diff --git a/include/QF/GLSL/qf_textures.h b/include/QF/GLSL/qf_textures.h
index 0a6e3ba6d..2298c3e16 100644
--- a/include/QF/GLSL/qf_textures.h
+++ b/include/QF/GLSL/qf_textures.h
@@ -31,14 +31,6 @@
 #include "QF/qtypes.h"
 
 typedef struct scrap_s scrap_t;
-typedef struct subpic_s {
-	const struct subpic_s * const next;
-	const scrap_t * const scrap;
-	const struct vrect_s * const rect;
-	const int width;					///< requested width
-	const int height;					///< requested height
-	const float size;					///< size factor for tex coords (mult)
-} subpic_t;
 
 int GLSL_LoadQuakeTexture (const char *identifier, int width, int height,
 						   byte *data);
@@ -55,9 +47,11 @@ scrap_t *GLSL_CreateScrap (int size, int format, int linear);
 void GLSL_DestroyScrap (scrap_t *scrap);
 void GLSL_ScrapClear (scrap_t *scrap);
 int GLSL_ScrapTexture (scrap_t *scrap) __attribute__((pure));
-subpic_t *GLSL_ScrapSubpic (scrap_t *scrap, int width, int height);	//XXX slow!
-void GLSL_SubpicDelete (subpic_t *subpic);	//XXX slow!
-void GLSL_SubpicUpdate (subpic_t *subpic, byte *data, int batch);
+//XXX slow!
+struct subpic_s *GLSL_ScrapSubpic (scrap_t *scrap, int width, int height);
+//XXX slow!
+void GLSL_SubpicDelete (struct subpic_s *subpic);
+void GLSL_SubpicUpdate (struct subpic_s *subpic, byte *data, int batch);
 void GLSL_ScrapFlush (scrap_t *scrap);
 
 #endif//__QF_GLSL_textures_h
diff --git a/include/QF/render.h b/include/QF/render.h
index 7f02672e2..607b8b800 100644
--- a/include/QF/render.h
+++ b/include/QF/render.h
@@ -55,6 +55,15 @@ typedef enum {
 extern struct vid_render_funcs_s *r_funcs;
 extern struct vid_render_data_s *r_data;
 
+typedef struct subpic_s {
+	const struct subpic_s *const next;
+	const struct scrap_s *const scrap;	///< renderer specific type
+	const struct vrect_s *const rect;
+	const int width;					///< requested width
+	const int height;					///< requested height
+	const float size;					///< size factor for tex coords (mult)
+} subpic_t;
+
 // dynamic lights ===========================================================
 
 typedef struct dlight_s
diff --git a/include/r_scrap.h b/include/r_scrap.h
new file mode 100644
index 000000000..5539d7480
--- /dev/null
+++ b/include/r_scrap.h
@@ -0,0 +1,49 @@
+/*
+	r_scrap.h
+
+	Renderer agnostic scrap management
+
+	Copyright (C) 2021 Bill Currie <bill@taniwha.org>
+
+	Author: Bill Currie <bill@taniwha.org>
+	Date: 2021/1/12
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+	See the GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to:
+
+		Free Software Foundation, Inc.
+		59 Temple Place - Suite 330
+		Boston, MA  02111-1307, USA
+
+*/
+
+#ifndef __r_scrap_h
+#define __r_scrap_h
+
+typedef struct rscrap_s {
+	struct vrect_s *free_rects;			///< linked list of free areas
+	struct vrect_s *rects;				///< linked list of allocated rects
+	int         width;					///< overall width of scrap
+	int         height;					///< overall height of scrap
+} rscrap_t;
+
+void R_ScrapInit (rscrap_t *scrap, int width, int height);
+void R_ScrapDelete (rscrap_t *scrap);
+struct vrect_s *R_ScrapAlloc (rscrap_t *scrap, int width, int height);
+void R_ScrapFree (rscrap_t *scrap, struct vrect_s *rect);
+void R_ScrapClear (rscrap_t *scrap);
+size_t R_ScrapArea (rscrap_t *scrap) __attribute__((pure));
+void R_ScrapDump (rscrap_t *scrap);
+
+#endif//__r_scrap_h
diff --git a/libs/video/renderer/Makemodule.am b/libs/video/renderer/Makemodule.am
index 3e5dd4f70..05740af60 100644
--- a/libs/video/renderer/Makemodule.am
+++ b/libs/video/renderer/Makemodule.am
@@ -37,6 +37,7 @@ libs_video_renderer_libQFrenderer_la_DEPENDENCIES=	$(renderer_libs)
 libs_video_renderer_libQFrenderer_la_SOURCES=\
 	libs/video/renderer/r_cvar.c \
 	libs/video/renderer/r_init.c \
+	libs/video/renderer/r_scrap.c \
 	libs/video/renderer/r_screen.c \
 	libs/video/renderer/r_progs.c
 
diff --git a/libs/video/renderer/glsl/glsl_textures.c b/libs/video/renderer/glsl/glsl_textures.c
index 8130dfdf5..1edd77b71 100644
--- a/libs/video/renderer/glsl/glsl_textures.c
+++ b/libs/video/renderer/glsl/glsl_textures.c
@@ -44,6 +44,7 @@
 #include "QF/cmd.h"
 #include "QF/mathlib.h"
 #include "QF/model.h"
+#include "QF/render.h"
 #include "QF/sys.h"
 #include "QF/vrect.h"
 
@@ -51,15 +52,15 @@
 #include "QF/GLSL/funcs.h"
 #include "QF/GLSL/qf_textures.h"
 
+#include "r_scrap.h"
+
 struct scrap_s {
+	rscrap_t    rscrap;
 	GLuint      tnum;
-	int         size;	// in pixels, for now, always square, power of 2
 	int         format;
 	int         bpp;
 	byte       *data;	// local copy of the texture so updates can be batched
 	vrect_t    *batch;
-	vrect_t    *free_rects;
-	vrect_t    *rects;
 	subpic_t   *subpics;
 	struct scrap_s *next;
 };
@@ -248,23 +249,22 @@ static void
 glsl_scraps_f (void)
 {
 	scrap_t    *scrap;
-	vrect_t    *rect;
 	int         area;
+	int         size;
 
 	if (!scrap_list) {
 		Sys_Printf ("No scraps\n");
 		return;
 	}
 	for (scrap = scrap_list; scrap; scrap = scrap->next) {
-		for (rect = scrap->free_rects, area = 0; rect; rect = rect->next)
-			area += rect->width * rect->height;
+		area = R_ScrapArea (&scrap->rscrap);
+		// always square
+		size = scrap->rscrap.width;
 		Sys_Printf ("tnum=%u size=%d format=%04x bpp=%d free=%d%%\n",
-					scrap->tnum, scrap->size, scrap->format, scrap->bpp,
-					area * 100 / (scrap->size * scrap->size));
+					scrap->tnum, size, scrap->format, scrap->bpp,
+					area * 100 / (size * size));
 		if (Cmd_Argc () > 1) {
-			for (rect = scrap->rects, area = 0; rect; rect = rect->next)
-				Sys_Printf ("%d %d %d %d\n", rect->x, rect->y,
-							rect->width, rect->height);
+			R_ScrapDump (&scrap->rscrap);
 		}
 	}
 }
@@ -309,11 +309,9 @@ GLSL_CreateScrap (int size, int format, int linear)
 	}
 	scrap = malloc (sizeof (scrap_t));
 	qfeglGenTextures (1, &scrap->tnum);
-	scrap->size = size;
+	R_ScrapInit (&scrap->rscrap, size, size);
 	scrap->format = format;
 	scrap->bpp = bpp;
-	scrap->free_rects = VRect_New (0, 0, size, size);
-	scrap->rects = 0;
 	scrap->subpics = 0;
 	scrap->next = scrap_list;
 	scrap_list = scrap;
@@ -341,26 +339,13 @@ GLSL_CreateScrap (int size, int format, int linear)
 void
 GLSL_ScrapClear (scrap_t *scrap)
 {
-	vrect_t    *t;
 	subpic_t   *sp;
-
-	while (scrap->free_rects) {
-		t = scrap->free_rects;
-		scrap->free_rects = t->next;
-		VRect_Delete (t);
-	}
-	while (scrap->rects) {
-		t = scrap->rects;
-		scrap->rects = t->next;
-		VRect_Delete (t);
-	}
 	while (scrap->subpics) {
 		sp = scrap->subpics;
 		scrap->subpics = (subpic_t *) sp->next;
 		free (sp);
 	}
-
-	scrap->free_rects = VRect_New (0, 0, scrap->size, scrap->size);
+	R_ScrapClear (&scrap->rscrap);
 }
 
 void
@@ -375,7 +360,7 @@ GLSL_DestroyScrap (scrap_t *scrap)
 		}
 	}
 	GLSL_ScrapClear (scrap);
-	VRect_Delete (scrap->free_rects);
+	R_ScrapDelete (&scrap->rscrap);
 	GLSL_ReleaseTexture (scrap->tnum);
 	free (scrap->data);
 	free (scrap);
@@ -390,47 +375,13 @@ GLSL_ScrapTexture (scrap_t *scrap)
 subpic_t *
 GLSL_ScrapSubpic (scrap_t *scrap, int width, int height)
 {
-	int         i, w, h;
-	vrect_t   **t, **best;
-	vrect_t    *old, *frags, *rect;
+	vrect_t    *rect;
 	subpic_t   *subpic;
 
-	for (i = 0; i < 16; i++)
-		if (width <= (1 << i))
-			break;
-	w = 1 << i;
-	for (i = 0; i < 16; i++)
-		if (height <= (1 << i))
-			break;
-	h = 1 << i;
-
-	best = 0;
-	for (t = &scrap->free_rects; *t; t = &(*t)->next) {
-		if ((*t)->width < w || (*t)->height < h)
-			continue;						// won't fit
-		if (!best) {
-			best = t;
-			continue;
-		}
-		if ((*t)->width <= (*best)->width || (*t)->height <= (*best)->height)
-			best = t;
+	rect = R_ScrapAlloc (&scrap->rscrap, width, height);
+	if (!rect) {
+		return 0;
 	}
-	if (!best)
-		return 0;							// couldn't find a spot
-	old = *best;
-	*best = old->next;
-	rect = VRect_New (old->x, old->y, w, h);
-	frags = VRect_Difference (old, rect);
-	VRect_Delete (old);
-	if (frags) {
-		// old was bigger than the requested size
-		for (old = frags; old->next; old = old->next)
-			;
-		old->next = scrap->free_rects;
-		scrap->free_rects = frags;
-	}
-	rect->next = scrap->rects;
-	scrap->rects = rect;
 
 	subpic = malloc (sizeof (subpic_t));
 	*((subpic_t **) &subpic->next) = scrap->subpics;
@@ -439,7 +390,7 @@ GLSL_ScrapSubpic (scrap_t *scrap, int width, int height)
 	*((vrect_t **) &subpic->rect) = rect;
 	*((int *) &subpic->width) = width;
 	*((int *) &subpic->height) = height;
-	*((float *) &subpic->size) = 1.0 / scrap->size;
+	*((float *) &subpic->size) = 1.0 / scrap->rscrap.width;
 	return subpic;
 }
 
@@ -448,8 +399,6 @@ GLSL_SubpicDelete (subpic_t *subpic)
 {
 	scrap_t    *scrap = (scrap_t *) subpic->scrap;
 	vrect_t    *rect = (vrect_t *) subpic->rect;
-	vrect_t    *old, *merge;
-	vrect_t   **t;
 	subpic_t  **sp;
 
 	for (sp = &scrap->subpics; *sp; sp = (subpic_t **) &(*sp)->next)
@@ -459,29 +408,7 @@ GLSL_SubpicDelete (subpic_t *subpic)
 		Sys_Error ("GLSL_ScrapDelSubpic: broken subpic");
 	*sp = (subpic_t *) subpic->next;
 	free (subpic);
-	for (t = &scrap->rects; *t; t = &(*t)->next)
-		if (*t == rect)
-			break;
-	if (*t != rect)
-		Sys_Error ("GLSL_ScrapDelSubpic: broken subpic");
-	*t = rect->next;
-
-	do {
-		merge = 0;
-		for (t = &scrap->free_rects; *t; t = &(*t)->next) {
-			merge = VRect_Merge (*t, rect);
-			if (merge) {
-				old = *t;
-				*t = (*t)->next;
-				VRect_Delete (old);
-				VRect_Delete (rect);
-				rect = merge;
-				break;
-			}
-		}
-	} while (merge);
-	rect->next = scrap->free_rects;
-	scrap->free_rects = rect;
+	R_ScrapFree (&scrap->rscrap, rect);
 }
 
 void
@@ -502,7 +429,7 @@ GLSL_SubpicUpdate (subpic_t *subpic, byte *data, int batch)
 			scrap->batch = VRect_New (rect->x, rect->y,
 									  rect->width, rect->height);
 		}
-		step = scrap->size * scrap->bpp;
+		step = scrap->rscrap.width * scrap->bpp;
 		sbytes = subpic->width * scrap->bpp;
 		dest = scrap->data + rect->y * step + rect->x * scrap->bpp;
 		for (i = 0; i < subpic->height; i++, dest += step, data += sbytes)
@@ -519,6 +446,7 @@ void
 GLSL_ScrapFlush (scrap_t *scrap)
 {
 	vrect_t    *rect = scrap->batch;
+	int         size = scrap->rscrap.width;
 
 	if (!rect)
 		return;
@@ -526,9 +454,9 @@ GLSL_ScrapFlush (scrap_t *scrap)
 	//should update to not update the entire horizontal block
 	qfeglBindTexture (GL_TEXTURE_2D, scrap->tnum);
 	qfeglTexSubImage2D (GL_TEXTURE_2D, 0, 0, rect->y,
-					   scrap->size, rect->height, scrap->format,
+					   size, rect->height, scrap->format,
 					   GL_UNSIGNED_BYTE,
-					   scrap->data + rect->y * scrap->size * scrap->bpp);
+					   scrap->data + rect->y * size * scrap->bpp);
 	VRect_Delete (rect);
 	scrap->batch = 0;
 }
diff --git a/libs/video/renderer/r_init.c b/libs/video/renderer/r_init.c
index f298538ba..733004a21 100644
--- a/libs/video/renderer/r_init.c
+++ b/libs/video/renderer/r_init.c
@@ -46,6 +46,7 @@
 #include "QF/plugin/general.h"
 
 #include "r_internal.h"
+#include "r_scrap.h"
 #include "vid_internal.h"
 
 cvar_t         *vidrend_plugin;
@@ -61,6 +62,7 @@ vid_render_funcs_t *r_funcs;
 
 #define U __attribute__ ((used))
 static U void (*const r_progs_init)(struct progs_s *) = R_Progs_Init;
+static U void (*const r_scrapdelete)(rscrap_t *) = R_ScrapDelete;
 #undef U
 
 static void
diff --git a/libs/video/renderer/r_scrap.c b/libs/video/renderer/r_scrap.c
new file mode 100644
index 000000000..86a4ca0a6
--- /dev/null
+++ b/libs/video/renderer/r_scrap.c
@@ -0,0 +1,183 @@
+/*
+	r_scrap.c
+
+	Renderer agnostic scrap management
+
+	Copyright (C) 2021 Bill Currie <bill@taniwha.org>
+
+	Author: Bill Currie <bill@taniwha.org>
+	Date: 2021/1/12
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+	See the GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to:
+
+		Free Software Foundation, Inc.
+		59 Temple Place - Suite 330
+		Boston, MA  02111-1307, USA
+
+*/
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "QF/sys.h"
+#include "QF/vrect.h"
+
+#include "compat.h"
+#include "r_scrap.h"
+
+static unsigned
+pow2rup (unsigned x)
+{
+	x--;
+	x |= x >> 1;
+	x |= x >> 2;
+	x |= x >> 4;
+	x |= x >> 8;
+	x |= x >> 16;
+	x++;
+	return x;
+}
+
+VISIBLE void
+R_ScrapInit (rscrap_t *scrap, int width, int height)
+{
+	width = pow2rup (width);
+	height = pow2rup (height);
+	scrap->width = width;
+	scrap->height = height;
+	scrap->rects = 0;
+	scrap->free_rects = VRect_New (0, 0, width, height);
+}
+
+VISIBLE void
+R_ScrapDelete (rscrap_t *scrap)
+{
+	R_ScrapClear (scrap);
+	VRect_Delete (scrap->free_rects);
+}
+
+VISIBLE vrect_t *
+R_ScrapAlloc (rscrap_t *scrap, int width, int height)
+{
+	int         w, h;
+	vrect_t   **t, **best;
+	vrect_t    *old, *frags, *rect;
+
+	w = pow2rup (width);
+	h = pow2rup (height);
+
+	best = 0;
+	for (t = &scrap->free_rects; *t; t = &(*t)->next) {
+		if ((*t)->width < w || (*t)->height < h)
+			continue;						// won't fit
+		if (!best) {
+			best = t;
+			continue;
+		}
+		if ((*t)->width <= (*best)->width || (*t)->height <= (*best)->height)
+			best = t;
+	}
+	if (!best)
+		return 0;							// couldn't find a spot
+	old = *best;
+	*best = old->next;
+	rect = VRect_New (old->x, old->y, w, h);
+	frags = VRect_Difference (old, rect);
+	VRect_Delete (old);
+	if (frags) {
+		// old was bigger than the requested size
+		for (old = frags; old->next; old = old->next)
+			;
+		old->next = scrap->free_rects;
+		scrap->free_rects = frags;
+	}
+	rect->next = scrap->rects;
+	scrap->rects = rect;
+
+	return rect;
+}
+
+VISIBLE void
+R_ScrapFree (rscrap_t *scrap, vrect_t *rect)
+{
+	vrect_t    *old, *merge;
+	vrect_t   **t;
+
+	for (t = &scrap->rects; *t; t = &(*t)->next)
+		if (*t == rect)
+			break;
+	if (*t != rect)
+		Sys_Error ("R_ScrapFree: broken rect");
+	*t = rect->next;
+
+	do {
+		merge = 0;
+		for (t = &scrap->free_rects; *t; t = &(*t)->next) {
+			merge = VRect_Merge (*t, rect);
+			if (merge) {
+				old = *t;
+				*t = (*t)->next;
+				VRect_Delete (old);
+				VRect_Delete (rect);
+				rect = merge;
+				break;
+			}
+		}
+	} while (merge);
+	rect->next = scrap->free_rects;
+	scrap->free_rects = rect;
+}
+
+VISIBLE void
+R_ScrapClear (rscrap_t *scrap)
+{
+	vrect_t    *t;
+
+	while (scrap->free_rects) {
+		t = scrap->free_rects;
+		scrap->free_rects = t->next;
+		VRect_Delete (t);
+	}
+	while (scrap->rects) {
+		t = scrap->rects;
+		scrap->rects = t->next;
+		VRect_Delete (t);
+	}
+
+	scrap->free_rects = VRect_New (0, 0, scrap->width, scrap->height);
+}
+
+VISIBLE size_t
+R_ScrapArea (rscrap_t *scrap)
+{
+	vrect_t    *rect;
+	size_t      area;
+
+	for (rect = scrap->free_rects, area = 0; rect; rect = rect->next) {
+		area += rect->width * rect->height;
+	}
+	return area;
+}
+
+VISIBLE void
+R_ScrapDump (rscrap_t *scrap)
+{
+	vrect_t    *rect;
+
+	for (rect = scrap->rects; rect; rect = rect->next) {
+		Sys_Printf ("%d %d %d %d\n", rect->x, rect->y,
+					rect->width, rect->height);
+	}
+}