPU_buffer_alloc(elementsize * dm->drawObject->tot_triangle_point, true);
+						if (buffer == NULL) {
+							GPU_buffer_unbind();
+							buffer = GPU_buffer_alloc(elementsize * dm->drawObject->tot_triangle_point, true);
+							return;
 						}
-						else {
-							/* if the buffer was set, don't use it again.
-							 * prevdraw was assumed true but didnt run so set to false - [#21036] */
-							/* prevdraw = 0; */ /* UNUSED */
-							buffer = NULL;
+						varray = GPU_buffer_lock_stream(buffer);
+						if (varray == NULL) {
+							GPU_buffer_unbind();
+							GPU_buffer_free(buffer);
+							fprintf(stderr, "Out of memory, can't draw object\n");
+							return;
 						}
 					}
+					else {
+						/* if the buffer was set, don't use it again.
+						 * prevdraw was assumed true but didnt run so set to false - [#21036] */
+						/* prevdraw = 0; */ /* UNUSED */
+						buffer = NULL;
+					}
 				}
-
+			}
+			
+			if (do_draw && numdata != 0) {
+				offset = 0;
+				if (attribs.totorco && attribs.orco.array) {
+					copy_v3_v3((float *)&varray[elementsize * curface * 3], (float *)attribs.orco.array[mface->v1]);
+					copy_v3_v3((float *)&varray[elementsize * curface * 3 + elementsize], (float *)attribs.orco.array[mface->v2]);
+					copy_v3_v3((float *)&varray[elementsize * curface * 3 + elementsize * 2], (float *)attribs.orco.array[mface->v3]);
+					offset += sizeof(float) * 3;
+				}
+				for (b = 0; b < attribs.tottface; b++) {
+					if (attribs.tface[b].array) {
+						MTFace *tf = &attribs.tface[b].array[a];
+						copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset], tf->uv[0]);
+						copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset + elementsize], tf->uv[1]);
+						
+						copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset + elementsize * 2], tf->uv[2]);
+						offset += sizeof(float) * 2;
+					}
+				}
+				for (b = 0; b < attribs.totmcol; b++) {
+					if (attribs.mcol[b].array) {
+						MCol *cp = &attribs.mcol[b].array[a * 4 + 0];
+						GLubyte col[4];
+						col[0] = cp->b; col[1] = cp->g; col[2] = cp->r; col[3] = cp->a;
+						copy_v4_v4_char((char *)&varray[elementsize * curface * 3 + offset], (char *)col);
+						cp = &attribs.mcol[b].array[a * 4 + 1];
+						col[0] = cp->b; col[1] = cp->g; col[2] = cp->r; col[3] = cp->a;
+						copy_v4_v4_char((char *)&varray[elementsize * curface * 3 + offset + elementsize], (char *)col);
+						cp = &attribs.mcol[b].array[a * 4 + 2];
+						col[0] = cp->b; col[1] = cp->g; col[2] = cp->r; col[3] = cp->a;
+						copy_v4_v4_char((char *)&varray[elementsize * curface * 3 + offset + elementsize * 2], (char *)col);
+						offset += sizeof(unsigned char) * 4;
+					}
+				}
+				if (attribs.tottang && attribs.tang.array) {
+					const float *tang = attribs.tang.array[a * 4 + 0];
+					copy_v4_v4((float *)&varray[elementsize * curface * 3 + offset], tang);
+					tang = attribs.tang.array[a * 4 + 1];
+					copy_v4_v4((float *)&varray[elementsize * curface * 3 + offset + elementsize], tang);
+					tang = attribs.tang.array[a * 4 + 2];
+					copy_v4_v4((float *)&varray[elementsize * curface * 3 + offset + elementsize * 2], tang);
+					offset += sizeof(float) * 4;
+				}
+				(void)offset;
+			}
+			curface++;
+			if (mface->v4) {
 				if (do_draw && numdata != 0) {
 					offset = 0;
 					if (attribs.totorco && attribs.orco.array) {
-						copy_v3_v3((float *)&varray[elementsize * curface * 3], (float *)attribs.orco.array[mface->v1]);
-						copy_v3_v3((float *)&varray[elementsize * curface * 3 + elementsize], (float *)attribs.orco.array[mface->v2]);
-						copy_v3_v3((float *)&varray[elementsize * curface * 3 + elementsize * 2], (float *)attribs.orco.array[mface->v3]);
+						copy_v3_v3((float *)&varray[elementsize * curface * 3], (float *)attribs.orco.array[mface->v3]);
+						copy_v3_v3((float *)&varray[elementsize * curface * 3 + elementsize], (float *)attribs.orco.array[mface->v4]);
+						copy_v3_v3((float *)&varray[elementsize * curface * 3 + elementsize * 2], (float *)attribs.orco.array[mface->v1]);
 						offset += sizeof(float) * 3;
 					}
 					for (b = 0; b < attribs.tottface; b++) {
 						if (attribs.tface[b].array) {
 							MTFace *tf = &attribs.tface[b].array[a];
-							copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset], tf->uv[0]);
-							copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset + elementsize], tf->uv[1]);
-
-							copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset + elementsize * 2], tf->uv[2]);
+							copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset], tf->uv[2]);
+							copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset + elementsize], tf->uv[3]);
+							copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset + elementsize * 2], tf->uv[0]);
 							offset += sizeof(float) * 2;
 						}
 					}
 					for (b = 0; b < attribs.totmcol; b++) {
 						if (attribs.mcol[b].array) {
-							MCol *cp = &attribs.mcol[b].array[a * 4 + 0];
+							MCol *cp = &attribs.mcol[b].array[a * 4 + 2];
 							GLubyte col[4];
 							col[0] = cp->b; col[1] = cp->g; col[2] = cp->r; col[3] = cp->a;
 							copy_v4_v4_char((char *)&varray[elementsize * curface * 3 + offset], (char *)col);
-							cp = &attribs.mcol[b].array[a * 4 + 1];
+							cp = &attribs.mcol[b].array[a * 4 + 3];
 							col[0] = cp->b; col[1] = cp->g; col[2] = cp->r; col[3] = cp->a;
 							copy_v4_v4_char((char *)&varray[elementsize * curface * 3 + offset + elementsize], (char *)col);
-							cp = &attribs.mcol[b].array[a * 4 + 2];
+							cp = &attribs.mcol[b].array[a * 4 + 0];
 							col[0] = cp->b; col[1] = cp->g; col[2] = cp->r; col[3] = cp->a;
 							copy_v4_v4_char((char *)&varray[elementsize * curface * 3 + offset + elementsize * 2], (char *)col);
 							offset += sizeof(unsigned char) * 4;
 						}
 					}
 					if (attribs.tottang && attribs.tang.array) {
-						const float *tang = attribs.tang.array[a * 4 + 0];
+						const float *tang = attribs.tang.array[a * 4 + 2];
 						copy_v4_v4((float *)&varray[elementsize * curface * 3 + offset], tang);
-						tang = attribs.tang.array[a * 4 + 1];
+						tang = attribs.tang.array[a * 4 + 3];
 						copy_v4_v4((float *)&varray[elementsize * curface * 3 + offset + elementsize], tang);
-						tang = attribs.tang.array[a * 4 + 2];
+						tang = attribs.tang.array[a * 4 + 0];
 						copy_v4_v4((float *)&varray[elementsize * curface * 3 + offset + elementsize * 2], tang);
 						offset += sizeof(float) * 4;
 					}
 					(void)offset;
 				}
 				curface++;
-				if (mface->v4) {
-					if (do_draw && numdata != 0) {
-						offset = 0;
-						if (attribs.totorco && attribs.orco.array) {
-							copy_v3_v3((float *)&varray[elementsize * curface * 3], (float *)attribs.orco.array[mface->v3]);
-							copy_v3_v3((float *)&varray[elementsize * curface * 3 + elementsize], (float *)attribs.orco.array[mface->v4]);
-							copy_v3_v3((float *)&varray[elementsize * curface * 3 + elementsize * 2], (float *)attribs.orco.array[mface->v1]);
-							offset += sizeof(float) * 3;
-						}
-						for (b = 0; b < attribs.tottface; b++) {
-							if (attribs.tface[b].array) {
-								MTFace *tf = &attribs.tface[b].array[a];
-								copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset], tf->uv[2]);
-								copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset + elementsize], tf->uv[3]);
-								copy_v2_v2((float *)&varray[elementsize * curface * 3 + offset + elementsize * 2], tf->uv[0]);
-								offset += sizeof(float) * 2;
-							}
-						}
-						for (b = 0; b < attribs.totmcol; b++) {
-							if (attribs.mcol[b].array) {
-								MCol *cp = &attribs.mcol[b].array[a * 4 + 2];
-								GLubyte col[4];
-								col[0] = cp->b; col[1] = cp->g; col[2] = cp->r; col[3] = cp->a;
-								copy_v4_v4_char((char *)&varray[elementsize * curface * 3 + offset], (char *)col);
-								cp = &attribs.mcol[b].array[a * 4 + 3];
-								col[0] = cp->b; col[1] = cp->g; col[2] = cp->r; col[3] = cp->a;
-								copy_v4_v4_char((char *)&varray[elementsize * curface * 3 + offset + elementsize], (char *)col);
-								cp = &attribs.mcol[b].array[a * 4 + 0];
-								col[0] = cp->b; col[1] = cp->g; col[2] = cp->r; col[3] = cp->a;
-								copy_v4_v4_char((char *)&varray[elementsize * curface * 3 + offset + elementsize * 2], (char *)col);
-								offset += sizeof(unsigned char) * 4;
-							}
-						}
-						if (attribs.tottang && attribs.tang.array) {
-							const float *tang = attribs.tang.array[a * 4 + 2];
-							copy_v4_v4((float *)&varray[elementsize * curface * 3 + offset], tang);
-							tang = attribs.tang.array[a * 4 + 3];
-							copy_v4_v4((float *)&varray[elementsize * curface * 3 + offset + elementsize], tang);
-							tang = attribs.tang.array[a * 4 + 0];
-							copy_v4_v4((float *)&varray[elementsize * curface * 3 + offset + elementsize * 2], tang);
-							offset += sizeof(float) * 4;
-						}
-						(void)offset;
-					}
-					curface++;
-					i++;
-				}
+				i++;
 			}
-			numfaces = curface - start;
-			if (numfaces > 0) {
-				if (do_draw) {
-					if (numdata != 0) {
-						GPU_buffer_unlock(buffer);
-						GPU_interleaved_attrib_setup(buffer, datatypes, numdata);
-					}
-					glDrawArrays(GL_TRIANGLES, start * 3, (curface - start) * 3);
+		}
+		numfaces = curface - start;
+		if (numfaces > 0) {
+			if (do_draw) {
+				if (numdata != 0) {
+					GPU_buffer_unlock(buffer);
+					GPU_interleaved_attrib_setup(buffer, datatypes, numdata);
 				}
+				glDrawArrays(GL_TRIANGLES, start * 3, (curface - start) * 3);
 			}
-			GPU_buffer_unbind();
 		}
+		GPU_buffer_unbind();
+		
 		GPU_buffer_free(buffer);
 	}
-
+	
 	glShadeModel(GL_FLAT);
 }
 
diff --git a/source/blender/editors/sculpt_paint/paint_vertex.c b/source/blender/editors/sculpt_paint/paint_vertex.c
index 376d3d3099c..929231186f4 100644
--- a/source/blender/editors/sculpt_paint/paint_vertex.c
+++ b/source/blender/editors/sculpt_paint/paint_vertex.c
@@ -3024,7 +3024,7 @@ static void vpaint_stroke_update_step(bContext *C, struct PaintStroke *stroke, P
 		 * avoid this if we can! */
 		DAG_id_tag_update(ob->data, 0);
 	}
-	else if (!GPU_buffer_legacy(ob->derivedFinal)) {
+	else {
 		/* If using new VBO drawing, mark mcol as dirty to force colors gpu buffer refresh! */
 		ob->derivedFinal->dirty |= DM_DIRTY_MCOL_UPDATE_DRAW;
 	}
diff --git a/source/blender/editors/space_view3d/drawmesh.c b/source/blender/editors/space_view3d/drawmesh.c
index 408b41719da..911403f45cb 100644
--- a/source/blender/editors/space_view3d/drawmesh.c
+++ b/source/blender/editors/space_view3d/drawmesh.c
@@ -562,14 +562,6 @@ static DMDrawOption draw_tface__set_draw_legacy(MTFace *tface, const bool has_mc
 	}
 }
 
-static DMDrawOption draw_mcol__set_draw_legacy(MTFace *UNUSED(tface), const bool has_mcol, int UNUSED(matnr))
-{
-	if (has_mcol)
-		return DM_DRAW_OPTION_NORMAL;
-	else
-		return DM_DRAW_OPTION_NO_MCOL;
-}
-
 static DMDrawOption draw_tface__set_draw(MTFace *tface, const bool UNUSED(has_mcol), int matnr)
 {
 	Material *ma = give_current_material(Gtexdraw.ob, matnr + 1);
@@ -929,24 +921,16 @@ static void draw_mesh_textured_old(Scene *scene, View3D *v3d, RegionView3D *rv3d
 			dm->drawMappedFacesTex(dm, me->mpoly ? draw_tface_mapped__set_draw : NULL, compareDrawOptions, &userData, uvflag);
 		}
 	}
-	else {
-		if (GPU_buffer_legacy(dm)) {
-			if (draw_flags & DRAW_MODIFIERS_PREVIEW)
-				dm->drawFacesTex(dm, draw_mcol__set_draw_legacy, NULL, NULL, uvflag);
-			else 
-				dm->drawFacesTex(dm, draw_tface__set_draw_legacy, NULL, NULL, uvflag);
-		}
-		else {
-			drawTFace_userData userData;
-
-			update_tface_color_layer(dm);
-
-			userData.mf = DM_get_tessface_data_layer(dm, CD_MFACE);
-			userData.tf = DM_get_tessface_data_layer(dm, CD_MTFACE);
-			userData.me = NULL;
-
-			dm->drawFacesTex(dm, draw_tface__set_draw, compareDrawOptions, &userData, uvflag);
-		}
+	else {		
+		drawTFace_userData userData;
+		
+		update_tface_color_layer(dm);
+		
+		userData.mf = DM_get_tessface_data_layer(dm, CD_MFACE);
+		userData.tf = DM_get_tessface_data_layer(dm, CD_MTFACE);
+		userData.me = NULL;
+		
+		dm->drawFacesTex(dm, draw_tface__set_draw, compareDrawOptions, &userData, uvflag);
 	}
 
 	/* draw game engine text hack */
diff --git a/source/blender/gpu/GPU_buffers.h b/source/blender/gpu/GPU_buffers.h
index ba461d5f8a2..e9b600a9267 100644
--- a/source/blender/gpu/GPU_buffers.h
+++ b/source/blender/gpu/GPU_buffers.h
@@ -54,6 +54,7 @@ typedef struct GPUBuffer {
 	int size;	/* in bytes */
 	void *pointer;	/* used with vertex arrays */
 	unsigned int id;	/* used with vertex buffer objects */
+	bool use_vbo;	/* true for VBOs, false for vertex arrays */
 } GPUBuffer;
 
 typedef struct GPUBufferMaterial {
@@ -85,6 +86,7 @@ typedef struct GPUDrawObject {
 	GPUBuffer *points;
 	GPUBuffer *normals;
 	GPUBuffer *uv;
+	GPUBuffer *uv_tex;
 	GPUBuffer *colors;
 	GPUBuffer *edges;
 	GPUBuffer *uvedges;
@@ -113,10 +115,6 @@ typedef struct GPUDrawObject {
 	/* caches of the original DerivedMesh values */
 	int totvert;
 	int totedge;
-
-	/* if there was a failure allocating some buffer, use old
-	 * rendering code */
-	bool legacy;
 } GPUDrawObject;
 
 /* used for GLSL materials */
@@ -129,7 +127,7 @@ typedef struct GPUAttrib {
 void GPU_global_buffer_pool_free(void);
 void GPU_global_buffer_pool_free_unused(void);
 
-GPUBuffer *GPU_buffer_alloc(int size);
+GPUBuffer *GPU_buffer_alloc(int size, bool force_vertex_arrays);
 void GPU_buffer_free(GPUBuffer *buffer);
 
 GPUDrawObject *GPU_drawobject_new(struct DerivedMesh *dm);
@@ -161,9 +159,6 @@ void GPU_buffer_draw_elements(GPUBuffer *elements, unsigned int mode, int start,
 /* called after drawing */
 void GPU_buffer_unbind(void);
 
-/* used to check whether to use the old (without buffers) code */
-bool GPU_buffer_legacy(struct DerivedMesh *dm);
-
 /* Buffers for non-DerivedMesh drawing */
 typedef struct GPU_PBVH_Buffers GPU_PBVH_Buffers;
 
diff --git a/source/blender/gpu/intern/gpu_buffers.c b/source/blender/gpu/intern/gpu_buffers.c
index b5a576b509c..54743247fea 100644
--- a/source/blender/gpu/intern/gpu_buffers.c
+++ b/source/blender/gpu/intern/gpu_buffers.c
@@ -62,6 +62,8 @@
 
 #include "bmesh.h"
 
+#include "gpu_extensions_private.h"
+
 typedef enum {
 	GPU_BUFFER_VERTEX_STATE = (1 << 0),
 	GPU_BUFFER_NORMAL_STATE = (1 << 1),
@@ -76,7 +78,6 @@ typedef enum {
 #define BUFFER_OFFSET(n) ((GLubyte *)NULL + (n))
 
 /* -1 - undefined, 0 - vertex arrays, 1 - VBOs */
-static int useVBOs = -1;
 static GPUBufferState GLStates = 0;
 static GPUAttrib attribData[MAX_GPU_ATTRIB_DATA] = { { -1, 0, 0 } };
 
@@ -111,10 +112,6 @@ static GPUBufferPool *gpu_buffer_pool_new(void)
 {
 	GPUBufferPool *pool;
 
-	/* enable VBOs if supported */
-	if (useVBOs == -1)
-		useVBOs = (GLEW_ARB_vertex_buffer_object ? 1 : 0);
-
 	pool = MEM_callocN(sizeof(GPUBufferPool), "GPUBuffer_Pool");
 
 	pool->maxsize = MAX_FREE_GPU_BUFFERS;
@@ -158,7 +155,7 @@ static void gpu_buffer_pool_delete_last(GPUBufferPool *pool)
 		return;
 
 	/* delete the buffer's data */
-	if (useVBOs)
+	if (last->use_vbo)
 		glDeleteBuffersARB(1, &last->id);
 	else
 		MEM_freeN(last->pointer);
@@ -226,7 +223,7 @@ void GPU_global_buffer_pool_free_unused(void)
  *
  * Thread-unsafe version for internal usage only.
  */
-static GPUBuffer *gpu_buffer_alloc_intern(int size)
+static GPUBuffer *gpu_buffer_alloc_intern(int size, bool use_VBO)
 {
 	GPUBufferPool *pool;
 	GPUBuffer *buf;
@@ -251,6 +248,10 @@ static GPUBuffer *gpu_buffer_alloc_intern(int size)
 	for (i = 0; i < pool->totbuf; i++) {
 		bufsize = pool->buffers[i]->size;
 
+		/* only return a buffer that matches the VBO preference */
+		 if (pool->buffers[i]->use_vbo != use_VBO)
+			 continue;
+		
 		/* check for an exact size match */
 		if (bufsize == size) {
 			bestfit = i;
@@ -279,8 +280,9 @@ static GPUBuffer *gpu_buffer_alloc_intern(int size)
 	/* no acceptable buffer found in the pool, create a new one */
 	buf = MEM_callocN(sizeof(GPUBuffer), "GPUBuffer");
 	buf->size = size;
+	buf->use_vbo = use_VBO;
 
-	if (useVBOs == 1) {
+	if (use_VBO) {
 		/* create a new VBO and initialize it to the requested
 		 * size */
 		glGenBuffersARB(1, &buf->id);
@@ -307,9 +309,10 @@ static GPUBuffer *gpu_buffer_alloc_intern(int size)
 }
 
 /* Same as above, but safe for threading. */
-GPUBuffer *GPU_buffer_alloc(int size)
+GPUBuffer *GPU_buffer_alloc(int size, bool force_vertex_arrays)
 {
 	GPUBuffer *buffer;
+	bool use_VBOs = (GLEW_ARB_vertex_buffer_object) && !(U.gameflags & USER_DISABLE_VBO) && !force_vertex_arrays;
 
 	if (size == 0) {
 		/* Early out, no lock needed in this case. */
@@ -317,7 +320,7 @@ GPUBuffer *GPU_buffer_alloc(int size)
 	}
 
 	BLI_mutex_lock(&buffer_mutex);
-	buffer = gpu_buffer_alloc_intern(size);
+	buffer = gpu_buffer_alloc_intern(size, use_VBOs);
 	BLI_mutex_unlock(&buffer_mutex);
 
 	return buffer;
@@ -577,6 +580,7 @@ void GPU_drawobject_free(DerivedMesh *dm)
 	GPU_buffer_free(gdo->points);
 	GPU_buffer_free(gdo->normals);
 	GPU_buffer_free(gdo->uv);
+	GPU_buffer_free(gdo->uv_tex);
 	GPU_buffer_free(gdo->colors);
 	GPU_buffer_free(gdo->edges);
 	GPU_buffer_free(gdo->uvedges);
@@ -585,6 +589,22 @@ void GPU_drawobject_free(DerivedMesh *dm)
 	dm->drawObject = NULL;
 }
 
+static GPUBuffer *gpu_try_realloc(GPUBufferPool *pool, GPUBuffer *buffer, int size, bool use_VBOs)
+{
+	gpu_buffer_free_intern(buffer);
+	gpu_buffer_pool_delete_last(pool);
+	buffer = NULL;
+	
+	/* try freeing an entry from the pool
+	 * and reallocating the buffer */
+	if (pool->totbuf > 0) {
+		gpu_buffer_pool_delete_last(pool);
+		buffer = gpu_buffer_alloc_intern(size, use_VBOs);
+	}
+	
+	return buffer;
+}
+
 typedef void (*GPUBufferCopyFunc)(DerivedMesh *dm, float *varray, int *index,
                                   int *mat_orig_to_new, void *user_data);
 
@@ -598,7 +618,7 @@ static GPUBuffer *gpu_buffer_setup(DerivedMesh *dm, GPUDrawObject *object,
 	int *mat_orig_to_new;
 	int *cur_index_per_mat;
 	int i;
-	bool success;
+	bool use_VBOs = (GLEW_ARB_vertex_buffer_object == 1) && !(U.gameflags & USER_DISABLE_VBO);
 	GLboolean uploaded;
 
 	pool = gpu_get_global_buffer_pool();
@@ -606,11 +626,7 @@ static GPUBuffer *gpu_buffer_setup(DerivedMesh *dm, GPUDrawObject *object,
 	BLI_mutex_lock(&buffer_mutex);
 
 	/* alloc a GPUBuffer; fall back to legacy mode on failure */
-	if (!(buffer = gpu_buffer_alloc_intern(size)))
-		dm->drawObject->legacy = 1;
-
-	/* nothing to do for legacy mode */
-	if (dm->drawObject->legacy) {
+	if (!(buffer = gpu_buffer_alloc_intern(size, use_VBOs))) {
 		BLI_mutex_unlock(&buffer_mutex);
 		return NULL;
 	}
@@ -628,8 +644,8 @@ static GPUBuffer *gpu_buffer_setup(DerivedMesh *dm, GPUDrawObject *object,
 		mat_orig_to_new[object->materials[i].mat_nr] = i;
 	}
 
-	if (useVBOs) {
-		success = 0;
+	if (use_VBOs) {
+		bool success = false;
 
 		while (!success) {
 			/* bind the buffer and discard previous data,
@@ -639,32 +655,22 @@ static GPUBuffer *gpu_buffer_setup(DerivedMesh *dm, GPUDrawObject *object,
 
 			/* attempt to map the buffer */
 			if (!(varray = glMapBufferARB(target, GL_WRITE_ONLY_ARB))) {
-				/* failed to map the buffer; delete it */
-				gpu_buffer_free_intern(buffer);
-				gpu_buffer_pool_delete_last(pool);
-				buffer = NULL;
-
-				/* try freeing an entry from the pool
-				 * and reallocating the buffer */
-				if (pool->totbuf > 0) {
-					gpu_buffer_pool_delete_last(pool);
-					buffer = gpu_buffer_alloc_intern(size);
-				}
-
+				 buffer = gpu_try_realloc(pool, buffer, size, true);
+				 
 				/* allocation still failed; fall back
 				 * to legacy mode */
 				if (!buffer) {
-					dm->drawObject->legacy = 1;
-					success = 1;
+					use_VBOs = false;
+					success = true;
 				}
 			}
 			else {
-				success = 1;
+				success = true;
 			}
 		}
 
 		/* check legacy fallback didn't happen */
-		if (dm->drawObject->legacy == 0) {
+		if (use_VBOs) {
 			uploaded = GL_FALSE;
 			/* attempt to upload the data to the VBO */
 			while (uploaded == GL_FALSE) {
@@ -677,15 +683,16 @@ static GPUBuffer *gpu_buffer_setup(DerivedMesh *dm, GPUDrawObject *object,
 		}
 		glBindBufferARB(target, 0);
 	}
-	else {
+	if (!use_VBOs) {
 		/* VBO not supported, use vertex array fallback */
-		if (buffer->pointer) {
+		if (!buffer || !buffer->pointer) {
+			buffer = gpu_try_realloc(pool, buffer, size, false);
+		}
+		
+		if (buffer) {
 			varray = buffer->pointer;
 			(*copy_f)(dm, varray, cur_index_per_mat, mat_orig_to_new, user);
 		}
-		else {
-			dm->drawObject->legacy = 1;
-		}
 	}
 
 	MEM_freeN(cur_index_per_mat);
@@ -1019,7 +1026,7 @@ static GPUBuffer **gpu_drawobject_buffer_from_type(GPUDrawObject *gdo, GPUBuffer
 		case GPU_BUFFER_UV:
 			return &gdo->uv;
 		case GPU_BUFFER_UV_TEXPAINT:
-			return &gdo->uv;
+			return &gdo->uv_tex;
 		case GPU_BUFFER_EDGE:
 			return &gdo->edges;
 		case GPU_BUFFER_UVEDGE:
@@ -1105,7 +1112,7 @@ void GPU_vertex_setup(DerivedMesh *dm)
 		return;
 
 	glEnableClientState(GL_VERTEX_ARRAY);
-	if (useVBOs) {
+	if (dm->drawObject->points->use_vbo) {
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, dm->drawObject->points->id);
 		glVertexPointer(3, GL_FLOAT, 0, 0);
 	}
@@ -1122,7 +1129,7 @@ void GPU_normal_setup(DerivedMesh *dm)
 		return;
 
 	glEnableClientState(GL_NORMAL_ARRAY);
-	if (useVBOs) {
+	if (dm->drawObject->normals->use_vbo) {
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, dm->drawObject->normals->id);
 		glNormalPointer(GL_FLOAT, 0, 0);
 	}
@@ -1139,7 +1146,7 @@ void GPU_uv_setup(DerivedMesh *dm)
 		return;
 
 	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-	if (useVBOs) {
+	if (dm->drawObject->uv->use_vbo) {
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, dm->drawObject->uv->id);
 		glTexCoordPointer(2, GL_FLOAT, 0, 0);
 	}
@@ -1156,8 +1163,8 @@ void GPU_texpaint_uv_setup(DerivedMesh *dm)
 		return;
 
 	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-	if (useVBOs) {
-		glBindBufferARB(GL_ARRAY_BUFFER_ARB, dm->drawObject->uv->id);
+	if (dm->drawObject->uv_tex->use_vbo) {
+		glBindBufferARB(GL_ARRAY_BUFFER_ARB, dm->drawObject->uv_tex->id);
 		glTexCoordPointer(2, GL_FLOAT, 4 * sizeof(float), 0);
 		glClientActiveTexture(GL_TEXTURE2);
 		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
@@ -1165,10 +1172,10 @@ void GPU_texpaint_uv_setup(DerivedMesh *dm)
 		glClientActiveTexture(GL_TEXTURE0);
 	}
 	else {
-		glTexCoordPointer(2, GL_FLOAT, 4 * sizeof(float), dm->drawObject->uv->pointer);
+		glTexCoordPointer(2, GL_FLOAT, 4 * sizeof(float), dm->drawObject->uv_tex->pointer);
 		glClientActiveTexture(GL_TEXTURE2);
 		glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-		glTexCoordPointer(2, GL_FLOAT, 4 * sizeof(float), (char *)dm->drawObject->uv->pointer + 2 * sizeof(float));
+		glTexCoordPointer(2, GL_FLOAT, 4 * sizeof(float), (char *)dm->drawObject->uv_tex->pointer + 2 * sizeof(float));
 		glClientActiveTexture(GL_TEXTURE0);
 	}
 
@@ -1202,7 +1209,7 @@ void GPU_color_setup(DerivedMesh *dm, int colType)
 		return;
 
 	glEnableClientState(GL_COLOR_ARRAY);
-	if (useVBOs) {
+	if (dm->drawObject->colors->use_vbo) {
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, dm->drawObject->colors->id);
 		glColorPointer(3, GL_UNSIGNED_BYTE, 0, 0);
 	}
@@ -1222,7 +1229,7 @@ void GPU_edge_setup(DerivedMesh *dm)
 		return;
 
 	glEnableClientState(GL_VERTEX_ARRAY);
-	if (useVBOs) {
+	if (dm->drawObject->edges->use_vbo) {
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, dm->drawObject->points->id);
 		glVertexPointer(3, GL_FLOAT, 0, 0);
 	}
@@ -1232,7 +1239,7 @@ void GPU_edge_setup(DerivedMesh *dm)
 	
 	GLStates |= GPU_BUFFER_VERTEX_STATE;
 
-	if (useVBOs)
+	if (dm->drawObject->edges->use_vbo)
 		glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, dm->drawObject->edges->id);
 
 	GLStates |= GPU_BUFFER_ELEMENT_STATE;
@@ -1244,7 +1251,7 @@ void GPU_uvedge_setup(DerivedMesh *dm)
 		return;
 
 	glEnableClientState(GL_VERTEX_ARRAY);
-	if (useVBOs) {
+	if (dm->drawObject->uvedges->use_vbo) {
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, dm->drawObject->uvedges->id);
 		glVertexPointer(2, GL_FLOAT, 0, 0);
 	}
@@ -1300,7 +1307,7 @@ void GPU_interleaved_attrib_setup(GPUBuffer *buffer, GPUAttrib data[], int numda
 	}
 	elementsize = GPU_attrib_element_size(data, numdata);
 
-	if (useVBOs) {
+	if (buffer->use_vbo) {
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, buffer->id);
 		for (i = 0; i < numdata; i++) {
 			glEnableVertexAttribArrayARB(data[i].index);
@@ -1343,7 +1350,8 @@ void GPU_buffer_unbind(void)
 	if (GLStates & GPU_BUFFER_COLOR_STATE)
 		glDisableClientState(GL_COLOR_ARRAY);
 	if (GLStates & GPU_BUFFER_ELEMENT_STATE) {
-		if (useVBOs) {
+		/* not guaranteed we used VBOs but in that case it's just a no-op */
+		if (GLEW_ARB_vertex_buffer_object) {
 			glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
 		}
 	}
@@ -1359,7 +1367,8 @@ void GPU_buffer_unbind(void)
 			break;
 	}
 
-	if (useVBOs)
+	/* not guaranteed we used VBOs but in that case it's just a no-op */
+	if (GLEW_ARB_vertex_buffer_object)
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
 }
 
@@ -1377,19 +1386,6 @@ void GPU_color_switch(int mode)
 	}
 }
 
-/* return 1 if drawing should be done using old immediate-mode
- * code, 0 otherwise */
-bool GPU_buffer_legacy(DerivedMesh *dm)
-{
-	int test = (U.gameflags & USER_DISABLE_VBO);
-	if (test)
-		return 1;
-
-	if (dm->drawObject == NULL)
-		dm->drawObject = GPU_drawobject_new(dm);
-	return dm->drawObject->legacy;
-}
-
 void *GPU_buffer_lock(GPUBuffer *buffer)
 {
 	float *varray;
@@ -1397,7 +1393,7 @@ void *GPU_buffer_lock(GPUBuffer *buffer)
 	if (!buffer)
 		return 0;
 
-	if (useVBOs) {
+	if (buffer->use_vbo) {
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, buffer->id);
 		varray = glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
 		return varray;
@@ -1414,7 +1410,7 @@ void *GPU_buffer_lock_stream(GPUBuffer *buffer)
 	if (!buffer)
 		return 0;
 
-	if (useVBOs) {
+	if (buffer->use_vbo) {
 		glBindBufferARB(GL_ARRAY_BUFFER_ARB, buffer->id);
 		/* discard previous data, avoid stalling gpu */
 		glBufferDataARB(GL_ARRAY_BUFFER_ARB, buffer->size, 0, GL_STREAM_DRAW_ARB);
@@ -1428,7 +1424,7 @@ void *GPU_buffer_lock_stream(GPUBuffer *buffer)
 
 void GPU_buffer_unlock(GPUBuffer *buffer)
 {
-	if (useVBOs) {
+	if (buffer->use_vbo) {
 		if (buffer) {
 			/* note: this operation can fail, could return
 			 * an error code from this function? */
@@ -1442,7 +1438,7 @@ void GPU_buffer_unlock(GPUBuffer *buffer)
 void GPU_buffer_draw_elements(GPUBuffer *elements, unsigned int mode, int start, int count)
 {
 	glDrawElements(mode, count, GL_UNSIGNED_INT,
-	               (useVBOs ?
+	               (elements->use_vbo ?
 	                (void *)(start * sizeof(unsigned int)) :
 	                ((int *)elements->pointer) + start));
 }