diff --git a/gfx.c b/gfx.c
index d0f6fd0441..1cb54b4625 100644
--- a/gfx.c
+++ b/gfx.c
@@ -190,7 +190,7 @@ void GfxDrawLine(int x, int y, int x2, int y2, int color)
 
 	// Check clipping first
 	{
-		DrawPixelInfo *dpi = _cur_dpi;
+		const DrawPixelInfo *dpi = _cur_dpi;
 		int t;
 
 		if (x < dpi->left && x2 < dpi->left) return;
@@ -560,7 +560,7 @@ int GetStringWidth(const char *str)
 
 int DoDrawString(const char *string, int x, int y, uint16 real_color)
 {
-	DrawPixelInfo *dpi = _cur_dpi;
+	const DrawPixelInfo *dpi = _cur_dpi;
 	FontSize size = _cur_fontsize;
 	byte c;
 	byte color;
@@ -753,6 +753,47 @@ static void GfxBlitTileZoomIn(BlitterParams *bp)
 			break;
 
 		default:
+#if 0
+			src = src_o;
+			do {
+				int offs = bp->start_x;
+
+				dst = bp->dst;
+				for (src = src_o;; src += num + 2) {
+					skip = src[1];
+					if (skip >= offs) {
+						dst += skip;
+						break;
+					}
+					offs -= skip;
+
+					done = src[0];
+					num = done & 0x7F;
+					if (num > offs) {
+						src += offs;
+						dst += offs;
+						num -= offs;
+						break;
+					}
+				}
+
+				src += 2;
+
+				for (;;) {
+					do {
+						*dst++ = *src++;
+					} while (--num != 0);
+
+					if (done & 0x80) break;
+
+					done = *src++;
+					num = done & 0x7F;
+					dst += *src++;
+				}
+
+				bp->dst += bp->pitch;
+			} while (--bp->height != 0);
+#else
 			do {
 				do {
 					done = src_o[0];
@@ -794,6 +835,7 @@ static void GfxBlitTileZoomIn(BlitterParams *bp)
 
 				bp->dst += bp->pitch;
 			} while (--bp->height != 0);
+#endif
 			break;
 	}
 }
diff --git a/screenshot.c b/screenshot.c
index 3c134cdcc4..7fe4b2cbd2 100644
--- a/screenshot.c
+++ b/screenshot.c
@@ -460,7 +460,7 @@ static void CurrentScreenCallback(void *userdata, Pixel *buf, uint y, uint pitch
 // generate a large piece of the world
 static void LargeWorldCallback(void *userdata, Pixel *buf, uint y, uint pitch, uint n)
 {
-	ViewPort *vp = (ViewPort *)userdata;
+	const ViewPort* vp = (const ViewPort*)userdata;
 	DrawPixelInfo dpi, *old_dpi;
 	int wx, left;
 
diff --git a/spritecache.c b/spritecache.c
index 4604f76026..f494e7db29 100644
--- a/spritecache.c
+++ b/spritecache.c
@@ -138,6 +138,30 @@ static void* ReadSprite(SpriteID id)
 			}
 		}
 
+#if 1
+		if (sprite->info & 8) {
+			byte* src = sprite->data + sprite->height * 2;
+			uint height = sprite->height;
+
+			do {
+				uint offset;
+				uint len;
+
+				offset = 0;
+				do {
+					uint skip;
+
+					skip = src[1];
+					src[1] = skip - offset;
+					offset = skip;
+
+					len = src[0];
+					src += (len & 0x7F) + 2;
+				} while (!(len & 0x80));
+			} while (--height != 0);
+		}
+#endif
+
 		return sprite;
 	}
 }
diff --git a/viewport.c b/viewport.c
index 7dc46e4a6b..1f522ab7ad 100644
--- a/viewport.c
+++ b/viewport.c
@@ -1177,8 +1177,6 @@ static void ViewportDrawStrings(DrawPixelInfo *dpi, const StringSpriteToDraw *ss
 
 		ss = ss->next;
 	} while (ss != NULL);
-
-	_cur_dpi = dpi;
 }
 
 void ViewportDoDraw(const ViewPort *vp, int left, int top, int right, int bottom)