diff --git a/ui.h b/ui.h
index b5fb9a27..a4a5737f 100644
--- a/ui.h
+++ b/ui.h
@@ -366,6 +366,8 @@ typedef struct uiDrawMatrix uiDrawMatrix;
 
 typedef struct uiDrawBrushGradientStop uiDrawBrushGradientStop;
 
+typedef struct uiDrawBitmap uiDrawBitmap;
+
 _UI_ENUM(uiDrawBrushType) {
 	uiDrawBrushTypeSolid,
 	uiDrawBrushTypeLinearGradient,
@@ -453,6 +455,15 @@ struct uiDrawStrokeParams {
 	double DashPhase;
 };
 
+struct uiRect {
+	int X;
+	int Y;
+	int Width;
+	int Height;
+};
+
+typedef struct uiRect uiRect;
+
 _UI_EXTERN uiDrawPath *uiDrawNewPath(uiDrawFillMode fillMode);
 _UI_EXTERN void uiDrawFreePath(uiDrawPath *p);
 
@@ -499,6 +510,12 @@ _UI_EXTERN void uiDrawClip(uiDrawContext *c, uiDrawPath *path);
 _UI_EXTERN void uiDrawSave(uiDrawContext *c);
 _UI_EXTERN void uiDrawRestore(uiDrawContext *c);
 
+// bitmap API
+_UI_EXTERN uiDrawBitmap* uiDrawNewBitmap(uiDrawContext* c, int width, int height);
+_UI_EXTERN void uiDrawBitmapUpdate(uiDrawBitmap* bmp, const void* data);
+_UI_EXTERN void uiDrawBitmapDraw(uiDrawContext* c, uiDrawBitmap* bmp, uiRect* srcrect, uiRect* dstrect, int filter);
+_UI_EXTERN void uiDrawFreeBitmap(uiDrawBitmap* bmp);
+
 // uiAttribute stores information about an attribute in a
 // uiAttributedString.
 //
diff --git a/unix/draw.c b/unix/draw.c
index a8f26d7f..8df798bc 100644
--- a/unix/draw.c
+++ b/unix/draw.c
@@ -141,3 +141,69 @@ void uiDrawRestore(uiDrawContext *c)
 {
 	cairo_restore(c->cr);
 }
+
+// bitmap API
+
+uiDrawBitmap* uiDrawNewBitmap(uiDrawContext* c, int width, int height)
+{
+	uiDrawBitmap* bmp;
+
+	bmp = uiprivNew(uiDrawBitmap);
+
+	bmp->bmp = cairo_image_surface_create(CAIRO_FORMAT_RGB24, width, height);
+	if (cairo_surface_status(bmp->bmp) != CAIRO_STATUS_SUCCESS)
+		uiprivImplBug("error creating bitmap: %s",
+			cairo_status_to_string(cairo_surface_status(bmp->bmp)));
+
+	bmp->Width = width;
+	bmp->Height = height;
+	bmp->Stride = cairo_image_surface_get_stride(bmp->bmp);
+
+	return bmp;
+}
+
+void uiDrawBitmapUpdate(uiDrawBitmap* bmp, const void* data)
+{
+	unsigned char* src = data;
+	unsigned char* dst = cairo_image_surface_get_data(bmp->bmp);
+	int y;
+
+	if (bmp->Stride == bmp->Width * 4) {
+		// stride 'good', can just directly copy
+		memcpy(dst, src, bmp->Stride*bmp->Height);
+	} else {
+		for (y = 0; y < bmp->Height; y++) {
+			memcpy(dst, src, bmp->Width * 4);
+			src += bmp->Width * 4;
+			dst += bmp->Stride;
+		}
+	}
+
+	cairo_surface_mark_dirty(bmp->bmp);
+}
+
+void uiDrawBitmapDraw(uiDrawContext* c, uiDrawBitmap* bmp, uiRect* srcrect, uiRect* dstrect, int filter)
+{
+	cairo_save(c->cr);
+	cairo_rectangle(c->cr, dstrect->X, dstrect->Y, dstrect->Width, dstrect->Height);
+
+	cairo_translate(c->cr, dstrect->X, dstrect->Y);
+	if ((dstrect->Width != srcrect->Width) || (dstrect->Height != srcrect->Height))	{
+		double sx = dstrect->Width / (double)srcrect->Width;
+		double sy = dstrect->Height / (double)srcrect->Height;
+		cairo_scale(c->cr, sx, sy);
+	}
+
+	cairo_set_source_surface(c->cr, bmp->bmp, -srcrect->X, -srcrect->Y);
+	cairo_pattern_set_filter(cairo_get_source(c->cr), filter ? CAIRO_FILTER_BILINEAR : CAIRO_FILTER_NEAREST);
+	cairo_clip(c->cr);
+	cairo_paint(c->cr);
+
+	cairo_restore(c->cr);
+}
+
+void uiDrawFreeBitmap(uiDrawBitmap* bmp)
+{
+	cairo_surface_destroy(bmp->bmp);
+	uiprivFree(bmp);
+}
diff --git a/unix/draw.h b/unix/draw.h
index d46d074f..cd7ce4a1 100644
--- a/unix/draw.h
+++ b/unix/draw.h
@@ -6,6 +6,14 @@ struct uiDrawContext {
 	GtkStyleContext *style;
 };
 
+struct uiDrawBitmap {
+	int Width;
+	int Height;
+	int Stride;
+
+	cairo_surface_t* bmp;
+};
+
 // drawpath.c
 extern void uiprivRunPath(uiDrawPath *p, cairo_t *cr);
 extern uiDrawFillMode uiprivPathFillMode(uiDrawPath *path);
diff --git a/unix/window.c b/unix/window.c
index c5ba2038..aaeaa8ef 100644
--- a/unix/window.c
+++ b/unix/window.c
@@ -260,6 +260,7 @@ uiWindow *uiNewWindow(const char *title, int width, int height, int hasMenubar)
 	gtk_widget_set_halign(w->childHolderWidget, GTK_ALIGN_FILL);
 	gtk_widget_set_vexpand(w->childHolderWidget, TRUE);
 	gtk_widget_set_valign(w->childHolderWidget, GTK_ALIGN_FILL);
+	gtk_box_set_homogeneous(GTK_BOX(w->childHolderWidget), TRUE);
 	gtk_container_add(w->vboxContainer, w->childHolderWidget);
 
 	// show everything in the vbox, but not the GtkWindow itself
diff --git a/windows/draw.cpp b/windows/draw.cpp
index a5e5033a..95d8abf1 100644
--- a/windows/draw.cpp
+++ b/windows/draw.cpp
@@ -38,7 +38,7 @@ ID2D1HwndRenderTarget *makeHWNDRenderTarget(HWND hwnd)
 		logLastError(L"error getting DC to find DPI");
 
 	ZeroMemory(&props, sizeof (D2D1_RENDER_TARGET_PROPERTIES));
-	props.type = D2D1_RENDER_TARGET_TYPE_DEFAULT;
+	props.type = D2D1_RENDER_TARGET_TYPE_HARDWARE;
 	props.pixelFormat.format = DXGI_FORMAT_UNKNOWN;
 	props.pixelFormat.alphaMode = D2D1_ALPHA_MODE_UNKNOWN;
 	props.dpiX = GetDeviceCaps(dc, LOGPIXELSX);
@@ -62,8 +62,16 @@ ID2D1HwndRenderTarget *makeHWNDRenderTarget(HWND hwnd)
 		&props,
 		&hprops,
 		&rt);
-	if (hr != S_OK)
-		logHRESULT(L"error creating HWND render target", hr);
+	if (hr != S_OK) {
+		props.type = D2D1_RENDER_TARGET_TYPE_DEFAULT;
+		hr = d2dfactory->CreateHwndRenderTarget(
+			&props,
+			&hprops,
+			&rt);
+		if (hr != S_OK)
+			logHRESULT(L"error creating HWND render target", hr);
+	}
+
 	return rt;
 }
 
@@ -509,3 +517,54 @@ void uiDrawRestore(uiDrawContext *c)
 	// no need to explicitly addref or release; just transfer the ref
 	c->currentClip = state.clip;
 }
+
+
+// bitmap API
+
+uiDrawBitmap* uiDrawNewBitmap(uiDrawContext* c, int width, int height)
+{
+	uiDrawBitmap* bmp;
+	HRESULT hr;
+
+	bmp = uiprivNew(uiDrawBitmap);
+
+	D2D1_BITMAP_PROPERTIES bp2 = D2D1::BitmapProperties();
+	bp2.dpiX = 0;
+	bp2.dpiY = 0;
+	bp2.pixelFormat = D2D1::PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_IGNORE);
+
+	//c->rt->BeginDraw();
+
+	hr = c->rt->CreateBitmap(D2D1::SizeU(width,height), NULL, 0, &bp2, &bmp->bmp);
+	if (hr != S_OK)
+		logHRESULT(L"error creating bitmap", hr);
+
+	//c->rt->EndDraw();
+
+	bmp->Width = width;
+	bmp->Height = height;
+	bmp->Stride = width*4;
+
+	return bmp;
+}
+
+void uiDrawBitmapUpdate(uiDrawBitmap* bmp, const void* data)
+{
+	D2D1_RECT_U rekt = D2D1::RectU(0, 0, bmp->Width, bmp->Height);
+	bmp->bmp->CopyFromMemory(&rekt, data, bmp->Stride);
+}
+
+void uiDrawBitmapDraw(uiDrawContext* c, uiDrawBitmap* bmp, uiRect* srcrect, uiRect* dstrect, int filter)
+{
+	D2D_RECT_F _srcrect = D2D1::RectF(srcrect->X, srcrect->Y, srcrect->X+srcrect->Width, srcrect->Y+srcrect->Height);
+	D2D_RECT_F _dstrect = D2D1::RectF(dstrect->X, dstrect->Y, dstrect->X+dstrect->Width, dstrect->Y+dstrect->Height);
+
+	c->rt->DrawBitmap(bmp->bmp, &_dstrect, 1.0f,
+		filter ? D2D1_BITMAP_INTERPOLATION_MODE_LINEAR : D2D1_BITMAP_INTERPOLATION_MODE_NEAREST_NEIGHBOR, &_srcrect);
+}
+
+void uiDrawFreeBitmap(uiDrawBitmap* bmp)
+{
+	bmp->bmp->Release();
+	uiprivFree(bmp);
+}
diff --git a/windows/draw.hpp b/windows/draw.hpp
index c271e4db..b4bbc6c0 100644
--- a/windows/draw.hpp
+++ b/windows/draw.hpp
@@ -11,6 +11,14 @@ struct uiDrawContext {
 	ID2D1PathGeometry *currentClip;
 };
 
+struct uiDrawBitmap {
+	int Width;
+	int Height;
+	int Stride;
+
+	ID2D1Bitmap* bmp;
+};
+
 // drawpath.cpp
 extern ID2D1PathGeometry *pathGeometry(uiDrawPath *p);